Postoperative aphakia in modern cataract surgery: part 1: analysis of incidence and risks based on 5-year data from the Swedish National Cataract Register.

PURPOSE: To study the incidence of aphakia after cataract extraction and evaluate the relative risk for this outcome in subgroups of patients based on preoperative conditions.

SETTING

Sixty-two community-run or private clinics participating in the Swedish National Cataract Register.

METHODS

Data on cataract extractions were collected prospectively from 1997 through 2001. The set of data also covered type of surgery and type of intraocular lens (IOL), including a "no lens implanted" option. All data were stored in a database. Database calculations were made of frequencies and risk ratios of postoperative aphakia in the subgroups of patients based on preoperative conditions.

RESULTS

For the entire study period, postoperative aphakia was reported in 1410 of 287,951 surgeries for which complete IOL data were available, corresponding to an overall frequency of 0.49%. The occurrence of ocular comorbidity and poor preoperative visual acuity (< or = 0.1) in the eye to be operated on was significantly related to postoperative aphakia for each year of the study (P<.001). Glaucoma and poor visual acuity (< or =0.1) in the surgical eye meant a 12.8 higher risk for aphakia after surgery than a better visual acuity (>0.1) and no ocular comorbidity.

CONCLUSIONS

This national 5-year survey showed that in routine cataract surgery performed during the study, 1 of every 200 operations ended in postoperative aphakia. Poor visual acuity (< or =0.1) in the eye to be operated on combined with ocular comorbidity was the highest risk factor for postoperative aphakia.