Purpose
Determine which HD-OCT value is the most sensitive indicator of recurrent fluid in Central Retinal Vein Occlusion (CRVO). HD-OCT numerical values for: Central Subfield Thickness (CST), Cube Volume (CV), Cube Average Thickness (CAT), superior (S), inferior (I), nasal (N), and temporal (T) fields of the 3mm (3mQ) and 6mm (6mQ) concentric circles around the 1mm CST were analyzed to determine which of the 11 values was the most sensitive indicator of disease recurrence in CRVO after treatment with intravitreal therapy (IVT).
Methods
Single Center, retrospective, study of consecutive CRVO patients with macular edema treated with IVT (anti-VEGF agent, and/or dexamethasone intravitreal implant, and/or triamcinolone acetonide). IRB approval was obtained. Recurrent fluid was determined by comparing Cirrus HD-OCT topography and raster line-scan images to previous visits. Recurrent fluid was defined as a significant recurrence in intraretinal or subretinal fluid on raster analysis and/or topographical analysis that required treatment. Change in HD-OCT values (microns) of disease recurrence scans to previous stable post-treatment scans was used to determine the variation of intraretinal fluid. Change in microns was converted to percentage change to allow more consistent comparison. We compared: CST, CV, CAT, the 3mQ and 6mQ of the S, I, N, T fields.
Results
Analysis of 168 disease recurrences in 34 eyes of 34 patients revealed that CST was the most sensitive indicator of disease recurrence in CRVO. Mean percent increase in CST (41.2%) was significantly greater (P<0.007) than mean increase in any other OCT value: 3mQT (25.9%), 3mQN (25.8%), 3mQI (22.8%), 3mQS (22.1%), CAT (14.2%), CV (14.1%), 6mQT (13.9%), 6mQS (12.2%), 6mQI and 6mQN (11.7%). In order to negate statistical outliers, the OCT parameter representing the single greatest percentile increase during each recurrence was determined. In 63/168 (37.5%) the CST represented the greatest percentile increase, significantly more often than any other OCT parameter (P<0.00008). The remaining values with the greatest percentile increase were: 3mQN (16.1%), 3mQS and 3mQT (10.7%), 3mQI (7.7%), 6mQN (6.0%), 6mQS (4.2%), 6mQT and 6mQI (3.6%), CV and CAT (0%).
Conclusions
CST is the most sensitive OCT parameter of disease recurrence in CRVO patients. CST had the largest mean percentile increase of the 11 OCT parameters evaluated.