Purpose: To identify the incidence rate and the clinical characteristics of unexplained visual loss after gas tamponade for primary macula-sparing rhegmatogenous retinal detachment.
Methods: Retrospective longitudinal analysis of all subjects undergoing vitrectomy with gas for primary macula-on rhegmatogenous retinal detachment from 2010 to 2019. Outcome was the unexplained visual loss evaluated after gas absorption, defined as a loss of vision to less than 20/200 without evident causes. The diagnostic workup was reviewed.
Results: Nine eyes with unexplained visual loss of 357 surgeries were found. The incidence proportion was 2.52 new cases every 1,000 eyes affected by macula-on rhegmatogenous retinal detachment treated with gas per year. All subjects had an absolute central scotoma, with a median postoperative visual acuity of 20/1,600 (counting fingers). Structural findings were consistent with an axonal damage; all eyes had microcystoid macular edema and reduced thickness of both macular ganglion cell and retinal nerve fiber layers. No photoreceptor structural damages were noted.
Conclusion: The incidence of unexplained visual loss after gas tamponade for primary macula-on rhegmatogenous retinal detachment is 2.52 new cases every 1,000 eyes per year. This rare complication, which findings are suggestive of an axonal damage within retinal ganglion cells, remains a serious and unexplained concern for vitreoretinal surgeons.