REPEATABILITY AND LONGITUDINAL ASSESSMENT OF FOVEAL CONE STRUCTURE IN CNGB3-ASSOCIATED ACHROMATOPSIA.
OBJECTIVE
Congenital achromatopsia is an autosomal recessive disease causing substantial reduction or complete absence of cone function. Although believed to be a relatively stationary disorder, questions remain regarding the stability of cone structure over time. In this study, the authors sought to assess the repeatability of and examine longitudinal changes in measurements of central cone structure in patients with achromatopsia.


METHODS
Forty-one subjects with CNGB3-associated achromatopsia were imaged over a period of between 6 and 26 months using optical coherence tomography and adaptive optics scanning light ophthalmoscopy. Outer nuclear layer (ONL) thickness, ellipsoid zone (EZ) disruption, and peak foveal cone density were assessed.


RESULTS
ONL thickness increased slightly compared with baseline (0.184 μm/month, P = 0.02). The EZ grade remained unchanged for 34/41 subjects. Peak foveal cone density did not significantly change over time (mean change 1% per 6 months, P = 0.126).


CONCLUSIONS
Foveal cone structure showed little or no change in this group of subjects with CNGB3-associated achromatopsia. Over the time scales investigated (6-26 months), achromatopsia seems to be a structurally stable condition, although longer-term follow-up is needed. These data will be useful in assessing foveal cone structure after therapeutic intervention.
*Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin; †Casey Eye Institute, Oregon Health & Science University, Portland, Oregon; ‡Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin; §Alexandria Faculty of Medicine, University of Alexandria, Alexandria, Egypt; ¶Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois; **Vitreo Retinal Associates, Gainesville, Florida; ††Bascom Palmer Eye Institute, University of Miami, Miami, Florida; ‡‡Applied Genetics Technologies Corporation (AGTC), Alachua, Florida; §§Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin; and ¶¶Department of Ophthalmology, University of Florida, Gainesville, Florida.
Christopher S
CS
Langlo
Laura R
LR
Erker
Maria
M
Parker
Emily J
EJ
Patterson
Brian P
BP
Higgins
Phyllis
P
Summerfelt
Moataz M
MM
Razeen
Frederick T
FT
Collison
Gerald A
GA
Fishman
Christine N
CN
Kay
Jing
J
Zhang
Richard G
RG
Weleber
Paul
P
Yang
Mark E
ME
Pennesi
Byron L
BL
Lam
Jeffrey D
JD
Chulay
Alfredo
A
Dubra
William W
WW
Hauswirth
David J
DJ
Wilson
Joseph
J
Carroll
D000293:Adolescent; D000328:Adult; D002648:Child; D003117:Color Vision Defects / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000235:genetics* / Q000378:metabolism; D004247:DNA / Q000235:genetics*; D004252:DNA Mutational Analysis; D004596:Electroretinography; D005260:Female; D005584:Fovea Centralis / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009154:Mutation; D009887:Ophthalmoscopy / Q000379:methods; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology* / Q000502:physiology; D041623:Tomography, Optical Coherence / Q000379:methods; D014792:Visual Acuity; D055815:Young Adult
C415904:CNGB3 protein, human; D054815:Cyclic Nucleotide-Gated Cation Channels; D004247:DNA