Effect of stromal hydration of clear corneal incisions: quantifying ingress of trypan blue into the anterior chamber after phacoemulsification.

Purpose: To use trypan blue as a quantifiable ingress tracer to determine whether stromal hydration reduces ocular surface fluid ingress at the end of phacoemulsification.

Setting: Iladevi Cataract and IOL Research Centre, Memnagar, Ahmedabad, India.

Methods: A prospective randomized study included 80 eyes having phacoemulsification through 2.2 mm incisions. These eyes were divided into 2 equal groups: 1 had stromal hydration (surgery completed by injecting fortified balanced salt solution [BSS Plus] to hydrate the lateral walls and internal entry of incision) and the other had no stromal hydration. One half milliliter of 0.0125% sterile trypan blue was instilled on the ocular surface and allowed to remain for 2 minutes. One-tenth milliliter of aqueous fluid was aspirated from the anterior chamber, and its optical density was measured using ultraviolet spectrophotometry. Logs of dilution of trypan blue were used for statistical analysis using the nonparametric Mann-Whitney U test.

Results: There was a statistically significant decrease and difference between groups in mean dilution of trypan blue in the aqueous aspirate (P<.001). The mean was 1:11,337 in the stromal hydration group and 1:220 in the no stromal hydration group. Logs of mean dilution of trypan blue had statistically significant lower values in the stromal hydration group than in the no stromal hydration group (3.21 and 2.14, respectively) (P<.001).

Conclusions: Stromal hydration of clear corneal incisions reduced ingress into the anterior chamber of the trypan blue instilled on the ocular surface. Clinically, these findings may have a beneficial effect in reducing the risk for postoperative endophthalmitis.