GAS-FOVEAL CONTACT: A New Approach to Evaluating Positioning Regimens in Macular Hole Surgery.

Purpose: To compare gas-foveal contact in face-down positioning (FDP) and nonsupine positioning (NSP), to analyze causes of gas-foveal separation and to determine how gas-foveal contact affects clinical outcome after idiopathic macular hole repair.

Methods: Single center, randomized controlled study. Participants with an idiopathic macular hole were allocated to either FDP or NSP. Primary outcome was gas-foveal contact, calculated by analyzing positioning in relation to intraocular gas fill. Positioning was measured with an electronic device recording positioning for 72 hours postoperatively.

Results: Positioning data were available for 33/35 in the FDP group and 35/37 in the NSP group, thus results are based on 68 analyzed participants. Median gas-foveal contact was 99.82% (range 73.6-100.0) in the FDP group and 99.57% (range 85.3-100.0) in the NSP group (P = 0.22). In a statistical model, gas fill had a significant relation to gas-foveal contact (P < 0.0001), whereas whether the surgeon prescribed FDP or NSP was not significant (P = 0.20). Of clinical relevance, gas-foveal contact seemed to influence idiopathic macular hole closure (P = 0.02).

Conclusion: We found no significant difference in gas-foveal contact between the positioning groups. The role of positioning after idiopathic macular hole surgery seems to be better characterized from examining both patient positioning and gas fill objectively. We propose gas-foveal contact as a new outcome for evaluating positioning regimens.