Progression of Primary Open Angle Glaucoma in Diabetic and Non-diabetic Patients

Abstract

Purpose : Diabetes mellitus (DM) has been suggested as a risk factor for the development of primary open angle glaucoma (POAG). DM may affect the progression of POAG. To test the hypothesis, this study compares the rates of visual field (VF) loss and retinal nerve fiber layer (RNFL) thinning in POAG patients with and without type 2 DM.

Methods : A total of 197 eyes (55 eyes of 32 POAG patients with DM in POAG/DM group and 142 eyes of 111 age-matched POAG patients without DM in POAG/DM- group) were included from the Diagnostic Innovations in Glaucoma Study (DIGS) observational cohort study. Type 2 DM participants were defined by self-report of DM history and anti-diabetic medication. DM participants with diabetic retinopathy were excluded. The rates of VF loss and RNFL loss were compared in POAG eyes with and without DM using univariate and multivariable mixed effects models.

Results : The median (interquartile range) follow-up was 5.7 years (4.0, 6.4). The mean rate of global RNFL loss in the POAG/DM group was 2-fold slower than in the POAG/DM- group overall (-0.40µm /year vs. -0.83µm /year, respectively, P=0.01, Figure) and in the subgroup of participants who had not undergone glaucoma surgery (-0.54µm /year vs. -1.06µm /year, respectively, P=0.01). The mean percent/year rate of global RNFL thinning in the POAG/DM group was also significantly slower (-0.49%/year) compared to the POAG/DM- group (-1.13%/year) (P=0.005). After adjustment of age, gender, race, mean intraocular pressure during follow-up, initial mean deviation and hypertension, the differences in the rate of RNFL loss was still significantly slower in the POAG/DM group. Although a slower rate of VF mean deviation and pattern standard deviation loss was found in the POAG/DM group compared to the POAG/DM- group, the difference did not reach statistical significance (Figure).

Conclusions : These results suggest that treated type 2 DM does not worsen glaucoma progression and even may be protective against RNFL loss in DM patients without diabetic retinopathy.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.

 

Bar graph showing the distributions of the rates of mean deviation loss and global retinal nerve fiber layer thinning in eyes of POAG/DM and POAG//DM- patients. MD=mean deviation; RNFL= retinal nerve fiber layer.