Nature of subretinal fluid in patients undergoing vitrectomy for macular hole: a cytopathological and optical coherence tomography study

Background: Outer retinal defects (ORDs) may occur after surgical closure of full thickness macular holes (FTMH) and be associated with delayed visual recovery. This may be due to the nature of the subretinal fluid (SRF) cuff and/or the loss of retinal elements. Methods: Vitrectomy with internal limiting membrane (ILM) peel was performed for FTMH. After fluid‐air exchange, SRF was either aspirated from the hole (group 1) or left in situ (group 2). The SRF specimens obtained were examined by light microscopy and correlated with optical coherence tomography (OCT). Results: In group 1, cellular material was found in 6 out of 12 cases. Photoreceptors were seen in 3 and macrophages in 3 cases. Nine of 12 holes closed and ORDs were seen in 3 of these. In group 2, 7 out of 8 holes closed, with 4 having ORD. There was no difference in visual acuity (LogMAR) for closed holes at 3 months between groups 1 (0.61, range 0.3–1) and 2 (0.51, range 0.3–0.78) nor between patients with ORD (0.57, range 0.3–1.0) or without ORD (0.57, range 0.3–1.0). Conclusions: SRF from FTMH may contain macrophages and photoreceptors. Such photoreceptor loss may contribute to reduced retinal function. ORDs occur commonly in spite of fluid aspiration, but their presence is still compatible with good vision. Aspiration of SRF did not appear to confer added benefit in this series.