Nystagmus with pendular low amplitude, high frequency components (PLAHF) in association with retinal disease

Purposes: To establish a relation between pendular low amplitude high frequency (PLAHF) components and congenital retinal disorders.Methods: Patients who showed PLAHF components in their eye-movement recording between January 2016 to January 2019 were included. Best corrected visual acuity (BCVA), refraction, strabismus assessment, fundus photograph, spectral domain-optical coherence tomography (SD-OCT), full-field electroretinography (f-ERG), clinical ophthalmological examination, and gene tests were used to determine their clinical conditions, especially their retina conditions in all patients.Results: Among 136 patients there were 76 males and 60 females with mean age of 11.4.5 ± 4.5 years. Pure PLAHF waveforms were found in 38 patients (28%), the amplitude of the PLAHF was 2°±1.6° and frequency was 5-10 Hz. Superimposed PLAHF waveforms were found in 98 patients (72%). BCVA was worse than Log MAR1.0 in 94 patients (69%), between LogMar 0.5-1.0 (20/63-20/200) in 30 cases (22%); higher than LogMar 0.5 (20/63) in 12 cases (9%). Fifty-eight patients were diagnosed with exotropia and six patients with esotropia. Abnormal Fundus were found in 71 cases (52%), fovea hypoplasia was identified with OCT in 95 cases (70%) and retinal thinning in 92 cases (68%). Abnormal on-off VEP were found in 116 cases (85%). The f-ERG responses were reduced in all patients. In 46 patients, gene mutations were found to related to retinal disease, including 3 congenital stationary night blindness (CSNB), 14 achromatopsia (ACHM), 5 Aland Island eye disease (AIED), 7 Alstrom syndrome (AS), 11 Leber congenital amaurosis (LCA), 6 cone-rod dystrophy (CRD).Conclusions: Patients presenting with PLAHF usually had retinal disorders.