Quantitative Analysis of Retinal Structure Using Spectral-Domain Optical Coherence Tomography in RPGR-Associated Retinopathy.
OBJECTIVE
To quantify retinal structure and progression using spectral-domain optical coherence tomography (SDOCT) in patients with retinitis pigmentosa (RP) associated with retinitis pigmentosa GTPase regulator gene (RPGR) mutations.


METHODS
Retrospective observational case series.


METHODS
Setting: Moorfields Eye Hospital, London, United Kingdom.


METHODS
Both eyes of 32 patients. SDOCT follow-up period of >1 year (3.1 ± 1.4 years).


METHODS
Ellipsoid zone (EZ) width (EZW) and outer nuclear layer (ONL) and inner retinal layer (IRL) thickness measurements. Progression rates, interocular symmetry, and association with age and genotype were investigated.


RESULTS
Significant differences were observed between baseline and final measurements of EZW and ONL thickness, but not for IRL thickness. Baseline and final EZWs were 2438 ± 1646 μm and 1901 ± 1423 μm for right eyes (P < .0001); 2420 ± 1758 μm and 1922 ± 1482 μm for left eyes (P < .0001). EZW constriction rates were 176.6 ± 130.1 μm/year and 173.1 ± 146.8 μm/year for right and left eyes. ONL thinning rates were 2.58 ± 2.85 μm/year and 2.52 ± 3.54 μm/year for right and left eyes. Interocular differences in EZW and ONL progression were not significant (P = .8609 and P = .6735, respectively). Strong correlations were found between EZW constriction rates of right and left eyes (rs= 0.627, P = .0002) and between EZW constriction and baseline EZW (rs= 0.714, P < .0001). There was moderate negative correlation between EZW constriction and age (rs= -0.532, P < .0001). Correlation between ONL thinning and age was not significant, as were differences between EZW and ONL progression rates with respect to genotype.


CONCLUSIONS
This study provides SDOCT progression rates for RPGR-associated RP. There is overall interocular symmetry with implications for future treatment trials where 1 eye could serve as a control.
UCL Institute of Ophthalmology, University College London, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom.
James J L
JJL
Tee
Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin.
Joseph
J
Carroll
UCL Institute of Ophthalmology, University College London, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom.
Andrew R
AR
Webster
UCL Institute of Ophthalmology, University College London, London, United Kingdom; Moorfields Eye Hospital, London, United Kingdom. Electronic address: michel.michaelides@ucl.ac.uk.
Michel
M
Michaelides
D000328:Adult; D018450:Disease Progression; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D009154:Mutation; D012160:Retina / Q000473:pathology*; D012174:Retinitis Pigmentosa / Q000175:diagnosis* / Q000235:genetics; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity
D005136:Eye Proteins; C099929:RPGR protein, human