The Moorfields Safer Surgery System: preventing glaucoma blindness in the Caribbean

Introduction: Glaucoma is the leading cause of blindness in the Caribbean, accounting for 28.4% in Barbados and 32% in Trinidad and Tobago (T&T). In T&T, 28% of glaucoma patients miss clinic appointments and 40% are non-compliant with eye drops. There is a role for surgery in preventing glaucoma blindness. However, the complications of mitomycin C trabeculectomy (MMCT) have deterred local ophthalmologists and patients from selecting this option. The Moorfields Safer Surgery System (MSSS) allows simple modification of surgical technique which can be implemented to improve surgical outcomes. Purpose: To demonstrate the safety and efficacy of the MSSS in the Caribbean. Methods: Thirty-three consecutive MMCT procedures were performed by a single surgeon using the MSSS. Patients were of African descent, 16 male and 8 female. Median age was 56 years (range 34-79 years). Mean pre-operative intraocular pressure (IOP) 23.2 mmHg. In 38%, best-corrected visual acuity (BCVA) was ≤3/60 in at least one eye. Results. IOP was ≤21 mmHg in 92.6% of patients at 1 year and in 87.5% at 5 years. Removal of scleral releasable suture(s) was required in 85%, 5-fluorouracil injection(s) in 85% and bleb needling in 36%. The most common complication was early bleb leak (52%). 91% had excellent or satisfactory bleb morphology. No patient developed endophthalmitis. 73% had equal or better BCVA in the operated eye. Conclusion: Glaucoma in the African Caribbean population is an aggressive disease which affects young adults. Late presentation and non-adherence to topical treatment favour surgical intervention. This study provides evidence that knowledge and skills transfer of the MSSS to the Caribbean is possible. Surgical success and complication rates comparable to best published international data can be achieved.

Optic disk anomalies [abstract]

There are a number of development defects of the nerve that result in disk anomalies that present as diagnostic and management problems. These include pseudo-papilloedema, disk hypoplasia; crescent anomalies; and partial colobomas. These will be discussed in clinical context, especially "misdiagnosis". (AU)

The black eye

PURPOSE: The paper highlights the differences in appearance of the normal and diseased states and frequency and nature of disease processes as they occur in the eye of persons of African descent compared with the Caucasian. METHODS: The observations of an opthalmologist who has practised in a racially mixed population, but predominantly among individuals of African descent for over 20 years, have been catalogued and compared with his experience in a predominantly Cacucasian community. Photographic images of these differences are presented. RESULTS AND CONCLUSIONS: Significant differences in both the normal apperance and clinical features of important ocular diseases occur between patients of predominantly African origin and Caucasians. It is important that ophthalmologists practicising among these racial groups be aware of the differences.(AU)

Health policy and eye care services in Jamaica

PURPOSE: To test the hypothesis that access to and amount of eye care services in Jamaica are inadequate and that this is related to insufficient eye care personnel and legal limitations on optometric practice in Jamaica. METHODS: An eye care provider survey, a consumer survey, and a literature search were used for data collection. The consumer sample consisted of 500 subjects (aged 16 to 84 years or older) recruited from a stratified random sample of food markets in Jamaica. The provider sample consisted of 10 opthalmologists and 10 optometrists, randomly selected from licensing rosters. Adequacy of amount of eye care services was measured by comparing the frequency of eye examinations in Jamaica with professinal practice guidelines. Access was measured by the eye provider to population ratio compared with calculated need for adequate care. RESULTS: Only 38.6 percent of the study population had received an eye examination within 3 years and only 23.4 percent reported having eye examinations at least once every 3 years. Over 43 percent had never received an eye examination. The total eye care provider/population ratio was only 2.04/100,000 and only 1.32/100,000 when optometrists are excluded. CONCLUSION: Access to and amount of eye care professionals services are severely inadequate in Jamaica. Outdated optometric laws governing the activities of eye care professionals compound the problem. (AU)

The Barbados eye study: major prevalence findings - abstract

This study has been designed to provide information about the visual loss in the predominantly Afro-Caribbean population in Barbados. The prevalence, incidence and risk factors of eye disease were studied in a random population sample of 4,709 Barbadian-born people 40 - 84 years of age. Data collected included visual acuity, applanation tonometry, automated perimetry, lens grading, disc and macula photographs along with histories and other clinical measurements such as blood pressure. Data on visual acuity showed that 12 percent of subjects had impairment of vision worse than 6/12 whislt 3.4 percent had severe loss ( > 6/60). Open angle glaucoma (OAG) was diagnosed on the criteria of visual field loss and typical optic disc pathology in at least one eye. Six percent (309 persons) were diagnosed as having OAG, 3.6 percent as suspect OAG and 12 percent had intraocular pressure higher than 21 mm Hg. Prevalence of OAG increased with age, reaching 25 percent in men and 22 percent in women 80 years of age and over. Half of the cases found had been previously diagnosed. Analysis suggests that the risk factors for OAG are: older age, males, high intraocular pressures, a history of cataract and a lean body mass. Diabetes, hypertension, cardiovascular disease and obesity were not identified as risk factors in this study. Lens opacities were frequent (44 percent), and increased in frequency with age. Of those persons with visual acuity less than 6/12, 75 percent had cataracts. These findings should be helpful in implementing blindness prevention programmes (AU)

The general practitioner and the diabetic eye - abstract

Diabetic patients are 25 times more likely to suffer blindness than non-diabetics. General practitioners form the first link in the clinical care of diabetic patients, and their role as screeners is extremely important. An early detection and a prompt control of the disease can greatly minimize the disabilities and the associated psychological and social consequences. The aim of the therapy is to prevent the development, or at least to reduce the severity, of retinopathy, nephropathy, neuropathy and macro-vascular disease. It may not be possible to adequately control this non-specific vascular disease, but the risk factors like hypertension, hyperlipidaemia and obesity can be fully controlled by using simple measures to reduce the morbidity. A good control of diabetes mellitus certainly decreases the incidence as well as the severity of retinopathy. It is well accepted now that the lower the mean blood glucose level, the lower are the micro-vascular complications, and the younger the patient the tighter should be the glycaemic control. The quality of glycaemic control can be assessed more accurately nowadays by the levels of glycated haemoglobin. Primary care physicians must be particularly thorough when examining these patients and look for abnormalities in other systems also. The rising incidence of morbidity is related to increased longevity and an inability to detect and prevent the various complications. A regular observation for an early recognition of retinal complications is essential. Non-insulin-dependent diabetics should be examined by an opthalmologist at the time of diagnosis and insulin-dependent diabetics should be seen once every year. A diabetic patient should be encouraged to actively participate in the self-management of the disease with proper education and motivation with a frequent review of compliance. A general practitioner may not have sufficient experience in recognizing the ocular complications of diabetes mellitus. Their screening performance can be greatly improved by short courses of instruction in opthalmology departments at various institutions (AU)

The clinical features of sickle cell disease

Evidence from structural studies of DNA suggest that the sickle cell mutation has arisen on at least three separate occasions in Africa and as a fourth independent mutation in the Eastern Province of Saudi Arabia or India. The pathophysiology of sickle cell disease is essentially similar in these different areas although the frequency and severity of complications may vary between areas. Generally, the chronic haemolysis and resulting anaemia is well tolerated, although serious morbidity and occasionally mortality may be associated with the aplastic crisis or cholelithiasis. Exacerbation of anaemia below steady state levels occurs with chronic glomerular damage and renal failure, especially in older patients. Most of the morbidity of the disease arises from bone marrow necrosis in the painful crisis or from vaso-occlusive manifestation. Changes in the splenic circulation results in life-threatening episodes of acute splenic sequestration, the chronic morbidity of hypersplenism, and splenic dysfunction renders children prone to pneumococcal septicaemia. Chronic organ damage contributes to chronic leg ulceration in adolescence and progressive renal,pulmonary,and occasionally cardiovascular impairment in later life. The clinical spectrum of homozygous sickle cell disease varies widely between patients. Factors contributing to this variability include alpha-thalassaemia,persistence of high HbF levels, haematology, social circumstances, and geographical and climatic variation. Many of the causes of mortality may be prevented or more effectively treated,leading to increased survival and an increased quality of life in affected subjects (AU)

The Barbados eye study: design and progress report - abstract

The Barbados Eye Study is determining the prevalence and risk factors of major causes of visual loss in a random sample of the population between ages 40 and 84 years. All participants have visual acuity (VA) measurements, applanation tonometry, computerized perimetry, lens gradings, fundus photography, glycosylated haemoglobin, interview, blood pressure and anthropometry. Persons with positive test results and a 10 percent sample of all participants also have an opthalmologic examination, additional threshold perimetry and tonometry. The study also has a longitudinal component, the glaucoma follow-up study, which provides continuing care and evaluation for newly detected cases of glaucoma and suspect glaucoma. Recruitment of the intended sample size of 4,000 persons is expected to end in 1991. By November 1990, 3,095 persons had completed data collection with a participation of 87 percent of those eligible. Preliminary findings show a prevalence of visual impairment (VA < 20/40 in the better eye) of 11.5 percent, age-related cataract, age-related maculopathy, open-angle glaucoma and diabetic retinopathy were main causes of decreased VA. Blindness prevalence (VA < 20/200 in the better eye) was 3.2 percent; open-angle glaucoma and age-related cataract were the major causes of blindness. Results suggest a high prevalence of open-angle glaucoma as found in an earlier pilot project. Hypertension and diabetes mellitus were also very frequent in this population (AU)

Variations of the prevalence of IgG and IgM antibodies to Toxocara in Trinidadian school children - abstract

Toxocara involvement in ocular lesions was suspected following the high frequency of IgG antibodies in serum samples of patients attending the Eye Clinic at the General Hospital, Port-of-Spain. Also, a high prevalence of IgG antibodies to Toxocara was found in 5-9 year-old children in certain Caribbean islands. Fifty children, aged 6-15 years with equal numbers of boys and girls, were randomly selected from 5 schools in rural South and Central Trinidad. A stool sample (examined for parasites) and a 5ml blood sample were obtained from each student. Serum from 17 patients with ocular symptoms and from 39 patients with other symptoms were also examined. Serum IgG and IgM antibodies (to Toxocara) were determined by ELISA method. Fifty children from one school were given a thorough eye examination. The prevalence of antibodies seemed to increase with age, from 54 per cent in 5-7 year olds to 87 per cent in 12-13 year olds for IgG, and from 56 per cent to 61-63 per cent for IgM antibodies. IgG antibodies to Toxocara were more prevalent in males than females, but there was no positive correlation with reported geophagia or association with domestic pets. There was a higher prevalence of IgGs (88 per cent) in sera from patients with ocular lesions than in those without such lesions (39 per cent, p<0.01). Results suggest the need for a comprehensive study of toxocariasis in childhood in Trinidad and Tobago (AU)

Eye lesions in leprosy - abstract

It has been reported that there has been a high incidence of eye lesions in leprosy. Thirty-seven patients of the Hansen Home, Spanish Town, have been examined clinically, by ophthalmoscope and slit lamp, as part of a preliminary survey. Thirteen cases showed no demonstrable eye lesions and fifteen cases had lesions considered due to leprosy.(AU)

Sickle cell retinopathy in young children in Jamaica

Ophthalmological examinations were performed on 59 of the 74 (80 percent) children with homozygous sickle cell (SS) disease and on 37 of the 54 (69 percent) children with sickle cell-haemoglobin C(SC) disease, aged 5-7.5 years, within the cohort study of sickle cell disease. Arteriolar sheathing was the commonest retinal vessel abnormality, occurring in 30/59 (51 percent) SS children and in 11/37 (30 percent) SC children. Peripheral arteriolar closure was observed in 14 (24 percent) SS children and in 6 (16 percent) SC children. Arteriovenous anastomoses were seen in 3 children, but proliferative retinopathy was not identified. Capillary changes often occurred in patients without confluent closure, suggesting that complex remodelling of the capillary bed may precede retinal nonperfusion. Discrete retinal patches similar to schisis cavities resulting from intraretinal haemorrhages were found in 22 (37 percent) SS children and in 9 (24 percent) SC children, but haemorrhages were observed in only 2 patients (1 SS, 1SC). Vitreous opacities were common and were generally associated with retinal vessel disease. Retinal changes were consistently more common in children with SS disease, though the differences failed to reach statistical significance. The prevalence of peripheral vascular closure and retinal patches showed a significant upward trend with age. These observations contrast with the greater prevalence of proliferative retinopathy characterising SC disease in adults.(AU)

Lens implant surgery in a developing country

Unilateral, mostly traumatic cataract in children and adults is considered a good indication for lens implant surgery in developing countries. In Suriname fourteen patients with unilateral, non-senile cataract underwent pseudophakos surgery from 1975 to 1980. No major complications occurred. In ten of the fourteen patients good binocular vision was achieved. Two patients had good visual acuity with poor fusion. One patient had persistent deprivation amblyoplia. Six patients were ultimately lost to follow-up.(AU)

Ocular findings in elderly cases of homozygous sickle-cell disease in Jamaica

The ocular findings in 60 patients with homozygous sickle-cell disease over the age of 40 years have been described. Peripheral retinal vessel disease was common and appeared to increase with age. Retinitis proliferans was common among older patients in the group. Angioid streaks occurred in 13 (22 percent) patients. (Summary)

The clinical features of haemoglobin SC disease in Jamaica

The clinical and haematological features of 90 Jamaican patients with haemoglobin SC disease are reviewed. Mean haemoglobin levels indicated mild anaemia although individual haemoglobin levels were often within the normal range. The clinical features were qualitatively similar to those of homozygous sickle cell disease(SS disease) although they were generlly less frequent and of lesser severity. Ocular pathology was an exception, occuring more frequently in SS disease even in age-sex-matched groups. There is some evidence that the higher haemoglobin level in SC disease may be aetiologically related to retinal vascular disease. (AU)