The association of postoperative subjective visual function with acuity, glare, and contrast sensitivity in patients with early cataract.

BACKGROUND: It has been shown in our previous studies that early cataracts affect vision in ways that can be measured by objective means and that this objective impairment in visual acuity, glare, and contrast sensitivity can be successfully reversed by cataract surgery. OBJECTIVE: To evaluate the association of subjective visual function with objective measures of acuity, glare, and contrast sensitivity in patients who were symptomatic from early cataract. METHODS: We administered a task-oriented questionnaire prior to and 4 months after cataract surgery to patients who were symptomatic from early cataract (median preoperative ETDRS [Early Treatment Diabetic Retinopathy Study] visual acuity of 20/40 [range, 20/20 to 20/80]); ETDRS visual acuity, disability glare, and contrast sensitivity were also measured at those times. RESULTS: Uncomplicated cataract surgery resulted in resolution or improvement of subjective symptoms for the great majority of subjects, and in a few subjects new symptoms developed or current symptoms worsened. We found a positive association between postoperative improvement in subjective visual function (as measured by the questionnaire) and postoperative improvement in objective visual function (as measured by visual acuity and contrast sensitivity). We also found that the greater the degree of preoperative impairment in objective visual function (as measured by visual acuity and contrast sensitivity), the greater the postoperative improvement in subjective visual function (as measured by the questionnaire). No such association was found for our disability glare test. CONCLUSIONS: Cataract surgery for symptomatic individuals with mild impairment in visual acuity does relieve visual symptoms, and preoperative measurement of contrast sensitivity can help determine who with early cataract is most likely to report subjective improvement in vision.

Prevalence of lens opacities in surgical and general populations.

The distribution and prevalence of lens opacities were examined and compared among three general population-based groups and a group that underwent cataract surgery. The population-based groups comprised subjects from the Framingham Eye Survey, the National Health and Nutrition Examination Survey, and the study of watermen in Maryland. Comparison among these groups revealed similar frequencies of lens opacities among age groups, with slightly higher rates for older individuals in the watermen study population. Comparison between the watermen and the surgical groups revealed that, of lenses with opacities, posterior subcapsular cataracts were present in a far greater percentage of surgery cases (60.6%) than in general population cases (5.3%). These findings confirm the generally held clinical belief that posterior subcapsular opacities are disproportionally represented in the surgical population and suggest that they cause more significant visual disability than do other types of cataracts.

Comparison of acuity, contrast sensitivity, and disability glare before and after cataract surgery.

We assessed vision before and after uncomplicated extracapsular cataract extraction and intraocular lens implantation in 72 symptomatic patients with acuity equal to or better than 20/80 and no other ocular abnormality. Contrast sensitivity was measured with the Pelli-Robson Letter Chart (Metropia Ltd, Cambridge, England) and disability glare was measured under daytime conditions with the Brightness Acuity Tester (Mentor O&O Inc, Norwell, Mass) and under nighttime conditions with a computer-controlled video display. Prior to surgery there was significant disability glare that was not correlated with acuity. There was also a loss in contrast sensitivity that was moderately correlated with acuity (r = -.43; P < .001). Following surgery, most patients' scores returned to normal on all tests. Improvement in disability glare and contrast sensitivity was independent of improvement in acuity. Furthermore, patients with the poorest preoperative vision were as likely to regain normal function after surgery as those with the best preoperative vision.

The effect of early cataracts on glare and contrast sensitivity. A pilot study.

To establish the effect of cataracts on glare and contrast sensitivity, we graded type and amount of lens opacity in 110 subjects who underwent two glare tests (Brightness Acuity Tester and Berkeley glare test) and two contrast sensitivity tests (a sine-wave test and Pelli-Robson chart). Twenty-seven subjects (25%) had clear lenses (mean visual acuity of 20/20) and 83 subjects (75%) had early lens opacities (mean visual acuity of 20/40) in otherwise normal eyes. Multiple regression techniques were used to control for the effects of age and visual acuity. Glare test scores were significantly lower for nearly all patients with lens opacities than for patients with clear lenses and were the lowest for patients with lenses with posterior subcapsular opacity. Contrast sensitivity scores were lower for all patients with lens opacities than for patients with clear lenses at high frequencies only; all lens opacity groups scores similarly with each other. These results indicate reduced visual function among patients with cataracts whose visual acuity is only minimally impaired.

A double-masked, randomized, 1-year study comparing the corneal effects of dorzolamide, timolol, and betaxolol. Dorzolamide Corneal Effects Study Group.

OBJECTIVE: To compare the long-term effects of dorzolamide hydrochloride (Trusopt, Merck and Co Inc, White-house Station, NJ), timolol maleate, and betaxolol hydrochloride on corneal endothelial cell density and corneal thickness. METHODS: This 1-year multicenter study was conducted in 298 patients with ocular hypertension or open-angle glaucoma who had a baseline central corneal endothelial cell density greater than 1500 cells/mm2 and central corneal thickness less than 0.68 mm in each eye. Patients were randomized to 0.5% betaxolol twice daily, 0.5% timolol twice daily, or 2.0% dorzolamide 3 times daily. Specular microscopy and ultrasonic pachymetry of the central cornea was performed at baseline and 6 and 12 months following institution of therapy. Endothelial cell densities were determined by a single masked observer. RESULTS: The mean percent changes from baseline for both outcome measures were similar in all 3 treatment groups at both 6 and 12 months. After 1 year of treatment, the mean percent loss in endothelial cell density from baseline was 3.6%, 4.5%, and 4.2% for the dorzolamide, timolol, and betaxolol groups, respectively. The mean percent change from baseline for corneal thickness was 0.47%, -0.25%, and 0.39% for the dorzolamide, timolol, and betaxolol groups, respectively. CONCLUSIONS: Dorzolamide is equivalent to timolol and betaxolol in terms of the change in central endothelial cell density and thickness after 1 year of therapy. All 3 treatments exhibit good long-term corneal tolerability in patients with normal corneas at baseline.

Comparison of the efficacy and safety of 2% dorzolamide and 0.5% betaxolol in the treatment of elevated intraocular pressure. Dorzolamide Comparison Study Group.

A multicenter, parallel-design, randomized, double-masked study was conducted to compare the efficacy and safety of 2% dorzolamide with those of 0.5% betaxolol in the treatment of elevated intraocular pressure (i.o.p). A total of 311 adults with ocular hypertension or open-angle glaucoma were randomly allocated to receive either 2% dorzolamide administered topically TID or 0.5% betaxolol administered topically BID plus placebo administered topically QD for 12 weeks. After the washout of previous ocular hypotensive drugs, patients with IOP > or = 23 mm Hg in at least one eye at 10 AM or 4 PM on study day 1 were randomly allocated to receive one of the study treatments. Throughout the study, IOP was measured 2 and 8 hours after instillation of study medication for the morning peak effect (hour 2) and afternoon trough effect (hour 8). After 12 weeks of therapy, the mean change in IOP was not significantly different between the dorzolamide and betaxolol treatment groups at hour 8 (-3.6 mm Hg in both groups) or hour 2 (-5.4 vs -5.3 mm Hg, respectively). The differences between treatments (and 95% CIs associated with these differences) in mean IOP changes from baseline were 0.02 mm Hg (-0.870 to 0.901) for hour 8 and -0.14 mm Hg (-0.959 to 0.685) for hour 2. The ocular adverse experience (AE) most frequently reported by patients was ocular burning and/or stinging, and the most frequently reported nonocular AEs were taste perversion, upper respiratory infection, and headache. Only the incidence of taste perversion was significantly different between treatment groups (14.6% for the dorzolamide group and 0.0% for the betaxolol group). Two percent of patients in each treatment group discontinued the study due to AEs. This study confirmed the similar IOP-lowering effect of 2% dorzolamide and 0.5% betaxolol. Both treatments were generally well tolerated, and their safety profiles were similar.

Dorzolamide versus pilocarpine as adjunctive therapies to timolol: a comparison of patient preference and impact on daily life.

The purpose of this study was to compare 2% dorzolamide three times daily with 2% pilocarpine four times daily to determine patient preference, tolerability, and impact on daily life in patients concurrently receiving 0.5% timolol twice daily for treatment of elevated intraocular pressure (IOP). Seventy-five patients were enrolled in this 4-week, randomized, two-period, crossover study. The Comparison of Ophthalmic Medications for Tolerability questionnaire was used to assess patient preference and perception of side effects and activity limitations resulting from the study medications. IOP measurements were obtained 2 hours after drops were instilled and visual field tests were performed at baseline and at the end of each crossover period. Significantly more patients receiving pilocarpine than dorzolamide reported adverse experiences and discontinued the drug because of these adverse experiences. Similarly, patients reported more interference with their daily life because of side effects and activity limitations when receiving pilocarpine. Vision difficulties, accommodation difficulties, and brow ache were reported more often and were considered more bothersome by patients receiving pilocarpine. Bitter/unusual taste was reported more frequently and was considered more bothersome by patients receiving dorzolamide. Patients also reported missing fewer doses and were more satisfied with their medication when receiving dorzolamide. All of these changes were considered statistically significant. IOP control was not significantly different with either dorzolamide or pilocarpine. However, patients experienced a significant worsening of the mean defect of automated visual field examinations when receiving pilocarpine. At the end of the study, among patients with a preference, dorzolamide was preferred to pilocarpine by a ratio of more than 9:1. Overall, 81.9% of patients preferred dorzolamide. Thus dorzolamide demonstrated better tolerability and less adverse impact on daily life than pilocarpine.

A new method for documenting lens opacities.

We tested an anterior segment camera and digital analyzer on 32 eyes of 22 patients to determine whether its measurement of lens opacities correlated with measurements obtained by a standardized clinical grading system. The lenses were graded clinically for nuclear opacity, nuclear color, cortical opacity, and posterior subcapsular opacity. The lenses were then photographed and analyzed with this new device, and the results were compared. The camera system showed good reproducibility. Its results correlated well with the clinical gradings for nuclear capacity (P = .001) and cortical opacity (P = .001) but less well with posterior subcapsular opacity (P = .3), although there were only seven eyes with posterior subcapsular opacities. This camera system could help document and follow up lens opacity with more accuracy and reproducibility than has been previously possible.

Comparison of the safety and efficacy of the fixed combination of dorzolamide/timolol and the concomitant administration of dorzolamide and timolol: a clinical equivalence study. International Clinical Equivalence Study Group.

AIMS: To compare the tolerability and efficacy of a fixed combination solution of dorzolamide/timolol (Cosopt), administered twice daily with the concomitant administration of its components, dorzolamide (Trusopt) twice daily and timolol (Timoptic) twice daily. METHODS: After a 2 week timolol run in, patients with open angle glaucoma or ocular hypertension were randomised (1:1) to receive treatment with either the dorzolamide/timolol combination solution twice daily (combination) or the dorzolamide solution twice daily plus timolol maleate solution twice daily (concomitant) for 3 months. RESULTS: 299 patients were entered and 290 patients completed the study. Compared with the timolol baseline, additional IOP lowering of 16% was observed at trough (hour 0) and 22% at peak (hour 2) at month 3 in both the concomitant and combination groups. The IOP lowering effects of the two treatment groups were clinically and statistically equivalent as demonstrated by the extremely small point differences (concomitant--combination) observed in this study--0.01 mm Hg at trough and 0.08 mm Hg at peak. The safety variables of the concomitant and combination groups were very similar. Both combination and concomitant therapy were well tolerated and few patients discontinued due to adverse effects. CONCLUSIONS: The dorzolamide/timolol combination solution administered twice daily is equivalent in efficacy and has a similar safety profile to the concomitant administration of the components administered twice daily.

Two-year safety study of dorzolamide as monotherapy and with timolol and pilocarpine. Dorzolamide Safety Study Group.

PURPOSE: To evaluate the safety of open-label 2.0% dorzolamide as monotherapy and when used with timolol and/or pilocarpine for as long as 2 years. METHODS: The safety of dorzolamide was evaluated in patients with open-angle glaucoma or ocular hypertension over a 2-year period. The incidence of the most common drug-related adverse experiences in the first year was compared with that in the second year using McNemar's test. The ocular hypotensive effect of dorzolamide as monotherapy and with adjunctive therapy was assessed using percent change in intraocular pressure (IOP) from baseline. RESULTS: Of the 304 patients enrolled, 164 (53.9%) continued to receive dorzolamide as monotherapy for 2 years and 140 (46.1%) required add-on therapy. Add-on therapy was initiated by month 6 in 112 of these 140 patients (80%). Of the 304 patients, 202 (66.4%) completed 2 years of therapy. Of the patients who received dorzolamide as monotherapy, drug-related adverse events occurred more frequently during the first year (29.7%) than the second year (13.8%), and the most common ocular drug-related adverse events included conjunctivitis, burning/stinging eye, follicular conjunctivitis, and eyelid edema. After 2 years of therapy, the mean percent decrease in peak IOP was 22.8% for patients receiving dorzolamide monotherapy and 31.2% to 36.0% for patients receiving add-on therapy. CONCLUSION: Dorzolamide was generally well tolerated for up to 2 years as monotherapy and when used with timolol and/or pilocarpine. Drug-related adverse events were less frequent during the second year of monotherapy than during the first year. Most patients who required add-on therapy did so within the first 6 months of initiating dorzolamide therapy.

The dorzolamide/timolol combination versus timolol plus pilocarpine: patient preference and impact on daily life. United States Patient Preference Study Group. International Patient Preference Study Group.

PURPOSE: To compare the 2.0% dorzolamide/0.5% timolol fixed combination (COSOPT; Merck & Co., Whitehouse Station, NJ) to 0.5% timolol plus 2.0% pilocarpine given concomitantly, and to determine patient preference, tolerability, and impact on daily life in patients with elevated intraocular pressure (IOP). METHODS: Two multi-center, randomized, cross-over, observer masked studies were conducted, one in the United States (97 patients) and one in Europe (93 patients). The Comparison of Ophthalmic Medications for Tolerability questionnaire was used to assess patient preference and perception of side effects and activity limitations resulting from study medications. Intraocular pressure was measured before and 2 hours after the morning dose of study medication (hour 0 and hour 2). RESULTS: In both studies, among patients with a preference, the combination was preterred to timolol plus pilocarpine by a ratio of 4 to 1. The most commonly cited reason for this preference was side effects. Patients in both studies also reported that the combination interfered significantly less with daily life in terms of side effects and activity limitations. They also reported missing significantly fewer doses of study medication while taking the combination and being significantly more satisfied with it. The efficacy of these two treatments was not significantly different, based on IOP measurements at hour 0 and 2 hours after administration. Patients reported significantly more adverse events while receiving timolol plus pilocarpine in both studies, and in the U.S. study, significantly more patients discontinued therapy while receiving timolol plus pilocarpine than while receiving the combination. CONCLUSION: Compared with timolol plus pilocarpine, patients preferred the combination of 2% dorzolamide/0.5% timolol, and reported less interference in daily activities, better tolerability, and better compliance with therapy.

The efficacy and safety of dorzolamide as adjunctive therapy to timolol maleate gellan solution in patients with elevated intraocular pressure. Additivity Study Group.

PURPOSE: Two parallel, randomized, double-masked, placebo-controlled studies were conducted to assess the efficacy and safety of 2% dorzolamide hydrochloride as adjunctive therapy to 0.5% timolol maleate ophthalmic gellan (gel-forming) solution in patients with elevated intraocular pressure (IOP) that was inadequately controlled with 0.5% timolol maleate gellan solution alone. METHODS: Both studies began with an open-label 2-week run-in period on 0.5% timolol maleate gellan solution once a day. The only variation in method between the two studies was the dosage of 2% dorzolamide. In one study, 202 patients received 0.5% timolol maleate gellan solution once daily plus either 2% dorzolamide or placebo three times daily. In the other study, 181 patients received 0.5% timolol maleate gellan solution once daily plus either 2% dorzolamide or placebo twice daily. RESULTS: After 85 days, additional mean percent reductions in IOP from baseline at morning trough for the groups receiving 2% dorzolamide three times daily and placebo three times daily were 12.5% and 8.4%, respectively. Mean percent reductions for the groups receiving 2% dorzolamide twice daily and placebo twice daily were 13.1% and 6.5%, respectively. Burning and/or stinging on instillation were the only adverse experiences that affected significantly more of the patients receiving 2% dorzolamide twice or three times daily than those receiving placebo. CONCLUSION: When administered concomitantly with 0.5% timolol maleate gellan solution, 2% dorzolamide three times daily or twice daily produced a statistically significant reduction in IOP at morning trough and peak and was generally well tolerated.

Visual function after surgery for early cataract.

Glare disability and contrast sensitivity loss can be present in cataract patients with minimally reduced visual acuity. Objective and subjective visual function was analyzed in 72 patients (mean visual acuity = 20/40) before and after cataract surgery. Following surgery, most subjects regained normal function in all tests. Improvement in contrast sensitivity and reduction of glare disability were independent of preoperative visual acuity. Subjective improvement in visual function was predicted by acuity and contrast sensitivity tests.

A multicenter study comparing dorzolamide and pilocarpine as adjunctive therapy to timolol: patient preference and impact on daily life.

BACKGROUND: A multicenter, 4-week, two-period crossover study, comparing 2% dorzolamide three times daily to 2% pilocarpine four times daily as adjunctive therapy to 0.5% timolol twice daily, was conducted on 81 patients with elevated intraocular pressure (IOP). The treatments were evaluated for patient preference, tolerability, impact on daily life, IOP control, and visual-field changes. METHODS: The Comparison of Ophthalmic Medications for Tolerability questionnaire was used to assess patient preference, as well as the perception of side effects and activity limitations resulting from the study medications. IOP measurements and visual-field examinations were obtained at baseline and at the end of each crossover period. RESULTS: Of the 77 patients who participated in both periods, 63 (82%) preferred dorzolamide. Patients who expressed a preference preferred dorzolamide over pilocarpine by a ratio of more than 10:1. Patients reported less interference with their daily life because of side effects and activity limitations while receiving dorzolamide than while receiving pilocarpine. Dorzolamide and pilocarpine were comparably effective in lowering IOP (16% to 17%). Also, significantly more patients reported adverse experiences and discontinued therapy as a result of adverse experiences while receiving pilocarpine than while receiving dorzolamide. CONCLUSION: The results of this multicenter study support those of two previous single-center studies; these results show that dorzolamide was greatly preferred over pilocarpine and had better tolerability and less adverse impact on patients' daily lives than pilocarpine.

The efficacy and safety of the dorzolamide-timolol combination versus the concomitant administration of its components. Dorzolamide-Timolol Study Group.

OBJECTIVE: To evaluate whether a fixed combination of 2% dorzolamide and 0.5% timolol given twice daily showed equivalent efficacy to the concomitant administration of 2% dorzolamide given three times daily and 0.5% timolol given twice daily in patients whose intraocular pressure (IOP) remained elevated during monotherapy with 0.5% timolol twice daily. DESIGN: Multicenter, parallel, randomized, double-masked clinical trial with an open-label extension. PARTICIPANTS AND INTERVENTION: In the masked phase, 242 patients received either the dorzolamide-timolol combination twice daily and placebo three times daily or dorzolamide three times daily and timolol twice daily for up to 3 months. In the open-label extension, 220 patients received the dorzolamide-timolol combination twice daily for up to 9 months. MAIN OUTCOME MEASURES: The criterion for establishing treatment equivalency was a 95% or greater confidence that the absolute difference in the mean change in IOP from baseline was less than 1.5 mmHg between treatments. RESULTS: During 3 months of treatment, the dorzolamide-timolol combination reduced IOP relative to the 0.5% timolol baseline by approximately 14% at hour 0 (just before the morning dose), 20% at hour 2, and 15% at hour 8. The IOP-lowering effect of concomitant therapy with dorzolamide and timolol was approximately 16% at hour 0.20% at hour 2, and 17% at hour 8. At hours 0, 2, and 8, there was greater than 97% confidence that the treatments were equivalent. During the open-label extension, the mean IOP reduction ranged from 14% to 15% at hour 0 and from 20% to 21% at hour 2. The treatment groups were generally comparable in terms of adverse events, symptoms, ocular signs, visual acuity, visual fields, physical examination, and laboratory measures. CONCLUSIONS: The IOP-lowering effect of the dorzolamide-timolol combination is comparable to that of dorzolamide three times daily plus timolol twice daily and is maintained for up to 1 year. The dorzolamide-timolol combination provides clinically important reduction in IOP relative to baseline treatment with timolol alone and is generally well-tolerated for up to 1 year.

The efficacy and safety of the dorzolamide-timolol combination versus the concomitant administration of its components.

OBJECTIVE: To evaluate whether a fixed combination of 2% dorzolamide and 0.5% timolol given twice daily showed equivalent efficacy to the concomitant administration of 2% dorzolamide given three times daily and 0.5% timolol given twice daily in patients whose intraocular pressure (IOP) remained elevated during monotherapy with 0.5% timolol twice daily. DESIGN: Multicenter, parallel, randomized, double-masked clinical trial with an open-label extension. PARTICIPANTS AND INTERVENTION: In the masked phase, 242 patients received either the dorzolamide-timolol combination twice daily and placebo three times daily or dorzolamide three times daily and timolol twice daily for up to 3 months. In the open-label extension, 220 patients received the dorzolamide-timolol combination twice daily for up to 9 months. MAIN OUTCOME MEASURES: The criterion for establishing treatment equivalency was a 95% or greater confidence that the absolute difference in the mean change in IOP from baseline was less than 1.5 mmHg between treatments. RESULTS: During 3 months of treatment, the dorzolamide-timolol combination reduced IOP relative to the 0.5% timolol baseline by approximately 14% at hour 0 (just before the morning dose), 20% at hour 2, and 15% at hour 8. The IOP-lowering effect of concomitant therapy with dorzolamide and timolol was approximately 16% at hour 0, 20% at hour 2, and 17% at hour 8. At hours 0, 2, and 8, there was greater than 97% confidence that the treatments were equivalent. During the open-label extension, the mean IOP reduction ranged from 14% to 15% at hour 0 and from 20% to 21% at hour 2. The treatment groups were generally comparable in terms of adverse events, symptoms, ocular signs, visual acuity, visual fields, physical examination, and laboratory measures. CONCLUSIONS: The IOP-lowering effect of the dorzolamide-timolol combination is comparable to that of dorzolamide three times daily plus timolol twice daily and is maintained for up to 1 year. The dorzolamide-timolol combination provides clinically important reduction in IOP relative to baseline treatment with timolol alone and is generally well-tolerated for up to 1 year.

A randomized trial comparing the dorzolamide-timolol combination given twice daily to monotherapy with timolol and dorzolamide. Dorzolamide-Timolol Study Group.

OBJECTIVE: To compare the efficacy and safety of a fixed combination of 2.0% dorzolamide and 0.5% timolol administered twice daily with each of the individual components administered in their usual monotherapy dose regimens in patients who had washed out all ocular hypotensive medications. DESIGN: A 3-month, parallel, randomized, double-masked, active-controlled, multicenter clinical trial. PARTICIPANTS: A total of 335 patients with bilateral ocular hypertension or open-angle glaucoma participated. INTERVENTION: After completing a washout of ocular hypotensive medications, patients were randomized to receive either the dorzolamide-timolol combination twice daily plus placebo once daily, 0.5% timolol twice daily plus placebo once daily, or 2.0% dorzolamide three times daily. MAIN OUTCOME MEASURES: Intraocular pressure (IOP) was measured at morning trough (hour 0) and peak (2 hours postdose) on day 1, week 2, and months 1, 2, and 3. Ocular and systemic safety were evaluated at each study visit. RESULTS: Intraocular pressure reduction was greater on average in the combination group than in the dorzolamide and timolol groups. At morning trough (month 3, hour 0), the mean reduction in IOP from baseline was 27.4% (-7.7 mmHg) for the combination, 15.5% (-4.6 mmHg) for dorzolamide, and 22.2% (-6.4 mmHg) for timolol. At morning peak (month 3, hour 2), the mean IOP reduction from baseline was 32.7% (-9.0 mmHg), 19.8% (-5.4 mmHg), and 22.6% (-6.3 mmHg) for the combination, dorzolamide, and timolol, respectively. Overall, the incidence of clinical adverse experiences was comparable between the combination and each of its components. The proportion of patients who discontinued from the study because of clinical adverse experiences was also comparable between the combination and dorzolamide, although it was significantly greater in the combination group than in the timolol group (7% vs. 1%, P = 0.035). Similarly, comparable numbers of patients in the combination and dorzolamide groups reported ocular symptoms; however, when compared to the timolol group, more patients receiving the combination reported blurred vision, burning eye, stinging eye, and tearing eye. CONCLUSIONS: After a washout of ocular hypotensive therapy, the IOP-lowering effect of the dorzolamide-timolol combination was greater than that of either of its components administered as monotherapy. The combination is generally well-tolerated and provides a convenient alternative to concomitant therapy with its individual components.

A randomized trial in patients inadequately controlled with timolol alone comparing the dorzolamide-timolol combination to monotherapy with timolol or dorzolamide. Dorzolamide-Timolol Combination Study Group.

OBJECTIVE: To compare the dorzolamide-timolol fixed combination twice daily to its components, timolol maleate and dorzolamide hydrochloride, given in their usual monotherapy regimens in patients whose intraocular pressure (IOP) was not controlled on timolol twice daily alone. DESIGN: Parallel, randomized, double-masked, and active-controlled study. PARTICIPANTS: Enrolled were 253 patients from 22 sites throughout the United States. INTERVENTION: After a 3-week run-in of timolol (TIMOPTIC; Merck & Co., Inc., Whitehouse Station, NJ) twice daily, eligible patients received either the combination (COSOPT; Merck & Co., Inc., Whitehouse Station, NJ) twice daily (plus placebo to ensure masking), timolol twice daily (plus placebo to ensure masking), or dorzolamide (TRUSOPT; Merck & Co. Inc., Whitehouse Station, NJ) three times daily for 3 months. MAIN OUTCOME MEASURES: Intraocular pressure taken at hours 0 (trough) and 2 (peak) after week 2 and months 1, 2, and 3 was compared to baseline within each treatment group and between the combination and each component group. The safety profile of the combination was compared to each component. RESULTS: The combination was numerically superior at all study timepoints and was statistically superior at all timepoints except for month 2, hour 0 for timolol, and month 2, hour 2 for dorzolamide. The safety profile of the combination reflected those of its two components. The number of patients reporting ocular or local adverse experiences was greater for the combination (45%) and dorzolamide (45%) than for timolol (27%), with burning and/or stinging eye being the most frequently reported. CONCLUSION: The dorzolamide-timolol combination provides additional IOP lowering compared to either of its individual components and generally is well-tolerated.