J. S. Stilma

Prevalence of visual impairment in adults with intellectual disabilities in the Netherlands: Cross-sectional study

PurposeTo obtain the first representative and valid population-based prevalence figures on visual impairment and blindness in adults with intellectual disabilities (ID) and to identify risk groups.MethodsStudy design: Cross-sectional survey. An age-Downs syndrome-stratified random sample of 1598 persons from a base population of 9012 adult users of ID services with mild to profound intellectual disabilities was screened. Participants underwent protocollised on-site screening of visual functions. Results were related to degree of ID, occurrence of Downs syndrome (DS) and age. Main outcome measure: Prevalences of visual impairment and blindness in the study population and in subgroups and weighted prevalences in the total Dutch population using ID services.ResultsPrevalences of visual impairment ranged from 2.2% (95% confidence interval (CI), 0.5–6.4) in young adults with mild ID and no Downs syndrome to 66.7% (95% CI, 41.0–86.7) in older adults with profound ID and Downs syndrome; prevalences of blindness ranged from 0.7% (95% CI, 0.1–4.1) to 38.9% (95% CI, 28.1–50.3). Weighted prevalences of visual impairment and blindness in the total Dutch population of adult users of intellectual disabity services are 13.8% (95% CI, 9.3–18.4) and 5.0% (95% CI, 3.8–6.2), respectively. Prior to this study, visual impairment or blindness had remained undiagnosed in 106/261 (40.6%) persons.ConclusionsAs compared to published figures for the general Dutch population aged 55 years and over (visual impairment 1.4%, blindness 0.5%), prevalences of visual impairment and blindness are higher in all subgroups with intellectual disabilities, including the young and mildly handicapped group. The diagnosis is too often missed. All persons with severe or profound intellectual disabilities, and all older adults with Downs syndrome, should be considered visually impaired until proved otherwise.

Visual field loss associated with vigabatrin: quantification and relation to dosage.

Summary:  Purpose: To describe the correlation between visual field loss and the duration, dosage, and total amount of vigabatrin (VGB) medication in a group of patients with epilepsy. Co‐medication of antiepileptic drugs (AEDs) and compliance were also studied.

Retinal detachment in ocular toxoplasmosis.

PURPOSE To report on the clinical course and prognosis of retinal breaks and detachment occurring in patients with ocular toxoplasmosis. DESIGN Retrospective cross-sectional observational study. PARTICIPANTS One hundred fifty consecutive patients with ocular toxoplasmosis. INTERVENTION A review of all records of patients with ocular toxoplasmosis who had consulted our department from 1990 through 1997 was performed. MAIN OUTCOME MEASURES The presence of retinal detachment or breaks and possible risk factors, such as age, myopia, the interval between the last recurrence of inflammation and the onset of retinal detachment, severity of vitritis, previous treatment methods, and the location of the retinal abnormalities, were analyzed. RESULTS We found a frequency of 6% (9/150) for retinal detachment and an additional 5% (7/150) for retinal breaks among our patients with ocular toxoplasmosis. Attacks of active ocular toxoplasmosis preceding the retinal detachment or retinal breaks were characterized by severe intraocular inflammation. The frequency of myopia in our patients with retinal detachment or retinal breaks was significantly higher than in patients with ocular toxoplasmosis without retinal detachment or retinal breaks. The functional prognosis for the patients with retinal detachment was poor; legal blindness (visual acuity < or = 20/200) resulting from retinal detachment occurred in five of the nine patients. CONCLUSIONS Careful retinal examination in ocular toxoplasmosis is warranted, especially in patients with myopia and severe intraocular inflammation.

Concentric contraction of the visual field in patients with temporal lobe epilepsy and its association with the use of vigabatrin medication.

Summary: Purpose: To describe concentric visual field loss found in the presurgical evaluation of patients with drug‐resistant temporal lobe epilepsy and relate the findings to potential causative factors.

Occurrence of retained lens fragments after phacoemulsification in The Netherlands

Purpose: To determine the incidence of retained lens fragments after phacoemulsification in The Netherlands and to evaluate the effect of vitrectomy on this complication. Setting: Eleven vitreoretinal centers in The Netherlands. Methods: We performed a retrospective analysis of all patients with retained lens fragments (N = 70) who were referred for vitreoretinal surgery to 11 specialized centers. Seven patients (10%) were treated with medication alone, and 63 (90%) had pars plana vitrectomy. Minimum follow‐up after vitrectomy was 3 months. Results: The incidence of retained lens fragments in The Netherlands was calculated at 0.9/1000 cataract operations. Retained lens fragments occurred during the learning curve and with experienced surgeons. After medical or surgical treatment, visual acuity was 20/40 or better in 43 of 70 patients (61%). Uveitis disappeared in all cases. Retinal detachment occurred in 10 patients (14%). Attached retinal breaks were treated in an additional 5 patients. Corneal grafting was performed in 2 patients. Patients who had immediate vitrectomy did not have better functional results than patients in whom vitrectomy was delayed. The iris‐fixated claw lens was implanted successfully when capsular support was insufficient. Conclusions: The introduction of phacoemulsification in The Netherlands is associated with an increase of patients with retained lens fragments. Retained lens fragments are complicated by an increased risk for retinal detachment and corneal decompensation. Vitrectomy resulted in a marked improvement of visual acuity and clearing of uveitis.

Reactivations of ocular toxoplasmosis after cataract extraction.

PURPOSE To determine the risk of reactivation of ocular toxoplasmosis following cataract extraction. DESIGN Retrospective case-control study. PARTICIPANTS Out of 154 patients with ocular toxoplasmosis, 14 patients (15 eyes) who had undergone a cataract extraction and 45 age- and sex- matched controls without cataract were selected. INTERVENTION A review of the medical records of 14 patients with ocular toxoplasmosis and cataract and 45 control patients with ocular toxoplasmosis but without cataract. The clinical records of the controls and patients were assessed for an identical 4-month period following the date of the cataract extraction in the index patients. MAIN OUTCOME MEASURES Development of a new active retinal lesion within 4 months after cataract surgery in patients and age -and sex matched-controls. The presence of risk factors such as sex, congenital or postnatal acquisition of ocular toxoplasmosis, age at first clinical manifestation of ocular toxoplasmosis, total number of attacks per affected eye, type of cataract, age at the time of cataract surgery and the intervals between surgery and first clinical manifestation of ocular toxoplasmosis and between surgery and the last recurrence of ocular toxoplasmosis, as well as the use of antiparasitic medication during surgery, type and complications of surgery and optimal visual acuity before and after cataract surgery. RESULTS Reactivations of ocular toxoplasmosis following cataract extraction occurred in 5/14 patients (5/15 eyes), which was higher than the incidence of recurrences in age -and sex-matched controls (p < 0.001). No additional risk factors for the development of recurrences of ocular toxoplasmosis after cataract surgery were found. Incidence of recurrences preceding surgery did not differ between patients and controls. CONCLUSION We identified an increased risk of reactivation of ocular toxoplasmosis following cataract extraction which implies that prophylactic treatment with antiparasitic drugs during and after the cataract surgery might be worthwhile for patients at risk of visual loss.

Visual performance in specific syndromes associated with intellectual disability

Purpose To report visual performance in adults with specific causes of intellectual disability (ID) and to compare the test results to published reports. Methods In a large-scale multicenter epidemiologic study of sensory impairments in 1598 adults with ID, the authors performed ocular assessments in 1539 persons. They compared the test results of those with five specific genetic disorders (Angelman syndrome, Prader-Willi syndrome, fragile X syndrome, Williams-Beuren syndrome, and tuberous sclerosis). Results An overrepresentation of strabismus, low vision, and refractive errors was found. Apart from fragile X syndrome and Prader-Willi syndrome (with in general mild to moderate ID), the other syndrome groups contained one or more subjects with visual impairment or blindness. A number of them had never been seen by an ophthalmologist. Conclusions The authors confirm a number of ocular features previously reported by other studies and suggest some additional ocular features. They found increased frequencies of treatable ophthalmologic conditions in the subgroups. Because reliable ocular assessment is feasible for 85% of persons with ID, the results are an incentive to address visual functioning in people with ID in order to correct ocular problems and maximize their possibilities.

Ocular involvement in patients with onchocerciasis after repeated treatment with ivermectin.

We assessed ocular changes after therapy at six and 12 months with ivermectin (150 micrograms/kg of body weight) in a 12-month prospective study of 29 patients with ocular onchocerciasis and 15 patients with onchocerciasis without ocular involvement. The patients lived in a hyperendemic area in Sierra Leone, West Africa, where no vector control was instituted. Five months after initial treatment, the microfilarial load in skin and eyes had decreased significantly (P less than .0000), but 28 of 44 (63%) patients had positive skin-snip test results and nine of 29 (31%) patients with ocular involvement had active ocular disease. Twelve months after initial treatment, 15 of 41 (37%) patients had positive skin-snip test results and eight of 26 (31%) showed active ocular involvement. All patients with persistent ocular disease after therapy showed evidence of active onchocerciasis at that time, which suggests that a dose of ivermectin at six-month intervals is not sufficient for intensely infested patients with severe ocular disease. We developed an ocular involvement score to evaluate the patients total ocular status and observed a significant relation between the pretreatment severity of ocular involvement and the persistence of active ocular disease after treatment with ivermectin.

Combined sensory impairment (deaf-blindness) in five percent of adults with intellectual disabilities.

Our purpose in this cross-sectional study with 1,598 adult clients who had intellectual disabilities was to obtain valid prevalences of sensory impairments and to identify associations. The diagnoses were made through ophthalmologic and audiometric assessments, applying WHO/IASSID definitions. Re-weighted prevalences were 5.0% (95% CI 3.9- 6.2%) for the total adult population; 2.9% (1.9-4.1), less than 50 years; and 11.0% (7.9- 14.7), 50 years and over. Apart from being 50 years of age and over, p = .000, risk factors were more severe intellectual disability, p = .0001, and Down syndrome, p = .001. Results show that the risk of combined sensory impairment in this population is considerably increased compared with the general population. Part of the underlying conditions are treatable or can be rehabilitated. However, the complete diagnosis had been identified in only 12%.

Distinct cytokine patterns in the aqueous humor of children, adolescents and adults with uveitis.

Purpose: To determine the immune mediator profile in relation to age in the aqueous humor (AqH) of patients with uveitis. Methods: AqH of children, adolescents, and adults with uveitis was analyzed for 16 immune mediators. Results: No significant differences were found for IL-8, RANTES, and IP-10. The concentrations of the remaining 13 mediators were significant lower in adults compared with children and adolescents, except for IL-6, which was higher. Conclusions: Various immune mediators are present in higher concentrations in AqH of children and adolescents with different uveitis entities compared with that of adults, except IL-6, which was higher in adults.