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Biomedical subjects

G D Novack

Publications and source records attributed to G D Novack.

At least 37 records · Page 2Linked to original sources
PubMed1996

A placebo-controlled, double-masked evaluation of mitomycin C in combined glaucoma and cataract procedures.

PURPOSE: This study was performed to determine if adjunctive use of mitomycin C (MMC) would increase the success of combined phacoemulsification, intraocular lens implantation, and trabeculectomy surgery with releasable sutures. METHODS: Seventy-two eyes with cataract and glaucoma, requiring surgery for decreased vision, uncontrolled intraocular pressure, or to obtain a better view of the optic nerve, were randomized to receive a 2.5-minute subconjunctival exposure to either MMC (0.5 mg/ml) or placebo balanced salt solution. Postoperative evaluations at 3, 6, and 12 months were performed by a masked observer who recorded visual acuity, intraocular pressure, glaucoma medications, presence of filtering blebs, and complications. Endothelial cell counts were measured before and 3 months after surgery. RESULTS: The MMC group had significantly greater reduction in mean intraocular pressure through the first 12 months of follow-up (7.05-7.65 mmHg versus 2.62-3.84 mmHg; P = 0.001-0.028). In addition, through the first 6 months of follow-up, the MMC group required significantly fewer medications (0.4-0.5 versus 1.1-1.2; P = 0.002-0.004). Requirements for additional glaucoma surgery were less in the MMC group (4/ 36) than in the placebo group (7/35) (P = 0.301). Filtering blebs were significantly larger at 6 and 12 months (P = 0.002 and P = 0.001, respectively), and would leaks were more common (P = 0.101) in the MMC group. The mean decrease in endothelial cell count at month 3 was slightly, although not significantly, greater in the MMC treatment group (206.9 versus 91.3 cells/mm2* P = 0.377). CONCLUSION: The increased success of the glaucoma procedure in the MMC group together with relatively minor toxicity, suggests its use is beneficial in combined glaucoma-cataract surgery.

Aged↗
PubMed1995

Ocular toxicology.

In this review of recent articles on ocular toxicology, the author concentrates on undesirable effects on the eye induced by systemically used xenobiotics. These effects include increased tear flow elicited by systemic cyclosporine; uveitis associated with inactivated influenza vaccine, intravenous immunoglobulins, or skin tattoos; iritis associated with intravenous streptokinase; corneal epithelial erosion associated with the use of an alcohol-based antimisting spray; decreased color vision associated with workplace exposure to perchloroethylene, or to digoxin; myocardial ischemia induced by topical atropine; and systemic exposure to cyclopentolate after topical instillation. Ocular irritation associated with systemic use of 5-fluorouracil may be attenuated with prophylactic ice packs. At doses evaluated for treatment of choroidal neovascularization, systemic alpha interferon leads to toxicity in multiple organ systems. Promethazine precipitates when injected into intravenous lines with fluorescein. No drug achieves ultimate efficacy or ultimate safety. Thus, the decision to employ a given therapy involves a physician's evaluation of its therapeutic index-the ratio between efficacy and toxicity.

Drug-Related Side Effects and Adverse Reactions↗
PubMed1994

Ocular toxicology.

This review of recent articles on ocular toxicology concentrates on undesirable effects on the eye induced by systemically used xenobiotics. These effects include the corticosteroid-induced glaucoma and cataracts (especially in children), chloroquine-induced heart block and retinopathy, its possible protection by platelet aggregating factor antagonists, oculopathy after intracarotid chemotherapy with nitrosyl-urea or cisplatin, ketoconazole-induced papilledema, cytarabine-induced photophobia, ethambutol HCl-induced visual deficits, psychotherapeutic-agent overdose-induced ocular bobbing, amiodarone-induced cataracts, and imipramine HCl-induced angle-closure glaucoma. Also reviewed are the role of hormone levels in diabetic retinopathy, the therapeutic use of clonidine for perioperative intraocular pressure spikes, the increase in ocular blood flow by pentoxifylline, and decrease by nicotine, the potential for the reduction in drop size of mydriatic medications, a theory for sulfonamide-induced myopia, and guidelines for animal models of ocular toxicity. No drug achieves ultimate efficacy or ultimate safety. Thus, the decision to employ a given therapy involves a physician's evaluation of its therapeutic index, the ratio between efficacy and toxicity.

Drug-Related Side Effects and Adverse Reactions↗
PubMed1993

Vitreous surgery for macular holes.

BACKGROUND: To surgically treat patients with macular holes, the authors previously reported both anatomic (re-attachment) and visual success (2 lines of improvement) in a series of 52 eyes. They now have operated on an additional 118 eyes using similar techniques, for a total of 170 eyes. METHODS: After ophthalmologic examination and history, the authors operated on suitable patients. The surgical objectives included relief of all tangential traction and retinal tamponade with intraocular gas. All eyes were followed for at least 6 months postoperatively. RESULTS: In the total population of 170 eyes, anatomic success was achieved in 73% and vision improved at least two lines in 55%. Twenty-nine percent (49/170) of patients had a visual acuity of 20/40 or better at last examination. Patients with symptoms of less than 6 months' duration managed better than those with symptoms of longer duration (P = 0.3001). In the former group of 66 eyes, anatomic success was achieved in 80% (n = 53), whereas visual acuity improved at least two lines in 68% (n = 45) and at least four lines in 55% (n = 36). CONCLUSIONS: The authors suggest that macular hole surgery may provide meaningful improvement in visual acuity in most patients, especially in those whose symptoms are of less than 6 months' duration.

Aged↗
PubMed1993

Flurbiprofen 0.03% for the control of inflammation following cataract extraction by phacoemulsification.

We conducted a double-masked, vehicle-controlled study to evaluate the anti-inflammatory effect of topical flurbiprofen in cataract surgery by phacoemulsification and implantation of a posterior chamber intraocular lens. The 233 patients were randomized to receive either flurbiprofen or vehicle immediately prior to and for two weeks following surgery. No concomitant corticosteroid use was allowed. The flurbiprofen group had significantly less anterior chamber cells and flare at day 7 and significantly less conjunctival erythema, corneal edema, and lid edema at day 14. The investigator's global effectiveness rating was higher in the flurbiprofen group at day 14. Blood-aqueous barrier disruption, as measured by aqueous fluorophotometry, was statistically significantly diminished in the flurbiprofen group. Burning and stinging were rated significantly greater in the flurbiprofen group than in the vehicle group. Foreign-body sensation and photophobia were significantly more severe in the vehicle group than in the flurbiprofen group. Flurbiprofen provided postsurgical anti-inflammatory efficacy in clinical signs of inflammation and in blood-aqueous barrier disruption, and also showed improved subjective signs.

Adult↗
PubMed1992

Memory-enhancing effects of post-training dipivefrin and epinephrine: involvement of peripheral and central adrenergic receptors.

These experiments examined the effects, in mice, of post-training i.p. injections of dipivefrin (DPE), a lipophilic prodrug of epinephrine, and epinephrine (EPI) on 48-h retention assessed in inhibitory avoidance and Y-maze discrimination tasks. DPE, in doses of 0.3-10 micrograms/kg significantly facilitated retention: the effects were approximately 10-fold more potent than those of EPI obtained with similar experimental conditions. The alpha-adrenergic antagonists prazosin (alpha 1; 3.0 mg/kg; i.p.), yohimbine (alpha 2; 3.0 mg/kg; i.p.) and phentolamine (alpha 1 and alpha 2; 3.0 mg/kg; i.p.) did not block the enhancement of retention induced by either DPE (10.0 micrograms/kg; i.p.) or EPI (0.1 mg/kg; i.p.). However, the beta-adrenergic antagonist propranolol (2.0 mg/kg; i.p.) attenuated the effects of both DPE and EPI. Sotalol (2.0 mg/kg; i.p.), a peripherally-acting beta-adrenergic antagonist, attenuated the effects of EPI but not those of DPE. These findings suggest the DPE-induced enhancement of memory involves central beta- but not alpha-adrenergic mechanisms while EPI's effects are initiated by activation of peripheral beta-adrenergic systems.

Adrenergic Antagonists↗
PubMed1992

Once-daily versus twice-daily levobunolol (0.5%) therapy. A crossover study.

The authors executed a two-period, randomized, double-masked, crossover study comparing once-daily to twice-daily levobunolol hydrochloride (0.5%) in 20 patients with elevated intraocular pressure (IOP). Modified diurnal curves were performed at four times for each study arm: baseline, day 1, day 14, and day 28. The mean diurnal corrected decrease in IOP from baseline ranged from 16% +/- 11% to 22% +/- 9% when the subjects were treated twice daily, and from 14% +/- 10% to 18% +/- 8% when the same subjects were treated once daily. At day 1, patients had a significantly greater IOP lowering after twice-daily therapy than after once-daily therapy (P less than 0.05). At 14 and 28 days, there was no clinically significant difference between the two treatment regimens. The results of our crossover study suggest that once-daily treatment with levobunolol (0.5%) is as effective as twice-daily treatment.

Adult↗
PubMed1989

Trabecular outflow facility determined by fluorophotometry in human subjects.

We studied a new fluorophotometric method to determine trabecular outflow facility in man. Pilocarpine was selected to evaluate this non-invasive method, since its primary ocular hypotensive effect is to increase trabecular outflow facility. Levobunolol was used to decrease intraocular pressure and aqueous humor flow required for the calculation of trabecular outflow facility. In ten ocular hypertensive patients trabecular outflow facility in the pilocarpine-treated eyes was 0.42 +/- 0.16 (S.D.) microliters min-1 mmHg-1 compared with 0.17 +/- 0.14 microliters min-1 mmHg-1 in the vehicle-treated eyes (P less than 0.004). An ocular hypotensive additivity was also found in the eyes treated with both drugs. It was concluded that this non-invasive fluorophotometric method may be useful in evaluating the effect of a drug on trabecular outflow facility.

Aqueous Humor↗
PubMed1989

A comparison of the ocular hypotensive efficacy of once-daily and twice-daily levobunolol treatment.

The authors compared the ocular hypotensive efficacy of two different treatment regimens of levobunolol 0.5% in a double-masked, randomized, controlled clinical trial. Seventy-one patients with open-angle glaucoma or ocular hypertension received levobunolol 0.5% as their sole glaucoma medication either on a once-daily or twice-daily treatment regimen for 3 months. Approximately 81% of the patients in the once-daily treatment group and 88% of subjects in the twice-daily treatment group successfully completed the 3-month study period. The overall mean decrease in intraocular pressure (IOP) was 4.5 mmHg in the once-daily group and 5.6 mmHg in the twice-daily group. These differences were not statistically different. For both treatment groups, effects on mean heart rate and blood pressure were minimal. The authors' data from this population suggest that once-daily treatment with levobunolol is an effective glaucoma regimen.

Blood Pressure↗
PubMed1989

Efficacy and safety of once-daily levobunolol for glaucoma therapy.

We studied the ocular hypotensive efficacy and safety of 0.5% levobunolol hydrochloride and 0.5% timolol maleate administered topically once daily for 3 months in 91 patients (46 in the levobunolol group and 45 in the timolol group) with primary or secondary open-angle glaucoma or ocular hypertension. In this randomized double-masked parallel clinical study, intraocular pressure (IOP) was successfully controlled in 78% of the patients who received levobunolol and 89% of those who received timolol. The overall mean decrease in IOP was 5.6 mm Hg (decrease of 23%) in the levobunolol group and 6.7 mm Hg (26%) in the timolol group, a nonsignificant difference. In both groups the overall mean IOP during treatment was significantly lower than the pretreatment value (p less than 0.001). For both treatment groups changes in heart rate and blood pressure were minimal. We conclude that both 0.5% levobunolol and 0.5% timolol administered once daily are effective and safe in lowering IOP in most patients with ocular hypertension or open-angle glaucoma.

Administration, Topical↗
PubMed1988

Long-term evaluation of 0.25% levobunolol and timolol for therapy for elevated intraocular pressure.

In a one-year, double-masked, randomized study, the ocular hypotensive efficacy of twice-daily treatment with 0.25% levobunolol hydrochloride or timolol maleate was evaluated in 78 patients with glaucoma or ocular hypertension (phase 1). If intraocular pressure (IOP) was not well controlled during the study, the concentration of medication was increased to 0.5%, and the patient was followed up for an additional three months (phase 2). During phase 1, the mean IOP was reduced by 4.6 mm Hg in the timolol treatment group and by 5.1 mm Hg in the levobunolol treatment group. Seventy-one percent (29/41) of the patients in the timolol treatment group and 70% (26/37) of the patients in the levobunolol treatment group successfully completed phase 1. Of those patients who required the higher concentration of medication, 89% (8/11) in the timolol treatment group and 75% (3/4) in the levobunolol treatment group successfully completed phase 2. Higher concentration, however, did not produce greater IOP reduction. No statistically or clinically significant differences between the groups were noted in any of the efficacy or safety variables evaluated.

Adult↗