Pupil Block After DMEK: Frequency, Associations, and Outcomes
Narrative Responses:
Purpose
To report the frequency with which air bubble-related pupil block occurs following Descemet membrane endothelial keratoplasty (DMEK) and its management, associations, and outcomes.
Methods
Retrospective review of consecutive eyes that underwent DMEK for Fuchs endothelial dystrophy, bullous keratopathy, or previous failed graft and had a documented same-day postoperative exam. Primary outcomes were intracameral air bubble size, intraocular pressure, management, and the need for later air re-injection. Subgroup analysis was performed based on the type of surgery (single or triple procedure) and the status of the peripheral iridotomy (patent or not), posterior capsule (intact or open), and vitreous (present or post-vitrectomy).
Results
During a 28-week period beginning in July 2012, DMEK was performed in 250 eyes. Complete air fills were noted in 66 eyes (26%). Spontaneous resolution was noted in 46 eyes (18%) after an hour of close observation. In 20 eyes (8%), bubble size remained full or initial pressure and/or symptoms were immediately concerning, so air was reduced to 50-60% and the pupil was dilated. None of the 12 eyes needing air removal later required an air re-injection (0%), compared to 13% for the remaining cohort (P=0.07). Air removal was associated with more triple procedures and open capsules in existing pseudophakes.
Conclusion
DMEK patients should be examined the same day postoperatively because intracameral air can expand into pupil block in <10%. Association with triple procedures and open capsules suggests that air shifts some anterior chamber fluid posteriorly. Outcomes are excellent following air removal and there is a trend towards improved graft attachment.