Cataract in the Kingdom of Morocco: indications for surgery and functional results.

AIM: To investigate the results of cataract surgery in different settings in the Kingdom of Morocco. METHOD: At four separate health facilities, 100 consecutive patients undergoing ECCE cataract extraction for age-related cataract were examined pre-operatively and 6-8 weeks post-operative for changes in visual acuity. RESULTS: Thirty-four percent of patients (better eye acuity) and 95.5% of operated eyes had a visual acuity of less than 3/60 pre-operatively. Six to eight weeks post-operatively 84.0% of patients (better eye acuity) and 74.7% of operated eyes achieved a visual acuity of 6/18 or better. Of 198 eyes having an intraocular lens (IOL) implanted, 87.9% achieved 6/18 and 3.0% were less than 6/60 post-operatively. Of 202 eyes having cataract surgery without an IOL, 61.7% achieved 6/18 and 4.5% were less than 3/60. The proportion of eyes receiving an IOL in the 4 centres ranged from 29% to 74%. CONCLUSION: Monitoring the pre and post-operative acuity of cataract patients can give useful information on the indications for surgery in different settings, the use of IOLs and the visual outcome. Implantation of an IOL should be encouraged in all people having cataract surgery unless contra-indicated.

Refractive Error Study in Children: sampling and measurement methods for a multi-country survey.

PURPOSE: The Refractive Error Study in Children was designed to assess the prevalence of refractive error and vision impairment in children of different ethnic origins and cultural settings. METHODS: Population-based cross-sectional samples of children 5 to 15 years of age were obtained through cluster sampling. Presenting, uncorrected, and best-corrected visual acuity, along with refractive error under cycloplegia, were the main outcome measures. Amblyopia and other causes of uncorrectable vision impairment were determined. RESULTS: Study design and sample size calculations, survey enumeration and ophthalmic examination methods, quality assurance monitoring, and da ta analyses and statistical methods are described. CONCLUSIONS: The study design, sample size, and measurement methods ensure that the prevalence of age-specific and sex-specific refractive error can be estimated with reasonable accuracy in the target populations. With commonality of methods, a comparison of findings between studies in different ethnic origins and cultural settings is possible.

Refractive Error Study in Children: results from Mechi Zone, Nepal.

PURPOSE: To assess the prevalence of refractive error and vision impairment in school age children in the terai area of the Mechi zone in Eastern Nepal. METHODS: Random selection of village-based clusters was used to identify a sample of children 5 to 15 years of age. Children in the 25 selected clusters were enumerated through a door-to-door household survey and invited to village sites for examination. Visual acuity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, ocular motility evaluation, and anterior segment, media, and fundus examinations were done from May 1998 through July 1998. Independent replicate examinations for quality assurance monitoring took place in all children with reduced vision and in a sample of those with normal vision in seven villages. RESULTS: A total of 5,526 children from 3,724 households were enumerated, and 5,067 children (91.7%) were examined. The prevalence of uncorrected, presenting, and best visual acuity 0.5 (20/40) or worse in at least one eye was 2.9%, 2.8%, and 1.4%, respectively; 0.4% had best visual acuity 0.5 or worse in both eyes. Refractive error was the cause in 56% of the 200 eyes with reduced uncorrected vision, amblyopia in 9%, other causes in 19%, with unexplained causes in the remaining 16%. Myopia -0.5 diopter or less in either eye or hyperopia 2 diopters or greater was observed in less than 3% of children. Hyperopia risk was associated with female gender and myopia risk with older age. CONCLUSIONS: The prevalence of reduced vision is very low in school-age children in Nepal, most of it because of correctable refractive error. Further studies are needed to determine whether the prevalence of myopia will be higher for more recent birth cohorts.

The Madurai Intraocular Lens Study. I: A randomized clinical trial comparing complications and vision outcomes of intracapsular cataract extraction and extracapsular cataract extraction with posterior chamber intraocular lens.

PURPOSE: The Madurai Intraocular Lens Study (MIOLS) was designed to compare safety, efficacy, and quality of life outcomes after either intracapsular cataract extraction with aphakic glasses (ICCE-AG) or extracapsular cataract extraction with posterior chamber intraocular lens (ECCE/ PC-IOL). METHODS: The Madurai Intraocular Lens Study was a nonmasked randomized controlled clinical trial conducted at a single hospital. Thirty-four hundred patients with age-related cataracts and having a best-corrected visual acuity less than or equal to 20/120 in the better eye were randomly assigned to either of the two cataract operative procedures. The main clinical outcomes were safety (complication rates) and efficacy (best-corrected visual acuity at 1 year equal to or better than 20/40). In addition, a subset of 1,700 trial participants received questionnaires before surgery, at 6 months after surgery, and at 1 year after surgery to measure visual functioning and vision-related quality of life. RESULTS: Details of study design, study organization, clinical and quality of life outcome variables, sample size calculations, patient eligibility criteria and recruitment, randomization and masking, participant flow, adherence to follow-up, quality assurance, and statistical methods are presented. CONCLUSIONS: The Madurai Intraocular Lens Study has sufficient power to detect clinically significant differences between the treatment options. There were no statistically significant differences between the two treatment groups for any of the major study variables at baseline. A high level of quality assurance was maintained throughout the October 1993 to June 1996 study period. The results should be applicable to all settings where the requisite expertise and resources are present.

The prevalence and causes of blindness in the Sultanate of Oman: the Oman Eye Study (OES).

AIMS: To estimate the magnitude and the causes of blindness through a community based nationwide survey in Oman. This was conducted in 1996-7. METHODS: A stratified cluster random sampling procedure was used to select 12 400 people. The WHO/PBD standardised survey methodology was used, with suitable adaptation. The major causes of blindness were identified among those found blind. RESULTS: A total of 11 417 people were examined (response rate 91.8%) The prevalence of blindness in the Omani population was estimated to be 1.1% (95% CI 0.9 to 1.3), blindness being defined according to the WHO Tenth Revision of the International Classification of Diseases. Prevalence of blindness was clearly related to increasing age, with estimates of 0.08% for the 0-14 age group, 0.1% for the 15-39 age group, 2.3% for the 40-59 age group, and 16.8% for the group aged 60 +. There was a statistically significant difference between the prevalence in females (1.4%) and males (0.8%). The northern and central regions had a higher prevalence of blindness (1.3% to 3%). The major causes of blindness were unoperated cataract (30.5%), trachomatous corneal opacities (23.7%), and glaucoma (11.5%) CONCLUSIONS: Despite an active eye healthcare programme, blindness due to cataract and trachoma remains a public health problem of great concern in several regions of the sultanate. These results highlight the need, when planning effective intervention strategies, to target the eye healthcare programme to the ageing population, with special emphasis on women.

Prevalence of blindness and cataract surgery in Nepal.

BACKGROUND: A national eye care programme was launched in Nepal in the early 1980s. The impact of this programme on blindness and cataract surgery prevalence was evaluated in two geographic zones. METHODS: People aged 45 years and older were sampled using a stratified cluster design. Within randomly selected clusters, door to door enumeration was followed by visual acuity measurement and eye examinations at conveniently located sites. The full survey was preceded by a pilot study where operational methods were refined and quality assurance measures carried out. RESULTS: Of the 5112 enumerated individuals 90% were examined. Blindness, defined as presenting visual acuity less than 6/60 in both eyes, was found in 5.3% (95% CI 3.6, 6.8) of individuals examined, with cataract being the principal cause in at least one eye in 78% of cases. Considering both cataract operated and unoperated cataract blind cases, surgical coverage was approximately 42%. CONCLUSION: The findings suggest that blindness prevalence may have decreased slightly from that estimated in a 1981 national survey, both overall and cataract related. Similarly, cataract surgical coverage may have increased somewhat. None of these changes, however, are at statistically significant levels. Accordingly, the blindness problem remains challengingly high.

The global impact of eye injuries.

Using data compiled from the ophthalmic literature and WHO's Blindness Data Bank, the available information on eye injuries from an epidemiological and public health perspective has been extensively reviewed. This collection of data has allowed an analysis of risk factors, incidence, prevalence, and impact of eye injuries in terms of visual outcome. However, most of the estimates are based on information from More Developed Countries (MDCs). The severity of eye injuries can be assessed through proxy indicators such as: (i) potentially blinding bilateral injuries; (ii) open-globe injuries; (iii) endophthalmitis; (iv) enucleation or (v) defined visual impairment. Major risk factors for ocular injuries include age, gender, socioeconomic status and lifestyle. The site where the injury occurs is also related to a risk situation. Available information indicates a very significant impact of eye injuries in terms of medical care, needs for vocational rehabilitation and great socioeconomic costs. The global pattern of eye injuries and their consequences emerging from the present review, undertaken for planning purposes in the WHO Programme for the Prevention of Blindness, suggests that: some 55 million eye injuries restricting activities more than one day occur each year; 750,000 cases will require hospitalization each year, including some 200,000 open-globe injuries; there are approximately 1.6 million blind from injuries, an additional 2.3 million people with bilateral low vision from this cause, and almost 19 million with unilateral blindness or low vision. Further epidemiological studies are needed to permit more accurate planning of prevention and management measures; a standardized international template for reporting on eye injuries might be useful to this effect, along the lines of the reporting occurring through the US Eye Injury Registry.

Blindness and low vision in southeast Turkey.

In preparation for the planning of a regional prevention of blindness programme, a population-based survey of blindness and eye disease was conducted in two provinces (Diyarbakir and Mardin) of southeast Turkey. A stratified cluster random sampling procedure was used to select 8,571 persons. The main objectives of the survey were to assess the population need for basic ophthalmic services, both in rural and in rapidly growing urban communities, and to secure baseline data for subsequent evaluation of the programme. The prevalence of visual impairment (best binocular vision poorer than 6/ 18) was estimated at 1.9% with 95% confidence limits of 1.6% and 2.1%, amounting to 29,400 +/- 4500 visually imparied persons in the regional population of 1.6 million. The prevalence of blindness (best vision poorer than 3/60) was 0.4%, and an estimated 1.5% had low vision (best vision poorer than 6/18, but not blind). Compared to the blindness prevalence of 0.2% in the European Economic Community (EEC), the age-standardised prevalence of blindness in southeast Turkey was 8 times as high. The main causes of blindness in the sample were cataract (50%), corneal opacity (15%), glaucoma (12%), phthisis (6%) and optic atrophy (6%). Cataract and refractive errors were responsible for 52% and 26% of the low vision, respectively. Acute inflammatory trachoma was prevalent in a number of rural and urban communities, affecting an estimated 25,900 people in the region. The need for basic ophthalmic services was estimated for the two provinces. Some 26,600 were in need of cataract surgery, 4,400 needed eyelid surgery for trachoma-induced entropion, and 28,600 required spectacles to improve their visual acuity to 6/18 or better. More than half of the current burden of severe visual loss in the two provinces of southeast Turkey is potentially remediable through the provision of cataract surgery and of spectacles to correct aphakia. The survey findings suggest that as the age structure of the regional population approaches that of the EEC through the "ageing trend', a four-fold increase in the burden of blindness might be expected, unless improvements are made in curative and preventive ophthalmic services in parallel with the general development that improves survival.

2002 global update of available data on visual impairment: a compilation of population-based prevalence studies.

PURPOSE: For the past 25 years, the WHO Programme for the Prevention of Blindness and Deafness has maintained a Global Data Bank on visual impairment with the purpose of storing the available epidemiological data on blindness and low vision. The Data Bank has now been updated to include studies conducted since the last update in 1994. METHODS: An extensive literature search was conducted in international and national scientific and medical journals to identify epidemiological studies that fulfilled basic criteria for inclusion in the Data Bank, namely a clearly stated definition of blindness and low vision, and prevalence rates derived from population-based surveys. Sources such as National Prevention of Blindness Programmes, academic institutions or WHO country or regional reports were also investigated. RESULTS: Two-hundred-and-eight population-based studies on visual impairment for 68 countries are reported in detail, providing an up-to-date, comprehensive compilation of the available information on visual impairment and its causes globally.

[Monobloc lamellar autokeratoplasty (MLAK) and corneal cicatrization. Apropos of a comparative trial in a control group and a group treated with a L-cystine and pyridoxine hydrochloride combination]. / Autokératoplastie lamellaire monobloc (AKLM) et cicatrisation cornéenne. A propos d'un essai comparatif d'un groupe témoin et d'un groupe traité par l'association de L-Cystine et Chlorhydrate de Pyridoxine.

In pterygium cure, one piece lamellar corneo-conjunctival autokeratoplasty allows to perform a reproducible corneal injury in human clinic, and thus, to study the epithelial healing. The authors describe a comparative test on 2 groups of 18 subjects each, receiving in this blind study, either classical post-operative treatment (witness group), or in addition to this treatment: L-Cystine and Pyridoxine Chlorhydrate. Two tests are analysed: the duration of epithelial healing in one day (negative fluorescein test) and post operative "well being" (estimated on the intensity of photophobia, tears and pain). Statistical analysis (non parameter tests) display a significant difference in favor of the group treated by Cystine B 6.

[Ocular lesions in lepromatous leprosy (author's transl)]. / Les lésions oculaires de la lèpre lépromateuse.

Ocular lesions observed in III cases of lepromatous or borderline leprosy are described. Tables are included which indicate the visual acuity, corneal sensitivity, and lesions noted in the appendages. Particular attention is paid to lesions in the pars plana, which include true posterior cyclitis having the appearance of "ants eggs" or "pearls" deposits on the retina, associated with vascular lesions and peripheral hyalitis. The absence of associated mucular edema is strongly emphasized. The etiopathogenicity of lesions of this type is probably directly related to leprous erythema nodosum. Detailed studies should be conducted on the chronological stages of these affections and their subsequent progression.

[An Ota's naevus in a West African child (author's transl)]. / Naevus de Ota chez un Africain de l'ouest.

Report of a case of Ota's naevus fuscocaeruleus ophtalmomaxillaris in an african child. The authors are not aware of a previous report of this deformity in Africa (South of the Sahara). They review the clinical and histological features of this naevus and describe in this case a pigmentary infiltration of corneal stroma.

[Cataract-related blindness in Morocco. The Moroccan Group of Epidemiologic Evaluation of Blindness]. / La cataracte cécitante au Maroc. l'Equipe Marocaine d'Evaluation Epidémiologique de la Cécité.

The lack of sound and recent epidemiological data on the prevalence and causes of blindness has hampered the development and evaluation of the Moroccan Programme for the Prevention of Blindness. For this reason a population-based survey using a stratified (urban/rural) sampling design for random selection of clusters was carried out in the Kingdom of Morocco from May 15 until June 30, 1992. The procedures used for this survey were those proposed by the WHO Programme for the Prevention of Blindness. A total of 10,198 people were recruited and 8878 examined for a participation rate of 87%. The size and representativity of the sample satisfactorily guaranteed the order of magnitude and accuracy of eye health indicators used by health planners. The crude point prevalence of blindness was 0.8%, that of bilateral poor vision was 2.3%, and that of unilateral poor vision was estimated to be 2.8%. Based on these findings 195,000 people would be blind and 1,300,000 would be at risk of becoming so, for a total of approximately 1,500,000 people with serious visual impairment. Age-related cataract was the most important cause of blindness (45.5%) and bilateral poor vision (43.1%). The prevalence of cataract-related visual impairment--operable or inoperable--was estimated to be 2.1% of the survey sample. Applying a realistic algorithm to the survey data, it was estimated that the backlog for cataract surgery in Morocco in 1992 was in the order of 502,000 eyes in approximately 287,000 people. The percentage of patients who had undergone cataract surgery in hospital was 0.8%. Posterior lens dislocation according to the traditional "couching" method was noted in 0.1% of people studied. It was estimated that 25% of the demand for cataract surgery was covered by available facilities and that 40% of people with aphakia could not obtain eye care.

[Trachoma prevalence in the Sahel: report of a 1978 survey in Gourma area (Mali) (author's transl)]. / Réalité du trachome au Sahel. A propos d'une enquête dans la région du Gourma (Mali) 1978.

Report of a survey conducted in 1978 in the Niger sweep on a population consisting for one third of adults and for two thirds of children and adolescents. 2.571 persons have been controlled, giving evidence of 441 cases of trachoma (17,15 p. 100), 327 of which were evolutive and 114 cicatricial; 30,4 p. 100 of the cases were severe and 10 p. 100 suffered of a loss of visual acuity.

[Late aspects of palpebral anthrax (author's transl)]. / Le charbon palpébral en fin d'évolution.

Report of 5 cases of palpebral anthrax treated after the acute phase, in a cicatricial or precicatricial stade. The authors recommend to delay plastic surgery up to three months and to select total skin graft for upper eye-lid and pediculed skin flap for lower eye-lid.

[Corneal sensibility in 57 black Africans. A study based on 113 biomicroscopically normal ocular globes (author's transl)]. / Etude de la sensibilité cornéenne chez 57 Africains de race noire. A propos de 113 globes biomicroscopiquement sains.

This study of the corneal sensitivity in 57 sahelian black Africans with a biomicroscopically normal cornea demonstrated that most of them (80,8 p. 100) had a normal corneal esthesia. The others (19,2 p. 100) having an hypoesthesia are older than the average age of this group and have a lower sociocultural status.

[Blindness in Benin]. / La cécité au Bénin.

A population-based survey of the prevalence and cause of blindness and poor vision was conducted in the Republic of Benin in 1990 using a stratified cluster random sampling procedure. The survey was designed and implemented through the collaboration of the Ministry of Health of the Republic of Benin and the Programme for the Prevention of Blindness of the World Health Organization (WHO/PBL). Survey data were analyzed at the International Centre for Eye Health, Institute of Ophthalmology, University of London, United Kingdom. In accordance with the procedures recommended by WHO/PBL, 7272 individuals were recruited and 7047 were examined. The survey achieved excellent coverage in all locations with an overall coverage of 96.9%. The prevalence of blindness (visual acuity less than 3/60 in the better eye) was 0.6% (CI95% = 0.4%-0.9%). The prevalence of poor vision (best vision less than 6/60 but not blind in the better eye) was estimated at 2.6% (CI95% = 2.1%-3.1%). The major causes of blindness were age-related cataract and glaucoma (54% and 15% respectively of blind people recruited). The major cause of poor vision were cataract, refractive errors, and macular disorders (64%, 9.6%, and 9.0% respectively of people recruited with poor vision. The survey results indicate that there is an urgent need for basic eye care services. Cataract has been designated as a priority target in the recently designed National Blindness Prevention Programme now being implemented in the Republic of Benin. With proper management of this problem, the current prevalence of blindness and poor vision could be reduced by at least 45%. At the end of this cluster study, the design effect (D = 1.56) and rate of homogeneity (ROH = 0.002) were computed for an average number of 250 people per cluster.

[Trachoma in Senegal: results of a national survey]. / Le trachome au Sénégal: résultats d'une enquête nationale.

A national survey was conducted to determine the prevalence of trachoma in Senegal between February and July 2000. The methodology consisted of a cross-sectional survey based on random sampling with two levels of stratification in five areas or area groups. A total of 12,328 children under 10 years of age and 8753 women over the age of 14 years were examined from 150 clusters (30 clusters per stratum). Excluding the Dakar stratum, the estimated prevalence of active trachoma (TF/TI) and severe trachoma (TI) in children under 10 years of age was 10.8% (IC 95%: 9.2-11.4) and 1.2% (IC 95%: 0.5-2.3) respectively. The corresponding prevalence for the areas around Dakar were 3.3% et 0.3%. Prevalence rates were highest between the ages of 2 and 3 years (17.4%). However these rates concealed major differences between strata since prevalence ranged from 3.3% in Dakar to 14.2% in Thiès-Diourbel. Excluding Dakar, the estimated prevalence of entropion/trichiasis and corneal opacity among women over the age of 14 years was 2.6% (IC 95%: 1.9-3.4) and 1.4% (IC 95%: 0.9-1.8). The prevalence of trichiasis was over 1% in every area except Tambacouna and reached 4% in Thiès-Diourbel. Trichiasis was observed in 17.1% of women over the age of 70. Based on extrapolation of these data to the whole country, it can be deduced that 272,020 children have active trachoma requiring medical treatment and that 115,000 persons over 14 years of age present trichiasis requiring surgical treatment.

[Orbital and ocular tumors in the Republic of Mali]. / Les tumeurs orbito-oculaires en République du Mali.

Analysing 82 cases of oculo-orbital tumours in Malian patients, the authors find the classical features characterizing ocular carcinoma in Africa, i.e. early arising, development, late request for treatment. They stress on the age of the patients at the occasion of the first request for treatment in case of retinoblastoma, and notice the special frequency of squamous cell carcinoma with conjunctival or limbic localization.

[Prevalence and causes of blindness in the Tunisian Republic. Results of a national survey conducted in 1993. Tunisian Team on the Evaluation of Blindness]. / Prévalence et causes de la cécité en République tunisienne. Résultats d'une enquête nationale conduite en 1993. L'équipe tunisienne d'évaluation de la cécité.

AIMS: to estimate the prevalence of visual impairment and blindness; to identify the major causes of visual impairment and blindness and to estimate their overall impact, particularly on cataracts. METHODS: We used a population-based method. A cluster sample was selected, with the number of households randomly selected from a community depending on the size of the population. Examinations and data collection were carried out using the procedures recommended by the WHO. RESULTS: We included 3,981 individuals, 3,547 of whom were given a medical examination (89% participation). The structure of the sample differed from that of the Tunisian population, with people over the age of 60 years over represented in the sample. The crude prevalence of blindness was 1.2% (adjusted prevalence 0.8%) and that for bilateral visual impairment was 3% (adjusted prevalence 2%). There were 225,000 individuals with severely impaired vision, of whom 64,500 were blind (including 2,100 children under the age of 15 years) and 160,000 were visually impaired (including 8,700 children). Individuals over the age of 60 were eight times more likely to become blind and 6.7 times more likely to suffer visual impairment than those below the age of 60. Cataracts, particularly associated with aging, were the main cause of blindness (66%) and bilateral visual impairment (54.6%). Uncorrected aphakia accounted for a significant fraction of the visual deficiencies identified in this survey (6.4% of cases of blindness and 11.8% of cases of bilateral visual impairment). 1.7% of the individuals examined (135,000 people) had ocular surgery and 80,000 had undergone surgery for cataracts. Only 41% of those individuals who had cataracts had undergone surgery. The provision of cataract surgery was therefore inadequate. CONCLUSION: About 80% of the cases of blindness registered were preventable or treatable. The development of appropriate strategies for dealing with cataract blindness should significantly reduce the incidence of blindness.