Abstract
Purpose :
CLN3 disease is progressive neurodegenerative disorder affecting the brain and retina. Children at the age of 6-8 years present with rapid visual deterioration and subsequent motor and cognitive decline, epileptic seizures. Retinal degeneration is characterized by rapid macular degeneration followed by panretinal atrophy and legal blindness in all patients. The investigated study provides a clinical grading scale to quantify ocular function and morphology in patients with CLN3 disease.
Methods :
A retrospective chart analysis of 20 patients with genetically confirmed CLN3 mutation were included in the study. A total of 44 examination of 88 eyes were included into the data anaylsis consisting of the evaluation of best-corrected visual acuity (BCVA), fungus imaging and optical coherence tomography (OCT) imaging. Three independent ophthalmologists graded the funduscopic alterations (optic nerve pallor, macular orange pigment, vascular rarefication, peripheral bony spicules, macular striation) and scored the alteration from zero to three, resulting in a total score maximum score of six. Macular OCT scans were scored according the degree of disruption of the ellipsoid zone (EZ) (3 points: no disruption of the EZ, 2 points: foveal disruption of the EZ < 1000 um, 1 point: foveal disruption of the EZ 1000-2000 um, 0 points: complete disruption of the EZ). Concurrently visual function based on BCVA was scored from zero to three.(3 points: > 20/63; 2 points: 20/80 - 20-400, 1 point: 20/500 - Counting fingers, 0 points: below counting fingers)
Results :
Mean age of examination was 11.4 years (range: 5.8 - 18 years), all 88 examined eyes consisted of a BCVA, fundus image and an OCT image. The mean total score was 4.1 (range: 0-12) with a total mean BCVA score of 0.5 (range: 0-3), a total mean OCT score 0.4 (range: 0-3) and total mean fundus score of 3 (range: 0-6)
Based upon the total scoring, three stages (mild >9 points), moderate(5-8 points), advanced( < 5 points) were established. 8/88 eyes displayed with a mild phenotype, 22/88 eyes with a moderate phenotype and 58/88 eyes with an advanced phenotype.
Conclusions :
We provide a concise and quickly applicable ocular clinical grading scale to assess and monitor patients with CLN3 disease. The herein proposed grading scale incorporates functional and morphologic outcome measures to precisely evaluate the ocular status for upcoming clinical trials.
This is a 2020 ARVO Annual Meeting abstract.