Comparison of macular thickness and inflammatory cytokine levels after microincision versus small incision coaxial cataract surgery.

PURPOSE: To compare the macular thickness and volume change, and inflammatory cytokine levels after cataract surgery performed using two different sizes of incision (microincision versus small incision).

METHODS: In this randomized, comparative clinical trial, 84 eyes with nuclear density from Grade 3-4 were randomly divided into two groups (microincision, 2.2 mm; and small incision, 2.75 mm). Forty-two patients underwent phacoemulsification with microincision coaxial cataract surgery and 42 patients underwent phacoemulsification with small incision coaxial cataract surgery. Clinical measurements included preoperative, 1-week, 1-month and 2-month postoperative best corrected visual acuity, central corneal thickness (CCT) and endothelial cell count. ELISA and RT-PCR were performed for IL-1β, IL-6, VEGF and PGE2 preoperatively and at 1 week postoperatively.

RESULTS: The percentage increase in CCT in the microincision group was significantly higher than that in the small incision group at 1 week after cataract surgery (p = 0.01). The increase in macular thickness in the microincision group was significantly higher than that in small incision group at 1 month after cataract operation (p = 0.04). Also, IL-1β, IL-6, VEGF and PGE2 concentrations and their expression ratio in the microincision group were significantly higher than those in the small incision group at 1 week after cataract surgery compared to the preoperative period (p < 0.05).

CONCLUSIONS: Phacoemulsification with microincision coaxial cataract surgery may increase the macular thickness compared to phacoemulsification with small incision coaxial cataract surgery. Blood-aqueous barrier breakdown may occur more frequently after microincision cataract surgery than after small incision cataract surgery.