Comparison of the inhibitory effect of topical cyclosporine A 0.1% and topical anti-VEGF application in an experimental model of corneal neovascularization / Comparação do efeito inibitório da ciclosporina A 0,1% tópica e aplicação de anti-VEGF tópica em um modelo experimental de neovascularização da córnea

ABSTRACT Purpose: The aim of this study was to compare the effects of topical cyclosporine 0.1% and bevacizumab on experimentally induced corneal neovascularization in a rat model. Methods: A total of 30 adult Sprague-Dawley rats were used in this experimental study. The central cornea of the rats was cauterized chemically. The rats were randomly enrolled into three groups as follows: Group 1 received bevacizumab 1%, Group 2 received cyclosporine 0.1%, and Group 3 received isotonic saline twice a day for 28 days. Slit-lamp examination of all rats was performed at the 3rd and 28th day. The rats were then sacrificed, and the corneas were excised. The number of blood vessels, state of inflammation, and collagen formation were evaluated histopathologically in the corneal sections. Results: Corneal opacity and edema grades were significantly lower in Group 2 than in Group 3 (p=0.04 and 0.00, respectively). In the histopathological examination, Group 2 demonstrated significantly lesser number of blood vessels than Group 3 (p=0.001). Regarding collagen formation, Group 2 exhibited more regular collagen formation than Groups 1 and 3 (p=0.03). Inflammation grades were significantly lower in Groups 1 and 2 than in Group 3 (p=0.014 and 0.001, respectively). Conclusion: Topical bevacizumab is effective in inhibiting newly formed corneal neovascularization. The topical cyclosporine 0.1% treatment appears to be more effective than the topical bevacizumab treatment.

RESUMO Objetivo: Comparar os efeitos da ciclosporina tópica 0,1% e do bevacizumabe na neovascularização da córnea produzida experimentalmente em um modelo com ratos. Métodos: Trinta ratos Sprague-Dawley adultos foram usados neste estudo experimental. A córnea central dos ratos foi cauterizada quimicamente. Os ratos foram distribuídos aleatoriamente em três grupos. O grupo 1 recebeu bevacizumabe a 1%, o grupo 2 recebeu ciclosporina tópica a 0,1% e o grupo 3 recebeu solução salina isotônica duas vezes ao dia durante 28 dias. O exame de lâmpada de fenda de todos os ratos foi realizado no terceiro e no vigésimo oitavo dias. Os ratos foram então sacrificados e as córneas excisadas. Nos cortes da córnea, o número de vasos sanguíneos, o estado de inflamação e a formação de colágeno foram avaliados em uma análise anatomopatológica. Resultados: No Grupo 2, os graus de opacidade e de edema da córnea foram significativamente menores que no Grupo 3 (p=0,04 e 0,00, respectivamente). No exame histopatológico, o Grupo 2 apresentou um número significativamente menor de vasos sanguíneos do que o Grupo 3 (p=0,001). Em relação à avaliação da formação de colágeno, esta mostrou-se mais regular no Grupo 2 que no Grupo 1 e no Grupo 3 (p=0,03). Os graus de inflamação foram significativamente menores no Grupo 1 e no Grupo 2 em comparação com o Grupo 3 (p=0,014 e 0,001, respectivamente). Conclusão: O bevacizumabe tópico é eficaz na inibição da neovascularização da córnea recém-formada. O tratamento tópico com ciclosporina a 0,1% parece ser mais eficaz em comparação ao tratamento tópico com bevacizumabe.

Comparison of the inhibitory effect of topical cyclosporine A 0.1% and topical anti-VEGF application in an experimental model of corneal neovascularization.

PURPOSE: The aim of this study was to compare the effects of topical cyclosporine 0.1% and bevacizumab on experimentally induced corneal neovascularization in a rat model. METHODS: A total of 30 adult Sprague-Dawley rats were used in this experimental study. The central cornea of the rats was cauterized chemically. The rats were randomly enrolled into three groups as follows: Group 1 received bevacizumab 1%, Group 2 received cyclosporine 0.1%, and Group 3 received isotonic saline twice a day for 28 days. Slit-lamp examination of all rats was performed at the 3rd and 28th day. The rats were then sacrificed, and the corneas were excised. The number of blood vessels, state of inflammation, and collagen formation were evaluated histopathologically in the corneal sections. RESULTS: Corneal opacity and edema grades were significantly lower in Group 2 than in Group 3 (p=0.04 and 0.00, respectively). In the histopathological examination, Group 2 demonstrated significantly lesser number of blood vessels than Group 3 (p=0.001). Regarding collagen formation, Group 2 exhibited more regular collagen formation than Groups 1 and 3 (p=0.03). Inflammation grades were significantly lower in Groups 1 and 2 than in Group 3 (p=0.014 and 0.001, respectively). CONCLUSION: Topical bevacizumab is effective in inhibiting newly formed corneal neovascularization. The topical cyclosporine 0.1% treatment appears to be more effective than the topical bevacizumab treatment.

Comparison of the effects of intravitreal bevacizumab and dexamethasone in experimental posterior penetrating eye injury.

AIM: To compare the effects of intravitreal anti-vascular endothelial growth factor (VEGF) and dexamethasone in an experimental rabbit model of posterior penetrating ocular injury. METHODS: Thirty white New Zealand rabbits were included in the study. A posterior penetrating ocular injury was performed at the superotemporal quadrant. They were randomly divided into three groups. The rabbits in group 1 received intravitreal dexamethasone, in group 2 they received intravitreal bevacizumab and those in group 3 received intravitreal physiological saline solution in both eyes. All eyes were examined ophthalmologically on the 1st, 3rd, 7th, 14th and 28th days following the injury and the clinical findings were scored. On the day 28, the eyes were enucleated, evaluated and scored macroscopically, histopathologically and scanning electron microscopically. RESULTS: The median clinical score on the 14th and 28th days and the median macroscopic score of the dexamethasone group was significantly better than that of control (P=0.004, 0.018). Dexamethasone group was also better than that of bevacizumab group but the differences did not reach statistical significance. Retinal detachment rate was 8.3%, 16.6% and 12.5% in the dexamethasone group, bevacizumab group and control group, respectively (P=0.476). More extensive fibrocelluler proliferations were observed in controls compared with dexamethasone and bevacizumab groups. But these differences did not reach the statistical significance (P=0.538). In scanning electron microscopy all groups showed fibreous stalk and dense collagen fibrils in vitreous. CONCLUSION: This study shows that intravitreal injection of both dexamethasone and bevacizumab may reduce the intraocular fibrous proliferation after an experimental posterior penetrating ocular injury in rabbits.

IS THERE A ROLE OF ACTH IN INCREASED CHOROIDAL THICKNESS IN CUSHING SYNDROME?

PURPOSE: To evaluate choroidal thickness (CT) in patients with Cushing syndrome (CS) with enhanced depth imaging optical coherence tomography. METHODS: Twenty-eight patients with CS and 38 healthy volunteers were enrolled in this observational cross-sectional study. Patients with newly diagnosed CS who have been admitted to Erciyes University Department of Endocrinology in 3 years time interval were compared with age- and sex-matched healthy volunteers. Choroidal thickness was measured at the fovea and 2 points nasal and 2 points temporal to the fovea with 500-µm intervals each. RESULTS: Choroidal thickness measurements were higher in patients with CS than in the control group at all examination points; however, the difference was found to be significant at the center of the fovea (367.8 ± 94.4 µm vs. 329 ± 90.5 µm) and 1,000 µm temporal to the fovea. Choroidal thickness measurements were significantly higher in adrenocorticotrophic hormone (ACTH)-dependent CS group than in the control group at all measurement points (CT at fovea 388.2 ± 92.4 µm vs. 329.1 ± 90.5 µm). All CT measurements were found to be correlated with ACTH levels. CONCLUSION: Cushing syndrome is associated with increased CT. The ACTH-dependent CS may increase CT more than ACTH-independent CS. This effect may be directly related to ACTH itself or increased plasma cortisol levels or both.

A New Fitting Approach for Providing Adequate Comfort and Visual Performance in Keratoconus: Soft HydroCone (Toris K) Lenses.

OBJECTIVE: To evaluate the comfort and visual performance of soft HydroCone (Toris K) silicone hydrogel lenses in keratoconus patients. METHODS: Fifty eyes of 50 keratoconic patients who were fitted with the Toris K lens were included in the study. All patients were evaluated at baseline and after 2 weeks of lens wear. Uncorrected and best-corrected visual acuities were measured. Corneal topography, ocular aberrations, and point spread function (PSF) were obtained using NIDEK-OPD Scan. Comfort level and visual performance in daytime and nighttime conditions were scored from 0 to 5 after 2 weeks of lens wear. RESULTS: Best-corrected visual acuity was significantly better with the Toris K lens (P<0.001). Mean increase in visual acuity with the lens was 4.5 lines. Mean K1, K2, and Kmax values significantly decreased with the lens (P<0.001). Both total and higher-order root-mean-square errors were significantly corrected with the Toris K lens (P<0.001 and P=0.038, respectively). A significant correction of total coma and trefoil aberrations was achieved with the lens. Also, PSF values were significantly increased with the lens (P<0.001). Although comfort scores in 46 eyes (92.0%) were classified as good/excellent, only 4 eyes (8.0%) had moderate comfort scores. Visual acuity was classified as good/excellent in 46 eyes (92.0%) in daytime and in 38 eyes (76%) in nighttime conditions. CONCLUSIONS: Soft HydroCone silicone hydrogel keratoconus lenses should be considered as alternative visual correction for keratoconus patients. The soft and full-custom design provides optimal comfort and visual performance for the patients' daily requirements.