Effects of Myopia on Rates of Change in Optical Coherence Tomography Measured Retinal Layer Thicknesses in People with Multiple Sclerosis and Healthy Controls

Abstract

Purpose

To quantify the associations of myopia with longitudinal changes in retinal layer thicknesses in people with multiple sclerosis (PwMS) and healthy controls (HC).

Methods

A cohort of PwMS and HC with recorded refractive error (RE) prospectively scanned on Cirrus HD-OCT at the Johns Hopkins MS Center was assessed for inclusion. Exclusion criteria included OCT follow-up < 6 months, ocular comorbidities, incidental OCT pathologies, and inadequate scan quality. Eyes were classified as having high myopia (HM) (RE≤ −6 diopters), low myopia (LM) (RE> −6 and ≤ −3 diopters), or no myopia (NM) (RE> −3 and ≤ +2.75). Linear mixed-effects regression models were used in analyses.

Results

A total of 213 PwMS (eyes: 67 HM, 98 LM, 207 NM) and 80 HC (eyes: 26 HM, 37 LM, 93 NM) were included. Baseline average ganglion cell/inner plexiform (GCIPL) and peri-papillary retinal nerve fiber layer (pRNFL) thicknesses were lower in MS HM compared with MS NM (diff: −3.2 µm, 95% CI: −5.5 to −0.8, p = 0.008 and −5.3 µm, 95% CI: −9.0 to −1.7, p = 0.004, respectively), and similarly in HC HM, as compared with HC NM. Baseline superior, inferior, and nasal pRNFL thicknesses were lower in HM compared with NM, while temporal pRNFL thickness was higher, both in MS and HC (MS: 7.1 µm, 95% CI: 2.7–11.6, p = 0.002; HC: 4.7 µm, 95% CI: −0.3 to 9.7, p = 0.07). No longitudinal differences in rates of GCIPL change were noted between HM and LM vs. NM, either in MS or HC.

Conclusion

Cross-sectional differences in average GCIPL and pRNFL thicknesses are commonly seen in people with HM as compared to reference normative values from people with NM and can lead to false attribution of pathology if RE is not taken into account. However, our study suggests that longitudinal changes in average GCIPL thickness in PwMS with myopia are similar in magnitude to PwMS with NM, and therefore are appropriate for monitoring disease-related pathology.

Keywords:

• Myopia
• optical coherence tomography
• multiple sclerosis
• refractive error

Disclosure statement

GK, NP, NN, EV, HE, AR, OM, HM, AF, JL, AD, NF, OK, JN, SD, MD, AR, KE, AV, MRM, CH, and KF report no disclosures.

ESS has served on scientific advisory boards for Viela Bio, Alexion, and Genentech, and has received speaker fees from Viela Bio and Biogen.

SS has received consulting fees from Medical Logix for the development of CME programs in neurology, and has served on scientific advisory boards for Biogen, Genzyme, Genentech Corporation, EMD Serono, and Celgene. He is the PI of investigator-initiated studies funded by Genentech and Biogen, was the site investigator of a trial sponsored by MedDay Pharmaceuticals and received support from the Race to Erase MS foundation. He has consulted for Carl Zeiss Meditec, and has received equity compensation for consulting from JuneBrain LLC, a retinal imaging device developer.

PC has received consulting fees from Disarm and Biogen and is PI on grants to JHU from Biogen and Annexon.

Data availability statement

The data that support the findings of this study are available from the corresponding author, PAC, upon reasonable request.

Additional information

Funding

This work was supported by the National Institute of Neurological Disorders and Stroke under the grant R01NS082347 and Fundamental Research Funds for the Central Universities, NEU.