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Both the distribution of tear fluid over the conjunctiva and any injury to the conjunctival epithelium can be made visible by instilling a fluorescent solution into the eye and observing with an appropriate combination of excitation and barrier filters. Sulphorhodamine B, which has an orange fluorescence that can be separated from the green natural fluorescence of the ocular tissues, gives a greater contrast than fluorescein. The tear film is seen to cover the surface of the conjunctiva and to be concentrated in its folds. Small circular areas of thin tear film appear transiently in the neighbourhood of the limbus after a blink. Occasional cells stain on the normal conjunctiva, particularly in the interpalpebral area. The density of the staining increases in dry eye conditions. Conjunctival trauma is sensitively revealed by the method, and its healing can be followed. Hard contact lenses are seen to traumatize continually the inferior limbal conjunctiva in symptomless wearers. [ABSTRACT FROM PUBLISHER]

Non-ionic radiological contrast media have a high refractive index and are not toxic to living cells. They can be used as clearing media for unfixed ocular tissues. Corneal opacities in the rabbit could be made transparent, on a temporary basis, by soaking the stroma in contrast media, and no ill effects on the eye were noted. [ABSTRACT FROM PUBLISHER]

Aim: Antibody fragments, appropriately formulated, can penetrate through the ocular surface and thus have potential as therapeutic agents. The aim was to investigate the influence of protein fragment format on the kinetics and extent of ocular penetration in vitro. Methods: Immunoglobulin single chain variable domain fragments of a murine monoclonal antibody with specificity for rat CD4 were engineered with a 20 or 11 amino acid linker by assembly polymerase chain reaction, expressed in Escherichia coli and purified by chromatography. Fab fragments of the parental antibody were prepared by papa in digestion. Antibody fragments were formulated with a penetration and a viscosity enhancer and were applied to the surface of perfused pig corneas for up to 10 hours in vitro. Penetration was quantified by flow cytometry on rat thymocytes. Results: 20-mer antibody fragments formed natural monomers and dimers following purification that could be separately isolated, white 11-mer fragments were dimeric. All formats of fragment (20-mer monomers and dimers, 11-mer dimers, Fab) showed penetration through the pig cornea after 6 hours of intermittent topical administration. Conclusion: Antibody fragments of different shapes and sizes can penetrate the cornea after topical administration, thereby increasing the potential of this class of proteins for topical ophthalmic use. [ABSTRACT FROM AUTHOR]

AIM: To investigate the influence of anticorneal antibodies on the outcome of transplantation in recipients before penetrating keratoplasty. METHODS: 100 consecutive penetrating keratoplasties performed between July 1995 and June 1996 were included in this study. Donor corneoscleral rim cryosections were incubated with recipient serum. Fixation of recipient IgM on donor corneas was revealed with a polyclonal anti-human mu-chain antibody. The mean follow up time was 61 months. Five years after transplantation, 63% of patients were available for follow up. During the follow up period, 15% of keratoplasties failed because of irreversible rejection. RESULTS: Anti-donor stromal lamellae IgM were found in 14 recipients. Anti-donor keratocyte IgM were present in 28 recipients. Dilution of recipient serum (up to 1/800) did not modify the results of positive crossmatch assays. Crossmatch assays performed with positive recipient sera and negative donor corneoscleral rims were negative. No significant influence of IgM crossmatch results on graft survival and rejection-free graft survival was found. CONCLUSION: Donor specific anticorneal stroma IgM were found in 28% of recipients before transplantation. This pre-immunisation was not associated with a higher risk of transplantation rejection. [ABSTRACT FROM AUTHOR]

A trial of a mixture of guanethidine 5% and adrenaline 0.5% (Ganda 5.05) and of guanethidine 3% and adrenaline 0.5% (Ganda 3.05) was conducted on 90 eyes in 53 patients with open-angle glaucoma or ocular hypertension. The cases fell into 5 groups: untreated cases, cases on pilocarpine 1%, on pilocarpine 2%, on pilocarpine 2 to 4% and adrenaline 1%, and on separate guanethidine 5% and adrenaline 1%. Baseline pressures and average pressures on the previous treatment were established. Substitution with Ganda 3.05 or 5.05 was started, and the patients attended 2 weeks, 1 month, 3 months, and 6 months from the start of the trial. Applanation tonometry was carried out at the same time of day. The pupil was measured, ptosis and superficial punctate corneal staining were looked for and evaluated, and the patients were questioned for symptoms of side effects and acceptability. All the eyes that had previously been treated with pilocarpine 1% or 2% presented significantly lower intraocular pressures on Ganda 3.05. The patients on pilocarpine 4% and adrenaline 1% also had lower intraocular pressures on Ganda 5.05, but the significance was less, and the patients on separate guanethidine and adrenaline had a small but not statistically significant drop in pressure. Ptosis and discomfort were evaluated on a subjective scale. Patient acceptability was good. The trial was interrupted in 5 cases for various reasons. Tachyphylaxis and tolerance to the mixtures were not observed in this series. [ABSTRACT FROM PUBLISHER]

The endothelium of the normal corneas of 67 human subjects was studied in vivo with the specular microscope in order to quantify the method as a means of sampling the cell density of the tissue. It was found that (1) axial cell counts of the endothelium are reproducible in the same cornea after an interval of time; (2) the cell counts of the centre and periphery of the same cornea are similar; (3) the axial cell counts of pairs of eyes are similar; and (4) there is a gradual reduction of cell number with increasing age. The significance of these data is discussed. [ABSTRACT FROM PUBLISHER]

We present the results of a double-blind trial comparing the efficacy of a single dose combination of guanethidine 3% and adrenaline 0.5% with that of adrenaline 1% alone in reducing the intraocular pressure of eyes suffering from chronic open-angle glaucoma. The mean fall in ocular tension with the combined therapy was 10.67 mmHg, and with adrenaline 1% 6.31 mmHg, 24 hours after the commencement of phasing. The combined drop produced satisfactory control of ocular tension in all cases. These results indicate that a combined drop of guanethidine 3% and adrenaline 0.5% is a promising topical therapy for the control of chronic open-angle glaucoma. [ABSTRACT FROM PUBLISHER]

Nine specimens of the corneas of patients from Labrador and Northern Newfoundland affected by spheroidal degeneration (climatic droplet keratopathy) have been examined microscopically. Histochemical stains confirmed studies of similar corneal degenerations from other geographical areas that the droplets contain a protein which does not have all the characteristic properties of elastic tissue. Staining compatible in some instances with fibrin and "fibrinoid" was found. By immunoperoxidase techniques the droplets were located in the zones of greatest concentration of various plasma constituents, especially albumin and immunoglobulins G and A. Reasons are given why the abnormal deposits are not thought to be derived directly from corneal collagen. It is suggested that some of the plasma proteins, which are known to be diffusing through the cornea from the limbal vessels under normal conditions are acted upon by the ultraviolet light reflected from the ice of Labrador and degraded so that they accumulate in the superficial stroma. [ABSTRACT FROM PUBLISHER]

Patients in a randomised controlled trial were chosen either to have iris clip lens implantation after intracapsular cataract extraction or intracapsular extraction only. They were assessed in terms of corneal thickness, postoperative epithelial oedema, and endothelial cell counts. All patients had 1 eye submitted to operation, which was carried out by the same surgeon. There was significantly greater increase in corneal thickness (P less than 0.05) on the 5th postoperative day in eyes which had lens implants (23 patients with intracapsular extraction and 19 with implant), but the difference between the 2 groups became insignificant at 1 month (17 patients in each group). Daily corneal thickness measurements and observations of epithelial oedema in a subgroup (20 patients divided equally into 2 groups) showed that postoperatively there was greater and more widespread corneal oedema after implant surgery. When the operated eye was compared with the unoperated eye, endothelial cell loss was significantly greater in those with implants (P less than 0.01) than in those with simple intracapsular extraction. [ABSTRACT FROM PUBLISHER]

By cannulating the stroma of rabbit corneae, and introducing extracts of retina and vitreous from newborn kittens subjected to vaso-obliterative doses of oxygen, an attempt was made to test the hypothesis that ischaemic retinal tissue releases a factor with vasoformative properties. It was found that, although retino-vitreal extracts from the test animals elicited a positive response in just over half the experiments, the degree of corneal vascularisation provoked by extracts from intact control animals was only marginally less. Consequently our findings do not permit any definite answer regarding the existence of a specific factor responsible for the proliferation of new vessels on the retinal surface in states associated with retinal hypoxia. [ABSTRACT FROM PUBLISHER]

The effect of pilocarpine on visual acuity and on the dimensions of the cornea, anterior chamber, and lens were studied in two groups of subjects. Significant changes in ocular tension, corneal curvature, anterior chamber depth, and lens anterior radius were found in a group of 55 glaucomatous eyes as a result of pilocarpine treatment, but there was no change in corneal thickness. Out of 102 glaucomatous eyes 78 became relatively myopic, and this appears to be due to changes in the dimensions of the lens of the eye similar to those occurring in accommodation, as a result of the effect of the drug on the ciliary muscle. The effect of pilocarpine on anterior chamber depth, area, and volume was studied in 125 eyes using a photographic method, and a significant reduction in the dimensions of the anterior chamber was observed as a result of the administration of pilocarpine. A significant correlation between depth and volume was also noted and the implications of this are discussed. [ABSTRACT FROM PUBLISHER]

A functional study of the lacrimal drainage apparatus was made in 25 patients. Angiographin was instilled into the conjunctival sac and serial radiographs were taken. The films were interpreted in conjunction with the intubation macro-dacryocystograms. Although this is a useful procedure, the use of angiographin compares unfavourably with ultra-fluid Lipiodol in a similar procedure. [ABSTRACT FROM PUBLISHER]

AIM--To determine the relation between epithelial hyperplasia and regression of effect after photorefractive keratectomy (PRK). METHODS--Seventy unilaterally treated patients with PRK were examined. All eyes had been treated with the Summit excimer laser 27 (SD 7) months previously with zone diameters of 4.1 to 5.0 mm. The untreated fellow eyes served as controls. Epithelial thickness was measured centrally with a thin slit optical pachometer and manifest subjective refraction was performed. RESULTS--The epithelium was 21% thicker in the treated eye (p < 0.0001). The relation between refractive regression and epithelial hyperplasia was significant (r = 0.41; p < 0.001). CONCLUSIONS--Epithelial hyperplasia after PRK correlated with the myopic shift (including hyperopia reduction) after treatment with the Summit laser. A model is proposed suggesting that both subepithelial and epithelial layers contribute to regression in the Summit treated eyes with 18 microns of epithelial hyperplasia contributing each dioptre of regression. [ABSTRACT FROM PUBLISHER]

AIMS: The corneal temperature change following each blink was investigated in patients with dry eye using an infrared radiation thermometer. METHODS: Twenty patients with dry eye and 20 normal controls were enrolled in this study. Subjects kept their eyes open for 10 seconds without blinking and corneal temperature was measured every second with a recently improved infrared radiation thermometer. RESULTS: In the 20 patients with dry eye, corneal temperature change after keeping the eye open for 10 seconds was 0.21 (SD 0.06) degree C while it was 0.61 (0.28) degree C in the 20 normal patients (p = 0.0001). In an exponential equation, the inclination of the slope of a patient with dry eye was smaller than the normal. The correlation coefficient was r = 0.79 (0.16) in patients with dry eye and r = 0.90 (0.07) in normal patients. The mean K value of patients with dry eye was 0.20 (0.13)/second and that of normal subjects was 0.31 (0.19)/second (p = 0.03). CONCLUSION: Findings demonstrate the usefulness of this thermometer for measuring corneal temperature in the evaluation of dry eye. Decrease in corneal temperature with each blink in patients with dry eye was smaller than in normal subjects. [ABSTRACT FROM PUBLISHER]