Iris thickness measurements in patients with diabetic retinopathy.

PURPOSE

The aim of the study was to investigate iris alterations in diabetic retinopathy (DR).

METHODS

Sixty-nine eyes of 69 patients were recruited and three groups of patients were examined: proliferative DR ( = 25), non-proliferative DR ( = 21) and healthy controls ( = 23). Macular optical coherence tomography (OCT), anterior segment iris OCT, and slit lamp digital camera photographs were taken. The thicknesses of the iris at a distance of 1 mm, 2 mm, and 3 mm from pupil margin were measured via iris OCT. Iris crypt count, furrow extent, color tone and collarette/diameter ratio were measured by means of anterior segment photography. Visual acuity, refractive error, intraocular pressure, and numbers of intravitreal injections were also recorded.

RESULTS

The iris thickness measurements at 1 mm from pupil margin were significantly correlated with the macular thickness measurements ( = 0.32,  = 0.016). In the proliferative DR group, total number of injections were significantly correlated with the iris thickness measurements at 1 mm ( = 0.25,  = 0.04). The iris thickness measurements at distances 1 mm, 2 mm, and 3 mm from the pupil margin were similar in all of the groups ( > 0.05). Iris thickness did not correlate with age, intra-ocular pressure and collarette iris ratio in all the participants ( > 0.05).

CONCLUSION

Iris thickness is similar in diabetic patients and healthy controls. Meanwhile, iris thickness near the pupillary margin is positively correlated with macular thickness.