Optical coherence tomography characteristics of responses to intravitreal bevacizumab in idiopathic choroidal neovascularization.

AIM: To investigate factors associated with responses to intravitreal bevacizumab (IVB) in naive idiopathic choroidal neovascularization (iCNV) by high domain optical coherence tomography (OCT). METHODS: We retrospectively reviewed clinical data of 40 eyes of iCNV patients who received a single or multiple IVB on an as-needed basis (1.25 mg/0.05 mL). One month after the first injection, subretinal fluid (SRF) volume was evaluated and the eyes were divided into 3 groups based on responses to IVB. Good, moderate, and poor responses were defined as 61%-99%, 30%-60%, and <30% resolution of SRF on OCT after IVB in iCNV, respectively. OCT findings were analyzed to find factors associated with difference in response levels. Comparisons were made using Wilcoxon's matched-pairs signed-rank test, the Mann-Whitney U test for means with continuous data and Fisher's exact test for categorical data. RESULTS: The mean number of IVB was 1.28±1.50 and mean follow up time was 3.60±1.20mo. At postoperative 1mo, there were 8 (20%) eyes in good response, 20 (50%) in moderate response and 12 (30%) eyes in poor response group and at last visit there were 28 good responders (70%), 8 (20%) moderate responders and 4 (10%) poor responders. Statistically significant difference was detected between good responders and non good responders in choroidal neovessels thickness (P=0.029), SRF height (P=0.049) and SRF volume (P=0.031) at post treatment 1mo. CONCLUSION: OCT is a valuable diagnostic tool. Decrease in choroidal neovessels thickness, SRF height and volume predicts favorable response of iCNV to IVB therapy.

MICROSTRUCTURAL EFFECTS OF INTRAVITREAL BEVACIZUMAB IN IDIOPATHIC CHOROIDAL NEOVASCULARISATION.

BACKGROUND: Idiopathic choroidal neovascularization (ICNV) is a unilateral ocular disease which occurs in patients younger than 50 years and accounts for approximately 17% of patients with CNV. We evaluated microstructural effects of intravitreal bevacizumab in eyes with treatment-naïve idiopathic choroidal neovascularisation. METHODS: In this case series study we reviewed the treatment and follow up records of 40 symptomatic eyes having ICNV, who received an intravitreal injection of bevacizumab (1.25 mg/0.05 mL) followed by additional doses based on optical coherence tomography findings, including intraretinal fluid, subretinal fluid, or pigment epithelial detachment. We analysed the results of best-corrected visual acuity, central retinal thickness, neovessels size (thickness and diameter), and disrupted photoreceptor length at baseline and at final visit with paired t-test. Difference in best corrected visual acuity was correlated with difference in optical coherence tomography parameters by Pearson's correlation. RESULTS: Mean logarithm of the minimum angle of resolution best-corrected visual acuity improved from 0.60 initially to 0.24 after treatment (p=0.01). Difference in mean central retinal thickness (82.65 +/- 44.1) pm, choroidal neovessels thickness (149.58 +/- 71.1) microm, choroidal neovessels diameter (1250.8 +/- 145.1) pm, photoreceptor disruption length (2141.20 +/- 318.8) microm were all statistically significant (p=0.01). Difference in best corrected visual acuity was correlated with optical coherence tomography parameters found no statistically significant difference. CONCLUSION: Intravitreal bevacizumab therapy is safe and well tolerated in ICNV eyes. Restoration of photoreceptor disruption length, decrease in central retinal thickness and choroidal neovessels size has association with visual improvement in idiopathic choroidal neovascularisation.

OPTICAL COHERENCE TOMOGRAPHIC CHARACTERISTICS OF IDIOPATHIC CHOROIDAL NEOVASCULARISATION.

BACKGROUND: Idiopathic choroidal neovascularisation (ICNV) is the development of choroidal neovascularisation (CNV) in young adults without any apparent manifestations of primary ocular or systemic diseases We aim to assess characteristics and pathological changes at various stages in ICNV by optical coherence tomography (OCT). METHODS: We reviewed clinical charts of 40 ICNV eyes and classified them into three stages. Active stage < 1 month, intermediate 1-3 months and cicatricial > 3 months period after initiation of treatment in naïve ICNV eyes. OCT characteristics of these morphological changes were determined. Parameters such as mean volume (MV), central macular thickness (CMT) and neovessels size (thickness and diameter) were analyzed and compared using one -way ANOVA. RESULTS: We have 12 males and 28 females with a mean age of 30.1 ± 7.80 years. In active stage, heterogenous activity of CNV was observed, along with disrupted RPE layer, surrounded by subretinal fluids and loss of foveal depression. In intermediate stage, CNV reflection appears homogenous with smooth peripheral Retinal pigment epithelium (RPE) lesion and reduction in retinal thickness. In cicatricial stage, OCT presents dome shaped elevation, strong homogenous reflection, absence of subretinal fluids and reformation of foveal depression. We have found that difference in mean volume and choroidal neovessels thickness was statistically significant in the three stages. CONCLUSIONS: In our study we have concluded that OCT is useful tool for following the clinical course of ICNV and understanding the pathological changes in CNV regression.