bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ukraine implantation results of collagen‐based bioengineered substitutes of donor corneal allografts in rabbits
Authors: BOYCHUK IRYNA , PASECHNIKOVA NV , LEUS M , BUZNYK OI , GRIFFITH M 
Published: August 2012

AbstractPurpose Ukraine Implantation Results of Collagen‐Based Bioengineered Substitutes of Donor Corneal Allografts in RabbitsMethods Bioengineered corneal substitutes (BCS) were fabricated by cross‐linking porcine type I collagen with carbodiimide and N‐hydroxysuccinimide as described by Liu et al., 2006. BCS refractive indices were measured using an Abbe refractometer. The mechanical properties were evaluated by their ability to tolerate interrupted sutures placed during deep lamellar keratoplasty performed on isolated rabbit eye. BCS were then implanted into one cornea each of 8 rabbits and followed‐up for 12 months.Results Our BCS had refractive indices of 1.24‐1.3 (human cornea 1.37‐1.38). They tolerated placement of 12 interrupted sutures well. New technique of BCS “sutureless” implantation was elaborated. When implanted into rabbit corneas, the BCS remained stably integrated and optically clear during 12 month follow‐up. Grade 1.5 haze (scale 0‐4) was observed in 2/8 eyes during the 1st postoperative week. In one eye, the haze resolved. In the 2nd eye, the grade 1 haze remained. Light microscopy confirmed good integrity of the BCS and absence of inflammation.Conclusion Our current data suggest that the BCS fabricated in Ukraine by cross‐linking collagen is a good alternative to human donor corneas, if medical grade porcine collagen is used. The new “sutureless” implantation technique may decrease BCS damage and accelerate its epithelialisation
Influence of intraocular pressure on the photorefractive keratectomy for myopia correction. a numerical analysis
Authors: DEL BUEY MA , LANCHARES E , CALVO B , LAVILLA L , CRISTOBAL JA , CASAS P , ASCASO F , CRUZ N , JIMENEZ B , DOBLARE M , PALOMINO C 
Published: August 2012

AbstractPurpose To analyze the effect of the intraocular pressure (IOP) on the refractive correction achieved by the Photorefractive Keratectomy (PRK) surgery using a biomechanical model of the human eye.Methods A three‐dimensional finite element model of the human eye was used to simulate the PRK surgery. A hyperelastic constitutive behavior was assumed for all the tissues of the model. Simulations of PRK surgery for five levels of myopia (2, 4, 6, 8 and 10 diopters) at three physiological healthy values of IOP (10, 15 and 21 mmHg) were performed and the post‐surgical diopters were estimated.Results For low and medium values of IOP (10 and 15 mmHg), the computed results were close to those used by clinicians and defined without considering the IOP, while undercorrection was predicted for the highest value of IOP (21 mmHg) in the 8 and 10 diopter correction cases.Conclusion From these results, we suggest that IOP should be considered in the determination of the depth of ablation, in addition to other factors.
Combined treatments for keratoconus: a numerical approach
Authors: DEL BUEY MA , LANCHARES E , CRISTOBAL JA , CALVO B , CASAS P , ASCASO F , CRUZ N , LAVILLA L , JIMENEZ B , PEIRO C , PALOMINO C 
Published: August 2012

AbstractPurpose To compare the effects of two combined treatments, corneal collagen crosslinking (CXL) and insertion of intrastromal ring segments (ISRS), for the treatment of keratoconus, using a biomechanical model of the keratoconic corneaMethods Numerical simulations of both treatments are performed using a biomechanical model of a human keratoconic cornea. Then, simulations of the combination of the two treatments are performed: first CXL and afterwards, ISRS insertion; firs ISCRS insertion and afterwards, CXL.Results After the numerical simulation, the following effects are observed: the CXL causes a stiffening of the corneal tissue; the insertion of ISRS induces a flattening of the central area of the cornea causing a hyperopic effect and a decrease of the anterior chamber depth (ACD), as our clinical outcomes confirm. The insertion of ISRS achieve higher effect when the CXL treatment is previously performed.Conclusion The combination of the two treatments, collagen CXL and ISRS insertion, achieve a regularization of the shape of the cornea. According to the outcomes of numerical simulation, collagen CXL must be performed before the insertion of the ISRS in order to achieve better results.
Usefulness of the optical coherence tomography Spectralis® anterior segment module in the diagnosis and monitoring of corneal pathology
Authors: JIMENEZ DEL RIO B , DEL BUEY MA , CRISTOBAL JA , CRUZ N , RAMIRO P , MATEO J , CASAS P , PADGETT E 
Published: August 2012

AbstractPurpose The Spectralis® Anterior Segment Module that offers Spectral‐Domain Optical Coherence Tomography (SD‐OCT) Heidelberg Engineering, is a sign of the revolution who are suffering OCT teams nowadays. The aim of our study is to analyze the usefulness of optical coherence tomography of anterior segment in the diagnosis and monitoring of different corneal diseases.Methods Some ophthalmologists explored their patients from department of cornea and ocular superfie under slit lamp and later with the OCT Anterior Segment Module. The Spectralis SD‐OCT offers high quality images of cornea and anterior segment, without any contact and comfort for the patient. Because it is installed on a slit lamp is very intuitive and easy to use, so no special training is required.Results We present several cases where we used optical coherence tomography of anterior segment in the diagnosis of different corneal diseases: degeneration, infections, dystrophies... and also in following various surgical procedures such as intrastromal corneal rings, keratoplasty, lamellar corneal graft and amniotic membrane coatings.Conclusion We believe it is a useful diagnostic tool in every department of cornea, refractive surgery and ocular surface diseases to document, make measurements and studies of evolution and, especially, to evaluate the surgical results.
Adapting a dermatological multi‐laser fluorescent confocal microscope for ophthalmology applications
Authors: GRIOT O , GRIVET D , ESPINASSE M , PERROT JL , LABEILLE B , CAMBAZARD F , CAMPOLMI N , GAIN P , THURET G 
Published: August 2012

AbstractPurpose To adapt for ophthalmology the only multi‐laser fluorescent confocal microscope available on the market and initially developed for dermatology (Vivascope 1500, MAVIG, GmbH). The arm that maintains the microscope in contact with the skin was too rigid and imprecise, and the disposable plastic window placed at the interface between the tissue and the microscope objective was too large. Both were not convenient for high quality corneal and ocular adnexa imagingMethods We designed specific stands to create a take‐down interface between the confocal microscope, his dermatological arm support and an ophthalmology examination table comprising a 5 degrees of freedom stand (Zeiss, Germany). A male guide rail was machined in polyoxymethylene and permanently fixed on the confocal microscope to avoid repetition of assembly and disassembly. Two females guide rails machined in aluminium 7075 were fixed on the dermatological arm support on the one hand and on an ophthalmological stand on the other hand. Rails were blocked with simple screws. We also designed a new adapter to receive disposable caps already available for corneal confocal microscopy. A lateral camera allowed live visualization of the objective/eye contactResults These new interfaces allowed easy and solid fastening of the confocal microscope on each arms of the two specialties providing optimal conditions for clinical examination. The new ophthalmology arm allowed a precise positioning of the contact objective on the patient eyeConclusion Thanks to theses adaptations, the first multilaser fluorescent confocal microscope is now usable by ophthalmologists, and opens a completely innovative field of exploration
Revisiting corneal storage using a bioreactor: proof of concept
Authors: GAIN P , BERNARD A , NEFZAOUI C , CAMPOLMI N , GRIOT O , ACQUART S , PISELLI S , THURET G 
Published: August 2012

AbstractPurpose Cold storage (CS) or organ culture (OC) for corneal storage, have not been dramatically improved since the 70’. Basically, they consist of immersion of the cornea in a sealed vial or viewing chamber filled with storage medium containing macromolecules for permanent (CS) or sequential (OC) deswelling. None respects the corneal physiology (higher pressure to the endothelial side associated with a retrocorneal fluid circulation), resulting more or less rapidly in endothelial cell (EC) death, stromal swelling and Descemet folding (for OC) that accentuate EC death. In the past, several artificial chambers were built or patented, mainly for toxicology experiments and never with a view to improve graft storage. We developed a corneal bioreactor (BR) that reconstitutes both pressure and continuous slow medium renewal in order to improve corneal storageMethods The BR (patented) comprised sterile endothelial and epithelial chambers closed with transparent windows to allow easy controls (transparency, thickness, detection of interfaces, and EC count) from both sides. Adjustable fluid flow and pressure (15‐30 mmHg) in the endothelial side were maintained by a disposable infusion system connected to a microsolenoid valve controlled by a pressure sensor and a microcontroller. Furthermore, the height of the epithelial window could be adjusted to aplanate the cornea for femtosecond laser cutResults The BR maintained a stable gradient of pressure during at least 5 weeks with a controlled flow. A few hours after insertion of the cornea in the BR, transparency improved and thickness and folding decreased and were maintained without deswelling moleculesConclusion The BR could improve corneal storage in eye banks
Corneal ectasia after excimer surgery and the mandelbrot B. fractal theory in ophthalmology
Authors: KACHANOV ANDRE , NIKULIN SERGE , BAUER SVETA , ZIMIN BORIS 
Published: August 2012

AbstractPurpose To investigate corneal ectasia after LASIK surgery by using the Mandelbrot B. fractal theory in ophthalmology.Methods We reviewed our consecutive 55012 cases of excimer‐laser surgery including LASIK (48910 eyes) and PRK (6102 eyes). We used MEL‐60, MEL‐70 and MEL‐80 excimer laser (“Carl Zeiss Meditec”) and microkeratomes LSK‐Evolution 1, 2 and 3 (“Moria”) for LASIK. Follow‐up period was up to 14 years. The age of all patients was from 18 to 74 years. Some of them had hyperopia with sphere‐equivalence (SE) up to 6,5D, and the others had myopia with SE from –1,0D to –18,0D.Results There was NO corneal ectasia in the PRK and the hyperopic LASIK groups. 38 eyes (0,08%) had corneal ectasia after myopic LASIK (46294 eyes). There were 8 eyes with previous radial keratotomy, 8 eyes with subclinical keratoconus and 22 eyes with normal cornea (0,048% of all myopic LASIK) among the eyes . Pre‐op parameters of these eyes were the followings: central K ‐ 44,37±1,09D, CCT ‐ 530,4±34,4 microns, SE – 5,90±3,36D. Fractal theory allows to explain post‐op corneal ectasia phenomenon.Conclusion There are NO optical methods to predict corneal ectasia after LASIK surgery. But the risk factors of this complication were the followings: steep cornea (more than 44,0 D), corneal scars after previous corneal surgery (e.g. anterior radial keratotomy etc.), corneal topography irregularity and probably very thin residual corneal thickness. Myopic LASIK surgery can provoke post‐op corneal ectasia development in the long follow‐up period. We described post‐op myopic LASIK cornea as a “odd” (“curious”) attractor according to the Mandelbrot B. fractal theory.
Graft thickness and visual acuity after automated endothelial keratoplasty
Authors: RABOT A , SOLER V , FOURNIE P 
Published: August 2012

AbstractPurpose Endothelial keratoplasty has become the standard of care for endothelial disease. Descemet Membrane Endothelial Keratoplasty (DMEK) gives superior visual results but poses several surgical challenges, compared to Descemet Stripping Automated Endothelial Keratoplasty (DSAEK). Graft thickness was advanced as a reason for this difference. Ultrathin‐DSAEK, with a double microkeratome pass has been proposed to maintain the advantages of both DSAEK and DMEK. The purpose of this study was to evaluate the possible correlation between visual acuity (VA) and central graft thickness in DSAEK.Methods A preliminary retrospective study was conducted on 42 patients who underwent DSAEK: 26 operated on with a single microkeratome pass with a 350 microns (µm) head, and 16 with a double pass using a 200 µm head. Pre‐ and post‐operative VA, and post‐operative central corneal graft thickness measured by OCT and Scheimpflug imaging were collected with at least 6 months follow‐up.Results The overall mean of graft thickness was 127.25 ± 40µm. The overall mean VA was 0.16logMAR. 38% of patients had at least 0.1logMAR VA. Graft thickness was 136.8 ± 43.4µm with a single microkeratome pass compared to 111 ± 30µm with a double pass (p<0.05). Considering the overall cohort, we had a correlation between graft thickness and VA (p<0.05), but also between the pre and post‐operative VA (p<0.05). We had no correlation between graft thickness and VA in the double pass subgroup. No difference was found between the single and the double pass subgroups for VA.Conclusion There is no clear correlation between graft thickness and visual acuity. Other factors may come into account such as scarring of the interface, or the stage of endothelial failure.Preoperative VA could be a prognosis factor.
Functional and biomechanical changes in keratoconic corneas after implantation of intracorneal ring segments 5 and 6mm in diameter
Authors: PERIS‐MARTINEZ C , ARGUDO M , ESPANA‐GREGORI E 
Published: August 2012

AbstractPurpose To determinate biomechanical and functional changes in human keratoconic corneas after triangular section ring implantation in two designs.Methods Retrospective study of biomechanical properties of 46 patients (60 eyes) with keratoconus undergoing surgery Keraring® intracorneal ring segments divided into two groups according to 5 or 6 mm of diameter. Surgical technique to made the channel was with IntraLase femtosecond laser. UCVA and BSCVA were measured and biomechanical factors provided by the device ORA before surgery and postoperatively one month, 3 months and 6 months.Results After surgery, we obtained a significant increase (p<0.05) of the biomechanical parameters (CH and CRF) mean (0.87±2.59)mmHg for CH and (‐0.015±2.06)mmHg for CRF. This improvement is not homogeneous during the postoperative follow‐up in two groups in diameter. We found increased of CH top with rings of 6mm. The variations found in the CRF, are not significant at the descriptive level with any of the designs (p>0.05). At baseline‐ 6 months, the improvement in BSCVA (LogMAR) is 0.13 in 5mm diameter respect to 0.07 in 6mm in diameter. Among the changes in CH and BSCVA (LogMAR), there is a significant inverse correlation with 6mm rings at baseline‐ 1 month period (r=‐0.442) and 1 month‐ 3 month period 0.007 (r=‐0.511). No significant correlation was detected between CRF and BSCVA.Conclusion Intracorneal rings improve corneal biomechanics. The CH undergoes improvement in postoperative follow up with any of the ring designs, while the CRF is not affected significantly with any of the types. 5mm rings further improve best corrected visual acuity. This improvement is not related to changes in the biomechanical properties.
Cis‐urocanic acid eye drops are safe and well tolerated in healthy adults – results from a randomised phase 1 clinical study
Authors: LEINO L , JAUHONEN HM , KARI E , PYLKKäNEN L , POUTANEN J , LAIHIA JK , KAARNIRANTA K 
Published: August 2012

AbstractPurpose Cis‐urocanic acid (cis‐UCA) is an endogenous small molecule of the skin. Preclinical data suggest that topical cis‐UCA could be used as an anti‐inflammatory treatment in ophthalmology. We investigated the safety, tolerability and pharmacokinetics (PK) of cis‐UCA in healthy adults in a randomised, double‐blind and placebo‐controlled phase 1 study.Methods The 37 subjects in 3 groups received either 0.5% or 2.5% cis‐UCA eye drops, or placebo. In part I, the eye drops were administered on one eye 3x in one day. In part II, the same subjects received the same eye drops on both eyes 3x a day for 14 days. Clinical evaluations included complete physical examination and safety laboratory tests, physical examination of the eyes, and ocular comfort rating by 5 parameters.Results Both cis‐UCA eye drops were safe and well tolerated throughout the study. None of the ocular safety parameters differed between cis‐UCA and placebo. Of the ocular comfort rating, only burning of the eyes was significantly higher with cis‐UCA than with placebo; however, this reaction was mild, transient and infrequent in all cases. PK analysis showed that 2.5% cis‐UCA eye drops may be absorbed after repeated ocular dosing, as 7/12 subjects in this group had low cis‐UCA levels (< 10 µg/ml) in the urine. However, plasma cis‐UCA levels were negligible.Conclusion The observed good local and systemic safety and tolerability of cis‐UCA eye drops warrants further clinical studies in patients with inflammatory ocular diseases.
Commercial interest
Monochromatic aberrations in children and youth in different cycloplegic conditions
Authors: MOCKO L , WYLEGALA E , ZAJAC M 
Published: August 2012

AbstractPurpose The aim of the study was to quantify low and high order Zernike aberrations in children and youths as well as to investigate influence of fogging and cycloplegia on the refraction and aberrations measurement.Methods KR‐1W Topcon aberrometer was used to measure aberrations in refractometer and aberrometer mode. Children were examined three times. First examination in whole group was performed after fogging stimulus used once ‐ in first of three continuous measurements, second after fogging stimulus performed for each measurement and third after pharmacological cycloplegia with 1% Tropicamid. Second and third measurements were performed in selected group of children. Totally 556 schoolchildren and 74 young sportsmen aged from 6‐to‐18 years were investigated. Average age was 13.87, SD 2.29 in large group and 11.33 years, SD 2.7 in smaller group.Results We found significant differences in spherical refraction measured after pharmacological cycloplegia compared to that after fogging. Refraction after cycloplegia was more hyperopic. There were higher differences in high hyperopic children. There were no differences between fogging and cycloplegic measurements in myopes higher then ‐2.00 D.. Aberrometry has given more myopic results then refractometry. Cylinder values were almost the same. Keratometer readings were the same in all measurements conditions. We found similar levels of high order aberrations in myopic, emmetropic and hyperopic children. There was no noticeable symmetry in high order aberrations between right and left eye.Conclusion Both methods of low order aberrations measurement are similar. Optical parameters of cornea do not depend on the cycloplegic status. Low order Zernike aberrations strictly correspond to the refraction error.
We don’t graft as many endothelial cells as we think (Part 1): what early post‐operative endothelial cell counts tell us
Authors: NEFZAOUI C , TRONE M , CAMPOLMI N , ACQUART S , THEILLIERE C , THURET G , GAIN P 
Published: August 2012

AbstractPurpose The decrease of endothelial cells density (ECD) after penetrating keratoplasty (PK), is calculated form ECD given by eye banks (ebECD) and post‐operative specular counts. To better understand the difference between both counts, usually considered caused by EC mortality, we have introduced a new concept of viable ECD (vECD) experimentally determined with a triple staining of viable and dead EC. We demonstrated that vECD just before graft was lower than the ebECD by 12+/‐9% (IOVS 2011.52:6018). The aim of this prospective study was to measure post PK ECD as early as possible in order to compare it with vECD and deduce the true post op EC mortalityMethods Standard ebECD were determined 48h before graft with a validated analyzer (Samba cornea) on a minimum of 300 EC. Postoperative central ECD were determined by a non‐contact specular microscope (Topcon SP2000P) with manual determination of contours of the maximum of EC. Thirty‐four PK done by the same surgeon (>1000 PK) were analysed at D5, D15, and M1. Non‐parametric tests for paired data were usedResults All PK were uneventful. ebECD (n=40) was 2585(482) cells/mm² (mean(SD)). Postoperative ECD at D5 (n=22), D15 (n=29), and M1 (n=33) were respectively 1850(386), 1655(285) and 1650 (408) cells/mm² and were lower than ebECD (P<0,05). They corresponded to apparent EC loss of respectively 28%, 36% and 36% compared to ebECDConclusion ECD at D5 is dramatically lower than ebECD but subsequent decrease seems low. Results are consistent with the vECD that we previously noticed and suggest that EC mortality triggered by surgery and perioperative events may only minimally contribute to the decrease of ECD
We don’t graft as many endothelial cells as we think (part 2): comparison of cell loss after autograft and organ cultured allograft in the same patient
Authors: TRONE M , NEFZAOUI C , ALDOSSARY M , CAMPOLMI N , ACQUART S , GARRAUD O , THURET G , GAIN P 
Published: August 2012

AbstractPurpose Reasons for endothelial cell density (ECD) decrease after corneal grafts remain unclear. We recently demonstrated that eye bank ECD (ebECD) overestimates the pool of viable EC really grafted to patients (Pipparelli.IOVS2011;52:6018) because standard ebECD cannot take account of acellular areas or area covered by dying EC. Autograft is a very rare situation where ECD can be easily determined by specular microscopy just before graft and almost all grafted EC are living. Aim: to compare EC decrease after simultaneous autograft and organ cultured (OC) allograft in the same patientMethods A 71 year‐old woman presented with pseudophakic corneal edema in left eye and amblyopic right eye with a normal cornea. She underwent two penetrating keratoplasties (PK): autograft of the left eye and allograft of the right eye with an OC cornea. Follow‐up at day (D)1, 5, 15, 20 and 30 comprised slit lamp examination and non‐contact central specular microscopy (Topcon SP2000P)Results Both grafts were uneventful. For the allograft, ebECD 48h before graft was 2787 cells/mm² and postop ECD decreased of 39%, 40%, 40% and 43% at D5, 15, 20 and 30. For the autograft, pregraft specular ECD was 2017 cells/mm² and postop ECD were 1941, 1934, 1924, 1909 and 1900 cells/mm² respectively at D1, 5, 15, 20 and 30Conclusion This exceptional case confirms a dramatic discrepancy between ebECD and very early postop ECD, likely to be explained mainly by an overestimation of the true EC pool of viable cells by standard eye banks count, rather than by overmortality due to peri‐operative events, since almost no early cell loss is observed during autograft