PURPOSE: Non-linear regression analysis was used to determine dark adaptation indices in people with retinitis pigmentosa and in control subjects.
METHODS: Dark adaptation data were collected for 13 people with retinitis pigmentosa and 21 controls using the Goldmann-Weekers Dark Adaptometer. Data were analysed using an exponential non-linear regression model and dark adaptation indices derived. The results were compared to age-related values.
RESULTS: The mean cone threshold of the group with RP (4.73 +/- 0.19 log units) was significantly greater than that found in the control group (3.69 +/- 0.12 log units). The rate of cone dark adaptation in the RP group was not significantly different from that of the control group. The a break in the RP group (6.46 +/- 0.70 minutes) was delayed when compared to the control group (4.29 +/- 0.21 minutes) and the rate of rod dark adaptation in the RP group was slower (10 +/- 2 per cent per minute) than that of the control group (15 +/- 1 per cent per minute).
CONCLUSIONS: This study has shown that a relatively simple data analysis can provide a more quantitative and intuitive description of dark adaptation rates in people with retinal disease. This technique will enable more effective use of dark adaptometry as a supplement to objective electrophysiology, when monitoring people with retinitis pigmentosa.
Study site: Retinitis Pigmentosa Society of NSW, the National Foundation of Blind Citizens in New South Wales and the Low Vision Clinic of the School of Optometry University of NSW, Australia
Kearns-Sayre syndrome (KSS) belongs to the group of neuromuscular disorders known as mitochondrial encephalomyopathies. It has characteristic syndromal features, which include: chronic progressive external ophthalmoplegia, bilateral atypical pigmentary retinopathy, and cardiac conduction abnormalities. So far, only a single case has been reported where a patient with KSS had a normal retina. Herein, we report this extremely rare variant of KSS, which not only presented later than the normal age of presentation, but also had minimal pigmentary retinopathy.
BACKGROUND: The most common autosomal form of Chronic Granulomatous Disease, p47-phox deficient CGD, generally features a GT (deltaGT) deletion in the GTGT sequence at the start of exon 2 on the NCF-1 gene. This consistency is due to the coexistence of and the recombination between 2 homologous pseudogenes (psi s) and NCF-1. The GTGT: deltaGT ratio mirrors the NCF-I: NCF-1 psi ratio and is 2:4 in normal individuals.
OBJECTIVE: To determine the molecular basis of the Autosomal-CGD in a family with 2 children, a male and female, affected by the disease. The female patient suffered recurrent infection, retinitis pigmentosa and discoid lupus.
METHODS: Chemiluminescence (CL) was used to study the respiratory burst, while genetic analysis was done by RT-PCR, PCR, deltaGT and the 20bp gene scans.
RESULTS: The CL response of the patient was profoundly low. The patient's p47-phox band was absent in the RT-PCR for NADPH-oxidase component mRNAs. The deltaGT scan showed that the patient's GTGT: deltaGT ratio was 0:6, the parents' and the younger brother's was 1:5 and the younger sister's was 2:4. Examination of other NCF-1/ NCF-1 psi s differences showed that the father had a compound deltaGT allele ie. deltaGT-20bp, inherited by the patient, and that both parents had compound GTGT alleles with a single 30bp segment in intron 1.
CONCLUSIONS: The patient was a classic, homozygous deltaGT p47-phox deficient CGD with one allele harbouring a compound deltaGT-20bp gene. The deltaGT and 20bp gene scans offer a relatively simple and efficient means of defining a p47-phox deficient CGD patient.
Key words: Chronic Granulomatous Disease, Primary Immunodeficiency, NCF-1, p47-phox, NADPH-oxidas
When medical and surgical intervention cannot alleviate all of the impairments resulting from diseases of the eye, visual rehabilitation can help reduce the disability and increase the quality of life. Data from 169 patients seen at the UKM Low Vision Clinic (UKM LVC) over the past 2 years were examined and analysed. The age ranged from 6 to 87 years of age. The main cause of ocular pathological categories was conduction (63.9%), media (24.9%) and congenital (11.2%) related problems. The main causes of low vision at UKM LVC were congenital cataract, retinitis pigmentosa, glaucoma, cataract and diabetic retinopathy. 84% of these patients received low vision devices to improve their near or/and distance vision. The most common optical devices dispensed at UKM LVC were near high addition spectacle, hand magnifiers and stand magnifiers. Medical, vision care and rehabilitation professionals working together can offer a comprehensive treatment plan for the visually impaired, offering these patients the very best services to increase their quality of life.
While the prevalence of visually impaired children constitutes a small portion of the visually impaired population, it is important to determine whether the low vision services available are utilised by these children. This is important as previous studies have shown that children have a very high rate of successful low vision device use compared to adults. This was a cross sectional retrospective study. Fifty nine low vision clinic children records were evaluated. The results showed that 25.4% of the children were categorised as with moderate low vision, 30.5% with severe low vision and 40.7% were categorised as blind. The major causes of low vision were congenital cataract, congenital nystagmus, congenital glaucoma, macular degeneration and retinitis pigmentosa. Low vision rehabilitation for near work using magnifiers improved the vision of 30.5% of the low vision children. This finding suggests that 1/3 of low vision children could benefit from low vision rehabilitation. The low vision devices most commonly prescribed to the children in this study were stand magnifiers, hand-held magnifiers and spectacles. This study illustrates the key role of optometrists in the management of visual impairment in Malaysian children. It would appear that the establishment of low vision services in government hospitals using trained optometrists is a cost effective method of service delivery. Therefore more low vision children would have access to proper low vision rehabilitation and through that rehabilitation, their quality of life can be improved.
Key words: children, low vision
Study site: Klinik Penglihatan Terhad Pusat Perubatana, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
One hundred and sixty-five children from the school for the deaf were screened to find out the aetiology of deafness. The screening included routine ophthalmological examination. Aetiology was unknown in 33 children (20%). Prenatal infection was found to be the cause of deafness in 61 cases (36.96%). Rubella eye signs were found in 59 children (35.76%), whereas the history of rubella infection during the first trimester of pregnancy was found in only 33 of these cases (55.93%). Perinatal complications were seen in 20 children (12.12%). Twenty children (12.12%) had meningitis during their early childhood period. Routine ophthalmological examination helped us to pick up cases with rubella eye signs. Ophthalmological examination should be included as part of any study done to find out the cause of deafness.
BACKGROUND: Causes of low vision and types of low vision devices (LVDs) prescribed in other low vision clinics have been studied extensively. Similar studies have not been conducted in Malaysia. This paper reports the results of a retrospective study of 573 patients seen at the Universiti Kebangsaan Malaysia-Malaysian Association for the Blind (UKM-MAB) low vision clinic in Kuala Lumpur. METHODS: The record cards of 573 patients seen at the UKM-MAB clinic over 10 years were examined and the following information extracted: date of first consultation, age, sex, cause of visual impairment as diagnosed by an ophthalmologist and types of low vision devices (LVDs) prescribed. RESULTS: The majority of patients were from the younger age groups with 423 (73.8 per cent) less than 50 years of age. Three hundred and ninety-five (68.9 per cent) of the subjects were males and 178 (31.1 per cent) female. The main causes of low vision were congenital structural defects including nystagmus among patients in the zero to 29 years age group, retinitis pigmentosa among the 30 to 59 years age group and age-related macular degeneration (ARM) among those over 60 years of age. CONCLUSIONS: Since the majority of the patients were from the younger age group the main causes of low vision were congenital and hereditary diseases. Three hundred and forty-one (59.5 per cent) patients seen at the low vision clinic accepted the use of LVDs.
A decrease in the anterior capsule opening after cataract surgery has been observed in eyes with weakened lens zonules. It commonly occurs in diabetes mellitus, uveitis, pseudoexfoliation syndrome, high myopia, and elderly patients. Herein, we report the case of a middle-aged man with advanced retinitis pigmentosa who developed a rapid contraction of the anterior capsule after an uneventful phacoemulsification surgery that resulted in severe visual loss during the early postoperative period.
Tunnel vision is a classic sign among patients with advanced glaucoma. However, other conditions such as retinitis pigmentosa, optic neuritis and rod-cone dystrophy may be characterized by similar visual field defects. A 52-year-old lady with a family history of glaucoma presented with bilateral gradual loss of peripheral vision for two years. She claimed to have poor night vision about 20 years prior to this presentation. Her visual acuity was 6/7.5 in both eyes. The anterior chamber depth was moderate bilaterally, with Schaffer grading on gonioscopy of grade I to II. The intraocular pressure was 14 mmHg in both eyes. The optic discs appeared normal. Fundus examination showed scattered hypopigmented changes sparing the fovea. Humphrey visual field test revealed bilateral constricted visual fields. She was diagnosed with retinitis punctata albescens (RPA) based on her symptom of poor night vision, supported by the diffuse hypopigmented changes in her fundi. The management of this condition involves careful counselling regarding the genetic nature of the disease and its progressive course. We discuss this case to illustrate the importance of a thorough history taking and careful fundus examination in the workup of patients presenting with tunnel vision.