Conjunctival impression cytology and its varying patterns in controlled and uncontrolled diabetic patients

Context: Diabetes mellitus (DM) is the most common endocrine disorder and is a significant cause of ocular morbidity, unstable refraction, corneal abnormalities, neovascular glaucoma, nerve palsies, and diabetic retinopathy (DR); it is being increasingly recognized that even the ocular surface is adversely affected in diabetic patients. Aims: The present study was undertaken to analyze the conjunctival surface changes by conjunctival impression cytology (CIC) and correlate them with glycosylated hemoglobin (HBA1c) levels. Settings and Design: Known cases of DM satisfying the inclusion criteria were included in this nonrandomized prospective study, which was undertaken after ethical clearance was obtained from our institutional ethical review board. Subjects and Methods: Eighty patients with DM who presented to the Department of ophthalmology at our center were included in the study; they were divided into Group 1 (HbA1c ≤6.5%) and Group 2 (HbA1c >6.5%). A detailed history, general physical examination, complete ophthalmological examination, and CIC were performed in all of the participants. Statistical Analysis Used: Data were analyzed using Chi-square test and statistical software EPI INFO Version 6 and Microsoft Excel. P < 0.05 was considered statistically significant. Results: CIC technique revealed that, after age and gender adjustment, there was a significantly higher percentage of uncontrolled diabetic patients (77.7%) who had lower goblet cell density and higher Nelson grades of conjunctival squamous metaplasia. This difference was significant for all age groups and both sexes (P < 0.001), and it was also significantly related to the duration of DM. In addition, there was a positive correlation between DR and decreased corneal sensation when associated with poor glycemic control (HbA1c >6.5%). Conclusions: Dry eye disease and ocular surface disorders are increasingly recognized in patients suffering from DM. The ocular surface evaluation must be included in the routine examination of all diabetic patients. CIC is a safe, minimally invasive procedure with no side effects and can serve as one of the diagnostic tools for the evaluation of the ocular surface.