Disorders of the blood-aqueous barrier after phacoemulsification in diabetic patients.

PURPOSE: To evaluate the function of the blood-aqueous barrier after phacoemulsification with implantation of a foldable intraocular lens (IOL) in diabetic patients.
METHODS: All patients were enrolled from those scheduled for phacoemulsification with intraocular lens implantation in Zhongshan Ophthalmic Center Guangzhou from March 2002 to June 2002. The classification on diabetic retinopathy (DR) was based on the fundus examination after cataract surgery. The blood-aqueous barrier function was examined using the laser flare cell meter (Kowa FC-2000) preoperatively and on postoperative days 1, 7, 30, and 90 by an independent examiner who was masked to the DR classification. Patients were operated by one experienced surgeon as per standard clinical protocol and were provided the same postoperative medical care. A linear regression and Wilcoxon test were used for the analysis.
RESULTS: A total of 112 patients were divided into three groups: patients without diabetic mellitus as normal control (n=56), diabetic patients without diabetic retinopathy (n=2), with nonproliferation diabetic retinopathy (NPDR) (n=37), and diabetic patients with proliferation diabetic retinopathy (PDR) (n=17). All patients were examined and successfully followed up for 3 months after cataract surgery. Aqueous flare mean photon counts in PDR, NPDR, and control eyes were 8.94+/-0.57, 7.03+/-0.27, and 6.94+/-0.34 before surgery and increased to 32.42+/-0.67, 26.07+/-0.83, 26.27+/-1.37 on the first day after surgery (P<0.05), then decreased to 19.86+/-0.78, 14.08+/-0.54 and 13.96+/-1.05 at 7 days after surgery (P<0.05), 13.24+/-0.29, 9.86+/-0.33, and 9.07+/-0.43 at 30 days after surgery (P<0.05); eventually, the counting decreased to 11.25+/-0.31, 7.24+/-0.67, and 7.16+/-0.27 at 90 days after surgery (P<0.05). Linear regression model suggested that other potential variables, such as age, sex, eye (left/right), phaco time, phaco energy, and hypertension were not related to the outcome. For patients without diabetes mellitus and diabetic patients with NPDR, highly statistically significant differences (P<0.05) were found between preoperative flare value and those measured on days 1, 7, and 30 after surgery, but no statistically significant differences (P>0.05) were found between the preoperative flare value and those measured on postoperative days 90. However, patients with PDR still had a higher flare value even on postoperative day 90. The patients with intraoperative iris prolapse had a higher flare value between days 1 and 7 postoperatively.
CONCLUSION: Phacoemulsification with a foldable intraocular lens implantation affects the blood-aqueous barrier more severely in diabetic patients with PDR than patients with NPDR and nondiabetic patients.