bluuebunny/crossref_metadata_2025 huggingface dataset:
Healing After Photorefractive Keratectomy in Cat Eyes With a Scanning Mid-infrared Nd:YAG Pumped Optical Parametric Oscillator Laser
Authors: Telfair William B , Bekker Carsten , Hoffman Hanna J , Yoder Paul R , Nordquist Robert E , Eiferman Richard A , Zenzie Henry H
Published: April 2021

ABSTRACT

PURPOSE: To evaluate the healing characteristics of cat corneas treated with a new scanning midinfrared laser system.

METHODS: Six adult cats were treated with 6-mm diameter photorefractive keratectomy (PRK) corrections. One eye in each animal was untreated as a control and the other was treated with either a -3.00 or -6.00 diopter ablation. The laser was a new Nd:YAG pumped optical parametric oscillator laser at 2.94 /im with a new scanning delivery system. The pulse width was 7 nanoseconds, the repetition rate was 10 Hz, the size of the laser spot on the eye was 1.0 mm, and the fluence was 150 m J/cm
p 2
. Healing of the cat corneas was followed for 4 months. Slit-lamp and corneal topography evaluations were done at each follow-up examination. Histology was performed at the end of the study.

RESULTS: The corneal epithelium healed within 1 week. There was no stromal haze in any eye after the epithelium healed. After the first 2 weeks, slitlamp examination could not identify which eye was treated, Corneal topography showed corneal flattening. Light microscopy at 4 months revealed normal epithelium and increased keratocyte density in the anterior third of the cornea. Electron microscopy showed discontinuities in the basement membrane and hemidesmosomes. The deep stroma and endothelium were normal.

CONCLUSIONS: Cat corneas treated with the new optical parametric oscillator laser healed normally with no adverse effects. Increased keratocyte activity in the anterior stroma was the only noticeable response besides the flattening shown by topography. [J Refract Surg 2000;16:32-39]
Photorefractive Keratectomy for Visual Rehabilitation of Anisometropia Induced by Retinal Detachment Surgery
Authors: Bilgihan Kamil , Özdek Sengul C , Gürelik Gökhan , Adigüzel Ufuk , Önol Merih , Hasanreisoglu Berati
Published: April 2021

ABSTRACT

PURPOSE: To evaluate the efficacy of unilateral photorefractive keratectomy to correct anisometropia induced by retinal detachment surgery.

METHODS: Photorefractive keratectomy was performed in 10 eyes of 10 patients with anisometropia induced by previous retinal detachment surgery. The Aesculap Méditée MËL 60 excimer laser was used.

RESULTS: Preoperative mean spherical equivalent refraction was -5.20 D. Mean postoperative spherical equivalent refraction was -0.25 D after a mean follow-up of 12.9 months. Mean preoperative spherical equivalent refraction difference between two eyes of 4.87 D was decreased to a mean 0.60 D postoperatively (f-test, P < .0001). All patients were free of anisometropic symptoms after laser surgery.

CONCLUSION: Unilateral photorefractive keratectomy seems to be an effective method to correct anisometropia induced by conventional retinal detachment surgery, especially for patients with spectacle and contact lens intolerance. [J Refract Surg 2000;16:75-78]
Feasibility of Intraoperative Corneal Topography Monitoring During Photorefractive Keratectomy
Authors: Moser Christophe , Kampmeier Juergen , McDonnell Peter , Psaltis D
Published: April 2021

ABSTRACT

PURPOSE: We propose a feasibility study of new corneal topography technology with the aim of monitoring intraoperative corneal topography during excimer laser photorefractive keratectomy. The PAR system measures corneal topography with single grid projection and triangulation but requires fluorescent fluid to be deposited on the corneal surface for shape extraction. We propose and demonstrate a novel corneal topography system based on structured incoherent visible light projection and triangulation that does not require addition of fluorescent fluid.

METHODS: We used a binary liquid crystal spatial light modulator to display multiple fringe patterns onto the cornea. The depth accuracy of the corneal topography system was measured using a white reflected test sphere mounted on a micrometer translation stage. The performance of the corneal topography system was tested on 5 deepithelialized swine eyes in vitro ablated with a VISX excimer laser.

RESULTS: Depth accuracy on the test sphere was 0.5 ± 0.75 µm over an area of 17.6 mm
p 2
. On de-epithelialized swine corneas, ablation at the apex of the cornea treated with an excimer laser was measured without addition of fluorescein.

CONCLUSIONS: This new corneal topography system achieved an adequate level of accuracy on a test sphere. [J Refract Surg 2000;16:148-154]
Laser in situ Keratomileusis Enhancement After Radial Keratotomy
Authors: Yong Li , Chen Guy , Li Walton , Chang John , Ngan Chen , Tong Patrick , Qun Cao
Published: April 2021

ABSTRACT

PURPOSE: To present results of laser in situ keratomileusis (LASIK) enhancement after radial keratotomy (RK).

METHODS: Sixteen eyes of 10 patients were treated with LASIK for residual myopia and hyperopia after RK. Mean preoperative spherical equivalent refraction was -3.14 ± 3.04 D (range, -6.675 to +6.00 D). Best spectacle-corrected visual acuity was 20/20 in 9 eyes, 20/25 in 6 eyes, and 20/30 in 1 eye. Uncorrected visual acuity was better than 20/40 in only 2 eyes. Patients were followed at 1 day, 1 week, 1, 3, and 6 months, and 1 year. Mean follow-up was 8.3 months (range, 1 to 17 mo).

RESULTS: All eyes received one LASDX enhancement. Mean final spherical equivalent refraction was +0.16 ± 0.68 D (range, -1.00 to +1.75 D). No eyes experienced any visual loss. Five eyes gained 1 line of best spectacle-corrected visual acuity. Uncorrected visual acuity was 20/20 in 9 eyes, 20/25 in 6 eyes, and 20/30 in 1 eye. Two eyes of one patient had the previous RK incisions open.

CONCLUSION: LASLK was an effective treatment for correction of residual myopia and hyperopia after RK. [J Refract Surg 2000;16:187-190]
Planned Undercorrection With Laser in situ Keratomileusis and Photorefractive Keratectomy for Myopes Over Age 40
Authors: Roudakova T E , Kourenkov V V , Polounine G S
Published: April 2021

ABSTRACT

PURPOSE: To evaluate the effectiveness of planned undercorrection in myopic patients over 40 years of age

METHODS: Two hundred eight eyes of 104 patients aged 40 to 60 years had photorefractive keratectomy (PRK) or laser in situ keratomileusis (LASIK). Full corrections were done for the dominant eye and undercorrection of -1.50 or -2.50 D for non-dominant eye. Planned undercorrection of -1.50 D was done for patients aged 40 to 50 years, and -2.50 D for patients aged 51 to 60 years.

RESULTS: In eyes with planned undercorrection of -1.50 D, the achieved refraction was a mean -1.67 ± 0.40 D after PRK and a mean -1.54 ± 0.30 D after LASIK. In eyes with planned undercorrection of -2.50 D, the achieved refraction was after PRK was a mean -1.82 ± 0.50 D and after LASIK, -2.31 ± 0.60 D. Estimation of the achieved refraction was made according to the condition of the lens: in the group with clear lenses, mean achieved refraction was -1.60 ± 0.30 D (planned -1.50 D, 52 patients) and -2.10 ± 0.40 D (planned -2.50 D, 19 patients). In the group with initial opacification of the lens, mean achieved refraction was -1.00 ± 0.40 D (planned -1.50 D, 9 patients), and -1.40 ± 0.20 D (planned -2.50 D, 24 patients).

CONCLUSIONS: According to analysis of the achieved results, nomograms for planned undercorrection in patients aged 40 to 60 years were refined for PRK and LASIK. [J Refract Surg 2000;16(suppl):S261-S263]
Long-term Results of Correction of High Myopia With an Iris Claw Phakic Intraocular Lens
Authors: Landesz Monika , Worst J G F , van Rij Gabriel
Published: April 2021

ABSTRACT

PURPOSE: Anterior chamber phakic intraocular lenses (PIOLs) are one of the modalities used to correct high myopia. We report the long-term results of our prospective study on the Artisan 5-mm optic myopia lens.

METHODS: We studied 67 eyes of 38 consecutive patients with preoperative myopia ranging from -5.38 to -28.00 D. All patients were operated by one surgeon. Mean follow-up was 35 months (24 months in 67 eyes and 36 months in 61 eyes).

RESULTS: In 45 eyes (67.2%), postoperative residual refraction was within ±1.00 D of emmetropia. The mean refraction was stable statistically during the entire follow-up period. Mean best spectacle-corrected visual acuity improved from 20/40 to 20/32. Mean endothelial cell loss at 6 months was 5.5% (range, -52.4% to +9.3%), at 12 months, 7.21% (range, -53.2% to +20.1%), at 24 months, 9.1% (range -43.6% to +13.6%), and at 36 months, 10.9% (range, -43.0% to +11.4%). The majority of eyes had an increase in best spectaclecorrected visual acuity; 5 eyes lost best spectaclecorrected visual acuity. We encountered no major complications.

CONCLUSION: Implanting the Artisan 5-mm optic myopia lens in high myopic eyes resulted in a stable and accurate refractive outcome. The apparent progressive corneal endothelial cell loss remains a matter of concern. [J Refract Surg 2000;16:310-316]
Intraocular Lens Power Calculation in Eyes After Corneal Refractive Surgery
Authors: Seitz Berthold , Langenbucher Achim
Published: April 2021

ABSTRACT

PURPOSE: The purpose of this review article is to discuss the major reasons for postoperative hyperopia after cataract surgery following radial keratotomy (RK) and photorefractive keratectomy (PRK) and to illustrate potential methods for improvement of intraocular lens (IOL) power prediction after keratorefractive surgery based on exemplary model calculations.

METHODS: We previously performed model calculations in eyes after PRK for myopia (-1.50 to -8.00 D, mean -5.40 ± 1.90 D) using keratometry readings as measured by the Zeiss keratometer and the TMS-I topography unit and as calculated using the "clinical history method" (spherical equivalent refraction change) and change in anterior surface keratometry readings.

RESULTS: We found that after PRK, mean measured keratometry readings were significantly greater than respective calculated values considering the preoperative to postoperative change of anterior corneal surface (P < .001), which itself was significantly greater than calculated keratometry readings considering the preoperative to postoperative change of spherical equivalent refraction (P < .001). IOL power underestimation correlated significantly with the difference between preoperative and postoperative spherical equivalent refraction (P = .001).

CONCLUSIONS: For correct assessment of keratometric readings to be entered into more than one modern third-generation IOL power calculation formula (but not a regression formula), the clinical history method should be applied whenever refraction and keratometric diopters before the keratorefractive procedure are available to the cataract surgeon. If preoperative keratometric diopters and refraction are not known, average central power on the postoperative videokeratograph may be used after RK, but refined calculation of keratometric diopters from radius of anterior and posterior corneal surface should be used after PRK and/or LASIK. [J Refract Surg 2000;16:349-361]
Preoperative Simulation of Outcomes Using Adaptive Optics
Authors: Bille Josef F
Published: April 2021

ABSTRACT

Measurements of the wavefront of light reflected from the retina of the human eye can be used to determine optical aberrations of the human eye for large pupils. An instrument based on the Hartmann-Shack principle was developed. The wavefront is refracted by a microlens array and detected by a CCD camera. In first clinical studies human volunteer eyes and preoperative and postoperative refractive surgical patient eyes have been examined. An adaptive optical closed loop system has been devised for preoperative simulation of refractive outcomes of aberration free refractive surgical procedures. [J Refract Surg 2000; 16: S608-S6101
Hydrostasis in Ophthalmic Microsurgery
Authors: Stern Mark D
Published: April 2021

SUMMARY

The use of Cottonoids* to achieve and maintain hydrostasis during ophthalmic microsurgery is discussed.
Diamond Knife
Authors: Rowsey J James , Balyeat Hal D , Yeisley Keith P
Published: April 2021

SUMMARY

We present a new diamond knife which allows for reasonably precise incisions in cornea or sclera. The knife may be ultrasonically cleaned and is sharper than any metal knife whose edge we have examined to date by scanning electron microscopy. The edge is approximately 0.1 micron in width, compared to 1-5 micron width edges of most metal knives. We feel that this prototype will allow investigators to recommend special modifications to the manufacturer of their own choice.
Nitrous Oxide Analgesia for Cataract Surgery
Authors: McMahan Lynn B
Published: April 2021

SUMMARY

Nitrous oxide, properly used, provides a rapid, readily reversible method of sedation for cataract surgery.
Inflammation of the Lacrimal Drainage System - Assessment by Thermography
Authors: Rosenstock Ted , Chart P , Hurwitz J J
Published: April 2021

SUMMARY

Thermography is an investigative tool without side effects. To our knowledge thermography has not been evaluated in the assessment of lacrimal passage inflammation and obstruction. It can give an objective assessment of presence and degree of inflammation.

An infrared scanning device was used to detect surface temperatures in 29 patients with known disorders of the lacrimal drainage passage. Thermal images were compared for bilateral symmetry and against the normal thermographic appearance of the face.

Acute dacryocystitis and canaliculitis showed gross hyperthermia and asymmetry. Forty-two percent of patients with a picture of chronic dacryocystitis and 40% of patients with only tearing and no clinical evidence of inflammation showed temperature elevation on the side of involvement, whereas 58% and 60% of these respective groups showed symmetrical thermal patterns, suggesting no active inflammation. In a few cases there were discrepancies between clinical assessment and objective thermographic evaluation of the degree of inflammation.

The implications of our results and possible applications of thermography are discussed.
Combined Procedure for Senile Entropion
Authors: Wesley Ralph E , Collins John W
Published: April 2021

SUMMARY

Entropion of the lower eyelid was corrected in 26 eyelids of 21 patients. All patients were found to have a disinsertion of the capsulopalpebral fascia, but not Müllers muscle layer, of the lower eyelid retractors. All cases were repaired by reattaching the anterior edge of the capsulopalpebral fascia to the inferior edge of the lower tarsus combined with A horizontal eyelid tightening procedure performed at the lateral canthus. With follow-up of six to 32 months, no cases of entropion have recurred. We have found a combined procedure of horizontal eyelid tightening and repair of the capsulopalpebral fascia gives best long-term results.
Evaluation of Local Anesthesia Agents Using a New Force-Sensitive Lid Speculum
Authors: Parrish Richard K , Spaeth George L , Poryzees Effie M , Hargens C William
Published: April 2021

SUMMARY

Three commonly used injection anesthetics, bupivacaine .75%, mepivacaine 2%, and lidocaine 2% were evaluated for onset, completeness and duration of akinesia following modified O'Brien facial nerve block, using a new force-sensitive lid speculum. All three agents provided facial akinesia that was profound within six minutes of the time of injection. The onset and the depth of anesthesia were roughly the same with all three agents. However, bupivacaine induced akinesia of greatest duration, lasting up to six hours, the time of final measurement in this study. Akinesia produced by mepivacaine was adequate for about 90 minutes, and lidocaine for 15-30 minutes.

A newly-described force-sensitive speculum was utilized in this study. It is an effective instrument for measuring completeness of akinesia, and may have clinical usefulness.
The Effect of Radial Keratotomy in the Rupture Strength of Pig Eyes
Authors: Rylander H Grady , Welch Ashley J , Fremming Bret
Published: April 2021

SUMMARY

Freshly enucleated pig eyes are significantly weakened following radial keratotomy surgery and are more susceptible to rupture under lateral or axial compression than their unoperated fellow eyes. Patients should be cautioned to restrict hazardous activity in the post-operative period to prevent disastrous globe rupture.
A Modified Gills' Block and its Effectiveness for Lid Muscle Akinesia
Authors: Kimbrough R L , Stewart R H , Okereke P C
Published: April 2021

ABSTRACT

We developed a prospective clinical study to determine the effectiveness of a new method of retrobulbar anesthesia and akinesia of the levator and orbicularis muscles. This study involved 50 patients who underwent extracapsular cataract extractions (ECCE) with intraocular lens implant (IOL). We found levator and orbicularis muscle akinesia was achieved in 49 of 50 eyes. One reblock was necessary.

We also wish to point out the advantages of this technique as a means of reducing the rare but serious complications associated with retrobulbar anesthesia.
Proposal for a New Contact Lens for YAG Laser Posterior Capsulotomies
Authors: March Wayne F , Rol Pascal
Published: April 2021

ABSTRACT

A contact lens designed for neodymium-YAG laser posterior capsulotomy which angula tes the beam with respect to the posterior capsule is presented. This lens may minimize injury to the corneal endothelium.
A Step-Zoom Probe for Laser Endophotocoagulation: I. Design
Authors: Pankratov Michail M , Pomerantzeff Oleg , Pflibsen Kent P , Bearse George R
Published: April 2021

ABSTRACT

A step-zoom probe for laser endophotocoagulation of the eye has been developed, using fiber optics and a grathent index (GRIN) rod lens. It provides the operator with five or more focused spots ranging in size from 50 to 500 pm, and the spot size on the target Is independent of the media filling the vitreous cavity, i.e., fluid or air. Each spot is located at the waist of the beam and therefore can be easily placed on the target, reducing the potential for overtreatment. A prototype model is currently undergoing animal testing.
The Effect of Intravitreal Botulinum Toxin on Rabbit Visual Evoked Potential
Authors: Hoffman Robert O , Archer Steven M , Zirkelbach Steven L , Helveston Eugene M
Published: April 2021

ABSTRACT

Intravitreal injections of botulinum A toxin in two doses, 1.25 and 25 units, were performed in two rabbit eyes. The fellow eyes were injected with an equal volume of saline to serve as controls. The visual evoked potential was unchanged at one and two weeks post-injection when compared to pre-injection recordings in both botulinum and saline injected eyes.
Ab Interno and Ab Externo Filtering Operations by Laser Contact Surgery
Authors: Gaasterland Douglas E , Hennings David R , Boutacoff Theodore A , Bilek Charles
Published: April 2021

ABSTRACT

A new method to create filtering tracts ab interno or ab externo which may eventually prove useful in eyes with poorly controlled glaucoma is described.

Fiberoptics of 200 µm diameter, with either cleaved or 500 µm ball lens tips, were coupled to the output of an argon gas laser emitting a number of radiation lines in the ultraviolet (333 to 363 nm) wavelengths. This system was used to perforate the corneoscleral limbal tissue of enucleated bovine eyes with a small number of laser applications to create a filtering fistula. Corneoscleral limbal perforation with a 200 µm cleaved fiber required 0.6 to 1.1 J total energy, delivered with a laser power of 0.5 W, or greater, for 0.1 second. With a 500 µm ball lens fiber tip a tract of nearly 0.5 mm diameter was created, requiring 5.1 to 10.4 J total energy, delivered with a laser power of 2.0 W, or greater, for at least 0.1 second. The energy required for perforation from the external surface to the anterior chamber was the same as the energy required for ab interno perforation.
Intercapsular versus Extracapsular Cataract Extraction
Authors: Naylor Gerald , Morrell A J , Sutton G Augustine , Pearce J L
Published: April 2021

ABSTRACT

Forty-five eyes that have undergone routine extracapsular cataract extraction with insertion of a posterior chamber intraocular lens were compared with a similar group of eyes that had undergone intercapsular extraction. Capsular fixation was more predictable following intercapsular (78%) than it was following extracapsular extraction (22%). Gonioscopy revealed prominence of the lens haptfc in 22% of the intercapsular group, with peripheral anterior synechiae (PAS) in 18%; haptics were prominent in 78% of the extracapsular group, with synechiae in 55%. Lens eccentricity of 2 mm or more was seen in 2 patients (4%) following intercapsular and in 10 (22%) following extracapsular extraction. Pupil irregularities were noted in three of the intercapsular group (7%) and in eight of the extracapsular group, (13%) with peripheral iris tucking alone in three. These data strongly support the view that intercapsular is superior to extracapsular cataract surgery in terms of facilitating capsular fixation of posterior chamber intraocular lenses.
Posterior Relaxing Retinotomies: Analysis of Anatomic and Visual Results
Authors: Alturki Walid A , Peyman Gholam A , Paris Christopher L , Blinder Kevin J , Desai Uday R , Nelson Norman C
Published: April 2021

ABSTRACT

Fifteen eyes with complicated retinal detachments-11 with proliferative vitreoretinopathy (C
3
D
3
), 2 with posterior segment trauma, and 2 with inflammatory retinopathy-were treated with vitrectomy, membrane peeling, and large posterior retinotomy. All posterior relaxing retinotomies were circumferential, including temporal quadrants in all cases. With a minimum follow up of 6 months, 12 eyes (80%) were attached posterior to the retinotomy. Reproliferation resulted in redetachment in 3 eyes (20%). Visual acuity improved in 53%, remained unchanged in 20%, and decreased in 27%. Of the 11 eyes that achieved stable or improved visual acuity, 5 (45%) achieved 20/400 to 20/25 vision, 5 achieved counts fingers perception, and 1 patient remained stable at hand motion perception. Of all the eyes undergoing surgery, hypotony (intraocular pressure < 5 mm Hg) occurred in 6 eyes (40%); 3 of these were among the 12 eyes with attached retinas.
A New Endoscope for Ophthalmic Microsurgery
Authors: Yaguchi Shigeo , Kora Yukiko , Takahashi Haruo , Fukado Yoshinao , Yamanaka Akio , Kusakabe Masahiro , Ishibashi Satoshi
Published: April 2021

ABSTRACT

We present an endoscope designed for ophthalmic microsurgery. The handpiece contains a chargecoupled device, a solid-state imager (250 000 pixels), and a probe (either 0.89 or 1.5 mm in diameter), including the light guide. The light source is a halogen lamp. The clear views the instrument provides of the ciliary sulcus and ciliary body behind the iris make it useful in secondary posterior chamber intraocular lens implantation using the ciliary sulcus suturing technique, and in endolaser photocoagulation of the ciliary body in end-stage glaucoma. It also is useful in performing vitrectomy in cases in which visualization is difficult because of corneal opacification or fluidgas exchange.
Fornix-Based Trabeculectomy With Mitomycin-C
Authors: Levkovitch-verbin Hanna , Goldenfeld Mordechai , Melamed Shlomo
Published: April 2021

* BACKGROUND AND OBJECTIVE: Mitomycin-C (MMC) has been shown to improve the surgical success of trabeculectomy; however, the advantages of MMC have been evaluated almost entirely as an adjunct to limbal-based trabeculectomy. This study evaluated the efficacy and safety of fornix-based trabeculectomy with MMC for glaucomatous patients.

* PATIENTS AND METHODS: Between January 1993 and April 1995, 71 patients underwent fornixbased trabeculectomy with topical application of 0.4 mg/ml of MMC for 3 minutes. The conjunctivaTenon's capsule flap was spread over the limbus and sutured in order to create a visible crease with a watertight closure. The mean follow-up time was 14.5 months.

* RESULTS: The mean intraocular pressure (IOP) before surgery was 32.4 ± 9.7 mm Hg. The average postoperative IOP was 14.04 ± 9.57 mm Hg. An IOP of 20 mm Hg or less was observed in 57 eyes (80%). Postoperatively, 37 eyes (52%) required no additional medical therapy. One month after surgery, only 2 patients had wound leakage with hypotony and choroidal detachment. Two eyes (3%) had suprachoroidal hemorrhage with loss of vision. A conjunctival "buttonhole" occurred in 2 eyes (3%), but only 1 persisted more than a month.

* CONCLUSIONS: Fornix-based trabeculectomy using intraoperative application of 0.4 mg/ml of MMC for 3 minutes was found to be as safe and effective as limbal-based trabeculectomy with MMC.

[Ophthalmic Surg Lasers 1997;28:818-822.]
Corneal Blood Staining Following Autologous Blood Injection for Hypotony Maculopathy
Authors: Ayyala Ramesh S , Urban Robert C , Krishnamurthy Mina S , Mendelblatt David J
Published: April 2021

Abstract. Hypotony is a common complication following trabeculectomy in which antimetabolites are used. Autologous blood injection is an accepted form of treatment for hypotony that occurs secondary to overfiltration; however, injection into the filtering bleb has been associated with a rise in intraocular pressure for some patients with chronic postoperative hypotony. The authors describe a patient in whom corneal blood staining with raised intraocular pressure and loss of vision occurred as a result of autologous blood injection. [Ophthalmic Surg Lasers 1997; 28:866-868.]
Simultaneous Use of Mitomycin-C With Baerveldt Implantation
Authors: Azuara-Blanco Augusto , Moster Marlene R , Wilson Richard P , Schmidt Courtland M
Published: April 2021

* BACKGROUND AND OBJECTIVE: To evaluate the outcome of Baerveldt implantation with adjunctive mitomycin-C in cases of complicated glaucoma.

* PATIENTS AND METHODS: The authors reviewed the charts of all patients who had undergone Baerveldt implantation with mitomycin-C between January 1993 and March 1995. Success was defined before data collection as an intraocular pressure (IOP) between 5 and 21 mm Hg, with or without medications. The success rate was calculated using the Kaplan- Meier actuarial method.

* RESULTS: Twenty-nine patients were identified. The mean preoperative IOP was 33.6 mm Hg, with an average of 2.0 antiglaucoma medications. The probability of success at 6 and 12 months for patients who received mitomycin-C during Baerveldt implantation was 82.4% and 73.3%, respectively. Choroidal effusion with a flat anterior chamber (10.3%), corneal edema (6.8%), and conjunctival erosion (6.8%) were the most frequent complications.

* CONCLUSION: In this retrospective series of complicated glaucoma, the implantation of a Baerveldt drainage device with adjunctive mitomycin-C had a satisfactory outcome. The complications encountered and the clinical efficacy were comparable to those of previously reported series in which mitomycin-C was not used.

[Ophthalmic Surg Lasers 1997;28:992-997.]
Improvements in Visual Acuity Following Limbal Lensectomy for Subluxated Lenses in Children
Authors: Yu Young Suk , Kang Yong Hong , Lim Key-Hwan
Published: April 2021

* BACKGROUND AND OBJECTIVE: To report the surgical results of limbal lensectomy using an automated vitrectomy instrument for the treatment of subluxated lenses in children.

* PATIENTS AND METHODS: The authors reviewed the charts of children who underwent surgery for subluxated lenses. Limbal lensectomies with an "in the bag" technique were performed on 18 eyes of 1 0 patients. The indications for surgery were a best-corrected visual acuity of less than 20/60, bisection of pupil by the lens, or both.

* RESULTS: Best-corrected visual acuity improved in all 18 eyes (paired t test, P< .01). In 1 eye, transient anterior chamber hyphema occurred during the early postoperative period. No other significant complications were found during an average follow-up of 19.6 months.

* CONCLUSION: Limbal lensectomy for subluxated lenses in children improved visual acuity without severe complications.

[Ophthalmic Surg Lasers 1997;28:1006-1010.]
Injectable Centbucridine and Lidocaine Hydrochloride for Intraocular Surgery
Authors: Beri Sarita , Biswas Nihar R , Shende Dilip R , Das Gopal K , Pandey Ravindra M , Ghose Supriyo
Published: April 2021

Abstract. Centbucridine, a recent anesthetic agent, has been shown to be effective for topical ocular anesthesia. However, its value has yet to be established for ophthalmic local anesthesia. Through a doublemasked, randomized study of 60 microsurgeries for the treatment of cataract, the authors graded and compared the efficacy of a facial nerve block with 0.5% centbucridine versus 2% lidocaine hydrochloride. (The topical as well as retrobulbar anesthesia was achieved with lidocaine.) Excluding the 7 cases that were graded as having a "poor" block, the authors noted "good" orbicularis oculi muscle response in 21 of 24 patients who were given lidocaine, compared with 26 of 29 patients who were given centbucridine. Both agents provided an acceptable nerve block for at least 60 minutes; however, the effect of lidocaine was found to have an earlier onset (P < .001). Side effects were not observed with either anesthetic. The findings of this study indicate that centbucridine seems to be a satisfactory agent as an injectable or topical anesthesia for ophthalmic microsurgery. [Ophthalmic Surg Lasers 1997;28:1027-1029.]
Intrastromal Holmium Laser Keratostomy: Long-Term Results
Authors: Kessing Sv Vedel , Boberg-Ans Jannik , Heegaard Steffen
Published: April 2021

* BACKGROUND AND OBJECTIVES: A new filtering procedure, the Intrastromal Holmium Laser Keratostomy (ILtQ has been developed. A laser canal is created intrastromally in the cornea anterior to Schwalbes line in the floor of a corneo-scleral tunnel incision made with a knife from the corneal site. Theoretically, the complications of the conventional Subconjunctival Holmium Laser Sclerostomy (SLS) can thus be avoided. Experimental and clinical evaluation of the new procedure, as well as clinical long-term results are presented.

* PATIENTS AND METHODS: The ILK was evaluated experimentally on bank eyes and clinically using postoperative Ultrasound Biomicroscopy (UBM). The clinical long-term effect was evaluated by a follow-up of the first 22 ILK performed on 17 eyes in 17 consecutive patients with complicated, refractory primary and secondary open angle glaucoma. Preoperative subconjunctival mitomycin-C injection (0.02 mL of 0.2 mg/mL) was used.

* RESULTS: The experimental and clinical evaluations show that the collateral thermal tissue coagulation made by the Holmium laser in ILK probably is an advantage, because the subsequent shrinkage prevents postoperative self sealing of the laser canal. Complete surgical success without medication and reoperations was reached in 63% of the eyes with a mean observation time of 22.5 months (range: 16.6-26.7 mos.). Any failure appeared within the first 10 months. Only 13% of the eyes had early iris incarcerations, there were no late incarcerations. Twenty-five percent had temporary shallow anterior chambers.

* CONCLUSION: The mitomycin-ILK procedure has shown obvious better results than the conventional SLS technique due to a considerable reduction in postoperative complications. Since the present material further developments in the ILK technique has made this procedure still more attractive.

[Ophthalmic Surg Lasers 2000;31:13-23]
Needling with Intra-bleb 5-Fluorouracil for Intractable Neovascular Glaucoma
Authors: Ophir Avinoam , Porges Yair
Published: April 2021

* BACKGROUND AND OBJECTIVE: Trabeculectomy for neovascular glaucoma (NVG) often results in filtering bleb scarring. The outcome of a needling procedure with intra-bleb 5-fluorouracil (5-FU) administration in NVG eyes is presented.

* PATIENTS AND METHODS: Following trabeculectomy with mitomycin C (MMC), intraocular pressures (IOPs) ranged between 36 to 56 mm Hg in 3 painful, neovascular glaucomatous eyes despite treatment. Each eye was then injected subconjunctivally with 1.0 mg of 5-FU, adjacent to and within the filtering bleb. The needle was advanced and penetration into the anterior chamber through the bled, anterior to the scieral flap, followed.

* RESULTS: In each eye, the IOP dropped immediately. After 18 to 29 months, IOPs were 11 to 22 mm Hg, and in two eyes-without hypotensive medications. Cataract progression was evident in the 2 eyes that had had cataracts preoperatively.

* CONCLUSION: The postoperative needling, in conjunction with the dual effect of intraoperative MMC and intra-bleb 5-FU, was found efficacious and saved further surgery in these intractable cases.

[Ophthalmic Surg Lasers 2000;31:38-42]
Effectiveness of LASIK to Correct Refractive Error After Penetrating Keratoplasty
Authors: Spadea Leopoldo , Mosca Luigi , Balestrazzi Emilio
Published: April 2021

* OBJECTIVE: Refractive errors may invalidate the good results of penetrating keratoplasty (PK). The Authors evaluate the effectiveness of excimer laser in situ keratomileusis (LASIK) in the correction of refractive error after PK.

* MATERIALS AND METHODS: Four patients, a 26-year-old woman, a 54-year-old man, a 19-year-old man, and a 51-year-old woman, showed refractive errors: -11 =-4.5 × 85°; -8, -4.5 = -11 × 95°; and -4.5 = -4 × = 120°, with a clear graft at least 20 months after penetrating keratoplasty secondary to keratoconus. However, they underwent the LASIK procedure with a nasal-hinged flap of 160 µm. No sutures were placed.

* RESULTS: At follow-up, 24, 18, 12, and 12 months, respectively, the graft remained clear and the endothelial cells were unchanged. The uncorrected visual acuities were 20/50, 20/25, 20/50, and 20/25, respectively with an unchanged best corrected visual acuity (20/20) for all patients. No significant complications were observed.

* CONCLUSIONS: LASIK procedure seems to be an effective technique to correct refractive error after successful penetrating keratoplasty.

[Ophthalmic Surg Lasers 2000;31:111-120]
Optical Coherence Tomography for Retinal Thickness Measurement in Diabetic Patients Without Clinically Significant Macular Edema
Authors: Schaudig Ulrich H , Glaefke Carsten , Scholz Frank , Richard Gisbert
Published: April 2021

* BACKGROUND AND OBJECTIVE: To evaluate the potential of optical coherence tomography (OCT) as a screening method for retinal thickness measurements in diabetic patients.

* PATIENTS AND METHODS: We used a previously described pattern of six 5 mm OCT scans through the center of fixation in 45 diabetic patients without clinically significant macular edema: 22 patients (group 1) had no diabetic retinopathy (ETDRS classification) ; 18 (group 2) had nonproliferative retinopathy; 5 patients with peripheral neovascularization did not enter statistical analysis; 25 normal healthy subjects were used as a control group. Retinal thickness was measured at five locations in each scan: in the fovea, at the foveal rim, and outside the macula. Measurements were identified in nonaligned images and taken from raw data A-scans. Locations were grouped into hemispheres, quadrants and rings, and mean values tested for statistically significant differences using Mann-Whitney U-Wilcoxon rank sum W test.

* RESULTS: Differences in retinal thickness were found to be significant in the macula (controls vs group 2P= 0.0266), at the foveal rim (controls vs group 1 and 2: P = 0.0386 and P = 0.0193), in the nasal and superior hemisphere (controls vs group 2: P = 0.0251 and P = 0.0187), and in the superior nasal quadrant (controls vs group 1 and group 1 vs group 2: P= 0.0022 and P= 0.0462).

* CONCLUSIONS: Significant differences of retinal thickness between patients with diabetic retinopathy and normals can be detected by OCT even in the absence of clinically significant macular edema. Significant differences between diabetic patients with and without retinopathy are most likely to be found in the superior nasal quadrant.

Ophthalmic Surg Lasers 2000;31:182-186]
Reattachment of Retina and Retinoschisis in Pit-Macular Syndrome by Surgically-Induced Vitreous Detachment and Gas Tamponade
Authors: Todokoro Daisuke , Kishi Shoji
Published: April 2021

Abstract. The origin of the subretinal fluid in pit-macular syndrome is unknown. Using optical coherence tomography, the authors observed that an optic disk pit is not a true pit but a cystic cavity covered with a superficial layer of the optic disk in a patient with retinal detachment and retinoschisis. The cyst was connected to the intraretinal space of the retina, which was split in several layers, or the retinoschisis in the papillomacular area. Vitrectomy and gas tamponade were performed to treat the patient. During surgicallyinduced vitreous detachment, strong vitreoretinal attachment at the disk margin and the fovea was observed. After surgery, the cystic space at the optic disk disappeared and the retinal detachment and retinoschisis reattached. Vitreous traction may play a role to introduce the fluid from the optic cyst to the subretinal space through the superficially split retina. [Ophthalmic Surg Lasers 2000;3 1:233-234]
Threshold and Retreatment Parameters of NPe6 Photodynamic Therapy in Retinal and Choroidal Vessels
Authors: Peyman Gholam A , Kazi Abdul Ahad , Moshfeghi Darius , Unal Melih , Khoobehi Bahram , Yoneya Shin , Mori Keisuke , Rivera Ingrid
Published: April 2021

* BACKGROUND AND OBJECTIVE: To deter mine the threshold fluence for producing choroidal and retinal vascular occlusion with mono-L-aspartyl chlorin e6 (NPe6) photodynamic therapy (PDT) during primary treatment and the effect of retreatment.

* METHODS: Primary treatment: Rats, rabbits, and monkeys underwent NPe6 PDT to determine the threshold fluences for choroidal and retinal vessel occlusion. The threshold was determined by analyzing fluorescein angiograms for areas of nonperfusion. Retreatment: Dutch-belted rabbits underwent NPe6 PDT followed by fluorescein angiography. Rabbits were retreated one week later at the same parameters.

* RESULTS: Fluence levels and vascular damage thresholds were always higher for retinal than for choroidal vascular occlusion. Retreatment caused choroidal vessel closure at all tested fluences but retinal capillaries closed only at a fluence > 17.7 J/cm2.

* CONCLUSION: NPe6 PDT has a lower threshold to occlude choroidal vessels than retinal vessels. The cumulative effect of retreatment does not damage retinal vessels unless the threshold is exceeded during a single retreatment session.

[Ophthalmic Surg Lasers 2000;31:323-327]
Canaloplasty for Pigmentary Glaucoma with Coexisting Conjunctival Lymphoma
Authors: Ichhpujani Parul , Barahimi Behin , Shields Carol L. , Eagle Ralph C. , Katz L. Jay
Published: April 2021

This case report presents canaloplasty as a bleb-free surgical option for lowering intraocular pressure in cases with postoperative conjunctival scarring.
Bilateral Fluorescein Angiographic Findings in Unilateral Coats’ Disease
Authors: Shane Thomas S. , Berrocal Audina M. , Hess Ditte J.
Published: April 2021

Two patients with clinically unilateral Coats’ disease were imaged with fluorescein angiography during an examination under anesthesia. Both patients were found to have abnormal retinal vasculature in their contralateral eye. These findings may represent a previously unrecognized bilateral component of Coats’ disease.
Restored Photoreceptor Outer Segment in Commotio Retinae
Authors: Itakura Hirotaka , Kishi Shoji
Published: April 2021

The authors report the retinal findings of the healing phase in commotio retinae. Retinal images were obtained using spectral-domain optical coherence tomography (SD-OCT) on 3 eyes from 3 patients with commotio retinae after blunt ocular trauma. The best-corrected visual acuity (BCVA) and fundus appearance from the medical records were retrospectively studied. All cases had commotio retinae in the posterior pole. OCT showed increased reflectivity of the line at the junction between the photoreceptor inner and outer segments (IS/OS) in the area of the opacified retina in all cases. The initial BCVA in cases 1, 2, and 3 was 1.5, 1.2, and 0.7, respectively. In all eyes, the neurosensory retinal edema had resolved and the IS/OS line returned to normal architecture. The final BCVA in cases 1, 2, and 3 was 2.0, 1.5, and 1.5, respectively. The authors found restored photoreceptor outer segment in commotio retinae by SD-OCT and improvement of BCVA.
SD-OCT to Differentiate Traumatic Submacular Hemorrhage Types Using Automatic Three-Dimensional Segmentation Analysis
Authors: Sampangi Raju , Chandrakumar H. V. , Somashekar Sandhya E. , Joshi Gauri R. , Ganesh Sri
Published: April 2021

Traumatic submacular hemorrhage may present with significant decrease in vision and may have varying outcomes. Following injury, the hemorrhage can collect either between the neurosensory retina and retinal pigment epithelium (RPE) or below the RPE. This differentiation may be important to prognosticate and to guide treatment. In two patients with post-traumatic submacular hemorrhage, Cirrius spectral domain high-definition optical coherence tomography (OCT) (Carl Zeiss Meditec, Dublin, CA) was used to differentiate traumatic submacular hemorrhage types using automation three-dimensional segmentation analysis. Based on the OCT findings, the patient with sub-RPE bleed was subjected to pneumatic displacement. En face C-scan imaging just below the RPE allowed for the diagnosis of the exact location of choroidal rupture that was masked due to hemorrhage.
Painlevé-Kuratowski convergences of the solution sets for vector optimization problems with free disposal sets
Authors: Tung Nguyen Minh , Duy Mai Van
Published: April 2021

This paper aims to present results on the Painlev\begin{document}$ \mathrm{\acute{e}} $\end{document}-Kuratowski set-convergence of the sets of both infimal and minimal points of a sequence of perturbed vector optimization problems through free disposal sets. By assumptions of sequential compactness of the feasible sets or the uniform coerciveness of objective functions, this convergence is obtained both in the image and given spaces under the perturbations of objective functions and feasible sets. Besides, we also establish set-convergences of sequences of approximation solution sets. Applications to the stability of conic, quadratic and linear vector optimization problems are given. Some examples are provided to illustrate our results.
A computational approximation for the solution of retarded functional differential equations and their applications to science and engineering
Authors: Gürbüz Burcu
Published: April 2021

Delay differential equations are of great importance in science, engineering, medicine and biological models. These type of models include time delay phenomena which is helpful for characterising the real-world applications in machine learning, mechanics, economics, electrodynamics and so on. Besides, special classes of functional differential equations have been investigated in many researches. In this study, a numerical investigation of retarded type of these models together with initial conditions are introduced. The technique is based on a polynomial approach along with collocation points which maintains an approximated solutions to the problem. Besides, an error analysis of the approximate solutions is given. Accuracy of the method is shown by the results. Consequently, illustrative examples are considered and detailed analysis of the problem is acquired. Consequently, the future outlook is discussed in conclusion.
Design of probabilistic $ l_2-l_\infty $ filter for uncertain Markov jump systems with partial information of the transition probabilities
Authors: Jin Liqiang , Liu Yanqing , Yin Yanyan , Teo Kok Lay , Liu Fei
Published: April 2021

In this paper, the problem of \begin{document}$ l_2-l_\infty $\end{document} probabilistic filtering for uncertain Markov jump systems with partial information of the transition probabilities is studied, where the uncertainties are caused by randomly changing interior parameters. Combining the original system and the filtering system, an augmented error system is proposed. Some concepts of probability theory are introduced to handle the uncertainties. Due to the complicated structure of real practical systems, only partial information on the transition probabilities are available. In this paper, by using Lyapunov functional method and probability theory, linear matrix inequalities (LMIs) type of sufficient conditions are derived. Based on these sufficient conditions, a probability filter is constructed such that the augmented error system with partial information of the transition probabilities is stochastically stable with a given confidence level and satisfying an \begin{document}$ l_2-l_\infty $\end{document} performance index. Furthermore, the gain matrices of the filter are obtained through the introduction of slack matrices. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.
Caputo fractional derivative operational matrices of Legendre and Chebyshev wavelets in fractional delay optimal control
Authors: Malmir Iman
Published: April 2021

Caputo derivative operational matrices of the arbitrary scaled Legendre and Chebyshev wavelets are introduced by deriving directly from these wavelets. The Caputo derivative operational matrices are used in quadratic optimization of systems having fractional or integer orders differential equations. Using these operational matrices, a new quadratic programming wavelet-based method without doing any integration operation for finding solutions of quadratic optimal control of traditional linear/nonlinear fractional time-delay constrained/unconstrained systems is introduced. General strategies for handling different types of the optimal control problems are proposed.
Detection of Malpractice in E-exams by Head Pose and Gaze Estimation
Authors: Indi Chirag S , Pritham Varun , Acharya Vasundhara , Prakasha Krishna
Published: April 2021

Examination malpractice is a deliberate wrong doing contrary to official examina-tion rules designed to place a candidate at unfair advantage or disadvantage. The proposed system depicts a new use of technology to identify malpractice in E-Exams which is essential due to growth of online education. The current solu-tions for such a problem either require complete manual labor or have various vulnerabilities that can be exploited by an examinee. The proposed application en-compasses an end-to-end system that assists an examiner/evaluator in deciding whether a student passes an online exam without any probable attempts of mal-practice or cheating in e-exams with the help of visual aids. The system works by categorizing the student’s VFOA (visual focus of attention) data by capturing the head pose estimates and eye gaze estimates using state-of-the-art machine learn-ing techniques. The system only requires the student (test-taker) to have a func-tioning internet connection along with a webcam to transmit the feed. The exam-iner is alerted when the student wavers in his VFOA, from the screen greater than X, a predefined threshold of times. If this threshold X is crossed, the appli-cation will save the data of the person when his VFOA is off the screen and send it to the examiner to be manually checked and marked whether the action per-formed by the student was an attempt at malpractice or just momentary lapse in concentration. The system use a hybrid classifier approach where two different classifiers are used, one when gaze values are being read successfully (which may fail due to various reasons like transmission quality or glare from his specta-cles), the model falls back to the default classifier which only reads the head pose values to classify the attention metric, which is used to map the student’s VFOA to check the likelihood of malpractice. The model has achieved an accuracy of 96.04 percent in classifying the attention metric.