Search

Cataracts are the commonest cause of blindness in Third-World countries and cataract extraction is the commonest eye operation performed anywhere. Patients require optical correction after surgery either in the form of an intra-ocular lens (IOL) or bifocal aphakic glasses. The standard operative procedure in First-World countries is an extracapsular cataract extraction with an IOL. This type of operation has been thought to be contraindicated in black patients because of the complications and lack of adequate postoperative follow-up. During 1987-1989 3,144 cataract extractions, of which 2,157 were simple extracapsular extractions and 987 had IOLs inserted, were performed at the above hospitals. The two groups were compared for complications and visual results. The complications were similar in both groups and were acceptable, therefore posterior lens implantation confers no additional risk on routine extracapsular cataract extraction. The visual results in the IOL group with and without additional glasses were compared with those patients who had correcting aphakic glasses. In the corrected IOL group, 98% of patients saw better than 6/24, whereas in the aphakic spectacle group, 87.5% saw 6/24 or better. Since the majority of black patients cannot afford costly prescribed spectacles, it was important to analyse the visual acuity in patients who had IOLs and were uncorrected; 81.6% saw 6/24 or better. IOLs in black patients are therefore indicated but the disadvantage is the cost.

During an 18-month period a prospective randomised trial was conducted on 40 selected patients with bacterial corneal ulcers. Two groups were compared: one was treated with antibiotic only and the other with antibiotic plus steroid. Complications were similar in the two groups. No delay in healing rate of the ulcers was seen with the use of topical steroid. Two methods of assessing visual improvement are discussed, but it was not possible to demonstrate a difference in visual outcome between the two groups.

Of 85 Indian patients with non-insulin-dependent diabetes in the young, 16 (19%) were found to have vascular disease. Of these 16 patients 14 had diabetic retinopathy and 6 nephropathy. Five of the patients with nephropathy also had retinopathy, and the 6th had bilateral cataracts. Three patients had ischaemic heart disease associated with nephropathy and/or retinopathy. No patient had peripheral or cerebrovascular disease, and 15 (18%) were found to have hypertension; 5 (31%) of the patients with vascular disease had hypertension.

Increasing numbers of patients with the acquired immunodeficiency syndrome (AIDS) are being reported. In the US literature the eye complications have been well documented but because so few cases of AIDS have been reported in South Africa, the retinal complications are largely unknown to those treating these patients. The retinal complications are due to cytomegalovirus (CMV) retinitis. The patient described here developed the typical signs in both eyes. It is essential to examine the fundi of AIDS patients regularly. The presence of cotton-wool spots always precedes CMV retinitis, which leads to blindness; it is also of prognostic significance since all reported patients with CMV retinitis have died.

Eye injuries sustained by 4 patients who took part in 'war games' (in which young men shoot at each other with pistols powered by compressed carbon dioxide and firing latex rubber bullets filled with non-toxic paint) are described. In 3 cases the injuries were severe, including traumatic cataract, and 1 of these patients has a permanent macula scar with vision reduced to 6/36. Although eye protection is recommended, it was found that in the 'battle situation' combatants did not always follow regulations. Attention is drawn to the seriousness of disregarding the need for correct protective glasses.

Labrador keratopathy (LK) is an acquired corneal degeneration thought to be caused by chronic exposure to solar irradiation. Reports so far suggest that it is a progressive or at least a stationary condition. There are no detailed reports on recommended therapy. A prospective clinical study was conducted to show regression of LK following extracapsular cataract extraction. Seventeen black patients (26 eyes) with LK and mature cataracts underwent extracapsular cataract extraction. The severity of the LK was recorded photographically pre- and postoperatively. The follow-up ranged from 6 to fifteen months. Twenty-four eyes (92%) showed regression of the LK. The reduction in exposure to ultraviolet light as a result of aphakic photophobia could be one of the factors which have led to the regression of the LK.

Contrast sensitivity was measured by means of Arden grating plates in 100 patients on medication for pulmonary tuberculosis. The scores were abnormal in 38.2% of the patients whose therapy included ethambutol for three months, and 36.7% of the patients on similar treatment for six months. In comparison with age matched groups of patients on a regimen where streptomycin replaced ethambutol a statistically significant number of the patients on ethambutol had abnormal scores. This study suggests that Arden contrast sensitivity plates would be effective in detecting subclinical toxic optic neuropathy due to ethambutol and therefore could be used for routine monitoring of ocular function of patients on ethambutol. Loss of contrast sensitivity may explain why some patients on ethambutol with normal visual acuity and colour perception may still complain of visual disturbance.

We have measured intra-ocular pressure (i.o.p.) in 20 patients anaesthetized with halothane or enflurance (0.6 MAC in oxygen) for repair of trauma to the eye. The changes in i.o.p. with halothane 0.5% were unpredictable, whereas enflurance 1% reduced intra-ocular tension consistently in all the patients studied. Enflurane is recommended as a possible alternative anaesthetic for surgery on the open eye.

An orbital varix is a pathological enlargement of the venous channels within the orbit. It is an unusual cause of proptosis, the proptosis being unilateral, painless and intermittent. The diagnosis is established by means of orbital venography, an investigation seldom performed.

Intraocular pressure remained stable when either pancuronium or alcuronium was used to produce muscle relaxation, suggesting that alcuronium may be a reasonable alternative to pancuronium for routine surgery of the open eye, particularly in elderly patients with limited cardiac reserve.

Pseudomonas keratitis is currently treated with antibiotics with a variable success rate. Part of the morbidity caused by pseudomonas is due to the action of lipopolysaccharide (LPS) present on the surface membrane of the bacteria. Specific IgG present in equine anti-LPS hyper-immune plasma has been found to bind to the LPS from a range of Gram-negative bacteria, including pseudomonas, and by activating complement it destroys these bacteria. Anti-LPS plasma was therefore used as a therapeutic agent in experimentally induced pseudomonas keratitis in rabbits. Thirteen out of 15 (86.7%) anti-LPS treated eyes improved, whereas four out of 17 (23.5%) saline treated control eyes improved (chi 2 = 12.76 p less than 0.001) No ill effects were noted when anti-LPS was administered to healthy rabbit or baboon eyes. Anti-LPS thus was protective in pseudomonas keratitis, and clinical trials appear to be warranted.

Ocular cysticercosis does not usually present with signs of systemic involvement. Stool examination and eosinophil count are invariably negative, but computed tomography and agglutination tests are more commonly positive. This condition is more common in the vitreous cavity where it may cause diagnostic problems. Removal of the cyst is a standardised procedure, but the prognosis is poor because of severe ocular reaction to the cysts. Prevention of cysticercus infection is very important.