Albinism Research Today is a free monthly online journal that collates and summarizes the latest research about Albinism, including details on pigmentation, genetic trait, heritability. | ||||||
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Structural Grading of Foveal Hypoplasia Using Spectral-Domain Optical Coherence Tomography A Predictor of Visual Acuity?Thomas MG, Kumar A, Mohammad S, Proudlock FA, Engle EC, Andrews C, Chan WM, Thomas S, Gottlob I Ophthalmology Group, School of Medicine, University of Leicester, Leicester, United Kingdom. PURPOSE: To characterize and grade the spectrum of foveal hypoplasia based on different stages of arrested development of the fovea. Grading was performed using morphologic findings obtained by ultra high-resolution spectral-domain optical coherence tomography. Best-corrected visual acuity (BCVA) was calculated for different grades. DESIGN: Observational case series. PARTICIPANTS AND CONTROLS: Sixty-nine patients with foveal hypoplasia (albinism, n = 34; PAX6 mutations, n = 10; isolated cases, n = 14; achromatopsia, n = 11) and 65 control subjects were examined. METHODS: A 7×7-mm retinal area was sampled using a 3-dimensional scanning protocol (743×75, A scans×B scans) with ultra high-resolution spectral-domain optical coherence tomography (SOCT Copernicus HR; 3-μm axial resolution). Gross morphologic abnormalities were documented. B-scans at the fovea were segmented using a longitudinal reflectivity profile. Logarithm of the minimum angle of resolution BCVA was obtained. MAIN OUTCOME MEASURES: Grading was based on presence or absence of foveal pit and widening of the outer nuclear layer (ONL) and outer segment (OS) at the fovea. Quantitative measurements were obtained for comparing atypical foveal hypoplasia in achromatopsia. Best-corrected visual acuity was compared with the grade of foveal hypoplasia. RESULTS: Four grades of foveal hypoplasia were distinguished: grade 1, shallow foveal pit, presence of ONL widening, presence of OS lengthening; grade 2, grade 1 but absence of foveal pit; grade 3, grade 2 but absence of OS lengthening; grade 4, grade 3 but absence of ONL widening. There was significant difference in visual acuity (VA) associated with each grade (P<0.0001). Grade 1 was associated with the best VA (median VA, 0.2), whereas grades 2, 3, and 4 were associated with progressively poorer VA with a median VA of 0.44, 0.60, and 0.78, respectively. The atypical features seen with foveal hypoplasia associated with achromatopsia were characterized by decreased retinal and ONL thickness and deeper foveal depth. CONCLUSIONS: A structural grading system for foveal hypoplasia was developed based on the stage at which foveal development was arrested, which helps to provide a prognostic indicator for VA and is applicable in a range of disorders associated with foveal hypoplasia. Atypical foveal hypoplasia in achromatopsia shows different characteristics. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article. Published 2 May 2011 in Ophthalmology. Articles on Albinism published 22 April 2011: Ocular straylight in albinism. Optom Vis Sci, 88(5): E585-92. PURPOSE.: Albinism is an inherited disorder that affects the melanin biosynthesis pathway, which results in reduced or absent pigment formation. This may lead to increased light transmission through the iris and more reflected light from the fundus. Both these effects contribute to the occurrence of ocular straylight. One aim of this study is to determine whether and how increased iris transmission and fundus reflection in subjects with albinism contributes to the occurrence of ocular ... [Abstract] [Full-text] Articles on Albinism published 21 April 2011: Optic nerve projections in patients with primary ciliary dyskinesia. Invest Ophthalmol Vis Sci. Purpose: Recently it has been suggested that misprojections of the temporal retina to the contralateral hemisphere might not be specific for patients with albinism and might also be associated with the Kartagener syndrome, i.e., with situs inversus totalis in the presence of primary ciliary dyskinesia (PCD). We tested whether such projection abnormalities are associated with PCD and situs inversus. Methods: In ten patients with PCD (five with situs inversus totalis) and in ten age- and ... [Abstract] [Full-text] Optic nerve projections in patients with primary ciliary dyskinesia. Invest Ophthalmol Vis Sci. Purpose: Recently it has been suggested that misprojections of the temporal retina to the contralateral hemisphere might not be specific for patients with albinism and might also be associated with the Kartagener syndrome, i.e., with situs inversus totalis in the presence of primary ciliary dyskinesia (PCD). We tested whether such projection abnormalities are associated with PCD and situs inversus. Methods: In ten patients with PCD (five with situs inversus totalis) and in ten age- and ... [Abstract] [Full-text] Articles on Albinism published 18 April 2011: Implementation of an optimized strategy for genetic testing of the Chinese patients with oculocutaneous albinism. J Dermatol Sci, 62(2): 124-7. Articles on Albinism published 13 April 2011: Severity in phenotypic expression of homozygous sickle cell disease (Hb.SS) - Does hypermelanotic or hypomelanotic skin status of affected patients play a role? Med Hypotheses, 76(5): 673-5. Abnormal hemoglobin distribution on global map, of which hemoglobin S (Hb.S) accounted for about 80% of the disorders resulting from them are more prevalent in the tropics and sub-tropics. Homozygous sickle cell disease (Hb.SS) is the most common and most severe form of sickle cell disease (SCD) in phenotypic expression. The prevalence and severity in phenotypic expression of SCD had been noted to decrease farther away from the equatorial region, with prevalence rate of sickle cell trait of ... [Abstract] [Full-text] Articles on Albinism published 11 April 2011: Clinical and Oculomotor Characteristics of Albinism Compared to FRMD7 Associated Infantile Nystagmus. Invest Ophthalmol Vis Sci, 52(5): 2306-2313. Purpose. Previous studies have found no difference between nystagmus characteristics associated with idiopathic infantile nystagmus (IIN) and that associated with albinism. The present aim is to compare the oculomotor characteristics and other associated clinical features of albinism and a genetically homogenous group of IIN volunteers where the nystagmus is associated with FRMD7 mutations. Methods. Oculomotor characteristics and related clinical features between albinism (n = 52) and ... [Abstract] [Full-text] Clinical and Oculomotor Characteristics of Albinism Compared to FRMD7 Associated Infantile Nystagmus. Invest Ophthalmol Vis Sci, 52(5): 2306-13. Purpose. Previous studies have found no difference between nystagmus characteristics associated with idiopathic infantile nystagmus (IIN) and that associated with albinism. The present aim is to compare the oculomotor characteristics and other associated clinical features of albinism and a genetically homogenous group of IIN volunteers where the nystagmus is associated with FRMD7 mutations. Methods. Oculomotor characteristics and related clinical features between albinism (n = 52) and ... [Abstract] [Full-text] Clinical and Oculomotor Characteristics of Albinism Compared to FRMD7 Associated Infantile Nystagmus. Invest Ophthalmol Vis Sci, 52(5): 2306-13. Purpose. Previous studies have found no difference between nystagmus characteristics associated with idiopathic infantile nystagmus (IIN) and that associated with albinism. The present aim is to compare the oculomotor characteristics and other associated clinical features of albinism and a genetically homogenous group of IIN volunteers where the nystagmus is associated with FRMD7 mutations. Methods. Oculomotor characteristics and related clinical features between albinism (n = 52) and ... [Abstract] [Full-text] © 2005-2011 Albinism Research Today. All Rights Reserved. |
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