Cataract surgery in relative anterior microphthalmos.

OBJECTIVE

To determine the prevalence of relative anterior microphthalmos (RAM) and evaluate intraoperative performance and surgical outcome in eyes with RAM undergoing cataract surgery.

METHODS

Nested case-control series.

METHODS

One thousand four hundred consecutive patients undergoing cataract surgery were evaluated to determine the prevalence of RAM. Relative anterior microphthalmos is defined as horizontal corneal diameter (HCD) < or =11 mm, anterior chamber depth (ACD) < or =2.2 mm, and axial length (AL) >20 mm, with no other morphologic malformation.

METHODS

Patients were examined preoperatively for HCD, ACD, and AL. Horizontal corneal diameter was measured with calipers. Anterior chamber depth and AL were measured with immersion shell with water. Associated ocular pathologic conditions were recorded. Two control groups were identified. Group I (normal eyes; n = 84) had HCD >11 mm, ACD >2.2 mm, and AL >20 mm. Group II (eyes with small corneal diameter; n = 84) had HCD < or =11 mm, ACD >2.2 mm, and AL >20 mm.

METHODS

Patients with RAM and controls were evaluated for intraoperative performance and postoperative outcome. The 2-tailed Fisher exact test was applied to compare the performance of RAM with each of the control groups. The odds ratio (OR) with 95% confidence intervals (95% CI) was determined.

RESULTS

The prevalence of RAM was 6% (84 of 1400 eyes; 95%CI, 0.048-0.074). Relative anterior microphthalmos was associated with the presence of small pupil, 34 (40.48%); corneal guttae, 31 (36.9%); glaucoma, 29 (34.5%); and pseudoexfoliation, 6 (7.14%). Intraoperatively, RAM was associated with overall surgical difficulty because of less working space in 59 eyes (70.24%; OR, 63.7; 95% CI, 18.3-221; P<0.001) compared with control groups I and II; uveal trauma in 12 (14.28%); Descemet's detachment in 5 (5.95%); and posterior capsule rupture in 2 (2.38%). Postoperatively, RAM was associated with transient corneal edema in 63 eyes (75%; OR, 9.0; 95% CI, 4.4-18.0; P<0.001; OR, 5.4; 95% CI, 2.7-10.5; P<0.001) on the first postoperative day.

CONCLUSIONS

The prevalence of RAM was 6%. Relative anterior microphthalmos with its associations posed significant intraoperative difficulties. The occurrence of transient corneal edema was frequent.