A comparative study of the effects of brinzolamide and dorzolamide on retinal oxygen saturation and ocular microcirculation in patients with primary open-angle glaucoma.

AIMS: To assess the effects of brinzolamide and dorzolamide on ocular haemodynamics and retinal oxygen saturation in patients with primary open-angle glaucoma (OAG). METHODS: Fifteen patients with OAG were evaluated in a randomised, cross-over, double-blind study. They were treated with either brinzolamide or dorzolamide for 3 months and then crossed-over after a 4-week washout period. They were given timolol during a 4-week run-in period and during washout. The following were performed after run-in, after washout and after each treatment period: adverse events check, measurement of visual acuity, contrast sensitivity, blood pressure, heart rate, and intraocular pressure, and fundus examination. Ocular blood flow was assessed using confocal scanning laser Doppler flowmetry (HRF) and colour Doppler imaging (CDI). Retinal oxygenation levels were determined using a non-invasive measurement of haemoglobin oxygen saturation by digital photographic fundus oximetry. RESULTS: Both brinzolamide and dorzolamide reduced the number of zero-flow pixels in the retina as measured by HRF, suggesting an increase in retinal blood flow (-6.86 and -0.452 respectively) with brinzolamide treatment resulting in fewer zero-flow pixels than dorzolamide (-6.41) (p = 0.024). Both brinzolamide and dorzolamide increased oxygen saturation in the retina as measured by photographic retinal oximetry in the superior (0.82 (p = 0.002) and 0.87 (p = 0.005)) and inferior (0.88 (p = 0.035) and 0.82 (p = 0.002)) retinal veins. No significant changes were found in CDI measurements of the retrobulbar blood supply during either treatment. CONCLUSION: This pilot study suggests that brinzolamide and dorzolamide may increase retinal oxygen saturation in patients with OAG.

Ocular penetration of levofloxacin, ofloxacin and ciprofloxacin in eyes with functioning filtering blebs: investigator masked, randomised clinical trial.

BACKGROUND/AIMS: To compare the penetration of levofloxacin, ofloxacin and ciprofloxacin in the aqueous humour of eyes with functioning filtering blebs. METHODS: In this investigator-masked study, 48 patients with functioning filtering blebs requiring cataract surgery were randomised into six groups of eight patients. Groups 1, 2 and 3 received topical ofloxacin 0.3% (Ocuflox), ciprofloxacin 0.3% (Ciloxan) and levofloxacin (Quixin) respectively; Groups 4, 5 and 6 received the same treatment with the corresponding oral dose of ofloxacin 400 mg (Floxin), ciprofloxacin 400 mg (Cipro) and levofloxacin 250 mg (Levaquin). Aqueous antibiotic levels were determined by mass spectrometry of aqueous samples from each patient. RESULTS: The mean aqueous level for topical levofloxacin was significantly higher than those achieved by topical ofloxacin or ciprofloxacin (p value = 0.02 and 0.01, respectively). The combination of topical and oral levofloxacin was significantly higher than topical levofloxacin alone (p = 0.05) and the ciprofloxacin combination (p = 0.003) but not significantly higher than the ofloxacin combination therapy. CONCLUSIONS: Topical levofloxacin penetrates better than ofloxacin or ciprofloxacin into the aqueous of eyes with functioning filtering blebs. The combination of topical and oral levofloxacin may be preferable in the treatment of bleb-associated infections (NCT 00392275; Clinical trials.gov).

Intraocular pressure-lowering efficacy of bimatoprost 0.03% and travoprost 0.004% in patients with glaucoma or ocular hypertension.

AIM: To evaluate the efficacies of bimatoprost and travoprost for lowering of intraocular pressure (IOP) for the treatment of glaucoma and ocular hypertension. METHODS: Prospective, randomised, investigator-blinded, parallel-group clinical trial. After completing a washout of all glaucoma drugs, patients (n = 157) were randomised to bimatoprost or travoprost for 6 months. Visits were at baseline, 1 week, and 1, 3 and 6 months. IOP was measured at 09:00 h at each visit and also at 13:00 and 16:00 h at baseline and at 3 and 6 months. RESULTS: No significant between-group differences were observed in IOP at baseline, at 09:00, 13:00 or 16:00 h (p> or =0.741). After 6 months, both drugs significantly reduced IOP at every time point (p< or =0.001). After 6 months, mean IOP reduction at 09:00 h was 7.1 mm Hg (27.9%) with bimatoprost (n = 76) and 5.7 mm Hg (23.3%) with travoprost (n = 81; p = 0.014). At 13:00 h, mean IOP reduction was 5.9 mm Hg with bimatoprost (25.3%) and 5.2 mm Hg (22.4%) with travoprost (p = 0.213). At 16:00 h, the mean IOP reduction was 5.3 mm Hg (22.5%) with bimatoprost and 4.5 mm Hg (18.9%; p = 0.207) with travoprost. Both study drugs were well tolerated, with ocular redness the most commonly reported adverse event in both treatment groups. CONCLUSIONS: Bimatoprost provided greater mean IOP reductions than travoprost.

A randomised, double masked, multicentre clinical trial comparing bimatoprost and timolol for the treatment of glaucoma and ocular hypertension.

AIM: To evaluate the safety and efficacy of bimatoprost 0.03% once daily or twice daily compared with timolol 0.5% twice daily in patients with glaucoma or ocular hypertension. METHODS: Multicentre, double masked, randomised, parallel group, 3 month trial comparing bimatoprost once daily (n=240), bimatoprost twice daily (n=240), and timolol twice daily (n=122). The primary efficacy end point was diurnal intraocular pressure (IOP) (8 am, 10 am, 4 pm). Safety measures included adverse events, ocular parameters, and systemic variables. RESULTS: Bimatoprost once daily provided significantly lower mean IOP than timolol twice daily at all times and follow up visits (p<0.001). At month 3, mean IOP reductions from baseline at 10 am (peak timolol effect) were bimatoprost once daily, 8.0 mm Hg (32.4%); bimatoprost twice daily, 6.3 mm Hg (25.2%); timolol, 5.5 mm Hg (22.7%). Bimatoprost twice daily was also more effective than timolol, but was not as effective as bimatoprost once daily. A higher percentage of patients achieved low target pressures with bimatoprost once daily than with timolol. The most frequent side effects with bimatoprost were eyelash growth and mild conjunctival hyperaemia. Systemic safety parameters were not affected by bimatoprost. CONCLUSIONS: Bimatoprost 0.03% once daily demonstrated superior efficacy compared with timolol 0.5% twice daily in patients with elevated IOP. Bimatoprost once daily was more effective than twice daily dosing.

Delayed suprachoroidal hemorrhage after glaucoma filtration procedures.

OBJECTIVES: To determine the incidence of, risk factors for, and outcomes of delayed suprachoroidal hemorrhage (DSCH) after glaucoma filtration surgery. DESIGN: Retrospective case-control study. PARTICIPANTS: All patients undergoing glaucoma filtration procedures between 1986 and 2000 at Indiana University who were diagnosed postoperatively with suprachoroidal hemorrhage. A total of 66 patients with DSCH were identified. These were compared with a randomly selected group of patients who underwent similar procedures but did not have suprachoroidal hemorrhage. METHODS: Total cases of DSCH were initially compared with the total number of glaucoma surgeries to determine the overall incidence and the incidence in the different procedures. Subsequently, a case-control study was performed comparing the group with hemorrhage to the control group to identify risk factors. Finally, outcomes and prognostic factors were determined by comparing vision preoperatively and postoperatively and parameters of patients with good and poor outcomes. MAIN OUTCOME MEASURES: Incidence of DSCH, risk factors associated with its occurrence, visual outcomes, and factors important for prognosis. RESULTS: Of a total of 2285 glaucoma filtration procedures, 66 (2.9%) cases of DSCH were identified. It developed in 9 of 615 (1.5%) trabeculectomies without antimetabolite, 30 of 1248 (2.4%) trabeculectomies with antimetabolite, 2 of 72 (2.8%) valved tube shunt implantations, and 25 of 350 (7.1%) nonvalved tube shunt implantations. The increased incidence of DSCH after tube shunts compared with trabeculectomy-associated DSCH was significant (P < 0.0001) with an odds ratio of 3.2. The risk factors for DSCH after glaucoma surgery include white race (P = 0.012), anticoagulation (P = 0.034), severe postoperative hypotony (P = 0.033), and aphakia/anterior chamber intraocular lens (P = 0.002). The visual outcomes of patients with hemorrhage were poor, with a decrease in logarithm of the minimum angle of resolution visual acuity from 0.72 to 1.36, which was statistically significant compared with the controls (P < 0.009). CONCLUSIONS: Delayed suprachoroidal hemorrhage occurs more frequently after tube shunt implantation than after trabeculectomy. Caution should be exercised when operating on patients with known risk factors, because the visual outcomes after DSCH are poor.

Measurement of iris color using computerized image analysis.

PURPOSE: To develop a standardized method for measuring from iris photographs, light and dark segments of areas and densities of iris color. METHODS: Computerized image analysis was used to measure the iris photographs. The reproducibility of this method was studied in 30 normal eyes with three different colored irides, green-brown, blue-grey brown and yellow-brown. Three photographs were taken of each iris with a slit lamp camera at three different exposures at baseline. The photographs were repeated with exposure providing for the best reproducibility at 6.5 +/- 1.7 months as a first follow-up after baseline and 3.6 +/- 0.8 months following the first follow-up visit. At least one measurement was made for each photograph. RESULTS: The mean percent coefficient of variation (standard deviation of triplicate measurements/mean x 100) ranged from 1.0 to 4.1% for area and density measurements. Furthermore, the range of mean percent differences between baseline and follow-up visits ranged from 1.2 to 6.3%. CONCLUSION: We have developed a standardized method which appears suitable for measuring changes over time in iris color.

Penetration of ofloxacin and ciprofloxacin into the aqueous humor of eyes with functioning filtering blebs: a randomized trial.

OBJECTIVE: To determine concentrations of ofloxacin and ciprofloxacin hydrochloride in aqueous humor after topical or combined topical and oral administration in eyes with filtering blebs. DESIGN: A prospective, investigator-masked, randomized, controlled comparative study involving 36 eyes of 34 patients with functioning filtering blebs who were to undergo cataract surgery. Treatment groups received either topical ofloxacin or topical ciprofloxacin (instillation of 0.3% ophthalmic solution every 30 minutes for 4 hours before surgery), or a combined topical plus oral regimen (ciprofloxacin hydrochloride, four 100-mg tablets, or ofloxacin, one 400-mg tablet, administered 24-26, 12-14, and 2 hours preceding surgery). The main outcome measure was antibiotic concentration measured by chromatographic separation and mass spectrometry of aqueous samples obtained during surgery. RESULTS: Topical antibiotic treatment yielded mean concentrations of ofloxacin, 0.75 microg/mL, and ciprofloxacin, 0.21 microg/mL, in aqueous. With combined topical and oral therapy, significantly more ofloxacin was measured than ciprofloxacin (3.84 microg/mL vs 0.35 microg/mL [P<.001]). The combination regimen produced significantly greater ofloxacin levels than did topical therapy alone (P =.007). CONCLUSIONS: Ofloxacin penetrates better than ciprofloxacin into the aqueous of eyes with filtering blebs, particularly after combined topical and oral administration, by which ofloxacin reaches more than a 10-fold greater concentration than does ciprofloxacin. Combined topical and oral therapy with ofloxacin may be beneficial in the treatment of bleb-associated infections.

Comparison of the clinical success and quality-of-life impact of brimonidine 0.2% and betaxolol 0.25 % suspension in patients with elevated intraocular pressure.

BACKGROUND: Brimonidine tartrate 0.2%, a selective alpha2-adrenergic receptor agonist, and betaxolol 0.25% suspension, a cardioselective beta1-adrenergic receptor antagonist, are used in the treatment of elevated intraocular pressure (IOP). OBJECTIVE: This study compared the clinical success and quality-of-life impact of 4 weeks of treatment with brimonidine 0.2% BID compared with those of 4 weeks of treatment with betaxolol 0.25% suspension BID in patients with elevated IOP. METHODS: This was a multisite, double-masked, comparative clinical trial in patients with glaucoma or ocular hypertension. Patients were randomly assigned to receive either brimonidine or betaxolol BID. Morning IOP was measured at baseline and at weeks 1 and 4 using Goldmann applanation. Efficacy was determined by reduction in IOP from baseline. Patients experiencing a > or =20% reduction in IOP were considered to have a successful IOP-lowering response. The Glaucoma Disability Index questionnaire was administered at week 4 to assess quality-of-life factors and the incidence of adverse events. Ophthalmic examinations were conducted at each visit. RESULTS: One hundred fifty-nine patients were randomized to treatment and completed the study, 81 receiving brimonidine and 78 receiving betaxolol. The majority were white (77.4%) and female (61.6%), and had a diagnosis of open-angle glaucoma (56.0%). After 4 weeks of treatment, both brimonidine and betaxolol effectively lowered IOP from baseline (mean IOP reductions: brimonidine, 5.96 mm Hg; betaxolol, 5.07 mm Hg; P = NS). However, a significantly higher percentage of brimonidine patients (52/81 [64.2%]) than betaxolol patients (37/78 [47.4%]) had a > or =20% reduction in IOP (P = 0.033). No serious adverse events were reported with either study medication. On the quality-of-life assessments, more betaxolol patients reported hyperemia (P = 0.011), and the reported hyperemia was significantly more severe in betaxolol patients (P = 0.009). CONCLUSIONS: After 4 weeks of treatment, brimonidine 0.2% BID was clinically successful in significantly more patients and was better tolerated than 4 weeks of treatment with betaxolol 0.25% BID in this population.

Autologous blood injection for late-onset filtering bleb leak.

PURPOSE: To report the outcomes of autologous blood injections for late-onset filtering bleb leak. METHODS: Retrospective chart review of all eyes that had autologous blood injection(s) for filtering bleb leak occurring at least 2 months after trabeculectomy at the Indiana University Medical Center. Successful treatment was defined as resolution of the bleb leak and no need for additional glaucoma medications. Failure was defined as a persistent bleb leak, intraocular pressure greater than 21 mm Hg, or the occurrence of a vision-threatening event related to the procedure. RESULTS: Thirty-two eyes of 31 patients had autologous blood injection for filtering bleb leak and were followed for a mean of 4.9 months (SD, 9.2; range, 1 to 37 months). Twenty-three eyes (72%) were outright failures because of persistence of the leak. Nine eyes (28%) had an initially successful outcome, but the success rate decreased over time as bleb leaks recurred in three of the nine eyes at 5, 6, and 37 months. No patient characteristics correlated with outcome. Mean intraocular pressure increased from pretreatment to final examination (4.5 to 6.5 mm Hg, P =.003). Mean logarithm of minimal angle of resolution (logMAR) vision remained unchanged from pretreatment to final examination (P =.55). Blood seepage into the anterior chamber after autologous blood injection was common but transient. CONCLUSIONS: Autologous blood injection is of limited success in treating late-onset filtering bleb leak.

Bimatoprost: a member of a new class of agents, the prostamides, for glaucoma management.

Bimatoprost, a synthetic analogue of endogenous prostamides, is in development as a topical ocular hypotensive agent for the treatment of glaucoma and ocular hypertension. Prostamides are a newly discovered class of compounds that have been shown to have potent ocular hypotensive activity in the laboratory. Bimatoprost mimics the endogenous prostamides by lowering intraocular pressure (IOP). Bimatoprost provides outstanding control of IOP throughout the day, and a high percentage of patients receiving bimatoprost achieve the low target pressures important for clinical success. In controlled clinical trials, bimatoprost 0.03% given once daily has displayed efficacy superior to timolol 0.5% given twice daily, the current standard for therapy. Analysis of pooled six month data from two large Phase III trials demonstrated that mean IOP was consistently 2 - 3 mmHg lower with bimatoprost q.d. than with timolol b.i.d. Bimatoprost 0.03% q.d. has also been shown to provide significantly better diurnal IOP control than latanoprost 0.005% q.d., probably the most efficacious topical medication currently available. Patients receiving bimatoprost q.d. were more likely than timolol or latanoprost patients to achieve low target pressures. In all clinical evaluations, bimatoprost q.d. has been demonstrated to be safe and well-tolerated. Bimatoprost will likely be available for clinical use in 2001 and it has great potential to be superior to all other medications in IOP-lowering efficacy. It is anticipated that bimatoprost will have an important role in therapy for glaucoma and ocular hypertension.

The effect of trabeculectomy on ocular hemodynamics.

PURPOSE: To evaluate the effects of chronic reduction of intraocular pressure (IOP) on ocular hemodynamics. METHODS: Multisite, prospective evaluation of patients requiring trabeculectomy for treatment of glaucoma. Patients were recruited from the glaucoma service of 2 university hospitals. Patients were evaluated prior to surgery and at 3, 6, and 12 months after trabeculectomy. Color Doppler imaging was used to measure blood flow in the ophthalmic artery, central retinal artery, and short posterior ciliary arteries. Heidelberg retinal flowmetry was used to evaluate perfusion in the peripapillary and optic disc capillary beds. IOP was measured at baseline and at each study visit. RESULTS: There were highly significant reductions in IOP from presurgical baseline measures. At 3 months, mean IOP reduction was 17.1 mm Hg (62.3%; P < .001). At the 6- and 12-month evaluations, the mean IOP reductions were 15.7 mm Hg (57.3%) and 15.5 mm Hg (56.5%), respectively, P < .001. Despite the significant reduction in IOP, there were no significant differences in any ocular blood flow parameters before and after trabeculectomy. CONCLUSIONS: The findings of this study suggest that chronic reduction of IOP does not alter ocular blood flow and that IOP may be an independent risk factor for progression of glaucoma. These findings also suggest that the eye has the ability to autoregulate to chronically increased IOP over time and that additional studies evaluating the long-term effects of IOP changes are needed to further define this relationship.

Cataract surgery after tube shunts.

PURPOSE: To determine the effect of cataract surgery on glaucomatous eyes with functioning tube shunts. METHODS: Retrospective analysis of 11 eyes of 11 patients with functioning tube shunts who underwent cataract extraction. RESULTS: The mean follow-up after cataract extraction was 21 +/- 27 months (range, 4-97 months). There was no statistically significant difference between the mean preoperative intraocular pressure and mean postoperative intraocular pressure (17.4 +/- 3.7 mm Hg vs 17.8 +/- 5.9 mmHg; P = 0.85, paired t test). Most patients exhibited a statistically significant rise or drop in pressure, but in none was there a clinically significant change. The mean number of preoperative and postoperative antiglaucoma medications was also not significantly different (1.5 +/- 1.1 vs 1.7 +/- 1.2; P = 0.44, paired t test). Snellen visual acuity improved at least 2 lines in 6 eyes (55%). Complications after cataract extraction included corneal edema in three eyes, one of which had subsequent loss of control of intraocular pressure. CONCLUSIONS: Eyes with a functioning tube shunt undergoing cataract extraction can maintain control of intraocular pressure while achieving visual improvement.

Revision of dysfunctional filtering blebs by conjunctival advancement with bleb preservation.

PURPOSE: To assess the outcome of advancing a conjunctival flap with preservation of the bleb in eyes undergoing filtration bleb revision after trabeculectomy. METHODS: A retrospective review of cases from a university-based referral practice identified 30 eyes of 30 patients that had undergone bleb revision after trabeculectomy by advancement of a conjunctival flap over the de-epithelialized bleb. Success was defined as resolution of the bleb-associated complication necessitating the revision (leak, hypotony, discomfort) with maintenance of intraocular pressure greater than or equal to 6 and less than or equal to 21 mm Hg without glaucoma medications. Qualified success met the above criteria but with the use of glaucoma medications. Summary data including visual acuity were obtained. RESULTS: On the 30 eyes, 30 conjunctival advancement procedures were performed. Seventeen were for bleb leaks, 10 for prolonged hypotony without bleb leak, and three for dysesthetic bleb. Eighteen eyes (60%) were classified as a complete success and 24 eyes (80%) achieved at least a qualified success. Cumulative probability of at least qualified success was 77% at 2 years. Failures included inadequate intraocular pressure control (one eye), recurrent bleb leak (three eyes), and hypotony without bleb leak (two eyes). The mean preoperative intraocular pressure for all eyes increased from 4.4 +/- 3.7 mm Hg to 12.3 +/- 6.2 mm Hg (P <.00001) at the final visit with a mean follow-up of 18.9 +/- 15.5 months. Visual acuity improved or remained within 1 line of preoperative acuity in all but five patients. Complications included two patients with mild ptosis and four patients with hypertropia. CONCLUSION: Advancement of a conjunctival flap with preservation the preexisting bleb often provides successful resolution of bleb-associated complications.

Altitudinal visual field asymmetry is coupled with altered retinal circulation in patients with normal pressure glaucoma.

AIM: To compare the effect of altitudinal asymmetric glaucomatous damage on retinal microcirculation in patients with normal pressure glaucoma (NPG). METHODS: In a prospective cross sectional study patients with NPG (washed out for antiglaucomatous therapy) and altitudinal asymmetric perimetric findings between the superior and inferior hemisphere (Humphrey 24-2) (n=18) were included and compared with 20 NPG patients with symmetrical field defects and 18 healthy subjects. Fluorescein angiograms were performed using a scanning laser ophthalmoscope. Using digital image analysis, arteriovenous passage time (AVP) and vessel diameters were assessed for comparison of corresponding affected and less affected temporal arcades. RESULTS: Both affected and less affected hemispheres showed significantly prolonged AVP times (p<0.001) when compared with healthy subject data. In hemispheres with more severe glaucomatous field loss the AVP times were significantly (p=0.04) prolonged compared with the less affected hemisphere (AVP affected 3.1 (SD 7) seconds v AVP less affected 2.61 (1.4) seconds). There was no asymmetry effect on arterial and venous diameter measurements. CONCLUSION: Altitudinal visual field defects are linked together with circulatory deficits of the retinal tissue. The attenuated circulation seems to be a considerable factor in the natural course of glaucomatous optic neuropathy.

Shunt revision versus additional tube shunt implantation after failed tube shunt surgery in refractory glaucoma.

PURPOSE: To compare tube shunt revision with additional tube shunt after failed tube shunt surgery. METHODS: We identified 281 patients who underwent a primary tube shunt procedure from 1985 to 1998 at Indiana University and reviewed 33 eyes of 33 patients that had failed and required further surgery. Shunt revision was performed in 12, whereas an additional shunt was placed in 21 eyes. Intraocular pressure, antiglaucoma medications, visual acuity, and complications were noted. Success was defined as at least a 25% reduction in intraocular pressure that was deemed clinically adequate. Qualified success was defined as a 25% intraocular pressure reduction but with additional medications or a significant reduction in medications with stable intraocular pressure for preoperative intraocular pressure less than 21 mm Hg. RESULTS: Preoperative intraocular pressures (mean +/- 95% confidence interval) for the revision and additional tube groups were 28.8 +/- 5.8 mm Hg and 29.8 +/- 2.7 mm Hg (P =.73), with an average follow-up period of 25.2 months (range, 3 to 108 months) and 34.8 months (range, 6 to 84 months), respectively. Final mean intraocular pressure was 25.3 +/- 6.7 mm Hg for the revision group and 17.7 +/- 3.4 mm Hg for the additional tube group (P =.037). Forty-two percent in the revision group versus 62% in the additional tube group achieved at least a qualified success (P =.30, Fisher exact test). Corneal edema was a common complication, especially in the additional tube group. Limitations of this study include the small sample sizes and the uneven distribution of neovascular glaucoma between the two groups (six of 12 in the revision group vs two of 21 in the additional tube group; P =.015, Fisher exact test). CONCLUSIONS: Our series showed that after failed tube shunt surgery, an additional tube shunt offers better intraocular pressure control than revision by excision of an encapsulated bleb.

Outcomes of sequential tube shunts in complicated glaucoma.

OBJECTIVE: To evaluate intraocular pressure (IOP) control, change in visual acuity, and complications in eyes that have undergone a second glaucoma tube shunt procedure. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Twenty-two eyes of 22 patients that have undergone sequential tube implants for management of glaucoma. METHODS: Parameters analyzed included IOP, visual acuity, and number of hypotensive agent before each shunt procedure and at last follow-up visit. The overall IOP lowering effect attributable to each tube shunt was calculated. Any ocular complications after the second tube shunt were recorded. Success was defined as an IOP between 6 and 21 mm Hg and a 20% reduction in IOP from the second tube shunt procedure. Qualified successes met one of these two requirements at the last follow-up visit. Total failures did not meet any of the above criteria, required additional surgical intervention to lower IOP, or both. MAIN OUTCOME MEASURES: Intraocular pressure control, visual acuity preservation, and complications. RESULTS: At the last follow-up visit, the average percent reduction in IOP from both tube shunt procedures was 42+/-21%. The average percent IOP reduction from the second tube shunt was 33+/-17%. Eleven (50%) patients met the criteria for success, 8 (36.4%) patients were qualified successes, and 3 (13.6%) were failures. The median number of hypotensive agents decreased from two to one. Ten patients experienced new or worse pseudophakic bullous keratopathy after the second tube shunt, six of whom underwent penetrating keratoplasty. Thirteen (59%) patients maintained visual acuity within one line of their second tube shunt pre-operative Snellen visual acuity. Seven (32%) patients lost more than 2 lines, and one patient lost light perception. CONCLUSIONS: Although corneal morbidity is a common complication, a second tube shunt does not cause higher-than-expected rates of other complications associated with tube shunt surgery. Eyes that undergo a second tube shunt procedure can achieve pressure control, require fewer hypotensive agents, and may maintain stable visual acuity.

The evolving pharmacotherapeutic profile of brimonidine, an alpha 2-adrenergic agonist, after four years of continuous use.

Since its introduction in 1996, use of brimonidine tartrate 0.2% ophthalmic solution (Alphagan, Allergan), a highly selective alpha 2-adrenergic agonist, has become increasingly popular for the initial and long-term management of ocular hypertension and glaucoma. Recently, ongoing clinical comparison trials of up to three years in length have reported sustained intraocular pressure (IOP) lowering efficacy with brimonidine 0.2% b.i.d., which was comparable with timolol 0.5% (Timoptic; Merck & Co.), accompanied by a favourable tolerability and safety profile. Also, many post-market studies have demonstrated the utility of brimonidine 0.2% b.i.d. as mono- and adjunctive therapy. Furthermore, major inroads have been made in the study of other possible pharmacotherapeutic benefits of brimonidine treatment, namely the potential for neuroprotection. This review will present a brief developmental history and examine key pharmacotherapeutic characteristics of brimonidine, including its receptor selectivity, IOP-lowering mechanism of action and potential neuroprotective activities. Moreover, the literature on brimonidine's efficacy and safety profiles in the treatment of ocular hypertension and glaucoma will be perused, and new four-year data from an ongoing double-masked clinical study comparing brimonidine tartrate 0.2% with timolol 0.5%, b.i.d. will be introduced. Brimonidine 0.2% b.i.d. provided sustained IOP-lowering efficacy comparable to timolol 0.5% b.i.d., with no significant differences at trough or peak during year four of continuous use. Visual fields were well preserved in both treatment groups with 93% of brimonidine patients and 91% of timolol patients showing no change or improvement. Brimonidine continued to appear safe and well-tolerated, with no clinically significant effects on mean heart rate or blood pressure, and no serious drug-related adverse events (AEs). Two out of 36 brimonidine patients developed ocular allergy; both were resolved without sequelae. Overall post-market surveillance found no reports of unexpected or serious drug-related AEs. These long-term results, in conjunction with those reported in the literature, suggest that brimonidine 0.2% b.i.d. is a highly appropriate first- and second-line therapy for long-term management of glaucoma and ocular hypertension. Potential neuroprotective effects of brimonidine therapy, which might provide additional vision sparing benefit, although supported by compelling animal studies, await clinical verification.

Primary open-angle glaucoma patients characterized by ocular vasospasm demonstrate a different ocular vascular response to timolol versus betaxolol.

We evaluated the retrobulbar response to a selective versus nonselective beta blocker in a subgroup of primary open-angle glaucoma patients (POAG) characterized by ocular vasospasm. Eleven patients who exhibited ocular vasospasm (i.e. a significant increase in ophthalmic artery blood flow velocity or a significant decrease in ophthalmic artery resistance index during hypercapnia) underwent medication washout for 4 weeks and were enrolled in a double-masked cross-over study (betaxolol versus timolol). Patients were evaluated for blood flow velocity of the retrobulbar vessels using color Doppler imaging, intraocular pressure, visual field sensitivity and contrast sensitivity at the beginning and end of each 4 week treatment period. Timolol treatment caused a significant reduction in IOP (p = .007), but no change in retrobulbar hemodynamics or visual function. After betaxolol treatment, resistance index fell significantly (p = .040) in the ophthalmic artery and increased significantly in both the central retinal (p = .003) and temporal posterior ciliary arteries (p = .030). Also following betaxolol treatment, contrast sensitivity improved significantly (p = .006), and a significant positive correlation was shown between change in contrast sensitivity and change in resistance index (r = .70; p = .015) of the ciliary arteries. POAG patients characterized by ocular vasospasm display a significant hemodynamic response to betaxolol, but not to timolol.

Prospective evaluation of extraocular motility following double-plate molteno implantation.

OBJECTIVE: To determine the incidence and type of extraocular motility disturbance after double-plate Molteno implantation. METHODS: In a prospective clinical series, we evaluated preoperative and postoperative ocular motility at 3 and 6 months in 24 eyes of 24 patients undergoing double-plate Molteno implantation. Visual acuity, motility testing, and subjective and objective diplopia were evaluated at each examination. RESULTS: Within the first 6 months postoperatively, new or worse strabismus developed in 11 (46%) of the 24 study patients. Three of the 11 patients had a generalized restriction of the superior rectus and the superior oblique muscles, all of which persisted 6 months after surgery. Four patients had clinical features consistent with an acquired Brown syndrome, and 6 months after surgery, 3 of the 4 patients had a residual deviation, although the deviation in 1 patient resolved. A superior oblique palsy developed in 3 patients, and a lateral rectus palsy developed in 1 patient. All 4 of the muscle palsies resolved or were resolving during the follow-up period, which ranged from 6 to 12 months. CONCLUSIONS: Extraocular motility disturbances are not rare after double-plate Molteno surgery. Muscle palsies, acquired Brown syndromes, and generalized restrictions occurred in similar proportions. CLINICAL RELEVANCE: Patients should be counseled before Molteno surgery concerning the risk of strabismus and diplopia.