Mechanical detachment of the anterior hyaloid membrane from the posterior lens capsule

Objective: To investigate the incidence of spontaneous detachment of the anterior hyaloid membrane from the posterior lens capsule and to explore the possibility of surgical separation of the anterior hyaloid membrane. Design: Prospective nonrandomized interventional comparative trial and comparative human tissue study. Participants: Thirty-eight eyes of 32 patients undergoing primary pars plana vitrectomy combined with cataract extraction and intraocular lens implantation and 3 eye bank eyes for histopathologic examination. Methods: The anterior hyaloid membrane and posterior lens capsule were observed with a fiberoptic endoscope. Surgical separation of the anterior hyaloid membrane was attempted by either the hydrodissection method before cataract extraction (18 eyes) or the direct suction method after cataract extraction (20 eyes). In eye bank eyes, histopathologic examination was performed with (one eye) and without (two eyes) surgical separation of the anterior hyaloid membrane. Main Outcome Measures: Incidence of spontaneous detachment and success rate of surgical detachment of the anterior hyaloid membrane. Results: No eye displayed spontaneous detachment of the anterior hyaloid membrane. Using the hydrodissection method, complete detachment of the anterior hyaloid membrane was achieved in 10 eyes (55.6%), partial detachment was attained in 2 eyes (11.1%), and detachment was not induced at all in 6 eyes (33.3%). With the direct suction method, the anterior hyaloid membrane was completely separated from the posterior lens capsule in 10 eyes (50%), partially detached in 10 eyes (50%), and not detached at all in any eye. The direct suction method had a significantly higher success rate than the hydrodissection method (P < 0.001, chi-square test). In eye bank eyes, the surgical manipulation induced complete separation of the anterior hyaloid membrane from the lens capsule. Conclusions: Spontaneous detachment of the anterior hyaloid membrane from the posterior lens capsule is very rare. Under endoscopic observation, surgical detachment of the anterior hyaloid membrane was possible in half of the patients. (C) 2001 by the American Academy of Ophthalmology.