| Introduction: Age related macular degeneration is top cause of blindness amongst the elderly.There are available therapies to treat the exudative form of the disease, however, they are expansive and repetitive. We aim to evaluate OCT features in the progression to advanced age related macular degeneration(AMD) to find a possible prognosticative indicator to facilitate therapeutic management.
Methods: A retrospective AMD database review was done to select patients aged 55 years or older with at least 12 months follow-up for ranibizumab therapy for neovascular AMD(NV-AMD). The best corrected visual acuity (BCVA) at baseline ranged between 24 and 73 ETDRS letters. All lesion subtypes (classic, minimally classic, occult choroidal neovascular membranes(CNVs). were included. Patients were divided into two groups based on the presence or absence of subretinal fibrosis on OCT. We evaluated the following OCT characteristics specifically at the fovea and at the parafoveal region: presence of high reflective band(HRB) representing the inner segment- outer segment (IS/OS) junction of photoreceptors, external limiting membrane(ELM), intra-retinal cysts; sub-retinal fluid , small dense particles in the retinal layers(SDP); outer retinal tubulations. These characteristics were compared between the two groups of patients
Results: Out of a total of 110 eyes, 67 eyes showed evidence of fibrosis.
Multiple regression was significant, F=46.04, mean square(0.53,2.43), p<.001. The R-square was 0.782 and the adjusted R-square was 0.765, indicating that the set of predictors were able, as a group, to predict 78.2% of the variance in fibrosis in the sample. The significant predictors of fibrosis were lower baseline visual acuity (p=0.001), the loss of IS-OS(p=0.02), SRF(p=0.048) and the presence of ORT(p<0.001)
Conclusions: In conclusion, we found that ORT, loss of IS-OS segment and reduced number of injections are associated with subretinal fibrosis in patients treated with ranibizumab in NV-AMD. |
