Abstract
Purpose: :
The prevalance of nystagmus in a population is unknown. An epidemiological study was carried out in Leicestershire (population 1 000 0000 approx) to establish this.
Methods: :
Patients were recruited over 4.5 years from hospital ophthalmologists and other specialties. Patients from the community were recruited from general practitioners (GPs), paediatricians, optometrists, charitable societies and the organisation for visually impaired (VISTA). Local radio, television and talking newspapers publicised the study. Patients had full ophthalmological assessments including eye movement recordings, electrodiagnostics to establish the cause of nystagmus. Further data collection for capture–recapture analysis involved obtaining names of patients with nystagmus who were not in the survey from GPs, community optometrists, teachers for visually impaired children and VISTA. Clinical notes, hospital correspondence and blind registration forms were used to confirm the nystagmus diagnosis. Log–linear models including all two–way intervals were used in statistical analysis.
Results: :
The survey recruited 373 patients. A further 486 patients with nystagmus were obtained from records of 2358 people registered as partially sighted or blind within Leicestershire. 31 people with nystagmus were identified from databases of optometrists, teachers and GPs. Within the hospital database of 275 patients used in the capture recapture analysis, there were 145 female and 130 male patients. The clinical diagnosis of these patients were albinism (28), congenital idiopathic nystagmus (50), nystagmus secondary to retinal disease (21), nystagmus secondary to low vision (33), latent/manifest latent nystagmus (26), other congenital disease (8), multiple sclerosis (24), stroke (10), vestibular (6) and other neurological diseases (32).
From the combined databases of other resources, there were 527 patients with acquired and congenital forms of nystagmus. The clinical spectrum of diseases included albinism (86), idiopathic infantile nystagmus (20), nystagmus secondary to retinal disease (94), nystagmus secondary to low vision (166), other congenital nystagmus (73), latent/manifest latent nystagmus (5), multiple sclerosis (26), stroke (10) and other neurological diseases (42).
Statistical analysis estimates there are another 118 unidentified people with nsytagmus (95% CI, 54 to 259) giving a total of 820 patients (95% CI, 756 to 961).
Conclusions: :
The prevalance of nystagmus in a population is estimated as 82 per 100 000.
Keywords: nystagmus • clinical (human) or epidemiologic studies: prevalence/incidence • eye movements