RNFL variation in gestational diabetes mellitus: An optical coherence tomography based study

Abstract

To study RNFL thickness in gestational diabetes mellitus based on OCT measurements. Methods: Case-control study with Inclusion criteria: 2groups of age 18-40yrs at 32-34weeks gestation Group 1: Healthy pregnant women Group 2: Pregnant women with GDM Exclusion Criteria: Preexisting hypertension/retinal diseases/renal disease/vascular disease/glaucoma/IOP>21mmHg/cataract/ refractive error correction more than or equal to +/-5D (spherical) or +/-3D (cylinder). Grouping-Study Design: more than 2 unrelated group study. Sample Size: n=182 Procedure: After detailed history taking &.written consent detailed ophthalmic examination is done Patients are classified into group1&2. Using CIRRUS HD OCT peripapillary RNFL is measured in superior, inferior, nasal and temporal fields. Results: Peripapillary RNFL showed significant thinning in GDM patients when compared to healthy pregnant female Conclusion: Peripapillary RNFL thinning in GDM patients measured in their third trimester suggest a neurodegenerative process preceding microvascular changes in gestational diabetes mellitus. The degree of retinal thinning at the level of macula correlated with the glycemic status of the patients. Thereby making it mandatory to carry out routine evaluation of retina with the help of OCT in all GDM patients to detect early neurodegenerative changes and to keep the blood glucose levels in normal range to prevent the occurrence of diabetic retinopathy.

<p>Macular and Retinal Nerve Fibre Layer Thickness in Pregnant Women with Gestational Diabetes Mellitus</p>

“…19,20 Both Acmaz et al and Sasikumar et al postulated that the thinning of the RNFL layer in GDM is due to excessive production of endothelin-1 and PEDF. 7,8 Neurodegenerative process began to occur 7.5 months after introduction of diabetes into their animal 21 We postulate that the transient glucose intolerance effect in our subjects was the reason for no significant difference being found in the mean macular and RNFL thickness in the GDM group. In addition, good treatment compliance, a low HbA1c level, and preexisting normal macular/retinal thickness possibly contributed to our study outcome.…”

“…They measured mean RNFL thickness in 176 pregnant women with GDM and 188 healthy pregnant women in India during their third trimester of pregnancy using the Cirrus HD OCT, 8 which was similar to the OCT system used in our study. Acmaz et al also reported contrary results to ours.…”

“…Meanwhile, both Sasikumar et al and Acmaz et al did not mention about their subjects' disease duration, glucose control and also treatment received in their reports. 7,8 In addition, the discrepancies could also be due to the different spectral-domain OCT systems used. Our study obtained measurements with the Cirrus Spectralis HD OCT, while Acmaz et al used the Heidelberg Spectralis OCT.…”

“…4 Changes in central cornea thickness, intraocular pressure, retinal microvasculature, and alteration in retinal nerve fibre layer and choroidal thickness had been reported in pregnant women with GDM. [5][6][7][8][9] There is a limited data about retinal changes in these patients. Pregnant women with diabetes have shown higher retina capillary blood flow which can be persistent up to threemonths postpartum.…”