title: Grading severity in retinitis pigmentosa using clinical assessment, visual acuity, perimetry and optical coherence tomography.
abstract: To develop a grading system for retinitis pigmentosa (RP), providing clinicians with a simple, objective measure of disease severity. An observational case series of 14 patients with RP. Disease severity was assessed using four criteria; clinical appearance, visual acuity (best corrected LogMAR, BCVA), perimetry (mean deviation, MD) and Fourier-domain optical coherence tomography (outer retinal thickness, ORT at the fovea). Each criterion was scored on a severity scale from 0 (mild disease) to 4 (severe disease), giving an overall score out of 16. The mean BCVA was 0.37 LogMAR (range 0.02 to PL), mean MD was -25.35 dB (range -7.48 to -34.38 dB), mean retinal thickness at the fovea was 189.4 μm (range 96.5-264.5 μm) and mean ORT at the fovea was 140.6 μm (range 63.4-193.4 μm). The clinical appearance correlated well with each of the quantitative measures of disease severity; BCVA (0.62, p = 0.022), MD (-0.903, p < 0.0001) and ORT (-0.698, p = 0.005). Applying the grading system to our patients, the severity scores were evenly spread between grades 1 and 14. We present a simple, objective grading system for RP offering a potential tool for grading disease severity with applications such as assessing progression, comparing patient populations and measuring outcomes in clinical trials.
authors.affiliation: Whipps Cross University Hospital, Leytonstone, London, E11 1NR, UK. hbs@doctors.net.uk
authors.forename: Henry B
authors.initials: HB
authors.lastname: Smith
authors.forename: Aman
authors.initials: A
authors.lastname: Chandra
authors.forename: Hadi
authors.initials: H
authors.lastname: Zambarakji
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005584:Fovea Centralis / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000503:physiopathology*; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult