The Volk steady mount holder for the +90D lens

Since its introduction in early 1985, the Volk +90D lens has become a very popular auxiliary lens for biomicroscopic fundus evaluation. The Volk +90D lens provides a wide field of view which is accessible by simple scanning of the biomicroscope. The necessity to hand hold the lens, however, has not always provided enough stability, particularly for the novice user. This article describes a newly introduced holder for the Volk +90D lens which mounts on the base of the biomicroscope headrest providing rapid and stable lens placement. Use of this holder improves the technique of retinal examination and photography by stabilizing the image and by freeing both hands to operate the slit lamp biomicroscope. The enhanced stability afforded by this holder also gives the examiner the practical capability of viewing the posterior pole without mydriasis.     

Severe herpetic keratitis. I: Prevalence of visual impairment in a clinic population.

We report a prevalence study of the best visual acuity in the affected eye of 100 selected patients with herpetic keratitis seen during a two-year period. Sixty-two patients retained an acuity of 6/9 or better without requiring penetrating keratoplasty (PK). The prevalence of reduced visual acuity severe enough to warrant PK was 33%. Patients requiring PK for whom full clinical records were available suffered a mean of 6.8 episodes of keratitis. In this group of patients the vision of 18 fell from 6/6 to 6/60 over a mean period of 8.5 years. Once visual acuity was permanently reduced to 6/12, 78% of patients proceeded to lose vision to 6/60. Unilateral visual impairment occurs in at least a third of patients with severe herpetic keratitis. Once vision falls permanently to 6/12, the long-term prognosis for vision appears to be poor.     

Shape changes produced in detergent extracted bovine retinal pigment epithelium when exposed to ATP. A comparison with fibroblasts and smooth muscle cells

The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy.     

Nutrient intake in insulin-dependent diabetic patients with incipient nephropathy

The onset of diabetic nephropathy is characterized by subclinical elevation of urinary albumin excretion, so-called 'microalbuminuria' (M). Dietary assessments were carried out in 15 insulin-dependent diabetic patients with persistent M and an equal number with persistently normal albumin excretion. The groups were matched for sex, age, duration of diabetes, body mass index, insulin dose and glycosylated haemoglobin; there were no significant differences in systemic blood pressure, glomerular filtration rate, blood glucose and serum albumin concentrations between the groups; retinopathy was significantly more frequent in patients with M. Diabetics with persistent M were found to consume a significantly larger amount of fat (expressed as grams and percentage of total energy) and a significantly smaller percentage of total energy as carbohydrate than patients with normal albumin excretion; total dietary energy was larger in those with persistent M, but the difference was not significant. No significant differences were found in protein and fibre intakes between the groups. Our findings suggest that an excess in the dietary consumption of fat relative to carbohydrate might play an important role in the pathogenesis of early nephropathy in insulin-dependent diabetes mellitus. We emphasize the importance of careful attention to nutrient intake in the prevention and treatment of diabetic complications.     

Tear mucus crystallization in children with cystic fibrosis

Cystic fibrosis is characterized by an abnormally high electrolyte concentration in exocrine secretions. The authors performed the tear mucus ferning test in 26 eyes of children with cystic fibrosis and compared the results to those in an equal number of age-matched normals. The results suggest that the increased electrolyte concentration could be responsible for the increased hyperviscosity of mucus. The tear mucus ferning test appears to be a suitable diagnostic test for the assessment of cystic fibrosis.     

Evaluation of keratoplasty in cases of post-inflammatory corneal opacity with vascularization

Penetrating keratoplasty was performed in 106 cases of post-inflammatory corneal opacity with vascularization. Donor material obtained post mortem was preserved in a moist chamber, MK-medium at 4 degrees C or in culture medium at room temperature. 55.7% of patients gained a useful vision after keratoplasty. The post-operative spherical error of refraction was found to be -1.4 +/- 3.6 D and the astigmatic error of refraction -3.3 +/- 2.0 D. The post-operative visual acuity was found to be 0.2 +/- 0.2. The ocular pathology associated with keratoplasty is discussed.     

Treatment versus no treatment in chronic open angle glaucoma

In a controlled randomized study 15 patients (20 eyes) with chronic open angle glaucoma and visual field defects were followed by greater than 1 year, 12 of them were followed for 3 years. Half of the group were untreated controls, the other half treated with pressure reducing medical therapy. At least 5 consecutive computerized visual fields were recorded (COMPETER) on each eye, and the linear regression coefficient was calculated. With the reservation for uncontrolled compliance no significant difference in the line of favourable effect of pressure reduction could be spotted, in spite of an average pressure reduction in the treated group of 4 mmHg. More important than this result, which is open to criticism for the smallness of the material, uncontrolled compliance etc, is the lesson that a randomized experiment with treated and non-treated glaucoma cases carried out in accordance with the Helsingfors convention is hardly feasible.     

Elimination of antibiotic-resistant plasmids by quinolone antibiotics

Of 7 plasmids we tested, the plasmid pORF2 was eliminated in vitro with the most efficiency by treatment with subinhibitory concentrations of novobiocin, coumermycin and 10 quinolones. It showed a cure rate of 43% by enoxacin; 12% by novobiocin, pefloxacin, ciprofloxacin and CI-934; 7% by coumermycin and ofloxacin; 9% by amifloxacin; and 4% by AM-833. On the other hand, pSC194, pBR322 and pMH612 were poorly cured in vitro by quinolones, except pSC194 which was cured 33% by enoxacin. R1, pP1603, and pUB110 were unaffected by the treatment. Mice were challenged intraperitoneally with a 2XLD50 of Escherichia coli carrying the ORF2 plasmid and were treated per os with 1 X or 1/2 X ED50 of either enoxacin or CI-934. The frequency of loss of ampicillin resistance determined 3 h after treatment shows curing effects of 92% for CI-934, 89% for enoxacin and 20% for untreated control.