Abstract
Purpose :
CACNA1F related disorders encompass x-linked incomplete congenital stationary night blindness(CSNB2A), Aland island eye disease(AIED) and cone-rod dystrophy (CORDX3), which are usually over lapping in clinical diagnosis. We summarized the phenotypic and genotypic features for better diagnosis.
Methods :
CACNA1F mutations were identified in 42 patients. Detailed ophthalmic evaluations were performed. Data from best corrected vision acuity(BCVA), fundus photos, optical coherence tomography (OCT), electroretinagraphy (ERG) and eye movement recording(EMR) are collected.
Results :
1. Gene screening revealed 41 different CACNA1F mutations.
2. 11 patients were diagnosed as CSNB2A disease, 11 patients were AIED disease and 20 patients were CORDX3 disease;
3.The mean BCVA were 0.48±0.20 logMAR in CSNB2A patients, 0.65±0.30 logMAR in AIED patients and 0.81± 0.18 logMAR in CORDX patients, p<0.05;
4. All CSNB2A patients were myopia with average spherical equivalent(SE) of - 8.09±3.15D; 6 AIED patients were myopia and mean SE was -1.82±4.70D; 13 CORDX3 patients were myopia with mean SE of -1.43±3.81D;
5. Abnormal optical nerve and retina thinning were found in all AIED and CORDX3 patients. Optical nerve atrophy (ONA) was found in all CORDX3 patients, 8 AIED patients and 4 CSNB2A patients. Optical nerve hypoplasia (ONH) was found in 3 AIED patients and 4 CSNB2A patients with high myopia. Fovea hypoplasia (FH) were only found in 7 AIED patients.
6. All patients had negative ERG waveforms. There were residual scotopic and photopic a and b-waves in CSNB2A patients but severe decreasing or extinguished in AIED and CORDX3 patients. Photopic 3.0Hz d wave were extinguished in all patients. 30-Hz flicker responses were reduced with a conspicuous double configuration in CSNB2A patients but extinguished in AIED and CORDX3 patients. All patients had abnormal OPS waveforms.
7. Nystagmus was recorded in all AIED and CORDX3 patients but only in 7 CSNB2A patients. The oscillation was featured with pendular waveforms with low amplitude and high frequency (PLAHF) components. 7AIED, 7 CSNB2A and 14 CORDX3 patients had head oscillation; 8 AIED, 7 CSNB2A and 12 CORDX3 patients had chin up head posture.
Conclusions :
1. CACNA1F-caused disorders had overlap clinical phenotype, ERG and OCT tests were helpful for diagnosis; 2.CORDX3 and AIED patients had severer vision function loss than CSNB2A patients; 3. PLAHF nystagmus are closely correlated to CACNA1F related diseases.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.