Large orbital masses due to longstanding hydrogel retinal explants

To describe the features of orbital masses occurring as a late complication of hydrogel retinal explants.

Retrospective review of patients presenting with orbital masses at decades after retinal surgery.

Two patients with huge orbital masses are described, their presenting 25 and 28 years after retinal detachment repair with expansile hydrogel explants. In one case, the preoperative diagnosis was pleomorphic adenoma, and the other-with extreme distortion of the globe-was considered to be lymphoma or chronic inflammation arising around prior retinal explants. At orbitotomy, the masses were found to be grossly expanded hydrogel explants that were removed piecemeal from their fibrous capsules. Histopathology showed very mild inflammation with occasional multinucleate giant cells and patchy capsular calcification, and an eosinophilic amorphous material staining strongly with Alcian-blue. Surgery was uncomplicated and both orbits healed with marked functional improvement.

Expansile hydrogel retinal explants were largely used in the 1980s and can present, often decades after the retinal surgery, with impaired orbital functions due to large parabulbar masses. The hydrophilic material appears to expand very slowly over decades, leading to gross distortion of neighbouring structures and a tumour-like mass.