The effect of transepithelial corneal collagen cross-linking treatment on optical quality of the cornea in keratoconus: 12-month clinical results.

PURPOSE: To evaluate the effect of transepithelial corneal collagen crosslinking (CXL) treatment on the optical performance of the cornea at 12-month follow-up after CXL in patients with progressive keratoconus. METHODS: One hundred and ten eyes of 67 patients were included. The following corneal optical aberrations over the 4-mm-diameter pupil were recorded via Sirius dual-scanning corneal tomography: total, anterior and posterior amount of corneal higher order aberrations [HOAs], vertical coma, horizontal coma, vertical trefoil, oblique trefoil, and spherical aberration, and Strehl ratio of point spread function (PSF). RESULTS: There were significant improvements in mean root mean square error values for corneal total HOA, total coma, anterior HOA, anterior coma, and vertical coma following CXL (P > 0.05, for all). No significant changes were found in the posterior aberometric parameters. PSF value did not change after CXL (P > 0.05). The corneal topographic measurements not revealed a change in the mean simulated keratometry-1, simulated keratometry-2, and maximum keratometry compared with the baseline measurements (P > 0.05, for all). At 12 months, there was a significant improvement in the uncorrected (UCVA) and best corrected (BCVA) visual acuity (P < 0.001, both). Most corneal aberrations correlated significantly with postoperative BCVA, but changes in HOAs were not statistically associated with improvements in visual acuity. CONCLUSIONS: Transepithelial CXL was effective in stabilizing the keratometric indices and improving the most corneal aberrations in keratoconic eyes 1 year after the procedure. While the healing effect on aberrations after CXL was in total and anterior parameters, no significant changes were observed in the posterior surface. In addition, it was observed that transepithelial CXL treatment did not cause a significant change in PSF distribution data.

Decrease of over-elevation in adduction after surgery of medial rectus muscles in partially refractive accommodative esotropia.

SIGNIFICANCE: The course of over-elevation in adduction after strabismus surgery has been evaluated in a small number of research in the literature, we believe our study is the first to report the results in a specific group of esotropia (ET) patients. AIM: To report the course of postoperative over-elevation in adduction in patients who underwent surgery for horizontal deviation on the medial recti in partially accommodative ET. METHODS: The medical charts of patients who had partially accommodative ET with over-elevation in adduction were reviewed retrospectively. A scale from -4 to +4 was used to grade the oblique muscle function. Among these, 17 patients who were operated solely on the horizontal rectus muscles were identified. The primary outcome measure was the degree of improvement in over-elevation in adduction after medial rectus surgery. RESULTS: Nine (52.9%) of the 17 patients (mean age: 5.18 ± 2.24 months) were males and 8 (47.1%) were females. The mean follow-up period was 17.06 ± 15.32 months. Overall, 15 patients (88.2%) achieved surgical success. The mean inferior oblique overaction was found 1.44 ± 0.56 preoperatively and the final postoperative mean inferior oblique overaction was 0.53 ± 0.51 (P = 0.001). Postoperative over-elevation in adduction after 3 months was significantly decreased compared to the preoperative value (P = 0.003, P = 0.001, P = 0.001 at 3rd and 6th months and final visits respectively). CONCLUSION: Over-elevation in adduction accompanying partially refractive accommodative ET seems to regress after medial rectus weakening surgery. This finding should be considered in the presurgical evaluation of these patients.

In vivo confocal microscopy of corneal nerve fiber damage in early course of multiple sclerosis.

PURPOSE: To evaluate the corneal nerve fiber morphology in patients with multiple sclerosis (MS) by in vivo corneal confocal microscopy (CCM). METHODS: Retinal nerve fiber layer thickness (RNFLT), central macular thickness (CMT), corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD) and corneal nerve fiber tortuosity (CNFT) were measured. Correlation of corneal nerve findings with duration and clinical severity of MS was calculated. RESULTS: CNFL (9.50 ± 0.60 vs. 11.20 ± 0.57 mm/mm2, P = 0.046) and CNBD (57.46 ± 5.04 vs. 77.65 ± 3.41 no/mm2, P = 0.001) were significantly lower with no significant difference in CNFD (21.24 ± 1.20 vs. 23.62 ± 0.95 no/mm2, P = 0.125), CNFT (2.00 ± 0.15 vs. 1.73 ± 0.12, P = 0.180), CMT (269.57 ± 12.53 vs. 271.10 ± 18.84 µm, P = 0.716) or RNFLT (102.82 ± 6.98 vs. 105.33 ± 12.70 µm, P = 0.351) between patients with RRMS compared to controls. There was no significant correlation between CCM parameters with EDSS and duration of disease in MS patients. CONCLUSION: The current study demonstrated that a decrease in CNFL, CNFD and CNBD in CCM analysis in the early course of MS.

Optical coherence tomography measurements in patients with systemic hypertension.

AIM: To evaluate the effect of systemic arterial hypertension (SAH) on retinal optical coherence tomography (OCT) parameters and investigate whether a correlation exists between ambulatory blood pressure monitoring (ABPM) and OCT measurements.Material-methods: 115 SAH patients (225 eyes) and 123 healthy control cases (234 eyes) were included. ABPM was performed on 89 of 115 SAH patients. All patients underwent detailed ophthalmologic examination including imaging with OCT. SAH patients were divided into two groups (dippers, non-dippers) according to their nocturnal blood pressure (BP) reduction, and OCT measurements were compared. RESULTS: Average and superior retinal nerve fiber layer (RNFL) quadrants were significantly thin in hypertensive cases (p:0.002, p < 0.001, respectively). Cup area, cup/disk (c/d) area, and c/d horizontal ratios were wider; the rim area was smaller in hypertensive cases (respectively: p:0.024, p:0.017, p:0.003, p < 0.001). Total macular volume (TMV), the thicknesses in 1-3 and 1-6 mm of the macula were less in hypertensives (p < 0.001). There was no significant difference between dippers and non-dippers in RNFL thickness, macula and optic nerve head (ONH) parameters. CONCLUSION: There were statistically significant differences between healthy cases and patients with SAH in terms of RNFL, macula thicknesses and ONH parameters.

Limited Vitrectomy in Patients with Idiopathic Macular Hole

Background: Partial posterior hyaloidectomy is suggested to minimize traction on the vitreous base and thus reduce the risk of iatrogenic breaks in patients with macular hole and epiretinal membrane. Aims: To evaluate the safety and efficacy of limited vitrectomy in patients with macular hole. Study Design: Retrospective cohort study. Methods: Fifty-two consecutive patients who underwent macular hole surgery without complete peripheral vitreous removal were included in the study. The improvement in visual acuity, the incidence of retinal breaks and detachment, anatomical results, and intraoperative and postoperative complications of this technique were evaluated. Results: The median visual acuity was 0.2 (0.1-0.4) before surgery and 0.5 (0.3-0.6) after surgery (p<0.001). None of the patients had retinal breaks or detachments. A sulfur hexafluoride was used in 24 patients (46.2%), and perfluoropropane was used in 28 patients (53.8%). Three patients (5.76%) had revision surgery because of recurrence of the macular hole. We did not observe proliferative vitreoretinopathy or surgery-related major complications in any patient during the follow-up period. Conclusion: Limited vitrectomy without removal of the peripheral vitreous seems to be effective and safe with minimal risk of peripheral retinal breaks and detachment.

Evaluation of nutritional status in children with amblyopia / Avaliação do estado nutricional de crianças com ambliopia

ABSTRACT Purpose: We aimed to compare the body mass index and vitamin and mineral status of children with and without amblyopia. Methods: Amblyopic children aged between 5 and 18 years (n=46) and age-matched control children (n=32) were evaluated in terms of anthropometric parameters, including height, weight, body mass index and demographic features. Serum vitamin B12 and folate were measured using an Advia Centaur XP (Siemens, Ireland) biochemistry analyzer. We evaluated the inorganic mineral elements from hair samples with inductively coupled plasma-mass spectrometry using a Thermo XSeries 2 analyzer (Thermo Fisher Scientific, Bremen, Germany). Results: No significant difference was found between the two groups in terms of height, weight, and body mass index or serum B12 and folate concentrations (p>0.05). Children with severe amblyopia had lower vitamin B12 and folate and higher body mass index. The levels of phosphorus (p=0.012), selenium (p=0.002), molybdenum (p<0.001), iodine (p=0.002), chromium (p=0.022), boron (p<0.001), and beryllium (p=0.005) were all significantly lower in the amblyopia group compared to the control group. All of these minerals, except phosphorus, were also significantly lower in those with severe amblyopia compared to those with milder amblyopia and controls (p<0.05). Conclusion: Amblyopic children are significantly deficient in some inorganic elements. Inorganic elements, vitamin B12, and folate may play an important role in the visual development of amblyopic children.

RESUMO Objetivo: Nosso objetivo foi comparar o índice de massa corporal e o nível de vitaminas e minerais de crianças com e sem ambliopia. Métodos: Crianças amblióticas com idades entre 5 e 18 anos (n=46) e crianças controle pareadas por idade (n=32) foram avaliadas quanto a parâmetros antropométricos, incluindo altura, peso, índice de massa corporal e características demográficas. A vitamina B12 e o folato séricos foram medidos utilizando um analisador bioquímico Advia Centaur XP (Siemens, Irlanda). Avaliamos os elementos minerais inorgânicos de amostras de cabelo com espectrometria de massa de plasma indutivamente acoplado usando um analisador Thermo XSeries 2 (Thermo Fisher Scientific, Bremen, Alemanha). Resultados: Não houve diferença significativa entre os dois grupos em relação à altura, peso e índice de massa corporal ou concentrações séricas de B12 e folato (p>0,05). Crianças com ambliopia severa tinham menor vitamina B12 e folato e maior índice de massa corporal. Os níveis de fósforo (p=0,012), selênio (p=0,002), molibdênio (p<0,001), iodo (p=0,002), cromo (p=0,022), boro (p<0,001) e berílio (p=0,005) foram todos significativamente menores no grupo com ambliopia em comparação com o grupo controle. Todos esses minerais, exceto o fósforo, também foram significativamente menores naqueles com ambliopia em comparação com aqueles com ambliopia leve e grupo controle (p<0,05). Conclusão: As crianças amblíopes são significativamente deficientes em alguns elementos inorgânicos. Elementos inorgânicos, vitamina B12 e folato podem desempenhar um papel importante no desenvolvimento visual de crianças com ambliopia.

Evaluation of nutritional status in children with amblyopia.

PURPOSE: We aimed to compare the body mass index and vitamin and mineral status of children with and without amblyopia. METHODS: Amblyopic children aged between 5 and 18 years (n=46) and age-matched control children (n=32) were evaluated in terms of anthropometric parameters, including height, weight, body mass index and demographic features. Serum vitamin B12 and folate were measured using an Advia Centaur XP (Siemens, Ireland) biochemistry analyzer. We evaluated the inorganic mineral elements from hair samples with inductively coupled plasma-mass spectrometry using a Thermo XSeries 2 analyzer (Thermo Fisher Scientific, Bremen, Germany). RESULTS: No significant difference was found between the two groups in terms of height, weight, and body mass index or serum B12 and folate concentrations (p>0.05). Children with severe amblyopia had lower vitamin B12 and folate and higher body mass index. The levels of phosphorus (p=0.012), selenium (p=0.002), molybdenum (p<0.001), iodine (p=0.002), chromium (p=0.022), boron (p<0.001), and beryllium (p=0.005) were all significantly lower in the amblyopia group compared to the control group. All of these minerals, except phosphorus, were also significantly lower in those with severe amblyopia compared to those with milder amblyopia and controls (p<0.05). CONCLUSION: Amblyopic children are significantly deficient in some inorganic elements. Inorganic elements, vitamin B12, and folate may play an important role in the visual development of amblyopic children.

Comparative proteome analysis of the tear samples in patients with low-grade keratoconus.

PURPOSE: To elucidate the metabolic processes playing roles in the formation of keratoconus (KC). METHODS: Tears samples were collected using capillary glass tubes without stimulation and without prior anesthesia from 17 patients and 16 controls. Proteomic analysis by fluorescent 2D gel electrophoresis (DIGE) coupled with MALDI-TOF/TOF was performed. The identified proteins that were differentially regulated were subjected to Ingenuity Pathway Analysis (IPA). Corneal topography analyses with Sirius topography system (Costruzioni Strumenti Oftalmici, Florence, Italy) were performed on all participants. The steepest keratometry index was lower than 50 diopters in all keratoconus patients. RESULTS: DIGE analysis showed changes in abundance of nine proteins. Six of these proteins, namely serum albumin, Keratin Type II Cytoskeletal 1, IgG gamma chain-1, GAPDH, alpha-1 antitrypsin and ApoA-I, were down-regulated in the KC samples in comparison with the controls. In addition, we detected up-regulation of lysozyme C, keratin type I cytoskeletal 10 and lipocalin. The subsequent IPA predicted that NADH repair pathway is activated in the KC patients. This pathway involves generation of NADHX as a by-product via catalysis by GAPDH. NADHX is an inhibitor of several dehydrogenases and must be removed. CONCLUSION: The involvement of NADHX repair pathway in KC should be investigated, since preliminary clues obtained in this study point to that direction. In particular, showing the presence of ATP-dependent NAD(P)H-hydrate dehydratase that eliminates NADHX would strengthen our findings and would be a major step toward understanding KC.

Comparative proteomic analysis of amnion membrane transplantation and cross-linking treatments in an experimental alkali injury model.

PURPOSE: In this study, by using a two-dimensional (2D) electrophoresis-based experimental approach, we aimed at understanding the nature of alkali injuries and the underlying mechanisms. A secondary aim was to compare the effects of cross-linking (CXL) and amnion membrane transplantation (AMT) on corneal protein compositions at the end of the early repair phase after injured with alkali. METHOD: The right corneas of 24 rabbits were injured with a 1 N solution of NaOH. Groups were formed based on the adjuvant therapies as (1) healthy group, (2) control group, (3) CXL group, (4) AMT group. In addition to the therapies, a conventional medical treatment was applied to all groups. Left eyes were used as within-subject healthy corneas (1). The corneas were excised at day 21, and a comparative proteomic analysis was performed using 2D gel electrophoresis coupled with MALDI-TOF/TOF. RESULT: 2D gel electrophoresis revealed the presence seven protein spots whose abundance changed among the groups. Those proteins were SH3 domain-binding protein, plant homeodomain finger protein 23, S100 calcium binding protein A-11(S100 A11), keratin type 2 cytoskeletal 1 and 2, transketolase and glyceraldehyde 3-phosphate dehydrogenase. Ingenuity pathway analysis predicted that the observed changes may be linked to a central metabolic pathway, transforming growth factor beta 1. Canonical pathway analysis focused our attention to two different pathways, namely nicotinamide adenine dinucleotide repair pathway and non-oxidative branch of pentose phosphate pathway. CONCLUSION: Our results shed some light onto the molecular mechanisms affected by alkali injury and adjuvant treatments. Further research is needed to propose medically significant target molecules that may be used for novel drug developments for alkali injury.

Comparison of Collagen Cross-Linking and Amniotic Membrane Transplantation in an Experimental Alkali Burn Rabbit Model.

PURPOSE: To compare the effects of collagen cross-linking (CXL) and amniotic membrane transplantation (AMT) on acute corneal alkali burns. METHODS: After establishment of an alkali burn model, 32 rabbits were divided into 4 groups: control group, AMT group, CXL group, and AMT + CXL (combined) group. Clinical parameters, including epithelial wound, opacity, ulceration, and neovascularization, were evaluated on postinjury days 1, 7, 14, and 18. Histological parameters were examined in hematoxylin/eosin (H&E) and Masson trichrome-stained corneal sections. Immunohistochemical analyses, including a terminal deoxynucleotidyl transferase-mediated biotin-deoxyuridine triphosphate nick-end labeling assay and cluster of differentiation 68 (CD68) labeling, were performed to determine the apoptotic index and macrophage activation. RESULTS: On postinjury day 18, the epithelial wound of AMT {4.08% [interquartile range (IQR), 0.68%-5.22%]}, CXL [1.84% (IQR, 0.01%-3.89%)], and combined [3.44% (IQR, 0.01%-4.36%)] groups were significantly lower than the control [15.23% (IQR, 9.86%-23.06%)] group (P = 0.003). No significant difference was detected between the groups in terms of opacity (P = 0.303). Neovascularization was the least severe in the CXL group [16.18% (IQR, 8.39%-21.28%)] and the most severe in the AMT [34.47% (IQR, 17.71%-62.77%)] and combined [35.12% (IQR, 31.96%-59.98%)] groups on day 18 (P = 0.033). Significant increases in the apoptotic index and CD68 labeling were detected in the CXL and combined groups compared with those in the control group (P = 0.047 and P = 0.001, respectively). CONCLUSIONS: CXL treatment is an effective adjuvant treatment for promoting reepithelialization, reducing inflammation and neovascularization, and preventing ulceration in acute alkali burns. Providing AMT after suppressing inflammation may be a more effective treatment.

Effect of eye trauma on mental health and quality of life in children and adolescents.

The purpose of this study is to evaluate the effects of eye traumas on mental health and quality of life of children, adolescents, and their parents. Medical records of 20 children and adolescents presented with blunt and open eye injuries between June 2009 and May 2014 were reviewed. Demographics of patients, timing and type of trauma, findings of initial examination, and medical and surgical interventions applied were recorded. To detect mental health, "Affect disorders and schizophrenia interview chart for school children, now and lifelong" (AFSIC-NL) and "Child Post-Traumatic Stress Reaction Index (CPTSD-RI)" were used. "Pediatric scale of quality of life" (PedsQL) was used to assess quality of life for both parents and children. According to AFSIC-NL, 9 patients were diagnosed with mental disorders including posttraumatic stress disorder (n = 3, 15 % patients), generalized anxiety disorder (n = 3, 15 % patients), and major depression (n = 3, 15 % patients). The PedsQL values of both children's and parents' were at their lowest in school and physical health domains for children and in physical health domain for parents. A reverse correlation was detected between the number of surgeries and PedsQL-child physical functionality, school functionality, psychosocial functionality, and total scale point. There was a statistically significant relationship between initial visual acuity or lens damage and PedsQL-parent emotional functionality scale. Regarding CPTSD-RI, the parents of these patients have a mild posttraumatic stress disorder. Eye injuries can lead development of psychopathology in children. Therefore, psychiatric support must be provided in follow-up period for these patients.

Correlation of the measurements of optical coherence tomography and diffuse tension imaging of optic pathways in amblyopia.

The aim of this study was to investigate whether a correlation exists between optical coherence tomography (OCT) of retina and diffusion tensor imaging (DTI) of the optic pathway measurements. All subjects underwent OCT measurements of optic nerve head, retinal nerve fiber layer, and macula. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of optic pathways were analyzed using DTI. Prechiasmatic FA values were significantly decreased in unilateral amblyopic group in both affected and sound fellow eyes (p = 0.019 and 0.013), but not in bilateral amblyopic group (p = 0.221) when compared with the control group. ADC values were significantly greater in sound eye in unilateral amblyopic group in prechiasmatic and postchiasmatic regions (p = 0.001 and 0.049). ADC values were also significantly greater in bilateral amblyopic group in postchiasmatic region (p = 0.037). There were no significant differences between the affected eye and sound eye side DTI measurements. There was no significant correlation between prechiasmatic DTI and OCT measurements in affected and sound eyes of unilateral amblyopia group. DTI results demonstrated that there is a functional underdevelopment of the anterior and posterior visual pathways in both affected and sound eye of unilateral amblyopic patients. Significantly reduced FA values in prechiasmatic region where OCT values of retina were normal can be explained by possible micro-structural changes.

Medial Rectus Muscle Injuries after Functional Endoscopic Sinus Surgery.

In recent years, functional endoscopic sinus surgery (FESS) has improved the treatment of sinus disorders. However, various orbital complications have been reported, including optic nerve damage, orbital hemorrhage, infection, lacrimal drainage system injury, and strabismus. Complications are rare but may cause severe morbidity. We describe two patients who underwent endoscopic sinus surgery procedures that resulted in trauma to the medial rectus muscle. The first patient had medial rectus paresia due to contusional trauma and showed spontaneous resolution in a month. The other patient had an orbital medial wall defect with medial rectus injury and he underwent orbitotomy. Medial rectus innervation returned at postoperative 8 months. Several extraocular muscles may be traumatized during FESS. Timing and method of treatment are based on the severity and type of injury and the number of muscles involved. Treatment strategies are dependent on accurate interpretation of magnetic resonance imaging scans.

Analysis of Choroidal Thickness Using Spectral-Domain OCT in Children With Unilateral Amblyopia.

PURPOSE: To compare the subfoveal, parafoveal, and peripapillary choroidal thickness in amblyopic eyes with those of fellow and control eyes. METHODS: This institutional study involved 114 eyes from 38 patients with unilateral amblyopia and 19 healthy children, aged 6 to 17 years. The cause of amblyopia was identified as hyperopic anisometropia in 17 cases and strabismus in 21 cases. All patients underwent central macular thickness (CMT) and choroidal thickness measurement at seven retinal sites with spectral-domain optical coherence tomography (OCT). Statistical analysis was performed to compare the CMT and choroidal thickness of amblyopic and fellow eyes with control eyes. RESULTS: Average CMT was 248.31 ± 24.18 µm in amblyopic eyes, 249.76 ± 26.08 µm in fellow eyes, and 243.65 ± 31.96 µm in controls (P = .604). Average subfoveal choroidal thickness was 394.15 ± 71.03 µm in amblyopic eyes, 356.07 ± 79.93 µm in fellow eyes, and 319.44 ± 87.29 µm in controls (P = .000). The choroidal thickness of the subfoveal area and at 750-µm intervals temporal and nasal to the fovea was significantly thicker in amblyopic eyes than in controls (P < .05). The choroidal thickness was significantly thicker in amblyopic eyes than in fellow eyes only at 750 µm nasal to the fovea. Type and depth of amblyopia did not differ significantly between foveal or parafoveal choroidal thickness (P > .05). There was a significant negative correlation between the nasal peripapillary choroidal thickness and the axial length in the amblyopic eyes (r = -0.37, P = .022). The choroidal thickness in the peripapillary area was not significantly different in the three groups (P > .05). CONCLUSIONS: This study demonstrated that choroidal thickness can be measured by spectral-domain OCT in children with amblyopia. Subfoveal choroidal thickness in amblyopic eyes was significantly thicker than in control eyes. The amblyopic process may involve the choroid, but not the macula. However, further evaluation is needed.

Comparison of two anesthetic methods for intravitreal ozurdex injection.

Purpose. To determine whether subconjunctival lidocaine injection maintains additional anesthetic effect during intravitreal Ozurdex injection. Methods. 63 patients who were diagnosed as central or branch retinal vein occlusion and planned to receive Ozurdex injection for macular edema were prospectively included in the study. The patients were randomized into one of the two anesthetic groups. The first group received topical proparacaine drop and lidocaine applied pledget. The second group received subconjunctival lidocaine injection in addition to the anesthetics in group 1. Results. Mean pain score was 1.90 ± 2.39 in group 1 and 1.71 ± 2.09 in group 2 (p = 0.746). Mean subconjunctival hemorrhage grade was 1.67 ± 0.17 in group 1 and 0.90 ± 0.14 in group 2 (p = 0.001). There was no relationship between the amount of subconjunctival hemorrhage and pain score of the patients. Conclusions. There was no difference in pain scores between the two anesthetic methods. The addition of subconjunctival lidocaine injection offered no advantage in pain relief compared to lidocaine-applied pledgets.

Quantitative Assessment of Optic Nerve With Diffusion Tensor Imaging in Patients With Thyroid Orbitopathy.

PURPOSE: To detect abnormalities of the optic nerve in patients with thyroid orbitopathy using diffusion tensor MRI. METHODS: Twenty-eight patients with Graves orbitopathy prospectively underwent diffusion tensor imaging scanning. A full ophthalmic examination including visual acuity, intraocular pressure, fundoscopy, and visual field analysis was performed. Clinical activity scores were also calculated. Fractional anisotropy (FA) and mean diffusivity values of the patients were compared with age and sex-matched healthy control subjects. RESULTS: The mean FA values were decreased and mean diffusivity values were increased significantly in patients with Graves orbitopathy compared with the control subjects (p < 0.001). There was a strong reverse correlation between the FA levels and the visual fields in 4 quadrants of the optic nerve. In addition, there was a strong correlation between the degree of proptosis and the FA values in both eyes. The mean diffusivity levels were also correlated with changes in the visual field and the degree of proptosis. CONCLUSION: FA and mean diffusivity levels measured with the diffusion tensor imaging of the thyroid orbitopathy patients were affected. The changes in diffusion tensor imaging were also correlated with the ophthalmologic tests of the patients.

Comparison of the effects of subconjunctival and topical anti-VEGF therapy (bevacizumab) on experimental corneal neovascularization.

PURPOSE: To compare the effects of bevacizumab applied either subconjunctivally or topically, in a rat model of corneal neovascularization induced by alkali burn. METHODS: The right corneas of 24 Wistar-Albino rats were cauterized with silver nitrate sticks. The rats were divided randomly and equally into three groups: no treatment control (n=8), subconjunctival bevacizumab treatment (n=8), and topical bevacizumab treatment (n=8). Immediately following cauterization, the subconjunctival group was treated with a 0.05 ml (1.25 mg) bevacizumab subconjunctival injection. The topical group was treated with 10 mg/ml bevacizumab twice daily, and the control group received subconjunctival saline injections twice daily. The burn stimulus and neovascularization scores were evaluated using a technique previously described by Mahoney and Waterbury. Digital photographs were obtained before the eyes were enucleated and corneal sections were then analyzed by histopathology. RESULTS: The mean burn stimulus score was 1.86 ± 0.6 and there was no statistical difference between the groups (p=0.730). The mean neovascularization scores in the subconjunctival and topical bevacizumab groups were statistically lower than the control group (p<0.05). The mean percentage area of corneal neovascularization was 82.5 ± 22.1 in the control group, 42.7 ± 15.0 in the subconjunctival group, and 55.8 ± 18.2 in the topical group. The differences between the control and treatment groups were statistically significant (p<0.05). Histopathology showed that the treatment groups presented less neovascularization, inflammation, and fibroblast activity than the control group (p<0.05). CONCLUSIONS: This study demonstrates that both subconjunctival and topical administrations of bevacizumab inhibit corneal neovascularization and decrease inflammation and fibroblast activity in a rat model of corneal neovascularization induced by alkali burn.