Optical Coherence Tomography Can Be Used to Assess Glaucomatous Optic Nerve Damage in Most Eyes With High Myopia.

Zane Z Zemborain,Robert Ritch,Emmanouil Tsamis,Donald C Hood,Carlos G De Moraes,Ravivarn Jarukasetphon

doi:10.1097/ijg.0000000000001631

Abstract

It is generally assumed that optical coherence tomography (OCT) cannot be used to diagnose glaucomatous optic neuropathy (GON) in high myopes. However, this study presents evidence that there is sufficient information in OCT scans to allow for accurate diagnosis of GON in most eyes with high myopia. The purpose of this study was to test the hypothesis that glaucomatous damage can be accurately diagnosed in most high myopes via an assessment of the OCT results. One hundred eyes from 60 glaucoma patients or suspects, referred for OCT scans and evaluation, had corrected spherical refractive errors worse than -6 D and/or axial lengths ≥26.5 mm. An OCT specialist judged whether the eye had GON, based upon OCT circle scans of the disc and cube scans centered on the macula. A glaucoma specialist made the same judgement using all available information (eg, family history, repeat visits, intraocular pressure, 10-2 and 24-2 visual fields, OCT). A reference standard was created based upon the glaucoma specialist's classifications. In addition, the glaucoma specialist judged whether the eyes had peripapillary atrophy (PPA), epiretinal membrane (ERM), tilted disc (TD), and/or a paravascular inner retinal defect (PIRD). The OCT specialist correctly identified 97 of the 100 eyes using the OCT information. In 63% of the cases, the inner circle scan alone was sufficient. For the rest, additional scans were requested. In addition, 81% of the total eyes had: PPA (79%), ERM (18%), PIRD (26%), and/or TD (48%). For most eyes with high myopia, there is sufficient information in OCT scans to allow for accurate diagnosis of GON. However, the optimal use of the OCT will depend upon training to read OCT scans, which includes taking into consideration myopia related OCT artifacts and segmentation errors, as well as PPA, ERM, PIRD, and TD.

Highlights

Optical coherence tomography (OCT) has demonstrated utility in the detection and management of glaucoma—an optic neuropathy in which the selective loss of retinal ganglion cells and their axons results in the subsequent thinning of the retinal nerve fibers.[1]
For most eyes with high myopia, there is sufficient information in OCT scans to allow for accurate diagnosis of glaucomatous optic neuropathy (GON)
Training to read OCT scans, which includes taking into consideration myopia related OCT artifacts and segmentation errors, as well as peripapillary atrophy (PPA), epiretinal membrane (ERM), paravascular inner retinal defect (PIRD), and tilted disc (TD)

Summary

Introduction

Optical coherence tomography (OCT) has demonstrated utility in the detection and management of glaucoma—an optic neuropathy in which the selective loss of retinal ganglion cells and their axons results in the subsequent thinning of the retinal nerve fibers.[1]. High myopes have greater axial lengths than the general population, and this can cause aberrant retinal anatomy, as well as affect the OCT image quality and analysis.[2,3,4,5,6,7,8]. The circumpapillary retinal nerve fiber layer (cpRNFL) measurement currently stands as the most commonly used OCT method to quantify structural loss in glaucoma.[9,10,11,12,13] Suspect eyes have their cpRNFL profiles qualitatively and quantitatively evaluated against a normative database.[14] in general, the commercial normative databases are restricted to eyes with refractive errors better than −6D.15. Clinicians who rely heavily on the cpRNFL measurement and, in particular, summary metrics such as global or sectoral thickness may be prone to misdiagnose healthy high myopes.[17,18]

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