Knowledge of visual experience during cataract surgery under local anaesthesia: a nationwide survey of UK ophthalmologists.

AIM: To evaluate the knowledge and practices of UK ophthalmologists regarding patients' subjective visual experience during cataract surgery under local anaesthesia. METHODS: A nationwide postal survey was conducted on UK ophthalmologists using a standardised questionnaire. RESULTS: The proportion of surgeons who operated under regional anaesthesia who thought that patients could experience the following visual sensations were: no light perception (54%); light perception (95%); one or more colours (93%); flashes of light (81%); movement (87%); instruments (61%); surgeon's hands or fingers (53%); surgeon (43%); and changes in light brightness (88%). Fifty-eight per cent of them thought that patients might be frightened by this, and 77% thought that preoperative counselling could help alleviate this fear. The proportion of surgeons who operated under topical anaesthesia who thought that patients could experience the following visual sensations were: no light perception (10%); light perception (94%); one or more colours (97%); flashes of light (86%); movement (96%); instruments (81%); surgeon's hands or fingers (65%); surgeon (51%); changes in light brightness (95%). Fifty-nine per cent of them thought that patients might be frightened by this, and 80% thought that preoperative counselling could help alleviate this fear. CONCLUSION: Most UK surgeons believed that during cataract surgery under local anaesthesia, patients might experience various visual sensations which could cause fear and that such fear could be alleviated by preoperative counselling.

The effect of topical treatment by timolol versus pilocarpine on visual field progression in chronic simple glaucoma.

OBJECTIVES: The objective of this study was to compare the intraocular pressure-lowering capacity, tolerability, and visual field conservation of topical timolol and pilocarpine at the concentrations usually prescribed.

Effect of timolol versus pilocarpine on visual field progression in patients with primary open-angle glaucoma.

BACKGROUND: Relatively few studies have been conducted linking decreasing intraocular pressure (IOP) to preservation of visual field. This investigation was conducted to determine if this link could be made and to compare the long-term effect of two ocular hypotensive agents on preservation of visual field. METHODS: In an observer-masked study, 189 patients with primary open-angle glaucoma received either timolol or pilocarpine by random allocation. The dose of antiglaucoma agent was increased from 0.25% to 0.5% twice daily for timolol or from 2% to 4% four times daily for pilocarpine if the initial IOP response was inadequate. After an on-treatment baseline, visual fields were followed every 4 months for 2 years using the Octopus program 32. RESULTS: Compared with timolol, significantly more patients receiving pilocarpine discontinued use because of inadequate IOP control (P < or = 0.01). By comparing the mean visual field scores, it can be seen that the pilocarpine group had a significantly worse score at all timepoints from month 4 to month 24. The pilocarpine group also had a greater mean number of test loci with decreased sensitivity of 5 or more decibels (dB) at all timepoints. The mean within-patient regression slope for timolol was 0.01 dB/month and for pilocarpine was -0.06 dB/month (P < 0.01). The study has shown that over a 2-year period, patients treated with pilocarpine 2% or 4% four times daily experienced a significantly greater visual field deterioration than that seen in patients receiving either 0.25% or 0.5% timolol twice daily. CONCLUSION: Although these data do not support a link between lowering of IOP and visual field preservation, treatment with timolol was associated with significantly less visual field loss than treatment with pilocarpine.

Comparison of the effect of acetazolamide tablets and sustets on diurnal intraocular pressure in patients with chronic simple glaucoma.

Twenty patients with primary open-angle glaucoma uncontrolled on single topical therapy completed a double dummy crossover study to compare acetazolamide tablets with a sustained release formulation (Sustet). The two preparations were equally effective, but no direct relationship was found between the intraocular pressure and the plasma concentration of acetazolamide. No difference between the formulations was found in the frequency or severity of side effects.

Equivalence of conventional and sustained release oral dosage formulations of acetazolamide in primary open angle glaucoma.

1. Outpatients with primary open angle glaucoma uncontrolled on single topical therapy with either pilocarpine or timolol were recruited for a stratified double dummy cross over trial. Once or twice daily sustained release acetazolamide (SRA) was compared with an identical regimen of conventional tablets (CA). 2. During the run in period the patients received 500 mg SRA once or twice daily as needed to control intraocular pressure (IOP). The dose was thereafter kept constant and patients were allocated randomly to 4 weeks treatment with CA followed by 4 weeks SRA or vice versa. IOP and venous plasma concentrations of acetazolamide were measured at weekly intervals. At the end of each 4 week course, patients were admitted for a 24 h profile of IOP and drug concentration measurements. 3. Thirty-five patients were recruited, but eleven were withdrawn during the run in period largely because of adverse effects; these became less troublesome when it was decided to give the once daily dose at 22.00 h. Four were withdrawn during the cross over, two because of inadequate IOP control. Twenty completed the trial. 4. The morning plasma concentration of acetazolamide measured each week showed no tendency to accumulation during the study. The mean swing (maximum minus minimum) in plasma acetazolamide concentration during the 24 h profile was less (P less than 0.005) with the SR formulation (11.6 +/- 4.9; mg l-1) +/- s.d.) than with the conventional (15.5 +/- 4.7) but the mean concentrations over the 24 h profile were indistinguishable (P greater than 0.05; 9.7 +/- 3.8 and 8.6 +/- 2.8 respectively). 5. Satisfactory control of IOP (no more than one reading above 22 mmHg) was maintained despite the changes in formulation in all but two of the patients who entered the cross over study. No close relationship between IOP and plasma concentration of acetazolamide was found. The 24 h IOP profiles whilst receiving each of the formulations were indistinguishable; thus the smoothing of the plasma drug concentration profile achieved by the SR formulation did not reduce the amplitude of swings in IOP. Similarly, no difference was observed between the formulations with respect to adverse effects. 6. It is concluded that the SR and conventional formulations were equivalent with respect to mean plasma acetazolamide concentration, IOP control and adverse effects. The SR formulation did not show practical advantages over the conventional formulation which was equally effective even with dosage intervals of 12 or 24 h.

A single-blind randomised trial comparing adrenaline 1.0% with dipivalyl epinephrine (propine) 0.1% in the treatment of open-angle glaucoma and ocular hypertension.

The results of this single-blind randomised trial comparing adrenaline 1% with dipivalyl epinephrine (Propine) 0.1% confirm that both have a significant effect in lowering the intraocular pressure in patients with open-angle glaucoma and ocular hypertension, but it is generally insufficient to warrant their use as the first line medical treatment of these two conditions. There was no significant difference between the intraocular lowering effect of the two preparations, and 60% of patients receiving Propine and 66% of those receiving adrenaline noted side effects.

A study of the effects of four concentrations of D-timolol, 0.25% L-timolol, and placebo on intraocular pressure on patients with raised intraocular pressure.

The intraocular pressure lowering effect in 30 patients with raised intraocular pressure and open angles following a single application in a randomised double-masked fashion of four concentrations of D-timolol (0.25%, 0.5%, 1.0%, and 2.0%), 0.25% L-timolol, and placebo are presented. The percentage reduction in intraocular pressure after four hours following single-drop instillation range from 20% to 25% in the D-timolol group, 32% in the L-timolol group, and only 8% in the placebo group of treated eyes.

Origin of disc new vessels assessed by videofluorography.

Ten patients with disc neovascularisation of various aetiologies were studied to ascertain the origin of their new vessels. Fluorescein angiography was carried out with an image intensified video camera. A retinal artery derivation was demonstrated for the first time and was seen in three cases. Six further patients showed a retinal venous supply, and finally there was one from a choroidal source.

A blind randomised cross-over trial comparing metipranolol 0.3% with timolol 0.25% in open-angle glaucoma: a pilot study.

A blind randomised cross-over study was conducted on 10 patients (20 eyes) to compare the effect in patients with open-angle glaucoma of metipranolol 0.3% with that of timolol 0.25% on intraocular pressure following one month's topical instillation with each preparation alone. There was no statistically significant difference in intraocular pressure reduction between these two preparations, and the ocular tolerance of both was good. There was no significant difference in the blood pressure, pulse, or pupil diameters of patients receiving either preparation.

Timolol and guanethidine plus adrenaline in combination in the treatment of chronic open angle glaucoma.

A four month study was conducted in patients with chronic open angle glaucoma to determine whether timolol and guanethidine plus adrenaline have an additive effect in lowering intraocular pressure. Thirty-five patients were assigned to four treatment sequences (timolol 0.25 per cent and 0.5 per cent supplemented with guanethidine 1 per cent plus adrenaline 0.2 per cent (Ganda 1.0/0.2) and vice-versa). There was a significant reduction in intraocular pressure after one month's combined therapy in three of the four treatment groups but this reduction was maintained in only one group (timolol 0.5 per cent with Ganda 1.0/0.2) after four months therapy. The results are discussed with particular reference to adrenergic influences on aqueous humour dynamics.

The effect of topical 0.5% triamterene suspension on the intraocular pressure of open angle glaucoma patients. A single dose study.

The effect of a topical 0.5% triamterene suspension on the intra-ocular pressure of 15 open angle glaucoma patients was investigated. On the first day measurements were made at 09.00, 12.00 and 16.30 hours without treatment. On the second day measurements were made at 09.00 hours and 1, 2, 4 and 6 hours following instillation of the suspension into the eye. Without treatment there were no significant changes in intra-ocular pressure. After topical triamterene the maximum group mean pressure reduction was -4.7 mm Hg at 6 hours and mean intra-ocular pressures were less than 22 mm Hg at both 4 and 6 hours. There was also a notable decrease in intra-ocular pressure in two thirds of the contralateral untreated eyes which was not attributable to diurnal variation. No local or systemic side effects were observed.

Blind randomised non-crossover long-term trial comparing topical timolol 0.25% with timolol 0.5% in the treatment of simple chronic glaucoma.

The results of a 12-month blind randomised trial comparing the intraocular pressure lowering effect of timolol 0.25% with timolol 0.5% are presented. 27% of patients (22% of eyes) required additional antiglaucoma medication after a minimum time interval of 6 months to maintain an intraocular pressure less than 23 mmHg. The mean reduction in intraocular pressure (from pretreatment values) at 12 months was 24% for eyes treated with timolol 0.25% and 19% for eyes treated with timolol 0.5%. When reductions in intraocular pressure at each follow-up interval were statistically significant (timolol 0.25% treated eyes compared with timolol 0.5% treated eyes), the significance always favoured timolol 0.25%.

Intraocular lens implantation following cataract extraction in Fuchs' heterochromic uveitis.

The results of intraocular lens implantation in eight cases of cataract secondary to heterochromic uveitis are presented. Follow-up was from 16 months to two years (mean 22 months). Visual acuity was restored to 6/9 or better in six cases and 6/18 in one, but remained hand movements in the remaining case. Postoperative complications included the development of inflammatory pupillary membranes, vitreous haze, and increased intraocular pressure.

Trabeculectomy: a retrospective long-term follow-up of 444 cases.

The results of the surgical procedure of trabeculectomy, as performed by the staff of the Manchester Royal Eye Hospital from 1974 to 1979 inclusive on 356 patients (444 eyes) are presented, with particular emphasis not only on intraocular pressure control but on operative and postoperative long-term complications. Its position in the surgical treatment of glaucoma is confirmed, but the attendant surgical and long-term side effects associated with trabeculectomy appear to be more widespread and problematical than previous reports would suggest.

Two blind randomized cross-over trials in the treatment of primary open angle glaucoma.

We present the results of two blind randomized trials comparing both guanethidine 3 per cent and adrenaline 0.5 per cent (Ganda 3.0/0.5) and guanethidine 1 per cent and adrenaline 0.2 per cent (Ganda 1.0/0.2) in single drop form with Timolol (Timoptol) 0.25 per cent. Results of 48-hour phasing at the end of one month's treatment demonstrated a significantly greater fall in intraocular pressure with Ganda 3.0/0.5 (9.8 mm Hg) than with Timolol 0.25 per cent (7.67 mm Hg) P less than 0.001. There was no significant difference in the fall in intraocular pressure between Ganda 1.0/0.2 (8.87 mm Hg) and Timolol 0.25 per cent (8.24 mm Hg).

Primary myxedema heart disease.

A case of primary myxedema heart disease in an 84-year-old man is presented. His history and physical examination were typical of myxedema. Electrocardiographic changes showing generalized low voltage, nonspecific S-T segment and T-wave changes, and nodal rhythm are characteristic of the disease. The patient showed remarkable improvement after oral liothyronine (Cytomel) therapy.

A double blind comparison of guanethidine-and-adrenaline drops with 1% adrenaline alone in chronic simple glaucoma.

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.