For diabetic eyes in the early stages of retinopathy, even small-incision cataract surgery can prompt increased aqueous flare and macular thickening for three months, although major changes in choroidal thickness may be less likely, a study in the British Journal of Ophthalmology reports.

Researchers from Japan evaluated how uneventful small-incision phacoemulsification cataract surgery impacted subfoveal choroidal thickness, central macular thickness and aqueous flare in diabetic patients.

The investigation included 59 randomly selected eyes—33 eyes of patients with diabetes and 26 healthy eyes in the control group—that underwent small-incision cataract surgery. Among the diabetic eyes, 26 did not have diabetic retinopathy (DR), while the remaining eyes had non-proliferative DR. The researchers measured aqueous flare, central macular thickness and subfoveal choroidal thickness prior to surgery and again at one week, one month and three months after the procedure.

Post-surgery, central macular thickness continued to increase significantly until three months in both groups. Although this was greater in patients with diabetes, the researchers noted there were no major differences in the results between the two groups.

Additionally, the investigators noted an increase in aqueous flare in both groups up to three months after surgery, although the increase was significant only in diabetic patients. The study also reported aqueous flare results differed greatly between the two groups before surgery and at the three-month follow up.

However, while subfoveal choroidal thickness tended to be thinner in patients with diabetes than in healthy patients throughout the follow-up period, the difference was not statistically significant. A possible reason for this result was that the study eyes did not have retinopathy or were in the early stage of the condition, the investigations said.

 “This report suggested that in diabetic eyes, minimally invasive cataract surgery could induce increased inflammation as indicated by the aqueous flare, which was accompanied by an increase in macular thickness. Therefore, more careful examination is required in diabetic eyes after cataract surgery,” the researchers wrote in their paper.

Further studies with a greater number of patients, longer follow-up duration and eyes in a more advanced stage of retinopathy are warranted, the investigators said.