Paracentral acute middle maculopathy following trabeculectomy: A case report and review of the literature

Purpose: To report a case of unilateral paracentral acute middle maculopathy (PAMM) in a patient with no cardiovascular risk factors immediately after trabeculectomy. Observations: A 63-year-old phakic male patient with pigmentary glaucoma in his left eye and progression despite maximal medical treatment, underwent uncomplicated trabeculectomy with mitomycin-C under sub-Tenon's anesthesia. His pre-operative best corrected visual acuity (BCVA) was 20/40 in his left eye. On the first post-operative day, visual acuity decreased to counting fingers at 2 m with an intraocular pressure (IOP) of 24 mmHg. There was no relative afferent pupillary defect, the cornea was clear and the anterior chamber (AC) deep without evidence of microhyphema or significant cell or flare. On the second post-operative day, the patient was noted to fixate eccentrically, his BCVA remained unchanged and IOP measured 20 mmHg. Fundoscopy of the left eye was unremarkable. Optical coherence tomography (OCT) showed a hyperreflective band-like area parafoveally. Fluorescein angiography revealed normal arterial filling. OCT angiography showed decreased vessel density of the deep capillary plexus in the left eye. These OCT findings were consistent with PAMM. Conclusion and importance: PAMM has been associated with several conditions, both systemic and ocular. We believe that this case of PAMM associated with filtration surgery could provide an insight into possible mechanisms that may account for reported cases of unexplained loss of vision after trabeculectomy.