bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Keratometry and Videokeratography After Penetrating Keratoplasty
Authors: Karabatsas Constantinos H , Cook Stuart D , Powell Kate , Sparrow John M
Published: April 2021

ABSTRACT

BACKGROUND: As new methods for corneal curvature measurement have evolved, users of videokeratscopes need to know the practical limitations of these instruments. We assessed agreement between keratometry and videokeratography in measuring highly astigmatic corneas.

METHODS: Two independent examiners made three keratometric and videokeratographic measurements on each of 33 corneas after penetrating keratoplasty. The non-orthogonal keratometric readings obtained with a Zeiss 10 SIVO keratometer (Carl Zeiss Ltd.) were compared to the non-orthogonal si m K readings (maxK, minK) calculated by the algorithms of a TMS-I videokeratoscope (Tomey). Measurement agreement was evaluated for steep and flat meridian power and location, and astigmatism magnitude (D).

RESULTS: A systematic bias of the TMS-I in measuring steeper than keratometry for the steep meridian was demonstrated (95% confidence interval: -0.34 to -1.20 D). The limits of agreement (d-2SD to d+2SD) between the two instruments were found to be unacceptable for clinical purposes in measuring steep meridian power (-3.17 to +1.63 D), flat meridian power (-4.92 to +4.48 D) and astigmatism magnitude (-5.84 to +4.87 D). Clinically acceptable differences were observed in identification of steep and flat meridian location.

CONCLUSIONS: The Zeiss 10 SL/O keratometer and the TMS-I videokeratoscope showed poor measurement agreement for irregular corneal surfaces, despite the good correlation previously shown between keratometry and videokeratography in calibrated spheres and regular corneas. The TMS-I showed a systematic bias, measuring a greater power in the steeper meridian than the Zeiss 10 SL/O keratometer. It is suggested that the two instruments cannot be used interchangeably in comparing the curvature of corneas after penetrating keratoplasty. [J Refract Surg 1998;14:420-426]
Corneal Wound Healing After Laser in situ Keratomileusis in Rabbits
Authors: Pérez-Santonja Juan J , Linna Tuuli U , Tervo Kaarina M , Sakla Hani F , Sanz Jorge L Alió Y , Tervo Timo M
Published: April 2021

ABSTRACT

BACKGROUND: The aim of this study was to characterize the cell biology of wound healing in rabbit corneas subjected to laser in situ keratomileusis (LASIK).

METHODS: Rabbit corneas underwent LASBK with various multizone photoablations or only a lamellar keratotomy followed by repositioning of the flap. We looked for indications for an active wound healing process. Immunohistoehemistry for the extradomain A cellular fibronectin (EDA-cFn) or tenascin (Tn) and routine histology were examined.

RESULTS: Four days after LASEK or lamellar keratotomy followed by repositioning of the flap, epithelial plugs and prominent keratocytes as well as Tn and EDA-cFn immunor eactions - indicative of a wound-healing process- appeared in the wound margins. Epithelial plugs were less conspicous, and prominent, presumably activated, keratocytes were no longer identified at the wound margin at 2.5 and 5 months after wounding. However, EDA-cFn and Tn immunoreactivities could still be observed. Only the stromal cells located in the periphery of the flap and in relatively close contact with the epithelium were surrounded by scar tissue expressing immunoreactivity for EDA-cFn or Tn. The central corneal stroma was devoid of scar tissue.

CONCLUSION: Results indicate that the wound healing reaction after LASIK takes place only at the periphery of the microkeratome wound, leaving the central optical zone clear. [J Refract Surg 1998;14:602-609]
Corneal Hydration Monitored by Laser-induced Breakdown Spectroscopy
Authors: Pallikaris Ioannis G , Ginis Harilaos S , Kounis Georgios A , Anglos Demetrios , Papazoglou Theodore G , Naoumidis Leonidas P
Published: April 2021

ABSTRACT

BACKGROUND: Corneal hydration is an important factor in laser corneal ablation. In photorefractive keratectomy (PRK), corneal ablation rate and final ablation surface quality are strongly dependent on corneal hydration. We used, a spectroscopic technique for monitoring corneal hydration during PRK.

METHODS: Hydroxyethylmethacrylate (HEMA) was employed for corneal hydration modeling. Hydrated HEMA samples were irradiated with a pulsed Nd:YAG laser (1064 run, 10 mJ/pulse, pulse duration 15 nsec). Successive emission spectra corresponding to different degrees of hydration were recorded on a gated optical multichannel analyzer. The weight of the sample and hence its water content was monitored during the entire procedure with a sensitive balance. One rabbit and one human cornea were used to demonstrate the spectral analogy between the model and corneal tissue.

RESULTS: The most noticeable dependence on water content of the substrate was that of atomic emission lines of Ca at 393 nm and 396 nm.

CONCLUSION: Plasma emission spectra exhibited significant dependence on sample hydration. This dependence can be used for estimation of water content of irradiated model material and real cornea. [J Refract Surg 1998;14:655-660]
Change in Intraocular Pressure in Myopic Eyes Measured With Contact and Non-contact Tonometers After Laser in situ Keratomileusis
Authors: El Danasoury M Alaa , El Maghraby Akef , Coorpender Steven J
Published: April 2021

ABSTRACT

PURPOSE: To study the change in the intraocular pressure (IOP) after laser in situ keratomileusis (LASIK) for correction of myopia.

METHODS: One hundred twenty consecutive myopic eyes (60 patients) were included in a prospective study. All eyes received LASIK with the Nidek EC-5000 excimer laser and the Chiron Automated Corneal Shaper. Baseline refraction, keratometry, pachymetry, ablation depth, and IOP measured by Goldmann applanation tonometry and non-contact air puff tonometry were correlated with the IOP change after surgery. Sixty healthy eyes of 30 subjects served as controls.

RESULTS: At 6 months, 108 eyes (90%) were examined. Compared to preoperative values, IOP decreased in 103 eyes (95.4%) when measured with applanation tonometry; it decreased in all eyes when measured with air puff tonometry. Mean change in IOP was -4.3 ± 2.1 mmHg (range, -10.0 to +1.0 mmHg) with the applanation and -6.1 ± 2.3 mmHg (range, -12.0 to -1.0 mmHg) with air puff tonometry. The IOP change measured with either instrument correlated significantly with the baseline IOP (P < .001) and the ablation depth (air puff, P < .001, applanation; P = .006).

CONCLUSION: Intraocular pressure decreased significantly after LASEK when measured with either Goldmann (mean 4.3 mmHg) or air puff (mean 6.1 mmHg) tonometers. This decrease may delay the diagnosis or affect the management of future glaucoma that may develop in a myopic eye that received LASEK. [J Refract Surg 2001;17: 97-104]
Influence of Temperature and Humidity on Laser in situ Keratomileusis Outcomes
Authors: de Souza Ivan Roque Urbano , de Souza Andréia Peltier de Queiroz Urbano , de Souza Alessandra Peltier de Queiroz Urbano , Figueiredo Paula , Jesus Rogério Santos , Kara-José Newton
Published: April 2021

ABSTRACT

PURPOSE: The influence of ambient factors on the results of refractive surgery is not well-known. This study evaluated the influence of temperature and humidity on laser in situ keratomileusis (LASIK) outcomes.

METHODS: Two hundred thirty-seven patients who underwent LASIK at the Clivan Instituto de Oftalmologia in Salvador - Bahia - Brazil, between May 1999 and March 2000, were evaluated. A total of 156 (65.8%) patients were female. Mean age was 30.3 ± 7.6 years. Refractive errors: 197 patients (83.12%) had compound myopic astigmatism, 17 patients (7.17%) had myopia, 11 patients (4.64%) had compound hyperopic astigmatism, and 12 patients (5.07%) had other. Results at 15 and 60 days after LASIK were compared according to different levels of temperature and humidity in the operating room during the procedure.

RESULTS: Patients whose spherical equivalent refraction varied between -0.50 to +0.50 D at 15 days after LASIK had surgery performed when the temperature was 25.1 ± 1.4° C and humidity was 45.1 ± 4.2%; for the others, temperature was 24.7 ± 1.5° C (P = .12) and humidity was 43.0 ± 4.0% (P = .002). The linear regression coefficient showed that lower temperature levels were associated with lower spherical equivalent refractions at 60 days after LASIK (r
p 2
= .14; P = .03) but not at 15 days after LASIK (P = .98). The evaluation of humidity indicated an influence at 15 days after LASIK (r
p 2
= .44; P = .04), as well as at 60 days (r
p 2
= .45; P = .0002).

CONCLUSION: Operating room environment may influence LASIK outcomes; humidity may be more significant than temperature. [J Refract Surg 2001;17(suppl):S202-S2041
Soft Contact Lenses for Irregular Astigmatism After Laser in situ Keratomileusis
Authors: Chou Brian , Wachler Brian S Boxer
Published: April 2021

ABSTRACT

PURPOSE: To investigate soft contact lenses for managing irregular astigmatism after laser in situ keratomileusis (LASIK). The prevailing notion has been that soft contacts conform to corneal surface irregularities and have a limited role for managing LASIK-induced irregular astigmatism.

METHODS: A 41-year-old man with bilateral central steep islands following LASIK had best spectacle-corrected visual acuity of 20/4O+1 in the right eye and 20/7O+2 in the left eye, despite 20/20 acuity in each eye with rigid contact lenses. Three soft lenses made of etafilcon A (58% H2O) in different center thicknesses were placed sequentially on each eye. All lenses were -2.00 D sphere, in the flatter of the two available base curves. With each lens, corneal topography, spherical over-refraction, and the resulting visual acuity were recorded.

RESULTS: In all instances, corneal topography showed reduced surface irregularity although at least some irregularity still transmitted through the lenses. Each spherical over-refraction gave better visual acuity than the corresponding best spectacle-corrected visual acuity. The right eye achieved 20/20 with the thickest lens and spherical over-refraction. The left eye achieved 20/25 with the lens of intermediate thickness and spherical overrefraction. The patient reported functional vision and good comfort with these lenses.

CONCLUSIONS: Disposable soft contact lenses can modestly mask irregular astigmatism caused by excimer laser ablation. [J Refract Surg 2001;17:692-695]
Changes in Intraocular Pressure After Laser in situ Keratomileusis for Myopia, Hyperopia, and Astigmatism
Authors: Agudelo Luz M , Molina Carlos A , Alvarez Diego L
Published: April 2021

ABSTRACT

PURPOSE: Reports have shown that photorefractive keratectomy changes intraocular pressure (IOP) in myopic eyes by changing the thickness and curvature of the cornea. Changes in intraocular pressure after laser in situ keratomileusis (LASIK) for hyperopia led the authors to evaluate IOP after LASIK for various refractive errors.

METHODS: The measurement of intraocular pressure with a Goldman applanometer in the central cornea was evaluated before and 3 months after LASIK in 100 eyes of 55 patients with various refractive errors. Corneal thickness (pachymetry) and corneal topography were evaluated.

RESULTS: After LASIK, a significant decrease of intraocular pressure was observed in most eyes: mean 11.9 ± 3.2 mmHg before and 9.8 ± 2.6 mmHg at 3 months after surgery (P<.001). Mean decrease in IOP was 2.75 ± 3.3 mmHg (P<.0001) for myopic eyes, 2.28 ± 2.43 mmHg (P<.001) for hyperopic eyes, and 1.47 ± 2.5 mmHg (P<0012) for astigmatic eyes. IOP reduction was not significantly correlated to the amount of ablation (r=0.05) or to corneal thickness.

CONCLUSION: Intraocular pressure decreased in myopic, hyperopic, and astigmatic eyes after LASIK. The reduction was not correlated to the amount of tissue removed or to flattening or steepening of the central cornea. [J Refract Surg 2002;18:472-474]
Interface Fluid After Laser in situ Keratomileusis
Authors: Lyle W Andrew , Jin George J C , Jin Yian
Published: April 2021

ABSTRACT

PURPOSE: To describe a case of interface fluid after laser in situ keratomileusis (LASIK) and review the literature on this rare complication after LASIK

METHODS: We present a case report and litera' ture review. Articles for this review were chosen from electronic database and manual literature searches. MEDLINE searches were made from 1990 to April 2002, using the key words "interface fluid" and "LASDX."

RESULTS: A 40-year-old man had uneventful LASDX for residual refractive error from previous penetrating keratoplasty in his right eye. Diffuse lamellar keratitis began 1 day postoperatively. Topical corticosteroids were administered. Six weeks after LASDi, a layer of interface fluid developed. Intraocular pressure was 9 mmHg when measured centrally by Goldmann applanation tonometry and 30 mmHg by Tono-pen tonometry. The interface fluid resolved with antiglaucoma agents and corticosteroids combined with cyclosporine.

CONCLUSIONS: This case, along with other reported cases, demonstrate the clinical features of interface fluid after LASIK. [J Refract Surg 2003;19:455-459]
Noncontact Optical Coherence Tomography for Measurement of Corneal Flap and Residual Stromal Bed Thickness After Laser in situ Keratomileusis
Authors: Thompson Robert W , Choi David M , Price Marianne O , Potrezbowski Laurie , Price Francis W
Published: April 2021

ABSTRACT

PURPOSE: Studies show significant variability in the thickness of laser in situ keratomileusis (LASIK) corneal flaps cut by various microkeratomes. Most studies of corneal flap thickness are based on contact ultrasonic pachymetry measurements taken during the surgical procedure. This study reports a technique to obtain reproducible corneal flap thickness and residual stromal bed thickness measurements using noncontact optical coherence tomography (OCT) following LASIK.

METHODS: The corneal flap thicknesses of 26 eyes of 15 patients were measured following LASIK in which the flap was created using the Amadeus microkeratome: 160-pm head, 9.5-mm ring, 4.0-mm/s translation speed, 8000 oscillations/m, and full vacuum. Zeiss Humphrey OCT-2 line scans were performed on postoperative days 1 and 7. The raw data from three scans for each eye and day were exported to Microsoft Excel for processing, averaging, and analysis.

RESULTS: The OCT corneal flap thickness and residual stromal bed thickness measurements correlated well with ultrasonic pachymetry measurements performed during surgery (R2=.92). The OCT technique yielded reproducible results, as the variance for repeated scans was only 2.5% of the variance between eyes. In bilateral cases a single blade was used for both eyes. The mean flap thickness of 15 first eyes was significantly greater than that of the 10 second eyes: 181 ± 31 um vs. 143 ± 41 um (P-c.Ol). A positive correlation was found between the preoperative pachymetry and corneal flap thickness.

CONCLUSIONS: The OCT scan averaging technique is a reproducible, noncontact postoperative method for measuring corneal flap and residual stromal bed thicknesses following LASIK. [J Refract Surg 2003;19:507-515]
Laser in situ Keratomileusis for Hyperopia and Hyperopic and Mixed Astigmatism With LADARVision Using 7 to 10-mm Ablation Diameters
Authors: Carones Francesco , Vigo Luca , Scandola Elena
Published: April 2021

ABSTRAGT

PURPOSE: To evaluate the results of laser in situ keratomileusis (LASIK) performed to correct hyperopia, and hyperopic and mixed astigmatism using wider ablation diameters (optical zone diameter and overall ablation diameter) than those commonly used with the same and other lasers.

METHODS: After flap creation using an Alcon SKBM microkeratome set for a 10-mm flap diameter, 53 eyes (33 patients) with a mean spheroequivalent attempted correction of +2.34 * 2.09 D underwent LASIK (Alcon LADARVision 4000) using a 7-mm optical zone diameter and a 3-mm transition zone for an overall 10-mm total ablation diameter. The nasal hinge was prevented from undesired ablation by the use of proprietary hinge protector software. Eyes were followed for 6 months after surgery.

RESULTS: Six months after surgery, mean spheical equivalent refractive error was -0.22 ± 0.41 D. There were 79.2% of eyes within ±0.50 D, and 98.1% within ±1.00 D of intended correction. Uncorrected visual acuity of 20/20 or better was achieved by 28 eyes (53%) and 20/40 or better by 50 eyes (94.3%). No meaningful visual complaints during nighttime hours, such as haloes or glare, were subjectively reported by patients.

CONCLUSION: The use of larger ablation diameters in LASDX for hyperopia, and hyperopic and mixed astigmatism produced accurate results, early refractive stability, and good visual performance. [J Refract Surg 2003;19:548-554]
Increase in Corneal Asphericity After Standard Laser in situ Keratomileusis for Myopia is not Inherent to the Munnerlyn Algorithm
Authors: Marcos Susana , Cano Daniel , Barbero Sergio
Published: April 2021

ABSTRACT

PURPOSE: Standard refractive surgery for myopia induces a shift in corneal asphericity toward positive values, resulting in an increase of spherical aberration. Analytical studies of changes in theoretical corneal shape after application of standard algorithms have yielded controversial conclusions. This study tries to resolve this controversy and discusses causes of optical degradation after refractive surgery.

METHODS: Computationally, we subtracted from real preoperative corneas the ablation depth given by the Munnerlyn equation and the parabolic approximation of the Munnerlyn equation. We compared the predicted postoperative corneal asphericity (and corneal spherical aberration) with real postoperative corneal asphericities of the same eyes, after laser in situ keratomileusis (LASIK).

RESULTS: Corneal asphericity increased after LASIK in real eyes, with an increase proportional to the amount of correction. This increase was not predicted by the computational application of the Munnerlyn algorithm, which predicted a slight decrease of corneal asphericity. The parabolic approximation of the Munnerlyn algorithm produced an increase in corneal asphericity that correlated with the amount of correction, but was less than the clinical findings.

CONCLUSION: Potential causes for increased asphericity (radial changes in laser efficiency, epithelial healing, and biomechanical response) are discussed. These conclusions are important for the design of optimized and customized ablation algorithms, since the theoretical performance of a given ablation algorithm (ie, Munnerlyn algorithm) can differ drastically from real outcomes. [J Refract Surg 2003;19:S592-S596]
Correlation of Aberrations With Visual Symptoms Using Wavefront Analysis in Eyes After Laser in situ Keratomileusis
Authors: Chalita Maria Regina , Xu Meng , Krueger Ronald R
Published: April 2021

ABSTRACT

PURPOSE: To evaluate the information assessed with the Alcon LADARWave wavefront measurement device and correlate it with visual symptoms in eyes previously treated with laser in situ keratomileusis (LASIK), and to analyze the influence of scotopic pupil size on visual symptoms.

METHODS: One hundred and five eyes of 58 patients who underwent LASIK were evaluated. Wavefront measurements were assessed using the Alcon LADARWave device. Visual symptoms were correlated to higher order aberrations in three different pupil sizes (5 mm, 7 mm, and scotopic pupil size). Generalized estimating equations were used for statistical analysis.

RESULTS: In eyes after LASIK, visual symptoms analysis showed positive correlation of double vision with total coma and with horizontal coma for the 5-mm and 7-mm pupil sizes, negative correlation between starburst and total coma for the 7-mm pupil size, positive correlation of double vision with horizontal coma, and glare and starburst with spherical aberration and with total aberrations. Scotopic pupil size had a positive association with starburst and negative association with double vision.

CONCLUSION: The LADARWave wavefront measurement device is a valuable diagnostic tool in measuring ocular aberrations in eyes after LASIK. A strong correlation between visual symptoms and ocular aberrations, such as monocular diplopia with coma, and starburst and glare with spherical aberration, suggest this device is valuable in diagnosing symptomatic LASIK-induced aberrations. Horizontal coma was correlated with double vision, while vertical coma was not, demonstrating a greater sensitivity with horizontally oriented multifocality. [J Refract Surg 2003;19:S682-S686]
Laser in situ Keratomileusis with Alcon CustomCornea
Authors: Lawless Michael A , Hodge Christopher , Rogers Christopher M , Sutton Gerard L
Published: April 2021

ABSTRACT

PURPOSE: To report the 3-month results of our first cases of laser in situ keratomileusis (LASIK) with Alcon's CustomCornea.

METHODS: Wavefront analysis was performed using the LADARWave aberrometer and ablation was performed with the LADARVision4000 system. Thirty-one eyes of 17 patients were analyzed prospectively, at 1 and 3 months after CustomCornea surgery. Psychophysical tests were performed, including high and low contrast acuity, and contrast sensitivity under scotopic and photopic conditions. In addition, psychometric testing was performed using a subjective vision questionnaire.

RESULTS: Mean spherical equivalent refraction improved from a baseline -3.05 ±1.92 D to +0.02 ± 0.28 D at 3 months (28 eyes). At 3 months, 46.4% (13 eyes) had uncorrected visual acuity of 20/16, 92.7% (26 eyes) had 20/20, and 100% (28 eyes) had 20/25 uncorrected visual acuity. Three months after CustomCornea surgery, there was a statistically significant improvement in contrast sensitivity under both scotopic and photopic conditions, and a statistically significant increase in third and fourth order aberrations. There was a statistically significant improvement in visual quality as measured by the subjective vision index, increasing from a preoperative mean 66.62 to 87.63 at 3 months after surgery.

CONCLUSIONS: CustomCornea was an improvement over conventional LASIK as measured by most psychophysical and psychometric parameters. The relationship between higher order aberrations and other psychophysical and psychometric measurements needs more analysis. [J Refract Surg 2003;19:S691-S696]
Wavefront-guided Treatment of Abnormal Eyes Using the LADARVision Platform
Authors: Carones Francesco , Vigo Luca , Scandola Elena
Published: April 2021

ABSTRACT

PURPOSE: To evaluate the clinical results of Alcon LADARVision4000 wavefront-guided customized treatment of eyes with myopia and/or astigmatism, and clinically significant visual symptoms related to the presence of higher order aberrations.

METHODS: Seven consecutive abnormal eyes from seven patients underwent wavefront-guided CustomCornea (1 PRK, 6 enhancements after previous LASIK) to correct low and higher order aberrations, using the Alcon LADARVision4000 platform. Eyes were examined at 1 to 3 months after treatment; the longest follow-up examination was used for analysis. Uncorrected and best spectaclecorrected visual acuity, manifest refractive spherical equivalent error, and subjective visual symptoms were measured, as well as wavefront measurement of higher order aberrations.

RESULTS: All seven eyes had an improvement in UCVA. One eye gained 2 lines of BSCVA, four eyes gained 1 line, and no eye lost any lines. Manifest refractive spherical equivalent error was slightly hyperopic in all eyes (+0.12 to +1.50 D). All eyes snowed a reduction in pre-existing higher order aberrations, ranging between 1% and 48%. Spherical aberration was reduced most (mean 38% reduction), coma was reduced by a mean 14%, and all other terms were reduced by a mean 17% compared to preoperative values. Subjectively, all patients noticed a reduction in their pre-existing visual symptoms and reported visual performance comparable to their fellow asymptomatic eye. Overall, the treatment was considered very satisfactory by patients in terms of visual quality gain.

CONCLUSION: Wavefront-guided custom ablation with Alcon's LADARVision4000 was effective in reducing higher order aberrations and related visual symptoms in this preliminary small series. Longer follow-up on more eyes is necessary to assess the accuracy of the algorithm in the correction of defocus, which resulted in a slight overcorrection in this study. [J Refract Surg 2003;19:S703-S708]
A New System of Intraocular Instruments: III. Guillotine Scissors
Authors: Rappazzo J Alan , Escoffery Richard F
Published: April 2021

ABSTRACT

The development of a new manual 20-gauge intraocular scissors provides several distinct advantages over prior models. They are compatible with standard vitrectomy systems and useful in applications in both the anterior and posterior segments of the eye particularly for resection of epiretinal and pupillary membranes.
The Surgical Management of Corneal Astigmatism After Penetrating Keratoplasty
Authors: Lavery G William , Lindstrom Richard L , Hofer Lee A , Doughman Donald J
Published: April 2021

ABSTRACT

Seventeen patients with high astigmatism ranging from 5.63 to 19.50 diopters after penetrating keratoplasty had further surgery performed to reduce the astigmatism. Twelve patients had a mean reduction of 4.70 diopters ranging from 1.75 to 10.50 diopters. Four patients had a mean increase of 4.81 diopters with a range from 2.13 to 9.00 diopters. We have found that large amounts of astigmatism can be corrected with relaxing incisions within or circumferential to the graft-host interface but the predictability of the surgical outcome is not satisfactory in all cases.
Modification of the Kestenbaum Operation for Correction of Nystagmic Torticollis and Improvement of Visual Acuity With the Use of Convergence
Authors: Economopoulos Nicolaos K , Damanakis Alexandros G
Published: April 2021

ABSTRACT

In five patients with congenital nystagmus and compensatory head turn we performed a modified Kestenbaum operation intended to correct the compensatory head turn and to improve visual acuity. All patients had nystagmus without strabismus and fully developed binocular function. The nystagmus decreased but did not cease completely during the lateral gaze, and the patients adopted compensatory head turn positions to improve their visual acuity. The near acuity was better than the distance and the head turn decreased on near fixation.

In such cases the original Kestenbaum procedure transfers the neutral zone to the primary position and corrects the head turn, but does not improve the visual acuity because a considerable amount of nystagmus is still present.

Our aim was to perform an asymmetric Kestenbaum operation with a greater amount of surgery to the eye that turns out and a lesser amount to the eye that turns in, thus creating a postoperative divergence of the eyes. The result of compensating for this divergence (through stimulation of the fusional reserve) blocks the residual nystagmus of the neutral zone and, consequently, improves visual acuity.

The results obtained from performing this modified Kestenbaum operation in five patients were very satisfactory. The compensatory head turn was corrected in all patients and remained so during the follow-up period. In four cases, the postoperative visual acuity in the neutral zone was better than before. There was no improvement in one case.
Preoperative Prediction of Hyphemas
Authors: Gorman Michael , Rittersbach George H , Eliason Joseph A , Rosenthal A Ralph
Published: April 2021

ABSTRACT

In a prospective study, 139 patients undergoing cataract extraction were evaluated preoperatively with a penal of coagulation studies: prothrombin time, partial thromboplastin time, platelet count, and total bleeding time. Patients were monitored postoperatively for the presence of a hyphema which was then correlated with the test results. There was an overall incidence of 10.8% hyphemas in the population, and a statistically significant correlation was revealed with abnormal test results only if all the tests were considered together.
A Form of Variable Astigmatism Induced by Pseudopterygium
Authors: Gridley Melissa J , Perlman Elliot M
Published: April 2021

ABSTRACT

Pterygium and Pseudopterygium have long been known to induce astigmatism and may do so without entering the visual axis. We present a case report of a 34-year-old man with a traumatic Pseudopterygium which produced a "dynamic" astigmatism, varying in different fields of gaze. Due to the Pseudopterygium 's attachment to the lateral canthus, it produced a tethering effect with markedly decreased vision and wrinkling of Descemets membrane when the eye was directed away from the anchoring point. This model may apply to other ocular diseases where perilimbal attachments and adnexal adhesions to the corneal surface may occur; such connections should be looked for in cases with unexplained low levels of visual acuity.
Pseudophakic Cystoid Macular Edema: A Revised Comparison of the Incidence With Intracapsular and Extracapsular Cataract Extraction
Authors: Severin Todd D , Severin Sanford L
Published: April 2021

ABSTRACT

A previous study by one of the authors found no significant difference in the incidence of cystoid macular edema with an intracapsular cataract extraction and the implantation of an iris-supported posterior chamber optic lens, compared with the incidence of cystoid macular edema with an extracapsular extraction and the implantation of a Shearing lens. To test the validity of that conclusion, the charts of 686 patients operated on by one of the authors were reviewed. It was determined that the incidence of both transient and persistent cystoid macular edema was significantly higher in the patients who had an intracapsular cataract extraction. Reasons for the contradictory findings are discussed.
Prediction of Post Cataract Extraction Visual Acuity: 10 Hz Visually Evoked Potentials
Authors: Odom J Vernon , Chao Gung-mei , Hobson Robert , Weinstein George W
Published: April 2021

ABSTRACT

Cataract patients suspected of having disease that might interfere with good postoperative visual function were evaluated by eliciting monocular steadystate luminance visual evoked potentials (VEPs) with closed eyes at a stimulus rate of 10 flashes/sec. VEPs were rated as either normal or abnormal. Patients with normal VEPs were predicted to have visual acuity of 6/15 (20/50) or better. Patients with abnormal VEPs were predicted to have acuities of 6/18 (20/60) or worse. Postoperative acuities were determined for all patients who underwent surgery and who had no intraoperative or early postoperative complications. The predicted and observed postoperative acuities were quantitatively compared for the 59 patients who met these criteria, using a 2 × 2 contingency table. The chisquare was significant (p<.001). The overall accuracy of prediction was 80%. Accuracy of the predictions for patients with preoperative acuities of 6/60 (20/200) or better was compared with the accuracy of the predictions for those with preoperative acuities of 60/120 (20/400) or worse. There was no significant difference (p>0.10).
Technique for Incisional Biopsy of a Lacrimal Gland Mass When the Diagnosis of Benign Mixed Tumor Cannot Be Excluded Clinically
Authors: Tse David T , Folberg Robert
Published: April 2021

ABSTRACT

In most cases of a lacrimal gland mass, the management course can be defined clearly based on an accurate history supported by characteristic radiographic features. There are, however, certain cases that do not fit cleanly into management algorithms and, on occasion, it may be necessary to obtain an incisional biopsy into a lacrimal gland mass when the diagnosis of benign mixed tumor cannot be excluded conclusively. We report a technique for incisional lacrimal gland biopsy under these circumstances. To prevent tumor spillage in the event of benign mixed tumor, the incision site into the gland is covered with several drops of butyl-2-cyanoacrylate. The biopsy specimen is submitted for frozen section examination. If the frozen section reveals benign mixed tumor, the entire gland may be removed, with the cyanoacrylate bond protecting the lacrimal gland contents from contaminating the orbit. The technique and its indications are described in detail.
"Proplast" for Keratoprosthesis
Authors: White James H , Gona Ophelia
Published: April 2021

ABSTRACT

'Proplast,' a Teflon® fluorocarbon polymer and carbon fiber composite, was used as support for a polymethyl-methacrylate cylinder in a keratoprosthesis that was implanted in rabbit corneas with successful retention for up to 3 years.
Use of Digital Compression Following Glaucoma Surgery
Authors: Wieland Mark , Spaeth George L
Published: April 2021

ABSTRACT

A survey of American glaucoma specialists showed that digital compression of the globe following filtering surgery for glaucoma is used extensively. Consensus regarding the method and timing of "massage" is lacking, as are controlled clinical studies supporting its assumed benefits.
Complications of Vitrectomy for Non-clearing Vitreous Hemorrhage in Diabetic Patients
Authors: Benson William E , Brown Gary C , Tasman William , McNamara J Archibald
Published: April 2021

ABSTRACT

One hundred consecutive patients with proliferative diabetic retinopathy underwent vitrectomy for nonclearing vitreous hemorrhage. Eighty-two had significantly improved vision; nine had no improvement in vision; and nine had complications which resulted in permanent loss of vision. Only three eyes lost vision because of neovascular glaucoma. Our results indicate that with improved surgical techniques, the incidence of vitrectomy complications is decreasing.
Limbal Wedge Resection at the Time of Intraocular Lens Surgery for Reducing Postkeratoplasty Astigmatism
Authors: Geggel Harry S
Published: April 2021

ABSTRACT

Thirteen limbal wedge resections performed to reduce postkeratoplasty astigmatism in patients undergoing secondary intraocular lens placement were reviewed. Eleven of the 13 procedures reduced preoperative astigmatism 3.12 diopters (±1.77 D; range, 0.50 D to 6.25 D). The average follow-up time was 17 months (range, 4 to 36 months). The average flat/steep ratio was 1.19 (±0.96), indicating approximately equal degrees of corneal flattening and steepening. Average central corneal keratometric values steepened 0.47 D, with a range of 0.56 D of flattening to 2.41 D of steepening. Keratometric values were stable by 4 months in most patients. All patients except one with amblyopia had a corrected visual acuity of 20/60 or better. A dellen formation developed in one case, but it caused no permanent negative visual complications. As generally found in previous studies, each 0.1-mm wedge-width resected induced 1 D of astigmatic correction. Limbal wedge resection in conjunction with intraocular lens implantation can safely and effectively reduce astigmatism following penetrating keratoplasty.
Avoiding Complications of Orbital Surgery: The Orbital Branches of the Infraorbital Artery
Authors: Coulter Vickie L , Holds John B , Anderson Richard L
Published: April 2021

ABSTRACT

Adequate exposure in surgery along the orbital floor requires recognition and often division of the orbital branches of the infraorbital artery. Failure to recognize this orbital vascular bundle may lead to severe complications, including visual loss.
An Improved Technique for Experimental Penetrating Keratoplasty in Rabbits
Authors: Beyer Craig F , Lin David T C , Insler Michael S
Published: April 2021

ABSTRACT

Penetrating keratoplasty is difficult to perform, especially for the beginning ophthalmologist or corneal surgeon. This investigation describes, step by step, a simplified technique of performing experimental keratoplasty on rabbit eyes. Use of this method resulted in 20 of 24 (83%) rabbit eyes maintaining technically successful clear grafts without anterior synechiae or angle-closure glaucoma for up to 3 months postoperatively.
A Modified Iris Fixation Suture Utilizing a Peripheral Iridectomy
Authors: Allinson Richard W
Published: April 2021

ABSTRACT

To help ensure proper placement of an iris fixation suture, a peripheral iridectomy can be performed to allow visualization of the superior haptic of a posterior chamber intraocular lens (PC-IOL). In cases where support for the PC-IOL is in question, an iris fixation suture using this technique provides an easy way of ensuring adequate support.
Filtering Bleb Encapsulation Increased by Steroid Injection
Authors: Loftfield Katherine , Ball Stuart F
Published: April 2021

ABSTRACT

In an attempt to enhance its pressure-lowering and fibroblast inhibiting effects, we administered 0.15 cc of 24 mg/ml dexamethasone, intra-Tenon's, directly over the fistula site following 16 consecutive filtering surgeries. The encapsulation rate in these eyes was 56% (9/15), as compared with 10% (2/20) in a retrospectively matched group of eyes that had undergone filtering surgery with dexamethasone given subconjunctivally 180° away from the filter site. The effective concentration of dexamethasone achieved by the injections at the filter site apparently did not maintain the fibroblast inhibitory drug level and, in fact, supported fibroblastic growth, resulting in increased encapsulation.

Because of the increased encapsulation rate and the lack of any demonstrable benefit associated with it, we do not recommend intralesional dexamethasone in filtering surgery. Commercial topical steroids with their lower concentrations also may act to promote rather than inhibit fibroblast growth. Prolonged steroid use after filtering surgery beyond the inflammatory phase of wound healing (about 2 weeks) may increase fibrosis in the area of the filter, resulting in a thick-walled bleb with few microcysts, one form of which is frank encapsulation. Thus, we recommend that topical steroids routinely be stopped by the third postoperative week if the level of inflammation permits.
Transconjunctival Nd:YAG Laser Revision of Failing Trabeculectomy
Authors: Rankin Gary A , Latina Mark A
Published: April 2021

ABSTRACT

We used a Q-switched Nd:YAG laser delivered transconjunctivally to restore filtration to a failing trabeculectomy of a 51 -year-old black woman with primary open-angle glaucoma and uncontrolled intraocular pressure (IOP) on maximally tolerated anti-glaucoma medical therapy. Initially, the Nd:YAG laser was directed via a goniolens at the interface of the trabeculectomy flap and scleral bed. This attempt to restore filtration was unsuccessful. In two separate treatment sessions the Nd: YAG laser was directed transconjunctival^ onto the visible trabeculectomy flap margins, followed by focusing the laser onto the gray-white episcleral fibrous tissue overlying the scleral flap. During the last transconjunctival treatment, the bleb elevated immediately and the IOP decreased from 30 mm Hg to 18 mm Hg. These effects have been sustained over 3 months of follow-up.
The Effect of Relaxing Incisions With Multiple Compression Sutures on Post-Keratoplasty Astigmatism
Authors: Lustbader Jay M , Lemp Michael A
Published: April 2021

ABSTRACT

We describe a surgical technique for correction of astigmatism following penetrating keratoplasty performed after all keratoplasty sutures have been removed. Two relaxing incisions of 3 clock hours, at 3/4 depth, 0.5 mm inside the keratoplasty wound are used in combination with two sets of three compression sutures placed 90° from the incisions. Selective removal of the compression sutures allows for a graded reduction in overcorrection. With this technique, a mean preoperative astigmatism in 10 patients of 14.25 diopters was reduced to 6.33 D 3 months postoperatively (P<.002). There were no intraoperative or postoperative complications such as inadvertent perforation, wound dehiscence, or graft rejection.
A New Glaucoma Filter Implant
Authors: Dobrogowski Michael J , Dolman Peter J , Douglas Gordon R
Published: April 2021

ABSTRACT

A new glaucoma filtration procedure was performed in nine rabbits in a preliminary trial. A silastic tube with an internal diameter of 0.35 mm was passed across the anterior chamber through two limbal openings, and the free ends were buried postequatorially in sub-Tenon's space. At a later date, using an Nd: YAG laser in the thermal mode, holes 0.05 to 0.30 mm in diameter were bumed in the tube in the anterior chamber. This procedure significantly lowered intraocular pressure in four rabbits on two successive tries; however, a third treatment given in two cases did not further decrease the pressure.
Effect of Intraocular Aspiration of Sodium Hyaluronate on Postoperative Intraocular Pressure
Authors: Stamper Robert L , DiLoreto David , Schacknow Paul
Published: April 2021

ABSTRACT

A prospective, randomized, masked study was conducted to evaluate whether intraocular aspiration of sodium hyaluronate used in cataract surgery influenced postoperative intraocular pressure (IOP). Ninety-nine patients (105 eyes) underwent uncomplicated extracapsular extractions with posterior chamber intraocular lens implantation using 1% sodium hyaluronate (AMVISC®). In 53 eyes, sodium hyaluronate was aspirated from the anterior chamber prior to wound closure. Sodium hyaluronate was left in the anterior chamber of 52 eyes.

The IOP of 33 of the patients was measured 4 hours after surgery. No significant difference was found between the pressure in the eyes from which the sodium hyaluronate had been aspirated and the pressure in those from which it had not. The IOP of all the patients was measured on the first postoperative day. The mean 24 hours after surgery was 23.4 mm Hg in the aspirated eyes and 23.1 mm Hg in the not-aspirated group. Thirteen eyes in the aspirated group and 14 in the not-aspirated group had pressures above 30 mm Hg during the first 24 hours after surgery. There were no significant differences in visual outcome, patient discomfort, corneal clarity, anterior chamber inflammation, or subsequent IOPs during 3 months of postoperative examination.

Aspiration of sodium hyaluronate at the end of cataract surgery does not appear to significantly reduce either the incidence or the degree of postoperative pressure elevations.
Matched Group Study of Surgical Resection Versus Cobalt-60 Plaque Radiotherapy for Primary Choroidal or Ciliary Body Melanoma
Authors: Augsburger James J , Lauritzen Kyra , Gamel John W , DeBrakeleer Donald J , Lowry Jonathan C , Eisenman Richard
Published: April 2021

ABSTRACT

We report the results of a nonrandomized, matchedgroup, survival and visual preservation study of patients with a choroidal or ciliary body melanoma managed by microsurgical resection of the tumor versus cobalt-60 episcleral plaque radiotherapy. Each treatment group consisted of 30 patients. All patients were matched on a case-by-case basis in terms of tumor size (largest linear tumor dimension), location of the anterior tumor margin relative to the ora serrata, location of the posterior tumor margin relative to the equator, and age at the time of treatment. Although the estimated actuarial 5-year survival probability was slightly greater in the resection group (85.2%) than in the cobalt plaque group (81.8%), this difference was neither clinically impressive nor statistically significant. In contrast, there was a substantially higher rate of early posttreatment severe visual loss in the resection group (P = .0008, MantelHaenszel test).
Trabecular Pigmentation Following Extracapsular Cataract Extraction and Posterior Chamber Intraocular Lens Implantation
Authors: Sugiyama Kazuhisa , Kitazawa Yoshiaki
Published: April 2021

ABSTRACT

We prospectively evaluated the change in trabecular pigmentation following extracapsular cataract extraction and posterior-chamber intraocular lens implantation in 70 patients (94 eyes) with senile cataracts. Using the Boys-Smith pigment gradation lens to measure semiquantitative^ the amount of pigment visible in the angle, we estimated the mean trabecular pigmentation preoperative^ and at 3month intervals postoperatively. Both the mean pigmentation and the number of eyes with heavy pigmentation rose after the operation and then gradually returned to preoperative levels. There was no correlation between the amount of trabecular pigmentation and intraocular pressure.
Retinal Toxicity and In Vitro Efficacy Study of Cilofungin (LY121019)
Authors: Shahsavari Mohsen , Peyman Gholam A , Niesman Michael R
Published: April 2021

ABSTRACT

We assessed the retinal toxicity of a new antifungal agent, cilof ungin, by injecting it into the vitreous body of albino rabbit eyes in dosages of 2.5 µg to 320 µg. The maximum intravitreal drug concentration (320 µg) produced no histological evidence of retinal toxicity. Electroretinography data showed some variations, but no toxicity at the highest dose (320 µg). When efficacy was evaluated in vitro against Candida albicans, the minimal inhibitory concentration was 2.50 µg/mL, using Sabouraud's broth or M3 medium. The minimal fungicidal concentration was 5 µg/mL with Sabouraud's broth, and 10 µg/mL with M3 medium. Cilofungin is a potentially safe antifungal for the treatment of candida endophthalmitis.
Role of Communities in Decision-Making Eye Care Programs
Authors: Chana Harjinder S , Lundstrom Karl J
Published: April 2021

ABSTRACT

The concept of primary health care involves educating people to live their lives in ways beneficial to their health. Communities as a whole must participate in the decision-making that is involved in such education, be it promotive, preventive, curative, or rehabilitative. I refer to this participation as "participatory communication." It is based on two fundamental tenets: 1) Everyone in a community has some special knowledge to contribute to the development of the health of that community; and 2) No person is superior to another. Subsequent to sociological and anthropological studies of communities in the Southern Sudan by the Norwegian Church Aid, the Norwegian Association of the Blind and Partially-Sighted conducted village workshops based on this concept.
Mycobacterium chelonei Keratopathy With Visual Rehabilitation by a Triple Procedure
Authors: Crane Timothy B , Stevens Rhoads E , Couch Rex D , Lee Timothy L , Terui Robin
Published: April 2021

ABSTRACT

We report a chronic keratouveitis following an eye injury, the etiology of which remained obscure despite repeated corneal scrapings and cultures. Eventually, the diagnosis was established by culturing Mycobacterium chelonei from a corneal biopsy specimen.

Topical amikacin resolved active inflammation, but dense corneal scarring and a cataract remained. Visual rehabilitation was achieved through a combined penetrating keratoplasty, extracapsular cataract extraction, and intraocular lens implantation. This case illustrates that there should be a high index of suspicion of atypical mycobacteria when faced with any unusual keratitis, particularly following penetrating injuries and corneal grafts.
The Use of Subconjunctivally Administered Tissue Plasminogen Activator After Trabeculectomy
Authors: Piltz Jody R , Starita Richard J
Published: April 2021

ABSTRACT

Blockage of aqueous flow in the early postoperative period can be devastating to the success of trabeculectomy. We used tissue plasminogen activator (tPA) subconjunctivally in an attempt to release a trabeculectomy flap that appeared to be adherent to its scierai bed. No change was noted 90 minutes after injection, but a highly elevated bleb was present on the first postoperative day. Subconjunctivally administered tPA may be useful in releasing the fibrin "glue" in cases with adherent trabeculectomy flaps.
Microbial Keratitis Following Penetrating Keratoplasty
Authors: Tavakkoli Hassan , Sugar Joel
Published: April 2021

ABSTRACT

A retrospective study of 36 cases of infectious keratitis in the graft following 885 consecutive penetrating keratoplasties was conducted to evaluate the spectrum of pathogens and the factors affecting graft survival. Gram positive cocci and gram negative rods were equally responsible (47% in both cases) for 94% of the infections. Epithelial defects were responsible for 64% of the ulcers; suture-related infections, for 36%. After the infectious keratitis resolved, only 50% of the patients had a clear graft. Because the visual prognosis is poor once infectious keratitis develops, aggressive treatment is essential as soon as any sign of infiltration appears.