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Show Clinical Correspondence Optical Coherence Tomography Angiography Findings in Superior Segmental Optic Nerve Hypoplasia Jong Hoon Shin, MD, Jae Ho Jung, MD, PhD S uperior segmental optic nerve hypoplasia (SSOH) is a nonprogressive congenital optic nerve head anomaly that is characterized by a localized inferior visual field defect, superior retinal nerve fiber layer (RNFL) defect, and good visual acuity (1). Liu et al (2) demonstrated that decreased peripapillary vessel density in sweptsource optical coherence tomography (OCT) angiography correlated well with the areas of RNFL thinning in FIG. 1. A. The left fundus shows superior entrance of the retinal vessels and pallor of the superior aspect of the disc. B and C. Peripapillary optical coherence tomography reveals superotemporal retinal nerve fiber layer thinning. D. Automated left visual field demonstrates an inferior field defect. OS, left eye. Department of Ophthalmology (JHS, JHJ), Pusan National University Yangsan Hospital, Yangsan, South Korea; Research Institute of Biomedical Science and Technology (JHS, JHJ), Pusan National University Yangsan Hospital, Yangsan, South Korea; and Department of Ophthalmology (JHS, JHJ), Seoul National University Hospital, Seoul, South Korea. The authors report no conflicts of interest. Address correspondence to Jae Ho Jung, MD, PhD, Department of Ophthalmology, Seoul National University Hospital, Seoul, South Korea 101, Daehak-ro Jongno-gu, Seoul, 03080, South Korea; E-mail: jaeho0130@naver.com Shin and Jung: J Neuro-Ophthalmol 2019; 39: 103-104 patients with glaucoma. Chen et al (3) reported that various kinds of optic neuropathies showed a decrease in peripapillary vessel density on OCT angiography, regardless of the etiology of the optic neuropathy, and peripapillary vessel loss on OCT angiography correlated well with the areas of RNFL thinning seen on OCT. However, to our knowledge, there are no previous reports evaluating the retinal peripapillary capillary network in SSOH. 103 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Clinical Correspondence FIG. 2. Swept-source optical coherence tomography angiography. A. There is no definite capillary focal defect in the peripapillary area. B. Cross-sectional OCT angiography shows retinal (red) and choroidal (purple) blood flow. C. The density of the perfused peripapillary region vessel in the radial peripapillary capillary layer in each quadrant is displayed as a percentage of the area occupied by the large blood vessel and retinal capillaries. The peripapillary region was defined from the B-scan image as a circle with a diameter 3.5 mm from the center of the optic disc. A 4-year-old boy with normal development was referred to our clinic for evaluation of left optic atrophy. There was no family history of diabetes mellitus or neurologic disease. Visual acuity was 20/20 in both eyes with no abnormalities detected in assessing pupillary reactions, color vision, extraocular movements, and anterior segments of each eye. His intraocular pressures were 10 mm Hg bilaterally. The right fundus was normal, while on the left, there was superior disc pallor and a relatively superior entrance of the retinal vessels (Fig. 1A). Peripapillary OCT (Carl Zeiss Meditec, Dublin, CA) demonstrated superotemporal RNFL thinning in the left eye (Fig. 1B, C). Annual examinations over the next 8 years revealed no change in the RNFL measurement or fundus appearance of the left eye. At age 12 years, automated visual field testing showed an inferior field defect in the left eye (Fig. 1D). Swept-source OCT angiography (DRI OCT-1; Topcon, Tokyo, Japan) with 4 layers (optic nerve head, vitreous, radial peripapillary capillary, and choroidal layer) showed no significant peripapillary capillary network focal defects. In addition, radial peripapillary capillary vessel density using image J program (4) demonstrated similar average vessel density in each quadrant of the peripapillary region (Fig. 2). In contrast to OCT angiography findings in other optic neuropathies, in our patient OCT angiography failed to demonstrate alterations in peripapillary vessel density in the area of decreased RNFL thickness. This discrepancy may arise from the developmental differences between ocular tissue types and the nonprogressive nature of SSOH. The 104 optic nerve and RNFL are formed from the ectoderm of the neural tube, whereas the vessels of the retina and choroid are formed from mesenchyme (5). In addition, there is no progressive tissue damage in SSOH and, therefore, peripapillary capillary networks may remain intact. Our findings may be useful in differentiating SSOH from acquired and progressive optic neuropathies. STATEMENT OF AUTHORSHIP Category 1: a. conception and design: J. H. Jung; b. acquisition of data: J. H. Shin; c. analysis and interpretation of data: J. H. Shin. Category 2: a. drafting the manuscript: J. H. Jung; b. revising it for intellectual content: J. H. Jung. Category 3: a. final approval of the completed manuscript: J. H. Jung. REFERENCES 1. Kim RY, Hoyt WF, Lessell S, Narahara MH. Superior segmental optic hypoplasia. A sign of maternal diabetes. Arch Ophthalmol. 1989;107:1312-1315. 2. Liu L, Jia Y, Takusagawa HL, Pechauer AD, Edmunds B, Lombardi L, Davis E, Morrison JC, Huang D. Optical coherence tomography angiography of the peripapillary retina in glaucoma. JAMA Ophthalmol. 2015;133:1045-1052. 3. Chen JJ, AbouChehade JE, Iezzi R, Leavitt JA, Kardon RH. Optical coherence angiographic demonstration of retinal changes from chronic optic neuropathies. Neuroophthalmology. 2017;41:76-83. 4. Schneider CA, Rasband WS, Eliceiri KW. NIH Image to ImageJ: 25 years of image analysis. Nat Methods. 2012;9:671-675. 5. Barishak YR. Embryology of the eye and its adnexae. Dev Ophthalmol. 1992;24:1-142. Shin and Jung: J Neuro-Ophthalmol 2019; 39: 103-104 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
