Yu Kato1,2, Gen Hanazono1, Kaoru Fujinami1,3,4, Tetsuhisa Hatase5, Yuichi Kawamura6, Takeshi Iwata6, Yozo Miyake1,7, Kazushige Tsunoda1. 1. Division of Vision Research, National Institute of Sensory Organs, Tokyo, Japan. 2. Department of Ophthalmology, Tokyo Metropolitan Komagome Hospital, Tokyo, Japan. 3. UCL Institute of Ophthalmology, London, United Kingdom. 4. Department of Ophthalmology, Keio University, School of Medicine, Tokyo, Japan. 5. Division of Ophthalmology and Visual Science, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan. 6. Division of Molecular and Cellular Biology, National Institute of Sensory Organs, Tokyo, Japan. 7. Aichi Medical University, Aichi, Japan.
Abstract
Purpose: To report the clinical characteristics of asymptomatic cases with RP1L1 gene mutations in four families with occult macular dystrophy (OMD). Methods: Four asymptomatic cases from four families were selected from a cohort of 40 subjects (16 families) with RP1L1 pathogenic variants. Clinical data of the four asymptomatic cases and three symptomatic patients in the same families were reviewed. The three asymptomatic cases did not have any visual symptoms in either eye, and one was unilaterally affected. Ophthalmologic examinations, including spectral-domain optical coherence tomography (OCT) were performed, and the morphologic characteristics of the photoreceptor layer of the asymptomatic cases were compared to those of the symptomatic patients within the same family. Results: The OCT images demonstrated photoreceptor abnormalities in the parafoveal regions in all of the four asymptomatic cases (i.e., absence of the interdigitation zone and blurring of the ellipsoid zone). However, these microstructures were preserved at the foveal center. The longitudinal reflectivity profiles clearly identified this distinct pattern in the asymptomatic cases. In contrast, no distinct abnormalities were detected by other examinations including perimetry, fundus autofluorescence images, and multifocal electroretinograms (ERGs). Conclusions: The sparing of the central foveal photoreceptor layer accounts for the well-preserved visual acuity in the asymptomatic patients. The sparing may represent either the initial phase of typical OMD or a subtype of macular lesion associated with OMD. It is necessary to examine asymptomatic subjects in families with OMD because some of them may progress to the typical phenotype of OMD.
Purpose: To report the clinical characteristics of asymptomatic cases with RP1L1 gene mutations in four families with occult macular dystrophy (OMD). Methods: Four asymptomatic cases from four families were selected from a cohort of 40 subjects (16 families) with RP1L1 pathogenic variants. Clinical data of the four asymptomatic cases and three symptomatic patients in the same families were reviewed. The three asymptomatic cases did not have any visual symptoms in either eye, and one was unilaterally affected. Ophthalmologic examinations, including spectral-domain optical coherence tomography (OCT) were performed, and the morphologic characteristics of the photoreceptor layer of the asymptomatic cases were compared to those of the symptomatic patients within the same family. Results: The OCT images demonstrated photoreceptor abnormalities in the parafoveal regions in all of the four asymptomatic cases (i.e., absence of the interdigitation zone and blurring of the ellipsoid zone). However, these microstructures were preserved at the foveal center. The longitudinal reflectivity profiles clearly identified this distinct pattern in the asymptomatic cases. In contrast, no distinct abnormalities were detected by other examinations including perimetry, fundus autofluorescence images, and multifocal electroretinograms (ERGs). Conclusions: The sparing of the central foveal photoreceptor layer accounts for the well-preserved visual acuity in the asymptomatic patients. The sparing may represent either the initial phase of typical OMD or a subtype of macular lesion associated with OMD. It is necessary to examine asymptomatic subjects in families with OMD because some of them may progress to the typical phenotype of OMD.
Authors: Merry Zc Ruan; S Amal Hussnain; Amanda Thomas; Mahesh Mansukhani; Stephen Tsang; Lawrence Yannuzzi Journal: Am J Ophthalmol Case Rep Date: 2019-05-09