Outcomes of small incision cataract surgery

Abstract

Purpose: To compare cataract surgery outcome measures 4 months postoperatively and determine their association with changes in the eye's functional state.

Setting: Department of Ophthalmology, Helsinki University Central Hospital, Finland.

Methods: This longitudinal study comprised 219 consecutive patients having first-eye or second-eye cataract surgery by one surgeon. In most patients, the technique consisted of small-incision cataract surgery with in-the-bag intraocular lens implantation. Patients were interviewed and clinical data obtained preoperatively and 4 months postoperatively. Adverse events occurring within 24 hours and 4 months postoperatively were compared with changes in global measures of vision. Surgical success in terms of surgically induced astigmatism (SIA) was measured at 4 months using vector analysis of the changes in astigmatism and defining the extent to which the surgical goal was achieved. The association between the surgical astigmatism goals and global measures of vision was analyzed.

Results: The percentage of patients showing improvement 4 months after first-eye cataract surgery varied by outcome measure: Snellen visual acuity (95.0%), VF-14 score (89.4%), satisfaction with vision (80.1%), self-reported trouble with vision (75.8%), and cataract symptoms (75.1%). Changes in Snellen acuity after second-eye cataract surgery were similar but VF-14 changes were significantly less than after first-eye surgery. Changes in global measures of vision were also better after first-eye surgery. The correlation between the change in VF-14 score and global measures of vision was stronger than between the change in Snellen acuity and the same general outcome measures. A good correlation was also seen between the changes in VF-14 scores and cataract symptoms. Mean SIA in all eyes was 0.2 diopter (D) +/- 0.7 (SD); 91.2% were within +/- 1.0 D of preoperative values. Failure to achieve surgical astigmatism goals was not associated with patients in whom global measures of vision did not improve, nor was there a correlation between adverse events occurring within 24 hours or 4 months postoperatively and global measures of vision. The only association was between ocular comorbidity or potential risk factors of phacoemulsification and adverse events seen within 24 hours and at 4 months.

Conclusion: Estimates of the proportion of patients benefiting from cataract surgery varied with the outcome measure used to determine benefit. The change in the VF-14 score was a better measure than Snellen acuity of the benefit of cataract surgery.