Burden and clinical profile of genetic eye diseases in children in Nigeria: a descriptive cross-sectional study

Introduction

ophthalmic genetics is rapidly evolving globally but is still nascent in much of sub-Saharan Africa, with gaps in knowledge about the burden in the region. This study evaluated the burden and manifestations of genetic eye diseases in children in Ibadan, Nigeria.

Methods

this was a hospital-based cross-sectional study in which new and follow-up paediatric eye clinic patients were recruited consecutively at the University College Hospital, Ibadan. Children with genetic eye diseases had comprehensive ocular and systemic examinations, and their pedigrees were charted to determine the probable modes of inheritance. The main outcome variables were the proportion of study participants with genetic eye diseases, the probable modes of inheritance, and the clinical diagnoses. Summary statistics were performed using means and standard deviations for numerical variables and proportions for categorical variables.

Results

fifty-two (12%) of 444 children had genetic eye diseases, and their mean (SD) age was 88.8 ± 50.4 months. Thirteen different phenotypic diagnoses were made following the evaluation of the 52 children, including primary congenital glaucoma (13, 25%) and familial non-syndromic cataracts (8, 15%). The probable modes of inheritance were derived from the pedigree charts, and 30 (58%) conditions were presumed to be sporadic.

Conclusion

this study demonstrated a significant burden and a wide range of paediatric genetic eye diseases in this tertiary referral centre in Nigeria. This information provides invaluable evidence for planning ophthalmic genetic services.

LONG TERM OUTCOMES OF AUGMENTED TRABECULECTOMY WITH 5-FLUOROURACIL IN NIGERIA

BACKGROUND

Glaucoma in sub-Saharan Africa has been described as a surgical disease because of the high cost of medical treatment, poor compliance and unavailability of medications.

AIM

This study reports the long-term outcomes and complication rates following trabeculectomy with 5-fluorouracil in a case series of Nigerians.

DESIGN OF STUDY

This was a retrospective, observational, non-comparative case series.

SETTING

University College Hospital, Ibadan, Nigeria.

METHODOLOGY

Each patient had complete ophthalmic evaluation. The post-operative intraocular pressure (IOP), visual acuity outcomes and post operative complications were assessed. The World Glaucoma Association consensus on surgical outcome was used to evaluate surgical outcome.

RESULTS

Of the 292 patients who presented with glaucoma during this period, a total of 47 eyes of 31 patients (10.6%) had trabeculectomy with 5-FU. The mean presenting intraocular pressure (IOP) was 31.8±12.2mmHg. At three years post-operatively, 48.5% achieved complete success without medications while 90.9% achieved success with or without medications at an IOP cut off of ≤21mmHg. At the same time point of 3 years and an IOP cut off of ≤15mmHg, 63.6% achieved success with or without medications. At a mean post-operative period of 43± 19.6 months, (range 12-86 months), mean IOP had reduced from a preoperative mean of 31.8±12.2mmHg to 15.4±4.7mmHg (P<0.001).

CONCLUSION

Trabeculectomy with 5-Fluorouracil is effective in the long term in reducing IOP with minimal complications in this population of Nigerians.

Visual outcome after cataract surgery at the university college hospital, ibadan

Aim:

The aim of this study was to determine the visual outcome of patients who had cataract surgery in the University College Hospital Ibadan.

Methodology:

This is an observational descriptive, longitudinal study of consecutive patients undergoing cataract surgery at the University College Hospital conducted between May and October 2007. A total of 184 patients who presented to the hospital and met the inclusion criteria were recruited into the study. Patients were examined preoperatively, 1st day postoperatively and 8th week postoperatively.

Results:

The mean age was 66.5 years; and the male to female ratio was 1.2:1. Preoperatively, 137 patients (74.5%) were blind in the operated eye, while 39 patients (23.6%) were blind in both eyes at presentation. At 1st day postoperatively, 87 patients (47.3%) had pinhole visual acuity of 6/6-6/18. Best corrected vision after refraction eight weeks postoperatively showed that 127 patients out of 161 patients (78.8%) had good vision while 28 patients (17.4%) had borderline vision, and six patients (3.8%) had severe visual impairment after refraction. The number of bilaterally blind patients also reduced from 39 (23.6%) to one (0.6%). Uncorrected refractive error was the commonest cause of poor vision prior to refraction. Glaucoma was the commonest ocular co-morbidity accounting for poor vision in 9.1% of patients eight weeks after cataract surgery.

Conclusion:

This study demonstrates that good results can be obtained with cataract surgery and intraocular lens implantation in the developing world. More attention should be directed towards ensuring that successful outcomes are indeed being realized by continued monitoring of postoperative visual outcomes and prompt refraction for all patients.

Risk factors for pterygium recurrence after surgical excision with combined conjunctival autograft (CAG) and intraoperative antimetabolite use

BACKGROUND

To identify the determinants of recurrence following primary pterygium excision combined with conjunctival autograft (CAG) and intraoperative use of Mitomycin C (MMC) or 5-Fluorouracil (5-FU).

METHODS

A randomized controlled clinical trial comparing 5-FU (50 mg/ml) plus CAG versus MMC (0.01%) plus CAG in preventing recurrence of primary pterygium following excision.

RESULTS

A total of 80 eyes of 80 subjects were studied, with 46 eyes in the 5-FU group and 34 eyes in the MMC group. The mean age was 50.7 +/- 13.1 years with a male: female ratio of 0.95:1. Mean follow up period was 35.2 +/- 29.1 weeks. The overall recurrence rate was 10%, with a rate of 8.7% in the 5-FU group and 11.8% in the MMC group. The mean age of the patients who had a recurrence was 38.1 +/- 13.3 years compared to 52.1 +/- 12.4 years in those without a recurrence (p = 0.003). The median size of the pterygium in patients who had a recurrence was 3.2mm, while the median size in patients who did not have a recurrence was 3.0mm (p = 0.8). Five (12.8%) males had a recurrence compared to three (7.3%) females (p = 0.48); while 10.5% of fleshy pterygia recurred compared to none (0%) of the non-fleshy pterygia (p = 1.00).

CONCLUSION

Younger age remains a risk factor for recurrence when both CAG and antimetabolites are combined in the treatment of pterygium, while the effect of gender, size and morphology of the pterygium may be diminished by such combination.

Congenital orbital teratoma: a case report and challenges of its management in a resource limited setting

We report a case of congenital immature teratoma of the orbit in a female neonate who presented on the second day of life. She was successfully managed by modified exenteration. The patient was lost to follow-up intermittently over a 24-month period without recurrence of the tumour. However the patient could not be traced again after 24 months of follow up. This happened despite concerted efforts to educate the parents. The possible implications of this and other social factors, in a challenging and resource limited setting, on the prognosis of the disease and cosmetic outcome are considered.

Perception and attitude of people toward onchocerciasis (river blindness) in South Western Nigeria

Background:

Onchocerciasis (river blindness) is a major cause of bilateral blindness with devastating socioeconomic consequences. Since Nigeria is the most heavily onchocerciasis endemic country in the world, the information on people’s knowledge about this disease is significant. This could influence their response to current preventive measures of the African Programme for Onchocerciasis Control.

Aim:

This study was designed to estimate the level of knowledge and attitudes of rural/semi-urban communities in Ife North Local Government Area of Osun State toward onchocerciasis.

Materials and Methods:

Cluster random sampling was used to select 500 adults for the study. Semi-structured questionnaires were administered to subjects. Data on knowledge of the local name, cause, mode of transmission, manifestation, severity, treatment, and prevention of onchocerciasis were collected and analysed. Statistical analysis included frequency distribution of the responses and a Chi-square test for comparison of variables with the P value for statistical significance set at 0.05.

Results:

Onchocerciasis was well known by its local name among 458 (91.6%) of the respondents. Only seven (1.4%) knew that it affects both the eyes and skin. The cause was commonly attributed to impure blood by 114 (22.8%), whereas transmission was thought to be through fomites by 161 (32.2%). Only 12 (2.4%) respondents attributed the disease to blackfly bites. The level of education and the association of onchocerciasis with a river were significantly associated (P = 0.001). Subcutaneous nodules were felt to contain water (85.4%), baby worms (3.2%), and fat (0.6%). There was a negative attitude toward sufferers of the disease.

Conclusion:

Adequate information transfer in simple local dialect by trained personnel to the communities at risk of onchocerciasis is essential for better uptake of all aspects of the onchocerciasis control programme.

Outcome of trabeculectomy with 5-fluorouracil using releasable suture technique in a Nigerian Tertiary Hospital

BACKGROUND

Trabeculectomy has undergone a series of modifications in recent times most of which are aimed at improving the efficacy of the procedure while reducing complications. The use of releasable sutures is one of such modifications.

OBJECTIVE

To assess the efficacy and complications associated with the use of releasable sutures and 5-Fluorouracil(5-FU) in trabeculectomy among indigenous African patients with primary open angle glaucoma.

METHODS

This was a chart review of 22 eyes of 17 patients diagnosed with primary open angle glaucoma. All the eyes included in the review had trabeculectomy with 5-Fluorouracil using releasable suture technique with postoperative clinic follow- up visit for a minimum period of 72 weeks. Information sought included patient's demographics, preoperative antiglaucoma medications, pre- and post- operative intraocular pressure, and associated complications.

RESULTS

There were 17(13 M, 4 F) patients with 22 eye surgeries. Their mean age was 49.8 ± 9.3 years. The mean preoperative intraocular pressure was 27.7 ± 5.9 mmHg. The intraocular pressure on the first post-operative day was 10.6 ± 11.1 mmHg. The mean pressure before the removal of the releasable suture was 14.1 ± 10.8 mmHg and after removal was 6.0 ± 7.2 mmHg, (p > 0.0001). The mean intraocular pressure at 72 weeks of follow up was 16.9 ±5.6 mmHg. A qualified success rate of 81.8% was achieved in terms of intraocular pressure control. There were two eyes complicated by blebitis and an eye complicated by malignant glaucoma.

CONCLUSION

The use of releasable suture in trabeculectomy helped in maintaining the intraocular pressure at a lower level in the early postoperative period and in reducing postoperative shallowing of the anterior chamber. The procedure appears to be associated with some sight- threatening complications such as endophthalmitis.

Survey of blindness and low vision in Egbedore, South-Western Nigeria

BACKGROUND

Developing efficient and cost-effective eye care programmes for communities in Nigeria has been hampered by inadequate and inaccurate data on blindness and low vision.

OBJECTIVE

To determine the prevalence and causes of blindness and low vision among adults 50 years and older in South-Western Nigeria in order to develop viable eye care programme for the community.

METHODS

Twenty clusters of 60 subjects of age 50 years and older were selected by systematic random cluster sampling. Information was collected and ocular examinations were conducted on each consenting subject. Data were recorded in specially designed questionnaire and analysed using descriptive statistical methods.

RESULTS

Out of the 1200 subjects enrolled for the study, 1183(98.6%) were interviewed and examined. Seventy five (6.3%)) of the 1183 subjects were bilaterally blind and 223(18.9%) had bilateral low vision according to WHO definition of blindness and low vision. Blindness was about 1.6 times commoner in men than women. Cataract, glaucoma and posterior segment disorders were major causes of bilateral blindness. Bilateral low vision was mainly due to cataract, refractive errors and posterior segment disorders.

CONCLUSION

The prevalence of blindness and low vision in this study population was high. The main causes are avoidable. Elimination of avoidable blindness and low vision calls for attention and commitment from government and eye care workers in South Western Nigeria.

The dangers of bunk beds to the eye - a case report and preventive measures

This is to illustrate the case of a 14 year old male student of a secondary school who fell off the top of an unguarded bunk bed in his hostel while sleeping and sustained a fracture of the left orbital margin, severe periorbital echymosis and conjunctivitis. He was managed conservatively. Two weeks post injury; the swelling resolved. At 2 months post injury, he improved tremendously and his visual acuity in the affected eye was 6/6. The swelling resolved and his anterior and posterior segments were normal. The patient was lucky to have had an intact eyeball. If it had been a penetrating eye injury, it could have been disastrous. Blinding eye injuries may be irreversible.Unguarded bunk beds may be dangerous to the eye. A recommendation of minimal standard for bunk-beds for children or no bunks at all in schools is suggested.

Visual impairment from age-related cataract among an indigenous African population

AIM

To determine the magnitude of visual impairment (VI) resulting from lens opacity/cataract among a rural population in southwestern Nigeria.

METHOD

A population-based cross-sectional survey using a multistage sampling method to select subjects >or=50 years. Participants with pinhole visual acuity of <or=6/18 in their better eye, exclusively from lens opacity/cataract, were further examined by an ophthalmologist. Their level of VI was categorised using the International Classification of Disease tenth revision and lens opacity was graded using the World Health Organization's cataract grading system.

RESULTS

From the enumerated population of 1200 subjects, 1031 subjects were examined. The prevalence of VI from cataract/lens opacity in the population studied was 11.9% (95% CI: 10.1-14.0) with a cataract blindness prevalence of 2.0% (95% CI: 1.3-3.0). The odds for VI increased with increasing age and female patients had 1.6 times the odds for cataract blindness than did male patients. Mixed cataract was the most prevalent of the visually disabling cataract. (3.9% (95% CI: 2.8-5.2)), whereas posterior subcapsular cataract was the least prevalent (2.5% (95% CI: 1.7-3.7)).

CONCLUSION

VI from cataract remains a public health problem in the Akinyele district of Nigeria. The need for a comprehensive cataract surgical service using the VISION 2020 model is necessary in the district if the burden from the backlog of visually disabling cataract is to be reduced.

Visual outcome of cataract surgery in University College Hospital, Ibadan Nigeria

BACKGROUND

Cataract is a leading cause of avoidable blindness, while cataract surgery is the commonest major surgical procedure worldwide.

OBJECTIVE

To evaluate the visual outcome and causes of poor vision in patients who had cataract extraction at a major hospital in Nigeria.

METHODS

A retrospective study of the case notes of patients who had cataract extraction in the Eye Clinic of University College Hospital, Ibadan between July and Dec. 2004 was done. The visual outcome was analyzed using the WHO categorization of visual outcome and those with poor visual outcome evaluated for the cause of such poor outcome.

RESULTS

Forty-seven (40.2%) of the eyes had good outcome before refraction and the number increased to 80 (67.8%) after correcting for postoperative refractive error. The highest single cause of poor visual outcome was uncorrected refractive error, 32 (47%) eyes. Other causes included posterior capsule opacification 7 (18.4%) eyes, preexisting ocular co-morbidity such as glaucoma, optic atrophy and maculopathy 6 (15.9%) eyes.

CONCLUSIONS

This review showed that uncorrected refractive error and posterior capsular opacification were the major causes of poor visual outcome after cataract surgery. Preoperative biometry for all patients, meticulous intra operative cortical clean up, adoption of the cataract surgery outcome tally sheet and better patient selection will help improve the outcome of our cataract surgeries.

Combined central retinal artery and vein occlusion complicating orbital cellulitis

Orbital Cellulitis is a dreaded ophthalmologic disease. It may destroy vision and the eye and may even become life threatening. Often visual loss is the result of exposure and subsequent destruction of ocular tissue commonly the cornea and the uvea. We report a case of combined central retinal artery and vein occlusion complicating orbital cellulitis in a 35 year old patient who was 37 weeks pregnant resulting in loss of vision in the affected eye. There have been few case reports of this type of complication of orbital cellulitis.

The effect of timolol maleate on tear film break-up time in Nigerians

The aim of this study was to evaluate the effect of Timolol maleate on tear film break-up time in a Nigerian population. 192 eyes of 96 subjects were examined in a hospital based case-control study after being administered pre-coded questionnaires. The mean tear film break-up time was measured. There was significant difference (t = 10.164, P < 0.001) in the mean break-up time of cases (10.45 secs) and controls (30.18 secs). Half of the cases had some ocular discomfort with the instillation of Timolol maleate, a significant number of them having just been commenced on the medication (chi2 = 8.889, P = 0.003). Long-term instillation of Timolol maleate impairs tear film stability. The ocular discomfort experienced by patients on Timolol may contribute to poor drug compliance observed in patients on chronic drug therapy. Regular screening of patients on Timolol maleate for tear film instability and dry eyes is important and drug manufacturers should explore the possibility of incorporating artificial tears in Timolol maleate preparation.

Visual standards in commercial driving

OBJECTIVES

The study was carried out to review the ocular factors involved in road traffic accidents (RTA) in order to reduce associated injuries and possibly suggest a standard for driving.

MATERIALS AND METHODS

The study was carried out in the eye clinic of Ladoke Akintola University of Technology Teaching Hospital, Osogbo between May and June 2004. A stratified random sample technique was used to select 99 drivers (198 eyes) from 6 motor park units. Information obtained included age, sex, past history of road traffic accident (RTA), visual acuity and field, colour vision and ability to read number plate tests.

RESULTS

Six drivers (6.1%) were visually impaired. There were 5 cases of monocular blindness. Twenty (20.20%) drivers had accidents in the past, 24(24.24%) could not read number plate at 20.5meters, 6 (6.1%) were colour blind while 36 had visual field loss within 120 degrees horizontally. All the six drivers that had visual field loss encroaching within 20 degrees of fixation had accidents in the past.

CONCLUSION

This study has shown that there is need to improve on the standard of vision testing before licenses are issued or renewed. Where visual acuity alone is used, it must be done properly by testing one eye at a time. However, a comprehensive eye test using a battery of tests comprising visual acuity, colour vision, visual field and number plate test at 20.5 meters before first issue of driving license and at renewals will be better. Drivers with visual impairment or inability to read number plate test at 20.5 meters should be disqualified from driving commercial vehicles. Drivers with monocular blindness or visual field loss encroaching within 20 degrees of fixation must also not be allowed to drive commercial vehicles. However, further large scale studies will be necessary in order to prove all these propositions scientifically.

Corneal diameters in infants born in two hospitals in Ibadan, Nigeria

OBJECTIVES

To measure the horizontal corneal diameters in infants at birth and compare with values reported in other studies.

DESIGN

A cross-sectional hospital based study.

SUBJECTS

All the healthy infants born within the period of one month in these hospitals were eligible for enrolment into the study. Horizontal corneal diameter measurements were performed with indirect caliper in both eyes of each of the 342 healthy full term infants and 25 preterm healthy infants born in these two hospitals. These results were evaluated according to the age of the infants

RESULTS

The corneal diameter in term infants was found to range from 9.00 mm to 12.50 mm during the first week of life with a mean of 10.26 mm (SD +/-0.59 mm, n = 64). This is higher than what was reported for Caucasian infants (P < 0.01). Mean horizontal corneal diameter in all male infants aged 1-238 days was 11.06 mm (SD 0.75 mm, n = 187), slightly higher than 10.93 mm (SD 0.22 mm, n = 154) in all females, though this difference was not statistically significant. Horizontal corneal diameter increased progressively with age, from a mean value (SD) of 10.26 mm (0.72) to a mean value (SD) of 12.0 mm at 34 weeks of age. There was no significant difference in the mean corneal diameter of the right and left cornea. A few infants had corneal diameters of 12.50 mm and had no congenital glaucoma. Mean corneal diameter in preterm infants less than 37 weeks of gestation was 8.90 mm at birth (SD 1.25 mm, n = 25).

CONCLUSION

The horizontal diameter increased with age from birth to the 34 weeks of age. Changes after this period were not studied. The values obtained in these African infants were slightly higher than those reported from other populations.

Neovascular glaucoma in a Nigerian African population

OBJECTIVE

To determine the ocular and systemic factors associated with neovascular glaucoma (NVG) in an African population.

DESIGN

Hospital based cross sectional study.

SETTING

Eye clinic, Department of Ophthalmology, University College Hospital, Ibadan, Nigeria.

SUBJECTS

Sixty one consecutive patients with clinical diagnosis of NVG seen between January 1995 and December 1999 had a complete ocular evaluation.

RESULTS

Among the 61 subjects studied with an identifiable aetiological factor presumably causing neovascular glaucoma, 82% had associated posterior segment diseases producing ischaemia. These were retinal venous obstruction (78.7%), retinal arterial occlusion (1.6%). Those with no identifiable vaso-occlusive disease had couching (11.5%), aphakia with vitreous loss (3.3%) and chronic uveitis (1.6%). Systemic arterial hypertension was present in 62.3% while diabetes mellitus was present in only 8.3% of the subjects studied. Chronic uveitis and penetrating eye injury were infrequently diagnosed. Chronic open angle glaucoma was present in the other eye of 37.7% of subjects. Neovascular glaucoma was unilateral in 95.1% of subjects. 84.4% of affected eyes were blind on presentation. Males outnumbered females among subjects with NVG above 40 years, while females outnumbered males in the subjects below 40 years of age. Eyes of that were couched constitute a significant proportion of subjects with neovascular glaucoma.

CONCLUSION

Medical conditions such as systemic hypertension, diabetes and ocular conditions like retinal vein, retinal artery occlusion, couching and glaucoma were associated with NVG. Most of these ocular and systemic associations should be identified early and treated to prevent neovascular glaucoma in the other eye of the subject.

Conjunctival hyperaemia and other ocular adverse effects on healthy African subjects after single dosing with 0.004% Travoprost

Conjunctival hyperaemia and ocular adverse effects induced by a single dose of 0.004% travoprost in healthy subjects were evaluated. A randomized, double-blind cross-over placebo controlled study was done. Conjunctival hyperaemia was evaluated clinically at 12, 24, 36 and 72 hours after dosing and volunteers reported all ocular adverse effects. 15 out of 20 subjects (70%) dosed with travoprost compared with 2 out of 20 (10%) dosed with placebo developed clinically moderate hyperaemia. However, significant difference in hyperaemia in the two groups occurred only at 24 hours (P < 0.048). The hyperaemia cleared by 72 hours. Travoprost may cause significantly short-term conjunctival hyperaemia even after a single dose in the eyes of healthy African subjects.

Pterygium treatment using 5-FU as adjuvant treatment compared to conjunctiva autograft

BACKGROUND

The use of conjunctiva autograft, adjunct antimetabolite therapy has been shown to be effective in preventing pterygium recurrence.

OBJECTIVE

To compare 5 fluorouracil (5-FU) to conjunctival autograft in the treatment of large, fleshy pterygium.

METHODS

A randomised controlled prospective study of outcome of pterygium treatment using 5-FU as adjuvant treatment compared to conjunctiva autograft. Thirty-five eyes with large pterygium treated with bare sclera conjunctival excision plus 5-FU were compared with 33 eyes treated with excision and conjunctival autograft alone.

RESULTS

Post-operative pterygium recurrence was observed in four (11.4%) eyes treated with 5-FU and 4 (12.1%) eyes treated with conjunctiva autograft (P>0.05). The post-operative complications included, granuloma formation 11.4% for 5-FU and 3.0% for autograft and conjunctival discharge 5.7% for 5-FU group only.

CONCLUSION

5-FU is marginally superior to conjunctival autograft in the prevention of pterygium recurrence but neither gives a more desirable single digit recurrence rate. Randomised studies combining both conjunctival autograft and 5-FU in pterygium treatment is advocated to further explore their effect.

Blindness and low vision in adults in Ozoro, a rural community in Delta State, Nigeria

BACKGROUND

The objective of this article is to determine the prevalence and causes of blindness and low vision in Ozoro, a rural town of Delta State in Nigeria, in order to provide baseline information for planning a prevention of blindness programme.

METHODS

A cross sectional study using a stratified random sampling method was used to select the compounds. The five communities in the town formed the different sub-groups or strata. Visual acuity were recorded for all adults 40 years and older. Persons who had visual acuity less than 6/18 were further examined to determine the cause of low vision or blindness. The WHO definition of visual impairment according to visual acuity was used as criteria for classification.

RESULTS

A total of 815 persons (coverage of 51.7%) were examined using a modified WHO PBL record of blindness form. The prevalence of blindness (VA < 3/60 in the better eye) for people of 40 years and above was 6.3% (95% CI, 4.6% to 8%) and low vision VA 6/24 to 3/60 in the better eye was 25.2%. The estimated prevalence of bilateral blindness for all ages was 1.3% and low vision was 5%. The rate of blindness and low vision increased with age being highest in subjects who were 60 years and above. The main causes of blindness and low vision were cataract, accounting for 60% of all bilateral blindness and 51.7% of all low vision. Other causes of blindness include, posterior segment diseases (11.7%). Glaucoma was presumed to be cause of blindness in 9.8% of cases; others were uncorrected aphakia 5.9%, and globe abnormalities 5.9%. Refractive error was the second major cause of low vision accounting for 22% of bilateral low vision.

CONCLUSION

The magnitude of blindness and low vision in this oil rich Ozoro community in Delta State is high and majority are avoidable causes of blindness.

Ocular findings seen among the staff of an institution in Lagos, Nigeria

BACKGROUND

The degree to which ocular morbidity affects workers productivity in the developing countries has not been studied adequately. A federal government research institute based in Lagos introduced an annual health screen for all its workers, which included eye tests. This provided an opportunity to study the pattern of ocular conditions among workers who were 30 years and above, and to determine the effect of eye diseases on the workers productivity.

STUDY DESIGN

Detailed eye examination including refraction, was done on every respondent at the institution's clinic by an ophthalmologist. A questionnaire on ocular health status and occupational history was administered independently by an ophthalmic nurse. Sickness absenteeism, use of the clinic were obtained from clinic records, and the results were analysed.

RESULTS

The common ocular conditions were uncorrected or poorly corrected refractive error, uncorrected or poorly corrected presbyopia and allergic. conjunctivitis. Glaucoma, maculopathy and optic atrophy were causes of severe visual impairment or blindness in 1.9 % of the subjects. Absenteeism and clinic use were more common in subjects with ocular morbidity than those with non-ocular morbidity. Subjects with ocular morbidity had more illnesses, absenteeism and used the clinic more.

CONCLUSION

Ocular problems which reduce worker's productivity are prevalent among the staff of the institution studied. They are mostly unrecognised.

Tear break-up time in eyes with pterygia and pingueculae in Ibadan

BACKGROUND

Ultraviolet (UV) rays and chronic irritation to dust have been implicated in the pathogenesis of degenerative conditions of the cornea and conjunctiva like pterygium and pinguecula. It has been postulated that exposure to these environmental factors cause corneal and conjunctival drying by disruption of the tear film. While some researchers have found tear film dysfunction in eyes with pterygia and pingueculae, others have found no such abnormalities. The differences in findings may be due to different methods of investigation, or differences based on geography and climate.

STUDY DESIGN

The tear film has been studied using tear break-up time (TBUT) in adults with pterygia and pingueculae disorders, TBUT was measured in 73 eyes with pterygia and 74 eyes with pinguecula and were compared to TBUT in 74 eyes of age and sex matched normal controls. Abnormal TBUT was defined as TBUT less than 15 secs. Unstable tear film was defined as TBUT less than 10 secs.

RESULTS

The mean TBUT was lower in eyes with pterygia (17.90 secs) than in control eyes (19.86 secs), although the mean difference was not statistically significant. Abnormal TBUT, defined as TBUT less than 15 secs, was found in 29 eyes out of 73 eyes with pterygia (39.7%), compared with 13 eyes out of 74 eyes with pingueculae (17.6%) and in 17(23.0%) of 74 control eyes (X2 = 10.01, df = 2, P = 0.0006). A TBUT of less than 15 secs was more significantly associated with eyes with pterygia compared to control eyes. Unstable tear film (TBUT less than 10 secs) was found in 12(16.4%) eyes with pterygia, compared to 4(5.4%) eyes with pingueculae and 4(5.4%) control eyes. Unstable tear film was significantly associated with eyes with pterygia (P = 0.027).

CONCLUSION

Tear film abnormalities are associated with pterygium but not with pinguecula in the subjects studied. TBHT may vary in different populations.

Presumed hereditary retinal degenerations: Ibadan experience

BACKGROUND

Retinitis pigmentosa (RP) is a hereditary retinal degenerative condition with no known treatment. Associated ocular conditions, such as cataract and glaucoma, when present further worsen vision, but these conditions are often treatable. There are, however, no known reports of cataract or glaucoma surgery in subjects with RP in Nigeria. This study describes the clinical presentation of RP, the prevalence of associated treatable disorders and the characteristics of patients with severe visual impairment and blindness.

METHOD

A retrospective review of 52 cases presumed and diagnosed to have. RP was performed on patients who presented at the Eye Clinic, University College Hospital, Ibadan over a three-year period. The cases were classified into clinical types; those with associated treatable eye conditions were identified and those with severe visual impairment and blindness were further evaluated.

RESULTS

Retinitis pigmentosa was an uncommon clinical condition in patients who presented at the Eye Clinic being 0.69% (n = 52) of a total of 7,520 new outpatients recorded during a 3-year period. Typical RP were 44 in number representing 84.0% of these cases. Those diagnosed with very early onset RP, with severe visual impairment and nystagmus may have been congenital Leber's amaurosis. Retinitis pigmentosa with systemic features and atypical RP were uncommon. However, 34.5% had cataract (mostly posterior subcapsular cataract), while 11.4% had high intraocular pressure and these were mostly in couched eyes. Risk factors for severe visual disability and blindness were cataract, age and secondary glaucoma as a result of couching.

CONCLUSION

Treatable ocular conditions associated with RP are not uncommon. RP patient tend to have cataract which if neglected may result in total blindness.

Modified bare sclera method for the treatment of primary pterygium: a preliminary report

INTRODUCTION

The bare sclera technique is still in use by many surgeons worldwide in spite of the attendant high recurrence rate. Any modification of this well known procedure may be more widely acceptable if associated with lower recurrence.

METHOD

The bare sclera technique was modified by performing a partial thickness sclerectomy from the pterygium bed. This modified technique was applied to 23 eyes of 17 patients with primary pterygium. The subjects were followed up for varying periods between 8 to 31months to determine the recurrence rate of pterygium after surgical excision and other complications.

RESULTS

Initial observation showed that the recurrence occurred in two eyes of two patients of a series who were followed up for a minimum of six months and up to thirty-one months. Two other eyes developed suture granuloma. There were no other complications observed in the remaining twenty eyes of fifteen patients.

CONCLUSION

Partial thickness sclerectomy when performed with standard bare sclera technique seems promising and may improve the results of pterygium excision by bare sclera method.

Use of limbal and central anterior chamber depth measurements in detecting eyes with gonioscopically occludable angles and primary angle closure glaucoma in Ibadan

The routine use of gonioscopy for the evaluation of drainage angles in developing countries is not always done because of the busy clinics. The purpose of this study was to evaluate the performance of 2 tests: Peripheral Anterior Chamber Depth (PACD) measurement and Central Anterior Chamber Depth (CACD) measurement in detecting occludable angles and primary angle closure within subjects with primary glaucoma and control subjects. Two hundred and forty subjects with primary glaucoma and a control group of 250 subjects were studied. PACD was measured with the Van Herrick's method while CACD was measured by the technique described by Lowe. The findings were compared to the gonioscopic appearance of the drainage angles in the two groups. PACD gradings 0 to 2 correctly identified 28 out of 36 eyes (77.8%) of subjects with PACG who had gonioscopically closed angles. The test identified correctly 168 out of 204 eyes (82.4%) with gonioscopically open angles among subjects with primary glaucoma. Among subjects with no glaucoma, PACD gradings 0 to 2 correctly identified 12 out of the 14 eyes with gonioscopically occludable angles, while the test identified 238 eyes without occludable angles, gonioscopy identified 236 out of 250 of such eyes. A CACD less than 2.5 mm was present in only 21 eyes of 36 eyes with occludable angles by gonioscopy among those with PACG. In the other 15 eyes with occludable angles, CACD was more than 2.5 mm. PACD performed well in detecting occluded angles in this study, CACD was useful but less so than PACD in established cases of PACG. Subjects with PACG but whose CACD was 2.5 mm or more may have plateau iris. PACD and CACD are both useful methods in identifying occludable angles in eyes of Nigerian subjects studied.

The anterior chamber angles in Nigerians

The anatomic configuration of the anterior chamber angles in 240 newly diagnosed cases of primary glaucoma in Nigerian adults 30 years and above have been studied. The gonioscopic features in eyes of glaucoma patients 30 years and over have been compared to 250 subjects without glaucoma. Closed angles (Scheie grade 0 or 1) was found in 15.0% of cases compared to 1.6% of controls. There was a statistical significant difference in the distribution of angle width between the 2 groups (X2 = 71.47, P < 0.0001). Grade angle 0 was not found in the control group, subjects with closed angles in the controls had at least grade 1 angle width. Anterior iris insertion characterized the anterior chamber angles in eyes of subjects in the glaucoma group occurring in 14.2% compared to 3.2% of eyes in the control group. This difference was statistically significant (X2 = 18.79, P < 0.0001). 38.8% of eyes with glaucoma were considered to have occludable angles compared to 10.4% of control eyes, a difference also statistically significant (X2 = 53.52, P < 0.0001). Trabecular meshwork pigmentation and peripheral iris curvature did not occur differently in the two groups. Mean central anterior chamber depth (CACD) was shallower in cases than in controls. This difference was statistically significant P = 0.002. The mean depth was shallower in female cases than male cases. It decreased with age in subjects with glaucoma and those without. The mean CACD increases with increasing angle width. Just over half of subjects with closed angles have mean CACD less than 2.5 mm. The other subjects with angle closure glaucoma with higher CACD may have plateau iris. Closed angles, anterior iris insertion and shallower central anterior chamber depth are statistically significantly associated with eyes glaucoma. Increased pigmentation and peripherally convex iris curvature were not significantly associated with eyes glaucoma.

Respiratory arrest after retrobulbar anaesthesia

This is a report of a patient who developed respiratory arrest some minutes after retrobulbar block was given for ocular anesthesia before cataract extraction. She was managed by artificial ventilation and haemodynamic support without any cardiac or neurological sequelae. This report highlights this rare but fatal complication of suspected brain stem anaesthesia after retrobulbar anaesthesia. Retrobulbar and peribulbar blocks should be performed in safe situations where individuals trained in airway maintenance and ventilatory support should be immediately available.

Refractive astigmatism and size of pterygium

The study evaluates the relationship between varying sizes of pterygium and refractive astigmatism. All patients with pterygium seen at the eye clinic of the University College Hospital within a six months period were included. The length, width and area of pterygium were measured. Refractive astigmatism in the subjects were measured. The findings showed that the length of pterygium on the cornea has a statistically significant relationship with the amount of refractive astigmatism. The amount of astigmatism increases with increase in the length of pterygia. A linear regression analysis showed that 38% of the total variability in astigmatism could be explained by the length of pterygium. The width and area of pterygium on cornea had no significant association with amount of refractive astigmatism. Size of pterygia could be an important predictor of the amount of astigmatism in an eye. However, a larger study need to be done to find other possible factors associating refractive astigmatism in eyes with pterygium.

A survey of eye trauma and diseases at a teaching hospital: implications for training in occupational ophthalmology in Nigeria

This study explores the amount of occupational ophthalmology that it is possible to encounter within an existing teaching hospital system, as this offers the primary training facilities for resident doctors who expect to specialize in occupational medicine. The study was based on an analysis of ophthalmology patient records available at the University College Hospital, Ibadan, which is Nigeria's largest teaching hospital. One thousand, three hundred and thirty-four patients with eye disease were seen during the 1-year study. Of these, 1052 (78.9%) did not have their occupations recorded. Accidents were the only occupational diagnoses recorded, and this occurred in 75 (5.6%) of cases. The findings indicate that doctors who train in this specialty should gain experience in industries that have sizeable occupational health services, in addition to their formal ophthalmology training, in order to acquire experience in primary and occupational eye care. It is suggested that greater emphasis be placed on occupational ophthalmology in teaching hospitals and that there is a general improvement in completing patients' records: in particular, a patient's occupation should be recorded.

Leukocyte migration inhibition studies and neutrophil cell function during aging in Nigerians

In this study, in vitro cell-mediated immune response was analysed in 150 healthy Nigerians between 6 and 95 years old by the leukocyte migration inhibitory factor (L-MIF) test. Lymphocytes were activated with the mitogen concanavalin A and candida, measles virus and mycobacterial antigens. Nonspecific cellular immune capacity was studied by the Nitroblue tetrazolium (NBT) test. Numerical estimates of leukocytes and lymphocyte subpopulations were done. Mean L-MIF activity obtained with the four lymphocyte activators decreased with rising age indicating a progressive decline in cellular immune function with age. There was no significant age-related change in formazan positivity rate for both unstimulated and stimulated NBT tests. No age-related change in number was observed for any of the leucocyte and lymphocyte subpopulations. These results show that cell-mediaging response in Nigerians immunity declines, but phagocyte function is unchanged during aging. Lymphocyte depletion or numerical alteration in resting T cell subsets could not be demonstrated to be responsible for depressed cell-mediated immunity in aging Nigerians.

Pterygium in Ibadan

This is a retrospective study of 500 eyes of 400 patients with pterygium seen over a 3 year period to determine the clinical presentations and outcome of surgery. The study showed that it was a fairly common eye condition in the south western part of Nigeria. It formed 9% of all new cases seen in the eye clinic of the University College Hospital, Ibadan and 20% of all planned ocular surgery in the same hospital. 70% of patients studied came to hospital because of the growth in their eyes. 80% of the pterygia were large, fleshy type in the nasal position. 65% of patients were outdoor workers. Surgical excision was by the 'Bare sclera' method. 40% of these patients had a recurrence of the growth. There is need to modify the available surgical method commonly performed at the University College Hospital and introduce B irradiation treatment to reduce the recurrence rate.

Refractive astigmatism and pterygium

The refraction of 50 patients with pterygium and their age- and sex-matched controls was carried out. Patients with pterygium had surgery by the bare sclera method. A post-operative refraction was carried out at 12 weeks. A refraction was also done in both eyes of patients with unilateral pterygium. There was a statistically significant association between refractive astigmatism and the presence of pterygium (P less than 0.01). Astigmatism was the rule in most patients. Surgical removal caused a reduction in refractive astigmatism. The change in refractive astigmatism was as high as 1.50DC (diopter cylinder). The majority of the patients were in the presbyopic age group. Surgical removal of pterygium will significantly alter the refraction of patients.