Phacoemulsification and intraocular lens implantation following pars plana vitrectomy: a prospective study

AIMS: To examine the intraoperative characteristics of phacoemulsification in eyes that had undergone pars plana vitrectomy and to determine complication rates and visual outcomes. METHODS: A prospective study of 45 consecutive cataract operations on vitrectomised eyes performed over a 9-month period by a single surgeon. Data were collected on preoperative characteristics, intraoperative observations and complications, postoperative complications, and visual acuities. RESULTS: Zonular laxity with abnormal deepening of the anterior chamber and mydriasis was noted in six eyes that had undergone extensive vitreous removal for the treatment of retinal detachment or proliferative diabetic retinopathy, but not in eyes that had had limited 'core vitrectomy' such as for macular hole or epiretinal membrane. In two eyes, the initial deepening of the anterior chamber was accompanied by paradoxical shallowing with miosis (the 'infusion deviation syndrome'). Sight-threatening complications were rare. Snellen visual acuity improved in 84.6% of eyes previously treated for 'macular hole, 85.7% of eyes treated for 'macula-on' retinal detachment, 66.7% of eyes treated for 'macula-off' retinal detachment, and 57.1% of eyes treated for diabetic retinopathy. CONCLUSIONS: Surgeons need to be aware of additional challenges arising from zonular instability in eyes that have had extensive vitreous removal. A lower infusion bottle height may guard against sudden changes in anterior chamber depth. The use of a corneal tunnel avoids difficulties associated with an unusually deep anterior chamber. Visual acuity is less likely to improve in patients previously treated for diabetic retinopathy or for macula-off retinal detachment.