Diabetes Control and POAG Progression
Ophthalmology Glaucoma, March/April 2021
Although diabetes has been proposed as a risk factor for glaucoma, objective evidence of the impact of poorly controlled diabetes on glaucoma progression is lacking. Johnson et al. investigated whether diabetes control had an effect on functional and cellular measures of glaucoma development. They found no significant association.
For this retrospective cohort study, the researchers evaluated data on 222 patients (351 eyes). At baseline, 167 eyes (47.6%) had primary open-angle glaucoma (POAG), and 184 eyes (52.4%) were glaucoma suspects. All patients had concomitant type 2 diabetes, and their mean baseline age was 62.5 ± 10.2 years. During follow-up of 6.9 ± 5.1 years, the participants had an average of 4.8 standard automated perimetry (SAP) tests (range, 2-28); 3.6 spectral-domain optical coherence tomography (SD-OCT) scans of the retinal nerve fiber layer (RNFL; range, 2-10); and 8.3 tests of glycated hemoglobin (HbA1c; range, 2-21).
As a proxy for diabetes control, the researchers used three distinct HbA1c measurements: mean, peak, and fluctuating HbA1c. The main outcome measures were the rates of change in SAP test results and RNFL thickness over time. Use of metformin, a widely prescribed diabetes medication, was also evaluated.
Results of the analysis showed that the mean rate of SAP change was –0.19 ± 0.20 dB per year, and the rate of RNFL loss was –0.83 ± 0.51 μm per year. After adjusting for confounding factors, the three HbA1c assessments were not found to be significantly associated with glaucoma progression over time. In addition, no association between metformin use and glaucoma status was observed.
The original article can be found here.