Intereye Symmetry in Bietti Crystalline Dystrophy

Zhengyang Liu; Lauren N Ayton; Fleur O'Hare; Janan Arslan; Monica L Hu; Alexander P Noar; Jiang-Hui Wang; Doron G Hickey; Myra B McGuinness; Andrea L Vincent; Fred K Chen; Thomas L Edwards

doi:10.1016/j.ajo.2021.07.009

Intereye Symmetry in Bietti Crystalline Dystrophy

Am J Ophthalmol. 2022 Mar:235:313-325. doi: 10.1016/j.ajo.2021.07.009. Epub 2021 Jul 18.

Authors

Affiliations

¹ From the Centre for Eye Research Australia, East Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., D.G.H., M.B.M., T.L.E.); Department of Surgery (Ophthalmology), University of Melbourne, Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., T.L.E.); Royal Victorian Eye and Ear Hospital, East Melbourne (Z.L., L.N.A., F.O., M.L.H., J.-H.W., D.G.H., T.L.E.); Royal Melbourne Hospital (Z.L.). Electronic address: zhengyang.liu.research@gmail.com.
² From the Centre for Eye Research Australia, East Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., D.G.H., M.B.M., T.L.E.); Department of Surgery (Ophthalmology), University of Melbourne, Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., T.L.E.); Royal Victorian Eye and Ear Hospital, East Melbourne (Z.L., L.N.A., F.O., M.L.H., J.-H.W., D.G.H., T.L.E.); Department of Optometry and Vision Sciences, the University of Melbourne (L.N.A., F.O.), Parkville.
³ From the Centre for Eye Research Australia, East Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., D.G.H., M.B.M., T.L.E.); Department of Surgery (Ophthalmology), University of Melbourne, Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., T.L.E.).
⁴ From the Centre for Eye Research Australia, East Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., D.G.H., M.B.M., T.L.E.); Department of Surgery (Ophthalmology), University of Melbourne, Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., T.L.E.); Royal Victorian Eye and Ear Hospital, East Melbourne (Z.L., L.N.A., F.O., M.L.H., J.-H.W., D.G.H., T.L.E.).
⁵ Austin Health, Heidelberg (A.P.N.).
⁶ From the Centre for Eye Research Australia, East Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., D.G.H., M.B.M., T.L.E.); Royal Victorian Eye and Ear Hospital, East Melbourne (Z.L., L.N.A., F.O., M.L.H., J.-H.W., D.G.H., T.L.E.).
⁷ From the Centre for Eye Research Australia, East Melbourne (Z.L., L.N.A., F.O., J.A., M.L.H., J.-H.W., D.G.H., M.B.M., T.L.E.); Melbourne School of Population and Global Health, University of Melbourne, Melbourne (M.B.M.), Australia.
⁸ Eye Department, Greenlane Clinical Centre, Auckland District Health Board (A.L.V.); Department of Ophthalmology, FMHS, New Zealand National Eye Centre, University of Auckland (A.L.V.), Auckland, New Zealand.
⁹ Centre for Ophthalmology and Visual Science (incorporating the Lions Eye Institute), The University of Western Australia (F.K.C.); and Department of Ophthalmology, Royal Perth Hospital (F.K.C.), Perth, Australia.

PMID: 34283985
DOI: 10.1016/j.ajo.2021.07.009

Abstract

Purpose: To evaluate anatomic and functional intereye symmetry among individuals with Bietti crystalline dystrophy (BCD) using clinical and multimodal imaging methods, with a focus on the number, area, and distribution of the characteristic retinal crystalline deposits.

Design: Observational case series with prospective and retrospective data.

Methods: Setting: Multicenter.

Study population: Thirteen Australian and New Zealand participants (26 eyes) with confirmed biallelic CYP4V2 mutations and a characteristic BCD fundus appearance. Procedures and main outcome measures: Crystals visible on color fundus photography were manually counted. Crystals were superimposed on aligned multimodal fundus images. Spearman's correlation coefficients (ρ), intraclass correlation coefficients (ICCs), and Bland-Altman plots were used to quantify symmetry between eyes.

Main outcome measures: Fundus crystal area and count, and absent-autofluorescence (absent-AF) area.

Results: Median participant age was 48 years (interquartile range: 40-60 years). Intereye symmetry was high for fundus crystal area (ρ = 1.00, 95% confidence interval [CI]: 1.00-1.00; ICC = 0.97, 95% CI: 0.88-0.99), fundus crystal count (ρ = 0.98, 95% CI: 0.92-1.00; ICC = 0.97, 95% CI: 0.89-0.99), and absent-AF area (ρ = 0.88, 95% CI: 0.53-0.98; ICC = 0.98, 95% CI: 0.90-0.99). Average foveal volume, foveal crystal count and area, average and central foveal thickness, best corrected visual acuity, and average macular and central foveal sensitivity were not highly correlated between eyes.

Conclusions: This study demonstrated strong intereye symmetry measured by fundus crystal area, fundus crystal number, and absent-AF area. This may influence the choice of outcome measures for future therapeutic trials for BCD and provides valuable clinical information for ophthalmologists involved in the care and counseling of patients with BCD.

Keywords: Bietti Crystalline Dystrophy; crystal quantification; fundus autofluorescence; inter-eye symmetry; multi-modal imaging.

Publication types

Multicenter Study
Observational Study
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Australia
Corneal Dystrophies, Hereditary
Cytochrome P450 Family 4 / genetics
Fluorescein Angiography / methods
Humans
Middle Aged
Mutation
Prospective Studies
Retinal Degeneration*
Retinal Diseases
Retrospective Studies
Tomography, Optical Coherence* / methods

Substances

Cytochrome P450 Family 4

Supplementary concepts

Bietti Crystalline Dystrophy