Off the Cuff: Best of Clinical Excellence Awards 2019 – Part 1

Prospective study of 76 males, 37 with type 2 diabetes with an average of duration between 7±5 years, and 36 males from control group to assess the meibomian glands, ocular surface and tear function in patients with type 2 diabetes, and study the correlation between these conditions. After completing an ocular surface disease index (OSDI) questionnaire, the non-invasive tear film break-up time (NIBUT) and the tear lipid layer pattern was performed using interferometry system and tear meniscus height/TMH. Ocular surface was studied with lissamine green staining and morphology of the glands with evaluation of Marx's line (lid margin abnormalities); meibomian secretion was expressed and was also assessed the quality. The results were analyzed using the statistical Kruskal-Wallis and Mann-Whitney, with correlations by Spearman Rho.

The mean age was 59±8 years; 71% of participants presented MGD (76% diabetics and 67% controls). OSDI were significantly higher in the diabetic group. A positive correlation was found between glycemia and symptoms, and a strong correlation between Hb1Ac and OSDI in MGD. NIBUT was lower in the control group (2.47±1.2s) than for the diabetic group (2.9±1.2s), with a significant inverse correlation (52.22%) with MG inflammation.

MGD in type 2 diabetic patients was more severe compared with nondiabetic patients. Longer duration of diabetes was associated with major symptoms and changes in MG. The diabetic group showed major changes in lids and tear function, accounting for evaporative dry eye and presenting a high degree of correlation with MG inflammation and obstruction.

In this randomized, double-blind interventional study, diabetics with dry eye disease (DED) ages 18 to 60 years were randomly assigned to TI or standard artificial tears (SAT) to assess the short-term effects of topical insulin (TI)—1 unit/drop four times per day for four weeks—on the symptoms and signs of diabetic with DED. Baseline Ocular Surface Disease Index (OSDI), Schirmer I test (ST), tear break-up time (TBUT) and ocular Sjögren's International Collaborative Clinical Alliance (SICCA) score were compared four weeks after treatment.

A total of 160 participants (involving 320 eyes) received either TI (n=80) or SAT (n=80). After four weeks of treatment, a significant number of participants in both TI and SAT groups showed improvement in their OSDI score, 66% and 63%, respectively, but were not significantly better than each other. However, most participants in both groups showed worsening of ST and TBUT. Most of the participants in both groups showed no change in their ocular SICCA score (p>0.05).

The study showed a significant and similar improvement in the OSDI score for TI 1 unit/drop four times daily and SAT in treating diabetics with DED. Researchers wrote that further research would be required to understand the long-term effects of TI on the ocular surface.

In 47 patients (one eye) with keratoconus (KC) and 20 healthy subjects (one eye), investigators assessed differences in epithelium thickness (ET) and Bowman's layer thickness (BLT) maps in keratoconic eyes and healthy eyes. Epithelium and Bowman's layer measurements were performed with a custom-designed polarization sensitive (PS)-OCT with a conical scanning optics design. En-face corneal ET and BLT maps with a diameter of 11mm were computed. The mean ET and BLT of 25 sectors, the thinnest (minET, minBLT) and the thickest sector (maxET, maxBLT) were assessed. Ratios between thinnest/thickest sector (R1) as well as between mean ET and BLT of the inferior temporal quadrant/the superior nasal quadrant (R2) were calculated (R1ET, R1BLT; R2ET, R2BLT). Receiver operator characteristic (ROC) curve analysis was used to assess the diagnostic power of statistically different parameters.

In healthy eyes, smooth ET maps were observed. KC eyes showed a "doughnut pattern." The BLT maps of healthy eyes had a smooth appearance, but a highly irregular "moth damage"-like pattern could be observed in keratoconic eyes. Highest AUC values were found for the thinnest sector of the BLT map, R1ET and the thinnest sector of the ET-map.

PS-OCT imaging enabled the visualization of significant differences of the corneal epithelium and the Bowman's layer in en-face maps covering almost the entire cornea. Investigators wrote that epithelial thickness and BLT profiles in this study showed their diagnostic importance for distinguishing keratoconic and healthy eyes.