Metipranolol-associated granulomatous anterior uveitis.

This paper presents for the first time documented evidence, clinical details, and photographic illustrations of metipranolol-associated granulomatous anterior uveitis in 26 eyes of 15 patients being treated for glaucoma. There were 56 episodes of granulomatous anterior uveitis, all associated with large (mutton-fat) keratic precipitates, flare, cells, and 'white eyes' (except in seven episodes). In 30 (53.6%) of these episodes there was loss of control of intraocular pressure. Metipranolol 0.6% was implicated in 54 of the 56 episodes and metipranolol 0.3% in the remaining two. Fifty-one other cases of metipranolol-associated granulomatous anterior uveitis have so far been reported from other parts of the country to the Committee on Safety of Medicines. As a result multidose metipranolol in 0.1%, 0.3%, and 0.6% strengths has been withdrawn from clinical use in the United Kingdom. The pathogenesis of this adverse drug reaction is uncertain.

Calculation of the power of anterior chamber implants.

Ninety seven eyes with anterior chamber implants and a best corrected visual acuity of at least 6/12 were studied, firstly, to compare the predictive accuracies of the commonly used formulas for intraocular lens (IOL) power calculation and, secondly, to determine the effect of optimising the 'A' constant on the predictive accuracies of the empirical Sanders-Retzlaff-Kraff (SRK) formulas. The accuracies of the empirical formulas (SRK and SRK II) were generally similar to those of the theoretical formulas (Binkhorst II and Colenbrander-Hoffer). However the original SRK formula was more accurate than the two theoretical formulas in long eyes and in all eyes overall. Optimisation of the 'A' constants did not improve the predictive accuracy of the empirical SRK formulas.

Clinical evaluation of automated refraction in anterior chamber pseudophakia.

Automated refraction with the Canon RK-1 Autoref keratometer was evaluated in 85 eyes of 85 patients with an anterior chamber intraocular lens implant and a best corrected visual acuity of at least 6/12. Autorefraction readings were obtained in 80 (94%) of these eyes. The agreement between autorefraction and clinical refraction data was 89% for spherical equivalence less than 0.51 dioptres (D), 91% for sphere power less than 0.51 D, 82% for cylinder power less than 0.51 D, and 91% for cylinder axis less than 11 degrees. Autorefraction provides acceptably accurate postoperative refraction values in anterior chamber pseudophakia.

The newer generation intraocular lens power calculation formulae in anterior chamber implants.

One hundred and fifty-one eyes with anterior chamber implants and a best corrected visual acuity of at least 6/12 were studied to compare the predictive accuracies of the newer generation intraocular lens power calculation formulae. There was no statistically significant difference between the predictive accuracies of the SRK (Sanders-Retzlaff-Kraff), SRK II, SRK/Theoretical (SRK/T) and Holladay formulae. All these four formulae were more accurate than the Binkhorst II formula.

Metipranolol-induced adverse reactions: II. Loss of intraocular pressure control.

This paper reviews the behaviour of intraocular pressure (IOP) in glaucomatous eyes treated with metipranolol with and without drug-induced adverse reactions (ADRs). Two hundred and forty seven patients with open angle glaucoma who were receiving the three different strengths of metipranolol (0.1%, 0.3%, and 0.6%) in our Department and the 7 patients who participated in the metipranolol rechallenge trial were included in this study. Out of the 247 patients, there were 52 eyes of 29 patients who showed 78 episodes of ADRs associated with metipranolol. Forty five of these 78 episodes (57.6%) were associated with loss of IOP control. Two of the 7 eyes treated with metipranolol in the rechallenge trial showed loss of IOP control, 1 of them without any signs of ocular inflammation. We further studied all the glaucomatous eyes controlled with metipranolol 0.6% only and 22 eyes were identified with loss of IOP control but without recognisable signs or symptoms of ADR. Five other eyes in this group later developed metipranolol-induced ADRs. The possible pathophysiological mechanisms for the loss of IOP control are discussed and it is suggested that the active drug, metipranolol, could be directly implicated.

Metipranolol-induced adverse reactions: I. The rechallenge study.

Previously unreported adverse drug reactions can be difficult to detect and it may be even more difficult to establish a cause and effect relationship, particularly if the adverse reactions mimic naturally occurring disease. In a previous paper we reported 29 patients with granulomatous anterior uveitis, blepharoconjunctivitis, periorbital dermatitis, marginal keratitis and elevation in intraocular pressure (IOP), suspected to be caused by metipranolol (Glauline). With the approval of the District Ethics Committee 7 of those patients were rechallenged with metipranolol 0.3% compared to timolol maleate 0.5% in a double blind trial. The 7 metipranolol treated eyes developed an adverse reaction within 14 days. Metipranolol (Glauline) has been conclusively proven to cause granulomatous anterior uveitis, blepharoconjunctivitis and elevation in IOP, adverse effects never previously reported with any of the ophthalmic topical beta-blockers. The multidose preparations of metipranolol (Glauline) in all three strengths 0.1%, 0.3% and 0.6% and the single dose minim preparation of metipranolol 0.6% have now been withdrawn from clinical use in the United Kingdom.

Comparative evaluation of the Allergan Humphrey 570 and Canon RK-1 autorefractors: I. Objective autorefraction in normal subjects.

Fifty normal subjects were studied comparing objective autorefraction using the Allergan Humphrey 570 (AH 570) and Canon RK-1 autorefractors in terms of ease of operation, the time taken and their accuracy compared with clinical refraction. Both the autorefractors were equally easy to operate but the AH 570 was quicker. Objective autorefraction with the AH 570 was more accurate than using the Canon RK-1 especially with respect to spherical equivalence, sphere power and cyclinder axis: approximately 80% of the values were within 0.51 dioptres or 11 degrees of clinical refraction compared to approximately 60% for the Canon RK-1. The possible reasons for the superior performance of the AH 570 are discussed.

Comparative evaluation of the Allergan Humphrey 570 and Canon RK-1 autorefractors: II. Objective autorefraction in pseudophakes.

Fifty patients (50 eyes) with posterior chamber intraocular lenses and a best corrected visual acuity of at least 6/12 were studied. The Allergan-Humphrey 570 (AH-570) and Canon RK-1 autorefractors were compared in terms of ease of operation, time taken and their accuracy relative to clinical refraction. Both the autorefractors were equally easy to operate but the AH-570 was quicker. The AH-570 had a higher percentage of eyes within 11 degrees of clinically determined cylinder axis while the Canon RK-1 had a higher percentage of patients within 0.51 diopters of spherical equivalence, sphere power and cylinder power as determined by clinical refraction. This difference in the accuracy of objective autorefraction was not statistically significant; the clinical significance is uncertain.

Glare testing in pseudophakes with posterior capsule opacification.

We measured Snellen visual acuity under standard and glare conditions using the Allergan Humphrey 570 autorefractor in 46 pseudophakes (46 eyes) undergoing Neodymium-YAG laser posterior capsulotomy before and after treatment. All the patients studied had a best corrected vision of at least 6/12 but complained of visual disability and had clinically observable posterior capsule opacification. The patients did not have other known causes of glare disability. Following posterior capsulotomy, 30 (65%) patients showed an improvement in standard Snellen visual acuity and 44 (97%) an improvement in Snellen visual acuity under glare conditions. This difference was statistically significant (p < 0.001). Of the 16 patients whose standard Snellen visual acuity did not improve after posterior capsulotomy, 14 showed a reduction in glare disability. Glare testing was clinically useful in evaluating pseudophakes with posterior capsule opacification who complained of visual disability in spite of good Snellen visual acuity under standard testing conditions.