Quantitative and comparative analysis of thermography parameters in posterior scleritis, choroiditis, and controls.

PURPOSE: To compare various ocular thermography parameters in posterior scleritis (PS), choroiditis (choroidal granuloma [CG], Vogt-Koyanagi-Harada [VKH] syndrome), central serous chorioretinopathy (CSCR), and healthy controls. METHODS: This retrospective, observational, comparative study evaluated cases undergoing ocular thermography between April 2017 and October 2023. The study groups included cases of PS, CG, and VKH, while the control group comprised CSCR cases and healthy individuals. Various thermography parameters were assessed, which were as follows: Ocular surface temperature (OST), central corneal temperature (CCT), average scleral temperature (ST), nasal scleral temperature (nST), temperature difference between both the eyes (∆t), and difference between scleral and corneal temperatures (ST - CCT, nST - CCT). RESULTS: It was found that ∆t was significantly higher in the PS group compared to the CG ( P = 0.005), CSCR ( P = 0.0001), and control groups (dilated control: P =0.006, undilated control: P = 0.0001). ST - CCT and nST - CCT were significantly higher in the undilated control and CSCR groups and significantly lower in the PS group. ST - CCT and nST - CCT showed less difference in the affected eyes compared to contralateral healthy eyes of PS and CG cases. OST, CCT, ST, and nST displayed statistically insignificant differences across all groups. CONCLUSION: It is advisable to focus on temperature differences between the affected and healthy eyes, or the difference between the central corneal and scleral temperature of the affected eye, utilizing parameters such as ∆t, ST - CCT, and nST - CCT. These composite parameters offer a more effective approach than individual measurements like OST, CCT, ST, and nST. Thermography can serve as a screening tool to suspect and differentiate PS.

New retinal tack designs: an analysis of retention forces in human scleral tissue.

PURPOSE: The study aimed to construct a new retinal tack design with high retention forces to prevent spontaneous disentanglement in cases of complicated retinal surgery. METHODS: Six new forms for the peak of a retinal tack were developed using computer-aided design (CAD); then a prototype was produced for each model. Finally, standardised design testing was conducted using human (ex vivo) sclera by logging 15 consecutive measurements for each model. RESULTS: Seven different models underwent pull-out testing (six new models and the original tack model), but two tack models (Model 4, Model 5) failed to penetrate the human tissue. The highest pull-out forces (median) were measured for Model 3, followed by Model 6, Model 2 and Model 1. The original Heimann tack (Model H) was found to have the lowest retention forces. CONCLUSION: The different tack designs altered the penetration and holding forces. The retention forces of the proposed peak design led to a significant increase in the retention forces that were more than twice as high as those in the original Heimann Model.

Treatment effect of posterior scleral reinforcement on controlling myopia progression: A systematic review and meta-analysis.

BACKGROUND: High myopia is a sight-threatening disease that causes axial length elongation and severe complications. Data on the benefits of posterior scleral reinforcement surgery in myopia control have been conflicting. The purpose of this study was to explore the treatment effect and complications of posterior scleral reinforcement in the treatment of myopia. METHODS: Articles were retrieved for relevant studies from inception to July 24, 2019, by PubMed, EMBASE, and Ovid. Analyses were conducted to compare the treatment effects of controlling spherical equivalent refraction and axial length elongation. The weighted mean difference and Hedges' adjusted g were used to evaluate the treatment effects, with a random-effects model. Heterogeneity was quantified using I2 statistic and explored by subgroup analysis. Publication bias was addressed by funnel plots and Egger's test. RESULTS: A total of 11 articles were included in this meta-analysis. On estimating the treatment effect, the mean differences of myopia progression and axial length changes between surgery and control groups were 0.41 diopters per year (95% CI 0.21 to 0.61; P < .001) and -0.17 mm per year (95% CI -0.22 to -0.11; P < .001). Subgroup analysis showed significant treatment effects of the single wide strip operation. Single-arm meta-analysis showed less annual axial elongation in children subgroup. These results were robust by sensitivity analysis. The incidence of some major complications in the operation group were significantly greater (5.8% vs 2.7% for myopic degeneration; 2.3% vs 1.6% for macular hemorrhage; 0.8% vs 0 for retinal detachment). CONCLUSION: Posterior scleral reinforcement may be an effective surgery on controlling myopia progression by slowing both refraction and axial length change. However, frequent surgical complications should be considered. Further well-designed studies are needed to determine the long-term safety and efficacy.

Scleral structure and biomechanics.

As the eye's main load-bearing connective tissue, the sclera is centrally important to vision. In addition to cooperatively maintaining refractive status with the cornea, the sclera must also provide stable mechanical support to vulnerable internal ocular structures such as the retina and optic nerve head. Moreover, it must achieve this under complex, dynamic loading conditions imposed by eye movements and fluid pressures. Recent years have seen significant advances in our knowledge of scleral biomechanics, its modulation with ageing and disease, and their relationship to the hierarchical structure of the collagen-rich scleral extracellular matrix (ECM) and its resident cells. This review focuses on notable recent structural and biomechanical studies, setting their findings in the context of the wider scleral literature. It reviews recent progress in the development of scattering and bioimaging methods to resolve scleral ECM structure at multiple scales. In vivo and ex vivo experimental methods to characterise scleral biomechanics are explored, along with computational techniques that combine structural and biomechanical data to simulate ocular behaviour and extract tissue material properties. Studies into alterations of scleral structure and biomechanics in myopia and glaucoma are presented, and their results reconciled with associated findings on changes in the ageing eye. Finally, new developments in scleral surgery and emerging minimally invasive therapies are highlighted that could offer new hope in the fight against escalating scleral-related vision disorder worldwide.

Sutureless transconjunctival intrascleral intraocular lens fixation: the modified Yamane technique / Fixação de lente intraocular intraescleral transconjuntival sem sutura: técnica de Yamane modificada

ABSTRACT Purpose: To evaluate the efficacy and safety of the modified Yamane technique with sutureless transconjunctival intrascleral intraocular lens fixation. Methods: Sutureless transconjunctival intrascleral haptic fixated intraocular lens implantation was performed in patients with aphakia and dislocated intraocular lenses. A clear corneal incision (2.8 mm) was made into the temporal quadrant and a three-piece intraocular lens was implanted into the anterior chamber. The haptics of the intraocular lens were externalized with a 27 G needle via transconjunctival scleral tunnels at the 6 and 12 o'clock positions. The transconjunctival scleral tunnels were prepared to conform to the haptic position and curvature. The site of the scleral tunnels was 2mm from the limbus with a length of 2 mm in the sclera and was aimed at the end of the posterior chamber. The tips of the haptics were cauterized to create a terminal knob. The haptics were pushed back and the knobs were implanted into the scleral tunnels. Results: The study cohort included 21 patients with unilateral aphakia and dislocated intraocular lenses. All patients were examined postoperatively and at postoperative day 1, day 7, month 1, and month 3. All examinations revealed formation of the anterior chamber and well-centralized intraocular lenses. No haptic-related complications of exposure, foreign body sensation, or discomfort were observed. Conclusion: Sutureless transconjunctival intrascleral haptic fixated intraocular lensimplantation is an effective, safe, and practical surgical alternative. This technique was superior to the Yamane method with regard to comfort and surgical duration. Further studies with longer follow-up evaluations are warranted to verify long-term complications.

RESUMO Objetivo: Avaliar a eficácia e a segurança da técnica de Yamane modificada com a fixação de lenta intraocular transconjuntival sem sutura. Métodos: O implante de lente intraocular intraescleral e transconjuntival sem sutura foi realizado em pacientes com afacia e lentes intraoculares luxadas. Uma incisão em córnea clara (2,8 mm) foi feita no quadrante temporal e uma lente intraocular de três peças foi implantada na câmara anterior. Os hápticos da lente intraocular foram externalizados com uma agulha 27G através de túneis esclerais transconjuntivais nas posições de 6 e 12 horas. Os túneis esclerais transconjuntivais foram preparados para se ajustarem à posição e curvatura hápticas. O local dos túneis esclerais foi de 2 mm do limbo com um comprimento de 2 mm na esclera e foi destinado ao final da câmara posterior. As pontas dos hápticos foram cauterizadas para criar uma saliência terminal. Os hápticos foram empurrados para tras e as saliências foram implantadas nos túneis esclerais. Resultados: A coorte do estudo incluiu 21 pacientes com afacia unilateral e lentes intraocular deslocada. Todos os pacientes foram examinados no pós-operatório e no dia 1, 7, 1 mês e 3 meses do pós-operatório. Todos os exames revelaram formação da uma câmara anterior e lentes intraoculares bem centralizadas. Nenhuma complicação hápticas relacionada à exposição, sensação de corpo estranho ou desconforto foram observadas. Conclusão: O implante de lente intraocular transconjuntival intraescleral sem sutura é uma alternativa cirúrgica eficaz, segura e prática. Esta técnica foi superior ao método de Yamane no que diz respeito ao conforto e duração cirúrgica. Mais estudos com avaliações de seguimento mais prolongados são necessários para verificar as complicações de longo prazo.

Sutureless transconjunctival intrascleral intraocular lens fixation: the modified Yamane technique.

PURPOSE: To evaluate the efficacy and safety of the modified Yamane technique with sutureless transconjunctival intrascleral intraocular lens fixation. METHODS: Sutureless transconjunctival intrascleral haptic fixated intraocular lens implantation was performed in patients with aphakia and dislocated intraocular lenses. A clear corneal incision (2.8 mm) was made into the temporal quadrant and a three-piece intraocular lens was implanted into the anterior chamber. The haptics of the intraocular lens were externalized with a 27 G needle via transconjunctival scleral tunnels at the 6 and 12 o'clock positions. The transconjunctival scleral tunnels were prepared to conform to the haptic position and curvature. The site of the scleral tunnels was 2mm from the limbus with a length of 2 mm in the sclera and was aimed at the end of the posterior chamber. The tips of the haptics were cauterized to create a terminal knob. The haptics were pushed back and the knobs were implanted into the scleral tunnels. RESULTS: The study cohort included 21 patients with unilateral aphakia and dislocated intraocular lenses. All patients were examined postoperatively and at postoperative day 1, day 7, month 1, and month 3. All examinations revealed formation of the anterior chamber and well-centralized intraocular lenses. No haptic-related complications of exposure, foreign body sensation, or discomfort were observed. CONCLUSION: Sutureless transconjunctival intrascleral haptic fixated intraocular lensimplantation is an effective, safe, and practical surgical alternative. This technique was superior to the Yamane method with regard to comfort and surgical duration. Further studies with longer follow-up evaluations are warranted to verify long-term complications.

Scleral Cross-Linking Using Glyceraldehyde for the Prevention of Axial Elongation in the Rabbit: Blocked Axial Elongation and Altered Scleral Microstructure.

BACKGROUND: This study aims to assess the efficacy of the scleral collagen cross-linking method using glyceraldehyde solution for prevention of lens-induced axial elongation in New Zealand rabbits and investigate the biochemical and microstructural changes that occur. METHODS: The right eyes of New Zealand rabbits aged seven weeks were randomly divided into three groups: the cross-linking group (n = 6), non-crosslinking group (n = 5), and untreated control group (n = 5). Eyes in cross-linking and non-crosslinking groups were treated with a -8.00 Diopter spherical lens over the course of two weeks. The cross-linking effects were achieved by a sub-Tenon's injection of 0.15 ml 0.5 M glyceraldehyde to eyes in the CL group. Ocular parameters were measured on the 1st, 7th, and 14th days. Biomechanical testing, light and electronic microscopy were used. RESULTS: Following the cross-linking treatment, eyes in the cross-linking group had a shorter axial length compared to those in the non-crosslinking group (p = 0.006). Collagen fibrils larger than 240 nm were observed in the scleral stroma of cross-linking group, which were absent in the scleral stroma of the non-crosslinking and untreated control group. The mean ultimate stress and Young's modulus was significantly greater in the cross-linking group compared to those in the non-crosslinking and untreated control group (p < 0.05). No histological damage observed in the retina or choroid. CONCLUSIONS: This study demonstrates that lens-induced axial elongation in rabbits can be effectively blocked by cross-linking using glyceraldehyde, with anatomical and mechanical modification and no deleterious effects.

Randomised Clinical Trial for Postoperative Complications after Ex-PRESS Implantation versus Trabeculectomy with 2-Year Follow-Up.

We compared complications between Ex-PRESS implantation and trabeculectomy for 2 years after surgery. Sixty-four open-angle glaucoma eyes were randomly assigned to treatment with trabeculectomy (n = 32) or Ex-PRESS implantation (n = 32). The primary outcomes were postoperative complications, including reduction of the endothelial cell density (ECD) of the cornea, cataract progression and the frequency of other late postoperative complications. The Ex-PRESS group had significantly greater reduction of postoperative corneal ECD than the trabeculectomy group did at 2 years after surgery (P = 0.026). Among the corneal areas measured using specular microscopy, the superior area, where the Ex-PRESS tube was inserted, had significantly more severe corneal ECD reduction than the inferior area after 2 years (-17.6% in superior area and -11.7% in inferior area, P = 0.04). More cataract progression occurred in the trabeculectomy group than in the Ex-PRESS group (P = 0.04). Twelve eyes (37.5%) in the trabeculectomy group and 4 eyes (12.5%) in the Ex-PRESS group underwent cataract surgery (P = 0.019). The total number of other postoperative complications between 3 months and 2 years was significantly higher in the trabeculectomy group than in the Ex-PRESS group (P = 0.02). Although Ex-PRESS implantation might be associated with an increased rate of corneal endothelial cell loss compared with trabeculectomy, it is beneficial for preventing cataract progression after filtering surgery.

Longitudinal Changes in Bleb Height, Vascularity, and Conjunctival Microcysts After Trabeculectomy.

OBJECTIVE: The objective of this article was to study longitudinal changes in bleb morphology (presence of microcysts and bleb height and vascularity) in subjects enrolled in the Singapore 5-Fluorouracil (5-FU) trabeculectomy study. STUDY DESIGN: Retrospective subgroup analysis of a randomized controlled trial. MATERIALS AND METHODS: Following trabeculectomy with either 5-FU or placebo, subjects were reviewed at day 1, weeks 1, 2, and 3, and months 3, 6, 9, 12, 16, 20, 24, 28, 32, and 36 and intraocular pressure (IOP), presence of microcysts and bleb height and vascularity graded and recorded. Statistical analyses were used to investigate baseline factors (demographics, eye drops use, IOP, treatment type, and comorbidities) that might account for long-term bleb changes and assess the influence of bleb morphology on mean, maximum, minimum, and variation in IOP following trabeculectomy. RESULTS: One hundred fifty-nine (61.2%) subjects completed follow-up and 71 subjects (44.7%) received 5-FU. Proportion of subjects with microcysts increased posttrabeculectomy till weeks 3 and 6 in 5-FU and placebo-treated eyes, respectively, before decreasing. Presence of microcysts at day 1 and week 2 was associated with lower mean (P=0.027 to 0.033), maximum (P=0.040), and minimum IOP (P=0.010). Mean bleb height decreased over 36 months and at months 20 and 36 was associated with maximum (P=0.031) and minimum IOP (P=0.032), respectively. Mean bleb vascularity decreased till month 9 and remained fairly constant after. CONCLUSIONS: Microcysts seen early posttrabeculectomy is associated with lower IOP. Blebs reduce in height as they remodel and the relationship between bleb vascularity and IOP is complex.

Riboflavin and ultraviolet A irradiation for the prevention of progressive myopia in a guinea pig model.

In this study, we evaluated the effect of oral administration of riboflavin combined with whole-body ultraviolet A (UVA) irradiation on the biochemical and biomechanical properties of sclera in a guinea pig model to control the progression of myopia. Experimental groups were administered 0.1% riboflavin solution with or without vitamin C by gavage from 3 days before myopic modeling and during the modeling process. Guinea pigs underwent 30 min of whole-body UVA irradiation after each gavage for 2 weeks. For control groups, guinea pigs were administered vitamin C and underwent either whole-body UVA irradiation without 0.1% riboflavin solution or whole-body fluorescent lamp irradiation with or without 0.1% riboflavin solution. Resultantly, myopia models were established with an increased axial length and myopic diopter. Compared with myopic eyes in the control groups, the net increase in axial length, diopter and strain assessment decreased significantly, and the net decrease in sclera thickness, ultimate load, and stress assessment decreased significantly in experimental groups. MMP-2 expression showed a lower net increase, while TIMP-2 expression showed a lower net decrease. In addition, hyperplasia of scleral fibroblasts was more active in myopic eyes of experimental groups. Overall, our results showed that oral administration of riboflavin with whole-body UVA irradiation could increase the strength and stiffness of sclera by altering the biochemical and biomechanical properties, and decreases in axial elongation and myopic diopter are greater in the guinea pig myopic model.

A New Method for Revision of Encapsulated Blebs after Trabeculectomy: Combination of Standard Bleb Needling with Transconjunctival Scleral Flap Sutures Prevents Early Postoperative Hypotony.

PURPOSE: A simple needling procedure is the standard method for restoring the function of an encapsulated bleb after trabeculectomy. However, postoperative hypotony represents a possible hazard. This study describes a new surgical approach for treating encapsulated blebs with reduced risk of early postoperative hypotony: bleb needling combined with transconjunctival sutures tightening the scleral flap directly. METHODS: The study included two groups of 23 patients with failing bleb following trabeculectomy: "Group 1" underwent simple needling revision of the filtering bleb and served as a control group, while "Group 2" received needling revision with additional transconjunctival scleral flap sutures, if intraoperatively the intraocular pressure was estimated to be very low. Intraocular pressure (IOP), postoperative management and complications were analyzed over a follow-up period of 4 weeks postoperatively. Results were compared using t-test or Mann-Whitney U-tests. RESULTS: Adverse effects occurred with a higher frequency after sole needling of the bleb (5 cases of choroidal effusion and 1 case of choroidal hemorrhage) than after the combined method with additional scleral sutures (1 case of choroidal effusion). The IOP on the first postoperative day was significantly lower in group 1, with 9.43 ± 9.01 mm Hg vs. 16.43 ± 8.35 mm Hg in group 2 (P = 0.01). Ten patients with ocular hypotony (IOD of 5 mmHg or lower) were found in group 1 and only two in group 2. One week and one month after surgery the intraocular pressure was similar in both groups (P>0.05). CONCLUSIONS: This new needling technique with additional transconjunctival scleral flap sutures appears to reduce postoperative hypotony, and may thus protect from further complications, such as subchoroidal hemorrhage.

Sclera as the target tissue in progressive myopia.

UNLABELLED: Introduction: The aim of the study was to study the eye corneoscleral shell and connective tissue (CT) system in children with acquired and congenital progressive myopia, and to identify the informative diagnostic criteria of weakened supporting function of the sclera. MATERIAL AND METHODS: 155 children aged 9-17 were examined: 18 had emmetropia or hyperopia, 20--low, 32--moderate and 85--high myopia. 32 children had complicated myopia (CM) due to peripheral retinal degeneration (PRD). Corneal hysteresis (CH), scleral acoustic density (SAD), X-ray vertebral topography, plantography, joint hypermobility, serum cortisol (SC), and autonomic balance were measured. RESULTS: Corneal hysteresis, mmHg and SAD, rel. units (mean ± SE) were lower if myopia was higher: in low myopia, CH was 13.0 ± 0.3, in moderate myopia, 11.9 ± 0.3#, in high myopia, 10.7 ± 0.3#; SAD was resp. 215.9 ± 5.2, 204.9 ± 3.7# and 192.8 ± 5.8# (#: p < 0.05 with regard to low myopia). The lowest CH (10.3 ± 0.4) and SAD (186.5 ± 7.3) were found in acquired CM. Congenital myopia with PRD showed CH and SAD greater than in acquired CM (p < 0.05). Serum cortisol (nmol/L) in hyperopia was 335.8 ± 40.9 and dropped with higher myopia: in low myopia--290.7 ± 58.6, in moderate--250.9 ± 26.4, in high--243.9 ± 20.5. The lowest SC was found in acquired CM, consistent with CH and SAD. Connective tissue dysplasia progressed with higher myopia: it was found in 76.9% of children with low, 82.4% with moderate, 89.2% with high acquired myopia, and 91.7% with congenital myopia. Biomechanical defects of CT and hormonal imbalance were combined with vegetative nervous system (VNS) imbalance: in high myopia only 20.5% of children were eutonic, 61.5%--sympathicotonic and 17.5% parasympathicotonic. CONCLUSIONS: School age children with progressive myopia showed biomechanical abnormalities of the corneosclera, along with CT dysplasia, decreased SC and imbalanced VNS, more pronounced in acquired complicated myopia. Our findings contribute to the understanding of myopia pathogenesis and to the diagnostic/prognostic evaluation of myopic children, in particular when deciding whether sclera-strengthening intervention is needed.

Evaluation of ocular and periocular elasticity after panretinal photocoagulation: an ultrasonic elastography study.

PURPOSE: Our aim was to evaluate the effects of argon laser panretinal photocoagulation on ocular and periocular ultrasound elastography values in diabetic retinopathy. Also, we wanted to test the applicability of ultrasound elastography in ophthalmological practice. MATERIALS AND METHODS: This is a prospective cross-sectional study comparing proliferative diabetic retinopathy patients (study group) who had undergone panretinal photocoagulation and non-proliferative diabetic retinopathy patients (control group). There were 15 participants (11 males and 4 females) in the study group and 16 participants (10 males and 6 females) in the control group. The ultrasound elastography measurements were done with the LOGIQ E9 Ultrasound Elastography. RESULTS: The elastography values of vitreous, retrobulbar fat, and optic nerve were similar in both groups (p > 0.05). But, the mean retina-choroid-scleral elastography value of the study group was higher than that of the control group, which indicates increased hardness (p = 0.002). CONCLUSIONS: The argon laser panretinal photocoagulation decreases elasticity of the retina-choroid-sclera complex. The ultrasound elastography technique, that gives reproducible and consistent values, could be used effectively in ophthalmological practice.

[Clinical and experimental aspects of investigation of biomechanical properties of corneoscleral shell].

The article summarizes the results of long-term clinical and experimental studies on biomechanical properties of corneoscleral shell performed over the last few years in the Research Institute of Eye Diseases of the Russian Academy of Medical Sciences. A total of 2432 patients (4775 eyes) were assessed. Dynamic bidirectional pneumatic corneal applanation, dynamic pneumatic corneal impression, and elastotonometry were used for in vivo evaluation. A new method of biomechanical assessment--luminescent polariscopy--was studied experimentally. The findings allow correct judgment on biomechanical properties of fibrous tunic in norm and pathology, such as ectatic cornea, glaucoma or previous refractive surgery.

Deep sclerectomy with mitomycin C in eyes with failed glaucoma surgery and pseudophakia.

PURPOSE: To report outcomes of deep sclerectomy (DS) with intraoperative mitomycin C (MMC) application in eyes with previous failed glaucoma surgery (GS) and/or cataract extraction (CE). PATIENTS AND METHODS: Single-surgeon case series of 82 eyes of 82 patients undergoing DS with MMC. The patients had previous CE with IOL and/or conjunctival GS and treated intraocular pressure (IOP) >18 mm Hg. MMC (0.2 mg/ml) was applied for 2-3 min before scleral flap dissection. Complete success was defined as IOP between 6 and 21 mm Hg or a reduction of 20% from baseline without medications. Reoperation for glaucoma or related complications, or loss of light perception vision was considered as failure. RESULTS: Mean follow-up was 57.7 ± 22.4 months with 78% of patients completing the 3-year follow-up. Mean IOP decreased from 24.0 mm Hg (22.3-25.6, 95% confidence intervals) to 13.4 mm Hg (12.0-14.2) at 3 years after surgery (P<0.001). There was a significant decrease in the number of glaucoma medications from 2.0 ± 1 preoperatively, to 0.3 ± 0.7, 3 years after surgery. Kaplan-Meier cumulative success rates were 85.6% at 1 year, 80.0% at 2 years, and 76% at 3 years. At 3 years, IOP was maintained <19 and 15 mm Hg in 83 and 70% of eyes, respectively. Fourteen eyes (17.1%) had complications. Delayed hypotony (IOP <6 mm Hg) was the commonest complication in five eyes (6.1%). CONCLUSION: DS with MMC appears to be a safe and effective surgical procedure for eyes with previous intraocular surgery.

Comparing the astigmatic outcome after paediatric cataract surgery with different incisions.

AIMS: To compare astigmatism with clear corneal incision versus scleral tunnel incision following paediatric cataract surgery with primary intraocular lens implantation. METHODS: Retrospective, comparative case series of 218 eyes of 138 children <12 years of age undergoing cataract extraction with intraocular lens implantation. The study cohorts were grouped into two categories based on incision location: group 1 comprising 108 eyes from 65 children with scleral incision; group 2 comprising 110 eyes from 73 children with clear corneal incision. Cycloplegic refraction was performed at 1, 3 and 6 months postoperatively. RESULTS: The mean age in group 1 was 61 ± 39 months and in group 2, 51 ± 41 months. The mean postoperative astigmatism in group 1 was 1.28 ± 0.97 D, 1.42 ± 1.00 D and 1.38 ± 0.98 D at 1, 3 and 6 months respectively. The change in astigmatism between 1 and 6 months was non-significant (p=0.26). The mean astigmatism in group 2 was 1.34 ± 1.20 D, 1.13 ± 0.88 D and 1.03 ± 0.89 D at 1, 3 and 6 months respectively. Astigmatism in group 2 decreased significantly with time (p<0.001). The amount of astigmatism was comparable between the two groups at 1 month postsurgery (p=0.90), while it was significantly lower in the corneal incision group at 3 (p=0.03) and 6 months (p=0.01). CONCLUSIONS: Postoperative astigmatism after paediatric cataract surgery by clear corneal incision was lower compared with scleral incision. However, the difference was small and clinically insignificant.

[Myopia update 2011]. / Myopie-Update 2011.

This review summarises some recent aspects of myopia research. The following conclusions have been drawn. As long as myopia progression is visually controlled, at least three different interventions are possible: (i) spectacles/contact lenses which correct only the centre of the visual field and leave the periphery somewhat myopic, (ii) outdoor activity or equivalent temporary increase in illuminance, (iii) pharmacological intervention of retinal growth signals that are transmitted to the underlying sclera. Options (i) and (ii) can be used without risks although there is still room for improvement of the variables. Option (iii) has re-entered a new phase of orientation with new searches for candidate targets after previous testing with muskarinic antagonists (pirenzepine) in children did not enter phase 3 level. If myopia is outside the range over which it is visually controlled by emmetropisation (in the case of high and pathological myopias), in principle the possibility exists to improve the mechanical stability of the sclera pharmacologically. However, there is still a need for more research. Up to now, the mechanical weakness of the sclera in highly mopyic eyes is surgically stabilised by "scleral buckling". However, these procedures have found limited acceptance since the effects were not very reliable. In 40 - 50 % of the cases of high myopia, degenerative processes are found in the retina which can be seen as consequence of the mechanical tension in the fundus, but may also be indepedent of this factor (no significant correlation with axial length!). In part they can be slowed down by intravitreal anti-VEGF therapy. A long-term study from Denmark has shown that most patients with myopia of between 6-9 dpt during puberty reach retirement age without disabling visual loss.

Effect of intravitreal gas tamponade for sutureless vitrectomy wounds: three-dimensional corneal and anterior segment optical coherence tomography study.

PURPOSE: To investigate the effect of gas tamponade on wound closure and postoperative hypotony by comparing fluid-filled and gas-filled eyes after 25-gauge sutureless vitrectomy using three-dimensional corneal and anterior segment optical coherence tomography. METHODS: Twenty-four eyes of 24 patients who underwent a 25-gauge transconjunctival sutureless vitrectomy were included in this prospective study. A total of 72 scleral wounds were observed using three-dimensional corneal and anterior segment optical coherence tomography at 3 hours and at 1, 3, 7, and 14 days postoperatively. Scleral wound closure was defined as the absence of a scleral gap at the sclerotomy site, as observed using three-dimensional corneal and anterior segment optical coherence tomography. The rate of wound closure, intraocular pressure, and the incidence of complications were compared between the fluid- and gas-filled eyes. RESULTS: The rates of scleral wound closure at 3 hours and at 1, 3, 7, and 14 days were 26.2%, 28.6%, 35.7%, 52.4%, and 85.7% in fluid-filled eyes and 53.3%, 73.3%, 76.7%, 83.3%, and 93.3% in gas-filled eyes; these rates were significantly higher for the gas-filled eyes. The intraocular pressure was significantly higher in the gas-filled eyes than in the fluid-filled eyes on postoperative Day 1 but did not differ significantly between the 2 groups on postoperative Day 3 and thereafter. CONCLUSION: Three-dimensional corneal and anterior segment optical coherence tomography provided clear images of 25-gauge sutureless vitrectomy wounds and revealed that the sclerotomies closed faster in gas-filled eyes than in fluid-filled eyes. Thus, gas tamponade might be effective for the closure of sutureless vitrectomy wounds.

The in vitro inflation response of mouse sclera.

The purpose of this research was to develop a reliable and repeatable inflation protocol to measure the scleral inflation response of mouse eyes to elevations in intraocular pressure (IOP), comparing the inflation response exhibited by the sclera of younger and older C57BL/6 mice. Whole, enucleated eyes from younger (2 month) and older (11 month) C57BL/6 mice were mounted by the cornea on a custom fixture and inflated according to a load-unload, ramp-hold pressurization regimen via a cannula connected to a saline-filled programmable syringe pump. First, the tissue was submitted to three load-unload cycles from 6 mmHg to 15 mmHg at a rate of 0.25 mmHg/s with ten minutes of recovery between cycles. Next the tissue was submitted to a series of ramp-hold tests to measure the creep behavior at different pressure levels. For each ramp-hold test, the tissue was loaded from 6 mmHg to the set pressure at a rate of 0.25 mmHg/s and held for 30 min, and then the specimens were unloaded to 6 mmHg for 10 min. This sequence was repeated for set pressures of: 10.5, 15, 22.5, 30, 37.5, and 45 mmHg. Scleral displacement was measured using digital image correlation (DIC), and fresh scleral thickness was measured optically for each specimen after testing. For comparison, scleral thickness was measured on untested fresh tissue and epoxy-fixed tissue from age-matched animals. Comparing the apex displacement of the different aged specimens, the sclera of older animals had a statistically significant stiffer response to pressurization than the sclera of younger animals. The stiffness of the pressure-displacement response of the apex measured in the small-strain (6-15 mmHg) and the large-strain (37.5-45 mmHg) regime, respectively, were 287 ± 100 mmHg/mm and 2381 ± 191 mmHg/mm for the older tissue and 193 ± 40 mmHg/mm and 1454 ± 93 mmHg/mm for the younger tissue (Student t-test, p<0.05). The scleral thickness varied regionally, being thickest in the peripapillary region and thinnest at the equator. Fresh scleral thickness did not differ significantly by age in this group of animals. This study presents a reliable inflation test protocol to measure the mechanical properties of mouse sclera. The inflation methodology was sensitive enough to measure scleral response to changes in IOP elevations between younger and older C57BL/6 mice. Further, the specimen-specific scleral displacement profile and thickness measurements will enable future development of specimen-specific finite element models to analyze the inflation data for material properties.