Short-term ocular tolerability of dorzolamide 2% and brinzolamide 1% vs placebo in primary open-angle glaucoma and ocular hypertension subjects

PURPOSE: To compare ocular tolerability of dorzolamide 2%, brinzolamide 1%, and placebo given three times daily. METHODS: A prospective, double-masked, three-centre, crossover comparison in which 25 ocular hypertensive or primary-open angle glaucoma subjects were randomized to receive dorzolamide, brinzolamide, or placebo three times daily for 3 days. Intraocular pressure, visual acuity, a visual analogue scale, and ocular and systemic symptom queries were completed at the end of each period. RESULTS: After chronic dosing, there was a significant difference in ocular pain on the visual analogue scale among the groups at the 10-s postinstillation time point with dorzolamide having the highest level (22.5+/-28.9) compared to brinzolamide (5.0+/-8.7) or placebo (3.2+/-10.4) (P=0.0006). No differences between groups were observed preinstillation nor following dosing at 3 or 10-min postinstillation. On the initial instillation, the 10-s postinstillation pain was rated as 43.3+/-77.1, which was significantly higher than after chronic dosing (P=0.017). On the ocular symptom query, dorzolamide had the highest incidence of burning/stinging and redness compared to the other groups, but was generally characterized as mild. There were no significant differences in the visual acuity at any time point. CONCLUSIONS: This study suggests that subjects treated with dorzolamide suffer more ocular pain upon instillation compared to brinzolamide or placebo. However, pain symptoms are fewer following chronic dosing and are generally characterized as mild.     

The efficacy and ocular discomfort of substituting brinzolamide for dorzolamide in combination therapy with latanoprost, timolol, and dorzolamide.

PURPOSE: The aim of this study was evaluate the efficacy and ocular discomfort of substituting brinzolamide for dorzolamide in patients with glaucoma treated by latanoprost, timolol, and dorzolamide. METHODS: An 8-week, prospective, randomized, open-label, comparative study was performed in 58 patients with primary open-angle glaucoma treated by latanoprost, timolol, and dorzolamide. These patients were randomly enrolled into two groups: (1) dorzolamide three times daily was substituted with brinzolamide twice-daily (substituting group); and (2) dorzolamide three times daily was continued (control group). Intraocular pressure (IOP) was measured at baseline, 4, and 8 weeks after the enrollment. Subjective ocular discomfort (irritation and blurred vision) at the time of the instillation of the patient was noted with interview. RESULTS: The IOPs at baseline, 4 and 8 weeks after the enrollment were 17.7 +/- 2.7 mmHg, 17.5 +/- 2.6 mmHg, and 17.4 +/- 2.9 mmHg in the substituting group, and 18.0 +/- 2.5 mmHg, 17.8 +/- 2.5 mmHg, and 17.9 +/- 2.6 mmHg in the control group, respectively. There were no significant differences in IOP changes between the two groups (P = 0.74). In the substituting group, ocular irritation was decreased significantly (P = 0.0014) from 63% to 20%. The slight increase of blurred vision from 27% to 37% that occurred in the substituting group was not significant (P = 0.58). In the control group, neither ocular irritation (P = 0.58, from 68% to 57%) nor blurred vision (P = 0.99, from 25% to 21%) was changed. CONCLUSIONS: Substituting brinzolamide for dorzolamide maintained stable IOP with improvement in ocular comfort in patients with glaucoma.     

Ocular comfort of brinzolamide 1.0% ophthalmic suspension compared with dorzolamide 2.0% ophthalmic solution: results from two multicenter comfort studies. Brinzolamide Comfort Study Group

Two independent, prospective, multicenter, double-masked, parallel group trials were conducted to compare the ocular comfort of brinzolamide 1.0% administered three times daily (t.i.d.) with t.i.d.-dosed dorzolamide 2.0% in patients with primary open-angle glaucoma or ocular hypertension. Patients were randomized to one of two treatment groups, receiving either brinzolamide 1.0% t.i.d. or dorzolamide 2.0% t.i.d. for 1 week. On the last day of dosing, patients received one drop of masked medication in both eyes, and ocular discomfort (burning or stinging) was evaluated by means of a 4-unit ocular discomfort scale. The incidence and extent of ocular discomfort across both treatment groups were analyzed. The results from both studies were confirmatory and demonstrated that the ocular discomfort score for brinzolamide 1.0% was 1.3 units lower than the score for dorzolamide 2.0%, which was both statistically significant and clinically relevant. In addition, a statistically significantly greater percentage of patients reported no ocular discomfort with brinzolamide 1.0% compared with dorzolamide. A greater percentage of patients receiving dorzolamide 2.0% also reported mild, moderate, severe, and very severe ocular discomfort compared with those treated with brinzolamide 1.0%. The most frequent ocular adverse event reported in the brinzolamide group was transient blurred vision, which ranged from 20% to 25%. Overall, adverse events associated with brinzolamide 1.0% and dorzolamide 2.0% were nonserious, were usually mild, and resolved without treatment. The findings of each study independently demonstrated that brinzolamide 1.0% was significantly more comfortable than dorzolamide 2.0% when instilled in the eye.     

Comparisons of intraocular-pressure- lowering efficacy and side effects of 2% dorzolamide and 1% brinzolamide

Forty-one healthy volunteers were recruited for a study to compare the intraocular pressure (IOP)-lowering efficacy and side effects of 2% dorzolamide and 1% brinzolamide. In a randomized double-blind design, one eye received one drop of 2% dorzolamide and the other eye received one drop of 1% brinzolamide. The IOP and side effects were evaluated by Goldmann applanation tonometry and slit lamp biomicroscopy before administration, and 3, 7 and 14 days after the initial administration of eyedrops. The IOP decreased significantly from baseline for both drugs (p < 0.05). However, there were no statistically significant differences between 2% dorzolamide and 1% brinzolamide either before or after eyedrop administration (p > 0.05). The most frequent side effect was ocular pain in the case of 2% dorzolamide and blurred vision in 1% brinzolamide. The results suggested that 2% dorzolamide and 1% brinzolamide have similar IOP-lowering efficacies with different side effects Copyright 2001 S. Karger AG, Basel     

Effect of artificial tears on visual performance in subjects with dry eye.

PURPOSE: Disruption of the anterior refracting surface of the eye (i.e., the tear layer) reduces visual performance. Tear layer breakup occurs soon after a blink in contact lens wearers and patients with dry eye. This study determined whether artificial tears stabilize the tear film and improve visual performance in contact lens wearers who also exhibit a dry eye. METHODS: Five subjects with mild to moderate dry eye (probably as a result of an evaporative dry eye) during spectacle and contact lens wear were fitted with a Focus Night & Day hydrogel lens for this study. A temporal, two-alternative, forced-choice paradigm was used to measure contrast sensitivity. The stimuli were vertically oriented sine wave gratings (between 0.5 and 14 cpd) presented for 16.67 msec. The stimuli were presented at two different times after blink detection: 2 sec after blink detection (i.e., before tear layer breakup) or 4 sec after tear film breakup. Four conditions were investigated at 4 sec after tear layer breakup: 1) without artificial tears added, 2) with Clerz2 (Alcon, Fort Worth, TX) instilled, 3) with Sensitive Eyes (Bausch & Lomb, Rochester, NY), and 4) with GenTeal (Novartis, Basel, Switzerland) applied. The artificial tears were instilled at 10-min intervals during the data collection. The short-term visual effects of drop instillation were also investigated by continually monitoring contrast sensitivity for a 14-cpd grating after a single-drop administration. RESULTS: High spatial frequency contrast sensitivity and visual acuity were found to be reduced after tear film breakup in the absence of supplementation with artificial tears. For the group data (and four of five subjects), the instillation of Sensitive Eyes improved the contrast sensitivity and visual acuity to the level attained before tear breakup, thus prolonging visual performance. Clerz2 and GenTeal did not produce any enhancement in visual performance. A short-term decrease in contrast sensitivity was also observed with a single administration of Clerz2 and GenTeal. CONCLUSIONS: This study indicates that there was a benefit of Bausch & Lomb Sensitive Eyes tear supplementation on visual performance in subjects with an evaporative dry eye. This may be the result of 1) aqueous supplementation in these subjects and/or 2) the minimal tear layer disruption found with Sensitive Eyes drop administration. The results suggest that practitioners need to identify those patients who can benefit from the use of appropriate artificial tear supplements.     

The efficacy and safety of topical brinzolamide and dorzolamide when added to the combination therapy of latanoprost and a beta-blocker in patients with glaucoma.

PURPOSE: Brinzolamide and dorzolamide are often used as adjunctive therapy to other antiglaucoma agents. The purpose of this study was to compare the efficacy and safety of brinzolamide 1% versus dorzolamide 1% when added to the combination therapy of latanoprost and a beta-blocker in patients with glaucoma. METHODS: An 8-week, randomized, open-label comparative study was performed in 52 patients with glaucoma. Brinzolamide 1% (twice a day) or dorzolamide 1% (3 times a day) was randomly administered to the patients who had been treated with both latanoprost and a betablocker. RESULTS: Intraocular pressure (IOP) were both decreased significantly (P < 0.0001) from 18.6 +/- 2.3 mmHg to 16.7 +/- 2.3 mmHg and from 18.4 +/- 2.6 mmHg to 16.6 +/- 2.5 mmHg, respectively, 8 weeks after the addition of brinzolamide or dorzolamide. However, the difference between the groups was not significant (P = 0.86). The incidence of ocular irritation was significantly higher (P < 0.0001) in the dorzolamide group (74%) than the brinzolamide group (16%), but there was no significant difference in blurred vision between the groups (dorzolamide 37% versus brinzolamide 52%, P = 0.40). CONCLUSIONS: We concluded that the efficacy of brinzolamide 1% was equivalent to dorzolamide 1%; however, the safety of brinzolamide 1% was superior to dorzolamide 1% as adjunctive therapy to the combination with latanoprost and a beta-blocker.     

Effects of dipivefrin and pilocarpine on pupil diameter, automated perimetry and LogMAR acuity

· Background: A study was carried out to ascertain, in ophthalmologically normal subjects, the short-term effects of dipivefrin hydrochloride 0.1% on visual performance and make comparisons with pilocarpine. · Methods: Twelve normal volunteers aged 20–26 years attended on three occasions. One eye, randomly selected, received one drop of either pilocarpine 2%, dipivefrin or saline 0.9%. High- and low-contrast LogMAR acuity at 6 m and pupil diameter (measured by infra-red pupillometry) were recorded at baseline (T0) and at intervals up to 90 min following instillation of drops. Program 30-2 of the Humphrey Visual Field Analyzer (HFA) was run at T0 and at 60 min after treatment instillation (T60). Saline was always instilled at visit 1, to allow for learning effects. On visits 2 and 3 either pilocarpine or dipivefrin was randomly instilled into the treated eye. · Results: Pilocarpine significantly worsened the field global indices mean deviation (P<0.001) and pattern standard deviation (P<0.01) compared with T0. There was no significant change with dipivefrin. A significant (P=0.01) pupil dilation from 5.44 mm (SD 0.79) at T0 to 6.19 mm (SD 1.09) at T90 occurred with dipivefrin. Pilocarpine caused significant miosis. No significant changes in LogMAR values were found with dipivefrin. Pilocarpine significantly (P<0.01) increased LogMAR values (i.e. reduced acuity) compared with dipivefrin. At T30 the mean increase in LogMAR was 0.76 (SD 0.30) for high and 0.83 (SD 0.11) for low contrast. By T90 recovery of acuity was virtually complete. · Conclusions: In normals dipivefrin causes mydriasis but does not affect the central visual field global indices (as assessed by STATPAC), or high- and low-contrast LogMAR acuity. Pilocarpine adversely affects the visual field and both measures of acuity. Knowledge of these effects is of value in glaucoma therapy and when monitoring the progression of visual loss. Received: 20 January 1998 Revised version received: 14 April 1998 Accepted: 4 May 1998     

An assessment of the discomfort associated with the use of rose bengal 1% eyedrops on the normal human eye: a comparison with saline 0.9% and a topical ocular anaesthetic

PURPOSE: To assess the time-dependent changes in ocular comfort following unilateral instillation of preservative-free rose bengal 1% eyedrops when compared with saline 0.9% or proxymetacaine 0.5%. METHODS: A total of 61 subjects, aged between 19 and 77 years, were asked to complete an ocular symptoms questionnaire, and then to indicate the comfort level for each eye on a 100-point visual analogue scale (VAS). A single drop of rose bengal was instilled in one eye (left or right) and a drop of saline or anaesthetic instilled in the other eye. The VAS assessments were repeated at an average of 4 and 7 min later. RESULTS: The instillation of rose bengal eyedrops produced an initial average reduction in comfort of 39.8 points, as compared with a reduction of 11.5 points following the anaesthetic and a reduction of 3.4 points for saline. However, the responses to rose bengal were highly variable, ranging from reductions of 1.5 to 84.6 points. In most subjects, some recovery had occurred within 6-8 min, but the comfort scores averaged 27.8 points below baseline levels prior to rose bengal. Slightly greater discomfort was noted by older subjects and those with darker irides. CONCLUSIONS: This study confirms that the use of rose bengal eyedrops can elicit a sensation of discomfort, but that this adverse reaction does not last very long. Based on the initial kinetics of recovery from discomfort, it is estimated that this should last no longer than 10-15 min (at least for those without significant ocular surface disease).     

The efficacy and safety of brinzolamide 1% ophthalmic suspension (Azopt) as a primary therapy in patients with open-angle glaucoma or ocular hypertension. Brinzolamide Primary Therapy Study Group

A randomized, multicenter, double-masked, prospective, parallel study was designed to establish the intraocular pressure (IOP)-lowering efficacy, safety, and tolerability of brinzolamide 1.0% (Azopt) as a primary therapy compared with dorzolamide 2.0% (Trusopt) and placebo in patients diagnosed with open-angle glaucoma (with or without a pseudoexfoliative or a pigmentary dispersion component) or ocular hypertension. Brinzolamide 1.0%, dosed two times (b.i.d.) and three times (t.i.d.) a day, dorzolamide 2.0% (t.i.d.), and placebo (t.i.d) were administered to patients during a 3-month treatment period. Diurnally corrected IOP reduction from baseline, including peak and trough times, was the primary end point. Sample sizes were chosen to establish statistical equivalence between treatments. Mean IOP changes observed on treatment were as follows: -3.4 mm Hg (-13.2%) to -4.1 mm Hg (-16.7%) with brinzolamide 1.0% b.i.d.; -4.1 mm Hg (-16.6%) to -4.8 mm Hg (-19.1%) with brinzolamide 1% t.i.d.; and -4.3 mm Hg (-16.9%) to -4.9 mm Hg (-20.1%) with dorzolamide 2.0%. IOP reductions after administration of brinzolamide 1.0% b.i.d. and t.i.d. were equivalent to each other and also clinically and statistically equivalent to those with dorzolamide 2.0% t.i.d. The incidence of ocular discomfort (burning and stinging) upon instillation was significantly higher for dorzolamide (10.7%) than brinzolamide (b.i.d. or t.i.d., 3.0% each). The most frequent non-ocular event reported was taste perversion, which was less (3.7%) with brinzolamide 1.0% b.i.d., but brinzolamide t.i.d. was similar to dorzolamide t.i.d. (6.8% vs. 5.3%). Brinzolamide 1.0% b.i.d., brinzolamide 1.0% t.i.d., and dorzolamide 2.0% t.i.d. equaled each other in IOP-lowering efficacy, and brinzolamide was significantly more comfortable than dorzolamide upon instillation.     

Comparative study of the pressure lowering efficacy and variations in the ocular pulse amplitude between fixed combinations of dorzolamide/timolol and brinzolamide/timolol

ObjectiveTo determine possible differences in the intraocular pressure (IOP) and ocular pulse amplitude (OPA) lowering capacity of the fixed drug combinations dorzolamide/timolol and brinzolamide/timolol.MethodsIn this cross-sectional study, one of the eyes of 25 healthy subjects was randomly assigned to treatment with dorzolamide/timolol and the other eye with brinzolamide/timolol. After instilling the drops, possible adverse effects (e.g., blurred vision, itching) were assessed in each eye. This assessment was repeated 30 minutes later. IOP and OPA were determined In each eye by dynamic contour tonometry at baseline and two hours following treatment.ResultsBoth fixed drug combinations significantly reduced IOP and OPA with no differences detected between treatment groups. Among the adverse effects recorded, itching was significantly greater in the first assessment in the eyes treated with dorzolamide/timolol (P = .011). This difference was no longer apparent in the second assessment.ConclusionsBoth fixed combinations were similarly effective in reducing intraocular pressure and ocular pulse amplitude. Adverse effects related to both treatments were mild and well-tolerated, though itching occurred most frequently in the eyes treated with dorzolamide/timolol.     

Local effect of topical FP‐receptor agonists on retinal vessels of the ipsilateral posterior retina in normal rabbit eyes

Purpose: To determine whether a topically instilled prostaglandin analogue inhibits endothelin‐1 (ET‐1)‐induced vasoconstrictive effects in the posterior retina by its local effects, and the duration of the effect in normal rabbit eyes. Methods: Travoprost, a potent selective FP‐agonist, or unoprostone, a prostone that also has a weak non‐selective FP‐agonistic activity, solution was instilled once, or once daily (travoprost) or twice daily (unoprostone) for 7 days in one randomly chosen Dutch rabbit eye, and vehicle in the contralateral eye. ET‐1 was intravitreously injected in both eyes 30 min after a single instillation of a test drug or its vehicle, or just after, 30, 60, 90 or 180 min after the final instillation of a 7‐day instillation, and fundus photographed before, 30 and 60 min after the injection to study whether difference was seen in the ET‐1‐induced constriction of retinal vessels between the drug‐ and vehicle‐instilled eyes. The same experimental procedures were conducted with indomethacin pretreatment. Results: In the rabbit eyes where travoprost was instilled for 7 days, the ET‐1‐induced constriction of retinal vessels was significantly inhibited only on the drug‐treated side, when ET‐1 was injected 30 or 60 min after the final instillation (P = 0.026–0.005), which was abolished by indomethacin pretreatment. A single instillation of travoprost or unoprostone and 7‐day instillation of unoprostone showed no effect. Conclusions: After a 7‐day instillation in normal rabbit eyes, topical travoprost suppressed ET‐1‐induced vasoconstrictive effects only in the ipsilateral posterior retina by its local effect; this effect was maintained at least for 30 min and mediated by endogenous prostaglandins.     

Does prior instillation of a topical anaesthetic alter the pupillary mydriasis produced by tropicamide (0.5%)?

PURPOSE: It is common clinical practice to instill a topical anaesthetic prior to the instillation of a mydriatic agent into the eye. The main rationale for using the anaesthetic is to increase corneal permeability, so that more of the mydriatic agent reaches the receptor sites within the anterior chamber. It addition, as mydriatics generally cause stinging, prior use of an anaesthetic should reduce the degree of discomfort. The aim of the present study was to determine whether the efficacy of mydriasis produced by an antimuscarinic agent is enhanced by prior instillation of a topical anaesthetic. METHOD: The study was performed using a double-masked protocol on 20 healthy young subjects. One drop of either proparacaine (proxymetacaine) (0.5%) or isotonic saline was instilled into the eye, followed by one drop of tropicamide (0.5%). Pupil diameter was measured using a customized photographic device at 0, 10, 20, 30 and 60 min following drug instillation. Additionally, subjects were asked to rate the degree of discomfort following the instillation of each drop on a scale from 0 (no discomfort) to 10 (agony). RESULTS: There was no significant difference in either the rate of onset of mydriasis, or the maximum pupil diameter achieved between the two conditions. The mean change in pupil diameter produced by tropicamide after the instillation of saline or proparacaine was 2.31 and 2.28 mm, respectively. The mean discomfort scores following instillation of saline and proparacaine were 1.15 and 1.65, respectively, while mean discomfort scores following the instillation of tropicamide after saline or proparacaine were 4.00 and 0.85, respectively. CONCLUSIONS: Instillation of a topical anaesthetic does significantly reduce the degree of discomfort produced by the instillation of tropicamide. However, it does not produce any significant increase in either the magnitude or rate of onset of mydriasis.     

最新型局部碳酸酐酶抑制剂派立明的临床前及临床研究

派立明是一种最新型的局部碳酸酐酶抑制剂。此药可选择性、高亲和力及明显地抑制碳酸酐酶同功酶Ⅱ的活性,有效地降低眼压。本品滴眼后可快速进入眼组织,在虹膜、睫状体、脉络膜、视网膜、晶状体和血液中有较长的半衰期(数天)。虽然用派立明滴眼后,可在全血中测出药物浓度,提示陔药可全身吸收,但主药和其代谢产物的血浆浓度非常低,在稳定状态下药物与红细胞内碳酸酐酶的结合达不到完全饱和。因此,不会出现全身酸中毒或其他与口服碳酸酐酶抑制剂有关的副作用。对兔眼滴用派立明还町增加视乳头血流量,而对全身酸碱平衡的影响极小。如这一作用在人眼被证实,将对有视神经病变的青光眼患者十分有益。1％派立明每日滴眼2次的降眼压效果最好,且患者的耐受性较多佐胺好,这可提高患者长期用药的依从性。滴眼后最常见的剐作用是视物模糊(6％)及口苦、口酸等味觉异常(6％),总之,派立明的降眼压作用强,副作用小,滴眼舒适,患者耐受性好,是一种非常有价值的抗青光眼新药。     

Effect of brinzolamide and dorzolamide on aqueous humor flow in human eyes.

PURPOSE: To measure the relative efficacy of brinzolamide hydrochloride 1% ophthalmic suspension, a new carbonic anhydrase inhibitor, compared with the currently used dorzolamide hydrochloride 2% ophthalmic solution as suppressors of aqueous humor flow in human eyes, and to study the difference of effect during the day and at night. METHODS: A randomized, double-masked, placebo-controlled study of 25 normal human subjects was carried out at Mayo Clinic. The daytime rate of aqueous humor flow was measured every 2 hours from 8 AM to 4 PM by means of fluorophotometry. Likewise, the night-time rate of aqueous humor flow was measured every 2 hours from 12 AM to 6 AM. Intraocular pressure was measured at 4 PM and 6 AM. RESULTS: Brinzolamide reduced aqueous flow by 0.47+/-0.20 microl per min (mean+/-SD) during the day, whereas dorzolamide reduced flow by 0.34+/-0.20 microl per min. Brinzolamide reduced aqueous flow by 0.16+/-0.12 microl per min during the night, whereas dorzolamide reduced flow by 0.10+/-0.13 microl per min. Brinzolamide reduced afternoon intraocular pressure by 1.5+/-1.1 mm Hg, and dorzolamide reduced afternoon intraocular pressure by 1.1+/-1.0 mm Hg. Brinzolamide reduced the morning awakening intraocular pressure by 0.3+/-1.6 mm Hg, and dorzolamide reduced it by 0.8+/-1.0 mm Hg. CONCLUSIONS: Our data support the idea that brinzolamide is at least as efficacious as dorzolamide as a suppressor of aqueous humor flow in normal human eyes and that there is probably not a clinically significant difference between the two drugs in this efficacy. Clinicians who prescribe brinzolamide should expect similar ocular hypotensive responses from brinzolamide and dorzolamide.     

Effectiveness of sodium hyaluronate eyedrops in the treatment of dry eye

Background Dry eye is a common condition, affecting approximately 10–20% of the adult population. Artificial tears are often effective in relieving symptoms in mild and moderate dry eye by replenishing deficient tear volume. Sodium hyaluronate has been proposed as a component in artificial tears, due to its viscoelastic rheology. This paper reports on a study carried out to assess the efficacy of two recently developed eyedrops containing 0.1% and 0.3% sodium hyaluronate (SH) in the treatment of moderate dry eye. Methods Thirteen subjects were recruited with moderate dry eye. Forty microlitres of 0.1% SH, 0.3% SH, or 0.9% saline were instilled in both eyes, and the subjects’ symptom intensity and non-invasive break-up time (NIBUT) were measured at 5, 15, 30, 45, and 60 min, and then hourly, until 6 h after drop instillation. This was repeated twice following an interval of 7(±1) days, but with a different treatment so that at the end of the final visit each subject had trialled all products. Drop allocation was randomized and double-masked. Results Both symptoms and NIBUT improved with all treatments. These changes were of a larger magnitude and longer duration with the SH containing eyedrops than with saline. SH of 0.3% tended to perform better than 0.1% SH and achieved statistical significance (P=0.04) for NIBUT when considered over the whole 6-h study period. Conclusions Sodium hyaluronate of 0.1% and 0.3% reduces symptoms of ocular irritation and lengthens NIBUT in subjects with moderate dry eye more effectively than saline, in terms of peak effect and duration of action.     

The mydriatic effect of multiple doses of tropicamide.

PURPOSE: We investigated whether two drops of 0.5% tropicamide produced a wider pupillary dilation when compared with a single drop and saline control in subjects with dark-colored irides. METHODS: Twelve young adult subjects with dark irides and who were free from ocular disease participated in the study. One eye of each subject, selected at random, was designated as experimental and the fellow eye as control. A single drop of 0.5% tropicamide was instilled in the lower cul-de-sac of each eye in turn. Immediately after, a second drop of 0.5% tropicamide was instilled in the experimental eye and a single drop of unpreserved saline into the control eye. A double-masked experimental protocol was followed. Digital images of both pupils of each subject were taken at baseline (predrug instillation) and then every 5 minutes up to 30 minutes postdrug instillation and at 40, 50, and 60 minutes. The images were subsequently viewed on a PC monitor, and pupil size was measured using a calibrated millimeter scale. RESULTS: Pupil diameter increased as a function of time for both conditions reaching a maximum between 20 and 30 minutes after drop instillation. Pupil diameter was greater under the experimental condition compared with the control (analysis of variance p < 0.001). Pupil diameter reached at least 6 mm under both the experimental and control conditions. CONCLUSION: In young healthy subjects, compared with a single drop of tropicamide, two drops were associated with a greater degree of pupillary dilation on average over the 60-minute study period. However, the magnitude of the difference was small and not clinically significant. A single drop of tropicamide produced a pupillary diameter of at least 6 mm, which should be sufficient for the conduct of a thorough dilated fundus examination.     

Ocular comfort of combination glaucoma therapies: brimonidine 0.2%/timolol 0.5% compared with dorzolamide 2%/timolol 0.5%.

PURPOSE: Successful management of glaucoma and ocular hypertension requires patient compliance with the therapeutic regimen. Because ocular discomfort affects compliance, we compared the comfort of brimonidine 0.2%/timolol 0.5% and dorzolamide 2%/timolol 0.5%. METHODS: In this single-centre, randomized, double-masked, internally controlled/paired-eye study, 30 subjects without a significant ocular surface disease received brimonidine 0.2%/timolol 0.5% in 1 eye and dorzolamide 2%/timolol 0.5% in the fellow eye. They evaluated discomfort at 30-40 s and 5 min postinstillation. RESULTS: At 30-40 s, brimonidine 0.2%/timolol 0.5% provided significantly lower mean ocular discomfort scores than dorzolamide 2%/timolol 0.5% (P < 0.0001). This pattern persisted at 5 min but was not statistically significant. Significant differences were seen in the subjects' determination of the more comfortable treatment (P < 0.0001): brimonidine 0.2%/timolol 0.5% was rated as more comfortable than dorzolamide 2%/timolol 0.5% by 80% of subjects at 30-40 s and by 27% at 5 min. Only 10% of subjects at each time point rated dorzolamide 2%/timolol 0.5% as more comfortable. The remaining subjects reported no preference at either time point. No adverse events were reported. CONCLUSIONS: Brimonidine 0.2%/timolol 0.5% was significantly more comfortable than dorzolamide 2%/timolol 0.5% upon instillation. Patients with ocular hypertension or glaucoma may be more compliant with brimonidine 0.2%/timolol 0.5% treatment.     

Efficacy of topical brinzolamide in children with retinal dystrophies

ABSTRACT

Background: Inherited retinal dystrophies are a leading cause of irreversible blindness in children in the United States. Topical carbonic anhydrase inhibitors have improved central vision and cystoid macular edema in patients with retinal dystrophies, but few studies have assessed their efficacy in children.

Materials and Methods: A retrospective chart review was performed with Institutional Review Board approval to identify pediatric patients with inherited retinal dystrophies who received topical brinzolamide at a single university center between 2008 and 2015. Serial visual acuity and central macular thicknesses were compared to assess the efficacy of brinzolamide.

Results: Seven subjects were identified who met the inclusion criteria. Four had juvenile X-linked retinoschisis, two had retinitis pigmentosa, and one had Leber congenital amaurosis. All were prescribed brinzolamide thrice daily; however, one patient was completely non-compliant. Four of the six treated patients exhibited a mild decrease in central macular thickness in both eyes during the study with all six treated patients having significantly improved vision at the first endpoint, 33.2 ± 8.2 months after treatment initiation. For treated patients, average visual acuity (LogMAR) ± standard error of the mean improved from 0.5 ± 0.04 pre-treatment to 0.3 ± 0.1 at the second endpoint, 50.2 ± 7.3 months after treatment initiation.

Conclusions: Mild anatomic improvement of macular cysts was seen in pediatric patients using brinzolamide. Visual acuity improvement occurred even without significant reduction in macular cysts. Further studies are needed to determine whether the beneficial effects of carbonic anhydrase inhibitors are sustained in children with inherited retinal degenerations.     

Effects of dorzolamide hydrochloride on ocular tissues.

We studied the intraocular pharmacokinetics of dorzolamide hydrochloride eye drops and the effect of dorzolamide on carbonic anhydrase activity and localization in ocular tissues. Carbonic anhydrase activity was detected in normal ocular tissues. The activity was inhibited in corneal endothelial cells, the ciliary body, lens epithelial cells, or the retina 1 to 8 hours after instillation of dorzolamide eye drops. In lens epithelial cells and the retina, the enzyme activity had not recovered even 10 hours after instillation of the drug. Immunostaining did not reveal any differences between the group administered dorzolamide eye drops and the control group administered a physiologically balanced solution. Time-related changes in dorzolamide concentrations in ocular tissues were measured by high-performance liquid chromatography (HPLC). In the cornea, anterior aqueous, iris, ciliary body and retina, drug concentrations increased 15 minutes after the instillation and peaked within 1 hour. These results suggest that dorzolamide immediately suppresses carbonic anhydrase activity in ocular tissues, and is rapidly distributed among the tissues of the eye when administered as eye drops.     

The effect of scleral search coil lens wear on the eye

BACKGROUND/AIM: Scleral search coils are used to measure eye movements. A recent abstract suggests that the coil can affect the eye by decreasing visual acuity, increasing intraocular pressure, and damaging the corneal and conjunctival surface. Such findings, if repeated in all subjects, would cast doubt on the credibility of the search coil as a reliable investigative technique. The aim of this study was to reassess the effect of the scleral search coil on visual function. METHODS: Six volunteer subjects were selected to undergo coil wear and baseline measurements were taken of logMAR visual acuity, non-contact tonometry, keratometry, and slit lamp examination. Four drops of 0.4% benoxinate hydrochloride were instilled before insertion of the lens by an experienced clinician. The lens then remained on the eye for 30 minutes. Measurements of the four ocular health parameters were repeated after 15 and 30 minutes of lens wear. The lens was then removed and the health of the eye reassessed. RESULTS: No obvious pattern of change was found in logMAR visual acuity, keratometry, or intraocular pressure. The lens did produce changes to the conjunctival and corneal surfaces, but this was not considered clinically significant. CONCLUSION: Search coils do not appear to cause any significant effects on visual function. However, thorough prescreening of subjects and post-wear checks should be carried out on all coil wearers to ensure no adverse effects have been caused.