Robert H Stewart

Evaluation of Dexamethasone Acetate as a Topical Ophthalmic Formulation

Penetration of an ophthalmic suspension of 0.1% dexamethasone acetate into the rabbit cornea and aqueous humor was unaffected by the status of the corneal epithelium or by the presence or absence of intraocular inflammation. However, the total quantity of this corticosteroid that could be measured in the cornea or aqueous humor was significantly less than that produced by either dexamethason alcohol or dexamethasone sodium phosphate. Despite this, dexamethasone acetate was the most effective of the three dexamethasone derivatives in suppressing inflammation in the cornea, which indicates that following topical administration to the eye it is the most potent of the dexamethasone derivatives studied. This greater therapeutic effect does not seem to be accompanied by a greater propensity to increase intraocular pressure. Comparison of the intraocular pressureincreasing effect in known corticosteroid responders of dexamethasone acetate with that of dexamethasone sodium phosphate, the least effective of the dexamethasone products studied, demonstrated no difference between the two drugs. These data support the conclusion that dexamethasone acetate is superior to the commercially available dexamethasone derivatives for use as a topical ocular anti-inflammatory agent.

A DOUBLE-MASKED THREE-MONTH COMPARISON BETWEEN 0.25% BETAXOLOL SUSPENSION AND 0.5% BETAXOLOL OPHTHALMIC SOLUTION

In 352 patients with primary open-angle glaucoma or ocular hypertension, a multicenter double-masked, parallel-group clinical study compared the effects on intraocular pressure and ocular comfort of 0.5% betaxolol ophthalmic solution, a cardioselective beta-adrenergic blocking agent, with 0.25% betaxolol suspension. With twice-daily dosages, baseline intraocular pressure was significantly reduced (P = .0005), with no significant difference between the two groups, at Week 2 and at Months 1, 2, and 3. Further, the prevalence of ocular discomfort upon topical instillation was significantly lower for 0.25% betaxolol suspension than for 0.5% betaxolol solution (P = .0005).

Pupillary block associated with posterior chamber lenses.

Two patients developed pupillary block glaucoma after extracapsular cataract extraction with implantation of a posterior chamber lens but without peripheral iridectomies. The intraocular pressure of each eye was successfully controlled with laser iridotomy. No long-term medication was necessary to control their intraocular pressures.

24-hour control of intraocular pressure with 2% dorzolamide/0.5% timolol fixed-combination ophthalmic solution in open-angle glaucoma

ABSTRACT Objective: To evaluate the 24-hour efficacy and tolerability of 2% dorzolamide/0.5% timolol fixed combination (DTFC) solution in open-angle glaucoma and ocular hypertension. Research design and methods: Randomized, parallel, doublemasked, multicenter study. Patients with insufficiently controlled intraocular pressure (IOP≥22 mmHg) were randomized to DTFC (N=117) or timolol (N=115). IOP was measured at baseline, 6 weeks, and 8 weeks, with measurements taken at 6 p.m., 8 p.m., 10 p.m., 2 a.m., 6 a.m., 8 a.m., 10 a.m., and 2 p.m. Main outcome measures: Statistically significant change in IOP from untreated baseline for DTFC at all hours at week 8. Secondary outcome measures included: IOP-lowering at week 6 at all individual time points, change from baseline to 8 weeks in mean daytime IOP (average of 8 a.m., 10 a.m., 2 p.m., 6 p.m., and 8 p.m. IOPs) and night-time IOP (10 p.m., 2 a.m., 6 a.m.), and comparison of DTFC with timolol after 8 weeks. Results: Patients receiving DTFC had a statistically significant and clinically relevant reduction in IOP at week 8 compared with baseline at all eight time points (p<0.001). Significant IOP reductions were also seen at all time points at week 6 (p<0.001). DTFC significantly lowered mean daytime IOP and night-time IOP (p<0.001 for both). Timolol alone also significantly reduced IOP from baseline at 8 weeks for all diurnal time points, and mean daytime and night-time IOP (p<0.001 for all). Compared with timolol alone, there were significantly greater reductions with DTFC at 10 a.m. (p=0.003) and 2 p.m. (p=0.016), and for mean daytime IOP (p=0.025) at 8 weeks. Significant between-treatment differences were not observed at other time points. Both treatments were well-tolerated, with no differences observed in the safety profiles between the treatment groups. Conclusions: Both DTFC and timolol provided significant IOP reduction over the entire 24-hour measurement period. timolol during the daytime, but not at night. Although this study was not designed or powered to compare DTFC and timolol, DTFC exhibited greater IOP-lowering than timolol during the daytime, but not at night. Trial registration: ClinicalTrials.gov identifier: NCT00108017.

Periocular Cutaneous Pigmentary Changes Associated with Topical Betaxolol

PurposeWe report two cases of periocular cutaneous hypopigmentation and one case of hyperpigmentation which appeared while the patients were on betaxolol. We propose several possible explanations for this phenomenon. MethodsCharts of three patients with glaucoma who developed periocular cutaneous pigmentary changes while on betaxolol were reviewed retrospectively. ResultsCase #1 was a 47-year-old black man with primary open angle glaucoma, started on betaxolol 0.5% in both eyes in January 1981. Bilateral hypopigmentation of the eyelids was first documented in October 1987. Betaxolol was discontinued in November 1987. In December 1990 the pigmentation had returned to normal. Case #2 was a 4-month-old white boy with unilateral primary infantile glaucoma who was started in September 1992 on betaxolol 0.25% in the left eye. Left lower eyelid hypopigmentation was seen in April 1993. Betaxolol was discontinued in July 1993. Since that time the pigmentation has returned to normal. Case #3 was a 75-year-old black man with primary open angle glaucoma. He was placed on betaxolol 0.5% in both eyes in 1987 and in March 1988 hyperpigmentation of the eyelids was seen bilaterally. Betaxolol was discontinued, and by December 1990 the pigmentation had returned to normal. ConclusionThese three case histories suggest that the periocular cutaneous changes described herein are secondary to local instillation of betaxolol.

Trabeculectomy with implantation of the Mendez Glaucoma Seton: early results.

We present the early results in a small series of 12 eyes of 12 patients with uncontrolled glaucoma who underwent trabeculectomy with implantation of a Mendez Glaucoma Seton. All eyes, except one with neovascular glaucoma, had had multiple glaucoma surgery and all, without exception, were on maximal tolerated medical therapy prior to surgery. The follow-up period ranged from one and one fourth to three and three fourths months. The surgical technique was the same in all cases. Our success rate was 33.3% or 40%, if one eye with persistent hypotonia could be counted as a success. This result is inferior to those quoted in the literature with the use of other types of setons, and especially to the results of Dr. Antonio Mendez who used a similar implant.

A Modified Gills' Block and its Effectiveness for Lid Muscle Akinesia

We developed a prospective clinical study to determine the effectiveness of a new method of retrobulbar anesthesia and akinesia of the levator and orbicularis muscles. This study involved 50 patients who underwent extracapsular cataract extractions (ECCE) with intraocular lens implant (IOL). We found levator and orbicularis muscle akinesia was achieved in 49 of 50 eyes. One reblock was necessary. We also wish to point out the advantages of this technique as a means of reducing the rare but serious complications associated with retrobulbar anesthesia.

Lidocaine: An Anti-Tussive for Ophthalmic Surgery

Intravenous lidocaine suppresses the cough reflex in patients undergoing local operative procedures. Many anti-tussive agents suppress the cough reflex by suppressing the respiratory center. Intravenous lidocaine produces no respiratory depression in doses that suppress the cough reflex. Intravenous lidocaine should be available during all intraocular surgical procedures so it can be used when indicated.