Local corneal thickness changes after small-incision cataract surgery.

PURPOSE

To assess whether a temporal limbal-corneal incision approach for phacoemulsification cataract surgery induces a gradient in corneal thickening along the horizontal meridian.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

Corneal thickness in 21 eyes of 21 patients was measured preoperatively as well as 1 day, 1 week, and 1 and 3 months after phacoemulsification through a temporal limbal-corneal incision. Measurements were performed using partial coherence interferometry (PCI) with a commercial instrument, the ACMaster (Carl Zeiss Meditec, Jena). Measurements were taken along the horizontal meridian centrally along the visual axis at 1.5 mm, 3.0 mm, and 4.5 mm eccentricity.

RESULTS

Preoperatively, there were slight nasal-temporal differences in corneal thickness at all eccentricities. The mean thickness was 522 microm +/- 34 (SD) at 1.5 mm nasally and 513 +/- 36 microm at 1.5 mm temporally (P<.01). On day 1, there was a significant mean increase in corneal thickness (38 +/- 43 microm) along all locations. The thickening was slightly more pronounced in the periphery than in the center, a difference not reaching statistical significance. At 1 week, corneal thickness returned almost to baseline at all locations except for 3.0 mm temporally, where it was slightly, but not significantly, thicker (mean 8 +/- 14 mum). At 1 month, corneal thickness at the 3.0 mm temporal location returned to baseline.

CONCLUSIONS

A nasal-temporal difference in corneal thickness was found preoperatively in all patients. Phacoemulsification through a temporal limbal-corneal incision caused an increase in corneal thickness along the horizontal meridian 1 day after surgery. The prolonged corneal thickening at 3.0 mm eccentricity temporally could be a result of the proximity to the incision site.