Photoreceptor Inner/Outer Segment Defect Imaging by Spectral Domain OCT and Visual Prognosis after Macular Hole Surgery

Abstract

PURPOSE: To evaluate photoreceptor inner/outer segment (IS/OS) defect parameters by using spectral domain-optical coherence tomography (SD-OCT) for correlation with visual outcomes in macular hole surgery (MHS). METHODS: This study was an interventional, retrospective case series. Twenty-three eyes (23 patients) were examined by SD-OCT before and after (median, 2.3 months) anatomically successful MHS. Two formats of OCT were analyzed: linear (raster) and composite (partial fundus image). Factors that may have confounded IS/OS measurements were controlled by using weighting and normalization of data. The main outcome measures were diameter and area of the IS/OS defect, weighted area of the IS/OS defect, macular density ratio (MDR), healing pattern of the macular hole, and preoperative and postoperative best corrected visual acuity (BCVA). RESULTS: Poorer preoperative BCVA correlated with larger preoperative diameter of the IS/OS defect (P = 0.005). A greater improvement in BCVA correlated with a larger preoperative area of IS/OS defect (P = 0.038) and smaller MDR (P = 0.012). Poorer postoperative BCVA correlated with a larger postoperative diameter of the IS/OS defect (P = 0.010), larger weighted postoperative area of IS/OS defect calculated by raster scan (P = 0.013), larger postoperative area of IS/OS defect measured from the partial fundus image (P = 0.003), and apparent glial sealing pattern on SD-OCT (P = 0.0005). The shape of the IS/OS defect area was round and regular before surgery, but irregular afterward. CONCLUSIONS: BCVA after MHS correlates with objectively ascertainable SD-OCT measurements of IS/OS defects and other features. The postoperative area of the IS/OS defect, when directly measured, correlates more strongly with BCVA than do linear-based measurements, perhaps because of the irregular shape of the IS/OS defect after surgery.