Müller cell cone-associated foveal detachment as a risk factor for visual acuity loss after glaucoma filtering surgery.

Purpose To examine hypotony-associated foveal lesions (FovLs) utilizing optical coherence tomography and to assess risk factors of visual deterioration after glaucoma filtering surgery. Methods Parameters that may be associated with post-surgical deterioration of visual acuity were retrospectively studied in 44 eyes of 44 patients who experienced post-surgical intraocular hypotension ≤6 mmHg between 2015 and 2019. Results Six eyes (14%) had FovLs, such as detachment of photoreceptors (five eyes, 11%) and acquired vitelliform lesions (one eye, 2%) at 3 months after trabeculectomy. Logistic regression analysis revealed that hypotony maculopathy (P=0.0141 at 3 months) and FovLs (P=0.0486 and 0.0296 at 3 and 12 months, respectively) were significant risk factors for VA loss after trabeculectomy. The FovLs were located just behind the Muller cell cone (MCC). Visual acuity at 3 and 12 months after surgery in patients with FovLs was significantly lower than in those without FovLs (P=0.0013 and P=0.006, respectively). Epiretinal membrane was more common in eyes with FovLs (5 of 6 eyes, 83%) than in eyes without FovLs (7 of 38 eyes, 18%; P=0.0037). Conclusion MCC-associated FovLs lead to long-lasting visual acuity loss after filtering surgery.