The incidence of atonic pupil following cataract surgery

To determine and compare the incidence of atonic pupil following modern extracapsular cataract extraction and small-incision phacoemulsification with lens implantation in a large series of consecutive patients.

A retrospective review was undertaken of 1283 consecutive cases of cataract surgery with posterior chamber intraocular lens implantation (919 extracapsular and 364 small-incision phacoemulsification) performed by two surgeons between October 30, 1991, and June 30, 1993. Postoperative atonic pupil was defined as a pupil that, following cataract surgery, was 6 mm or more in diameter and minimally or nonreactive to light, accommodation, or 1% pilocarpine hydrochloride.

Postoperatively, 25 (1.95%) of 1283 eyes developed an atonic pupil following cataract extraction with posterior chamber intraocular lens implantation (21 [2.29%] of 919 extracapsular and four [1.10%] of 364 phacoemulsification procedures). When an atonic pupil was present following surgery, disturbing glare often resulted, despite a well-centered intraocular lens.

To our knowledge, this is the first large, consecutive study of the incidence of atonic pupil following modern cataract surgery and the first study to compare the incidence of atonic pupil following extracapsular surgery vs small-incision phacoemulsification. Although the incidence of atonic pupil may be lower following phacoemulsification, caution is advised in the implantation of ever-smaller optic lenses.