[Pseudoexfoliation syndrome--a risk factor in modern cataract surgery?]

The pseudoexfoliation (PEX) syndrome has been described in the ophthalmic literature as a major risk factor of cataract surgery. Most of the authors have reported extracapsular cataract extraction (ECCE) complication rates of more than 10% for zonular dialysis, capsular rupture, and vitreous loss. However, Osher et al. (1993) found that these complications from in situ phacoemulsification (PE) cataract surgery were less than 1%. We compared ECCE with PE by using the same surgeons for both procedures and evaluated retrospectively the complications for each in our patients.

Of 10,450 patients who underwent cataract surgery from 1986 to 1993, 102 PEX cases (0.98%) occurred. ECCE was performed on 34 of these patients, PE on 68 of the 102 patients. The average age of the PEX patients was 78 years. Miosis of 4 mm or less occurred in 19 eyes. To dilate the pupils, sphincterectomies were performed and iris retraction hooks were applied to the iris in the last two years. Eight surgeons (four with long-term experience and the remainder in training) performed the operations.

The complication rates were 16.6% altogether for zonular dialysis, capsular rupture and vitreous loss, 26.47% for ECCE, and 11.76% for PE (p = 0.0664), in contrast to 1.3% for uncomplicated age-related cataract operations. However, these complications occurred in 14.28% of the ECCE patients and 9.09% of the PE patients with more or less normal dilation of the pupil. Still PE with miosis had fewer complications (23.07%) and was, thus, significantly safer (p = 0.0022) than ECCE (83.33%). Slight phakodonesis, observed during capsulorhexis, and an additional diagnosis of chronic open-angle glaucoma did not provide significant differences between the two surgical methods resulting in PEX.

Miosis is beside phacodonesis the primary risk factor of PEX associated with cataract surgery. Compared with ECCE, PE had significantly fewer complications from PEX with miosis, not from PEX with phacodonesis. Applying the small iris retraction hooks appeared to decrease the complication risks stemming from miosis.