Retina Patchy Scotoma Observed in Chorioretinal Patchy Atrophy of Myopic Macular Degeneration Jung Lo,1,2 Linda Yi-Chieh Poon,2 Yi-Hao Chen,2 Hsi-Kung Kuo,2 Yung-Jen Chen,2 Wei-Yu Chiang,1,2 and Pei-Chang Wu1,2 1Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan 2Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan Correspondence: Pei-Chang Wu, PURPOSE. To investigate the retinal sensitivity of highly myopic eyes with chorioretinal Department of Ophthalmology, patchy atrophy (PA) using microperimetry. Kaohsiung Chang Gung Memorial Hospital and Chang Gung University METHODS. Fifty-two eyes of 32 patients with high myopia were prospectively included. College of Medicine, Kaohsiung, Twenty-two eyes of 16 patients had PA lesions; eyes without PA were analyzed as controls. Taiwan; Testing points on microperimetry in eyes with PA were designated as 3 zones: zone 1 as [email protected]. the PA lesion including its borders; zone 2 including testing points adjoining PA; zone 3 Received: April 5, 2019 including all other testing points. Accepted: November 15, 2019 RESULTS. In the PA group, the mean retinal sensitivity in zone 1 was 2.1 ± 2.8 dB, zone Published: February 13, 2020 2 = 8.3 ± 4.3 dB, and zone 3 = 9.4 ± 4.1 dB. Sensitivity in zone 1 was significantly Citation: Lo J, Poon LY-C, Chen Y-H, reduced than zones 2 and 3 (P < 0.001). The mean retinal sensitivity in the PA group et al. Patchy scotoma observed in was lower than controls (6.5 ± 4.3 vs 13.9 ± 4.1 dB, P < 0.001), and combined zone 2 chorioretinal patchy atrophy of and 3 in the PA group also presented lower retinal sensitivity (8.8 ± 4.0 dB). myopic macular degeneration. Invest Ophthalmol Vis Sci. 2020;61(2):15. CONCLUSIONS. Eyes with PA generate patchy scotoma in PA lesions and reduced retinal https://doi.org/10.1167/iovs.61.2.15 sensitivity in regions beyond atrophic lesion on microperimetry. The presence of PA may be an indicator to reflect both significantly anatomical and functional alterations on myopic macular degeneration. Keywords: high myopia, patchy atrophy, chorioretinal atrophy, myopic macular degener- ation, microperimetry igh myopia is a major cause of visual impairment than tessellated fundus and diffuse atrophy to progress or H in developed countries,1,2 particularly in East Asia,3–5 develop myopic CNV and macular atrophy, causing severe because of several vision-threatening complications, such visual impairment.6,9,10 Several studies have investigated as myopic choroidal neovascularization (CNV), myopic the anatomical abnormalities of PA. PA is characterized by foveoschisis, and myopic chorioretinal atrophy.6–8 The main deformation of the sclera, complete loss of choriocapillar- alteration in high myopia is excessive axial length elongation ies, macular Bruch’s membrane defects, and degeneration of the globe. Additionally, posterior ocular segment defor- of the photoreceptors and the retinal pigment epithelium mities including posterior staphyloma and myopic macu- (RPE) when evaluated by optical coherence tomography lar degeneration may develop. According to the definition (OCT).11,12 Fluorescein fundus angiography at 1 minute after stated by the Meta-analysis for Pathologic Myopia (META- dye injection showed relative hypofluorescence around PA, PM) study group, myopic macular degeneration is defined and turned into mild hyperfluorescence at the late phase.11 as five categories based on funduscopic findings: category Progressive enlargement of PA could be observed during 0, no maculopathy; category 1, tessellated fundus; category long-term follow-up of fundus photography or evaluated 2, diffuse chorioretinal atrophy; category 3, patchy chori- by fundus autofluorescence.10,13 Although previous studies oretinal atrophy; and category 4, macular atrophy; three have mostly focused on the anatomical aspect of PA, func- additional features including lacquer cracks, myopic CNV, tional analysis of PA is currently not well established. and Fuchs spots were defined as plus lesions.9 A tessel- Best-corrected visual acuity (BCVA) has been the main lated fundus was suggested to be the first sign that high indicator of visual function in retinal diseases; however, myopia had progressed to the myopic maculopathy. It can it cannot reflect comprehensive macular function because progress to diffuse atrophy or lacquer cracks, and may it is mainly based on responses from the foveal cones. further progress to patchy atrophy (PA) and the formation Patchy atrophy does not commonly involve the foveal center of CNV.10 when it develops initially.6,14 For assessment of macular PA, classified as category 3, is a grayish-white chorioreti- disease especially when the foveal center is not involved, nal atrophic lesion with well-defined borders in the macu- microperimetry is gaining acceptance as an effective clin- lar area; it is of importance due to having a higher chance ical investigation. Microperimetry may provide additional Copyright 2020 The Authors iovs.arvojournals.org | ISSN: 1552-5783 1 This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. Patchy Scotoma in Myopic Patchy Atrophy IOVS | February 2020 | Vol. 61 | No. 2 | Article 15 | 2 information regarding fundus-correlated visual functional of 20 degrees from fixation. Because PA has been defined testing, severity and extent of macular disease, compensa- as unifocal or multifocal chorioretinal atrophic lesions, it tion for ocular movement, precise assessment of fixation is to be expected that microperimetry might not be able stability and location, and detect subtle changes in visual to measure the retinal sensitivity of PA region precisely. function when visual acuity measurements do not identify Therefore, fixation was considered unstable if less than 75% changes.15–17 of the fixation points were inside the 4° diameter circle.18 To our knowledge, there is limited functional analysis of Microperimetry was retested immediately if less than 75% of eyes with PA. Thus, the purpose of this study was to evaluate the fixation points were inside the 4° diameter circle, andthe the retinal sensitivity of highly myopic eyes with PA and to four crosses or a ring would be used as an alternative fixa- compare PA cases with highly myopic eyes not presenting tion target when retested to increase test accuracy.19 In the with PA by means of microperimetry. PA group, testing points of microperimetry measurements superimposed on color fundus image were further desig- nated into three zones based on their relative distance to MATERIALS AND METHODS the PA for analysis. Testing points were designated as zone Participants 1 if it falls within the areas or at the border of patchy atro- phy and were designated as zone 2 or 3 solely based on This is a prospective, cross-sectional study of highly myopic their relative distance to the PA lesion on the microperime- patients from the Kaohsiung Chang Gung Memorial Hospi- try image superimposed on color fundus image. Zone 2 was tal. The aims and examinations were explained to the defined as the perilesional region, which included testing subjects before the study, and informed consent was points immediately adjoining PA. Zone 3 was defined as the obtained from all subjects in agreement with the Decla- extralesional region, which included all other testing points ration of Helsinki for research involving human subjects. which were separated from PA by at least one testing point Institutional Review Board/Ethics Committee approval was or more than 2° away from PA (Fig. 1). The grading process prospectively obtained from the Committee of Medical was performed by two graders (J.L. and P.C.W.) according Ethics and Human Experiments of Chang Gung Memorial to the definitions described previously, and if there were Hospital. disagreements between the two graders, they were resolved This study included participants who were 18 years through consensus. In cases where PA coalesced with para- of age or older and diagnosed with high myopia (refrac- papillary atrophy, testing points located within the para- tive error ≤–5.00 diopters (D)). PA was defined as unifo- papillary atrophy were also designated as zone 1. A simi- cal or multifocal areas of chorioretinal and RPE atrophy lar classification was previously described by another study with well-defined borders on color fundus photography, in age-related macular degeneration-related geographic confirmed by spectral-domain optical coherence tomogra- atrophy.20 phy (SDOCT).9,11,12 Eyes with PA of any size and eyes The SDOCT (Spectralis OCT, Heidelberg Engineering, with foveal-involving PA were also included in this study. Heidelberg, Germany) images were acquired with 25 hori- Exclusion criteria were other macular diseases (e.g., age- zontal raster scans covering a 20 × 20° oblong rectan- related macular degeneration, myopic traction maculopathy, gle after microperimetry. Eyes with unifocal or multifocal foveoschisis, hereditary retinal dystrophies), history of CNV, areas of degeneration of the photoreceptors, RPE/Bruch’s or other potentially confounding diseases (e.g., significant membrane, and loss of choriocapillaries were considered as cataract, diabetic retinopathy, glaucoma, trauma, uveitis). PA cases.11,12 Eyes without chorioretinal and RPE/Bruch’s membrane atrophy but with any reported value for retinal Procedures sensitivity measurement were analyzed as controls