Ocular findings in homozygous sickle cell disease in Jos, Nigeria.

Ophthalmological examinations were performed in 78 homozygous sickle cell (Hb SS) patients, aged 4-42 years attending the sickle cell clinic of the Jos University Teaching Hospital, and the University Clinic, Jos, in Nigeria. Conjunctival signs present in about 77% of cases were observed in all ages and sexes. White without pressure present in 62.8% of the cases was the commonest retinal sign and in 56.3% of the cases was associated with peripheral retinal vessel disease. Salmon patches (6.4%), iridescent spots (10.3%), mottled brown areas (16.7%) and black sunbursts (7.7%) were seen as early as 10 years of age but showed an upward trend with age. Peripheral retinal vessel disease present in 52.5% of the cases was the second commonest retinal sign and with the exception of arteriolar occlusion showed no sex predilection, but an upward trend with age. Arterio-venous anastomosis (7.7%), vitreous haemorrhages and veils (3.8%) were the only severe proliferative signs noted. There were no cases of retinal neovascularization, retinal detachment or of angoid streaks, and the posterior poles were normal. Retinal signs were present as early as 8 years of age and showed an upward trend with age.

Clinical and pathological effects on the rabbit's eye of some plant-derived ophthalmic swabs.

The stems of corn, millet, sugar cane and the banana leaf frond excite some clinical and pathological effects in the rabbit's eye when implanted either into the anterior chamber (AC) or subconjunctivally. These effects have not been sight threatening. The materials can either be left to be cleared by the body's phagocytes when they produce mild inflammatory reaction or removed surgically if the inflammatory response is moderate when fragments have been left intraocularly.

Prevalence of trachoma among school children in Plateau State, Nigeria.

3005 primary school children from randomly selected primary schools in Jos and its environ were screened for trachoma. The schools were divided into 3 groups reflecting the socio-economic status, and the degree of personal hygiene of the pupils. The prevalence of trachoma was 7.5% in the group A schools attended by the children of the rich, 15.9% in the group B schools attended by children of the poor but living in the urban town and 19.4% in group C schools attended by children of the poor living in the sub-urban town. The difference in the prevalence and severity of trachoma in the 3 groups was found to be statistically significant (P less than 0.01). Trachoma was found to be more common in freshly scholarised pupils as compared to pupils in the terminal class. There was no difference in the frequency of trachoma among girls and boys in our study group. The type of water used in bathing was not found to be important in the prevalence of trachoma. The authors next discussed the simplicity of the Dawson's classification, the need to start a trachoma control programme in Nigeria and the possible role of community health workers in any programme for the eradication of trachoma.

Locally available plant materials for use as ophthalmic surgical swabs.

Four locally available plant materials have been studied and adapted for use as suitable surgical swabs for various ophthalmic surgical procedures. The corn, the millet, the sugar cane stems and the banana leaf frond provide very cheap, easily available and suitable materials for use as alternative surgical swabs to the much used and tested German Spontex swabs.

Mycolase II: an enzyme antifungal agent interacts with the polyene antibiotic pimaricin in the treatment of keratomycosis.

An animal model of keratomycosis was used to study the interaction between the new enzyme antifungal compound mycolase II and the polyene antifungal antibiotic pimaricin. Well established corneal infection caused by an ocular pathogenic candida albicans on New Zealand white male rabbits were treated with 3% mycolase II, 5% pimaricin and a combination of 3% mycolase II and 5% pimaricin respectively. The rates of resolution of the corneal lesions for each group of eyes treated by the various drugs were determined and the results were analysed by computer using a two-way analysis of variance to determine the interaction or independence of 3% mycolase II in combination therapy with 5% pimaricin in rabbit keratomycosis. The analysis of variance showed a significant level of positive interaction after each period of treatment. (P less than 0.001).

Ketoconazole: a new imidazole antifungal agent has both prophylactic potential and therapeutic efficacy in keratomycosis of rabbits.

A highly reproducible quantitative model of fungal infection of the rabbit's corneal stromal was produced using multiple corneal microtrephination. Aspergillus flavus (K4/77), at a concentration of 10(6) spores per ml was systematically implanted into the trephine sites in the cornea, and the degree of corneal infection determined. By pre-inoculation and post-inoculation challenge of these cornea with 1% ketoconazole in arachis oil, the prophylactic potential and the therapeutic usefulness of ketoconazole was determined. Ketoconazole, acetyl-dichlorophenyl-imidazole, has a significant prophylactic potential in inhibiting the development of corneal stromal fungal lesions when it is administered to the cornea of New Zealand white male rabbits as a 1% solution in arachis oil for two consecutive times hourly for two hours before the inoculation of the rabbits cornea with an ocular pathogenic Aspergillus flavus. Ketoconazole also has a therapeutic effect in the reduction of well established A. flavus keratitis in rabbits. When administered as 1% solution in arachis oil for ten consecutive hours daily to well established A. flavus lesions of the cornea of New Zealand albino rabbits, ketoconazole took about sixteen days to cure all the corneal lesions. Finally, using a yeast nitrogen base liquid medium, the in vitro minimal inhibitory concentrations of ketoconazole to twenty-five various human ocular pathogenic fungal isolates were determined and used to recommend those fungi for which ketoconazole would be a good choice for therapy.

Study of ketoconazole toxicity in rabbit cornea and conjuctiva.

Ketoconazole, acetyl-dichlorophenyl-imidazole, when administered topically to the eyes of normal New Zealand white rabbits in concentrations of 1%, 3% and 5% in arachis oil has been shown to have no toxic effect to the conjunctival and corneal epithelium of these animals. No toxic effects were also noted on the iris sphincter and the crystalline lens of these animals. Five per cent ketoconazole in arachis oil showed some minimal conjunctival hyperaemia in two of the test eyes (33.3%) after two weeks of continuous administration. Arachis oil, the carrier for the test drug showed no ocular toxicity in all the rabbits tested.

Development of quantitative methods of measuring antifungal drug effects in the rabbit cornea.

By means of multiple inoculation in each cornea with microtrephination a highly reproducible quantitative model of fungal infection of the rabbit corneal stroma has been produced. A known suspension of the chosen pathogen was systematically implanted into the trephine sites in the cornea. The degree of infectivity was monitored in both the preinoculation treated corneae (prophylaxis) and the postinoculation treated corneae (therapy). Examples measuring and comparing the antifungal effect of various imidazole drugs against Candida albicans are discussed.

The ocular effects of etomidate.

Etomidate, a new intravenous hypnotic agent, significantly lowered the mean intraocular pressure (IOP) of fifty patients within 30 s of an intravenous injection from 15.7 to 9.5 mmHg. This effect was present even during the administration (to twenty patients) of low doses (0.25 mg/kg) when the mean reduction was from 15.6 to 7.6 mmHg. The reduction in IOP was unaffected by the presence of muscle movement. Low frequency pendular nystagmus was observed in five patients.

Fundus signs in temporal arteritis.

A patient with temporal arteritis developed a variety of ischaemic lesions in the eyes. Infarction of the inner retina and optic nerve head was delineated on presentation by white swelling in the retinal nerve fibre layer. The role of interrupted axoplasmic transport in the production of this sign is discussed. Outer retinal infarction was also noted on presentation and subsequently gave rise to striking pigmented scars.

Partial central retinal artery occlusion.

The clinical picture of multiple circumpapillary cotton-wool spots and mild ischaemic swelling of the inner retina is attributed to partial occlusion of the central retinal artery. The pathophysiological basis of the fundus signs is discussed and the role of interrupted axoplasmic transport in the development of the cotton-wool spots is emphasized.