Glial proliferation after vitrectomy for a macular hole: A spectral domain optical coherence tomography study

Purpose: To characterize eyes with glial proliferation after macular hole (MH) surgery. Methods: We retrospectively reviewed patients who underwent vitrectomy for an idiopathic MH using spectral domain optical coherence tomography (SD-OCT). The pattern of the closed MH after surgery was categorized according to the presence (group 1) or absence (group 2) of apparent glial proliferation, which was determined by glial tissue reflectivity involving the external limiting membrane (ELM) and photoreceptor layers. Photoreceptor layer defect areas were categorized as mild or severe. Best-corrected visual acuity (BCVA) and pre- and postoperative OCT parameters were compared between the two groups. Results: Among 30 eyes followed-up for a median of 11 months, seven (23 %) were assigned to group 1 and 23 (77 %) to group 2. The median age was higher in group 1 (70 years) than in group 2 (63 years). The postoperative BCVA was poorer in group 1 than in group 2 at 3 months and at the final examination (P = 0.022 and P < 0.001 respectively). The median preoperative basal hole diameter in group 1 (1,219 μm) was larger than that of group 2 (590 μm) (P = 0.002). The MH index (hole height/basal hole diameter) was smaller in group 1 than in group 2 (P = 0.012). At the final examination, group 1 had larger mild and severe photoreceptor layer defect areas (medians 1,300 μm and 207 μm respectively) than group 2 (medians 110 μm and 70 μm respectively) (P < 0.001 and P < 0.001 respectively). Conclusions: Eyes with glial proliferation after surgery for MH had different preoperative characteristics than eyes with no evidence of glial proliferation. In addition to a large hole diameter, other factors such as a small MH index and advanced age could be involved in the development of glial proliferation.