Retinal Micropseudocysts in Diabetic Retinopathy: Prospective Functional and Anatomic Evaluation

Aim: To evaluate the prevalence, progression and functional predictive value of retinal micropseudocysts (MPCs) in diabetic patients. Methods: Prospective controlled observational study. From among all the type 2 diabetic patients evaluated during a period of 5 months between September 2009 and January 2010, we enrolled all patients with retinal MPCs at spectral-domain scanning laser ophthalmoscope/optical coherence tomography (SD-SLO/OCT) not previously treated for diabetic retinopathy. Forty diabetic patients without MPCs served as the control group. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), macular sensitivity and stability of fixation at SD-SLO/OCT microperimetry were measured monthly for 12 months. Results: 22/156 patients with type 2 diabetes (14.1%, 32 eyes) met the inclusion criteria. The 95% confidence interval for the prevalence estimate of MPCs was 12.3–16.6%. Mean BCVA, CRT and central retinal sensitivity at baseline were 77.53 ± 2.2 Early Treatment Diabetic Retinopathy Study letters, 242.31 ± 31.0 µm and 15.95 ± 0.61 dB, respectively. Fixation was stable in all cases. Compared to the control group, eyes with MPCs had similar BCVA but greater CRT (p = 0.01) and reduced macular sensitivity (p = 0.001) at baseline and at each follow-up visit. Over time, CRT remained stable in eyes with MPCs, whereas macular sensitivity progressively decreased. Conclusion: MPCs in diabetic retinopathy are associated, temporally or causally, with a progressive reduction of macular sensitivity despite a stable BCVA, CRT and fixation.