Ultrasound Cyclo Plasty for Treatment of Surgery-Naïve Open-Angle Glaucoma Patients: A Prospective, Multicenter, 2-Year Follow-Up Trial.

BACKGROUND: The purpose of this prospective study was to evaluate the efficacy and safety of the Ultrasound Cyclo Plasty (UCP) procedure using high-intensity focused ultrasound in surgery-naïve open-angle glaucoma patients. METHODS: prospective, non-randomized, single-arm, multicenter clinical trial. Sixty-six eyes with primary open-angle glaucoma, intraocular pressure (IOP) ≥21 mmHg and with no history of filtering surgery were enrolled. Patients were treated by UCP with a therapy probe comprising six piezoelectric transducers, consecutively activated for 8 s each. Complete ophthalmic examination was performed before the procedure, 1 day after the procedure, and 1, 3, 6, 12, 18 and 24 months after the procedure. Primary outcomes were complete success (defined as IOP lowering from baseline ≥20% without additional glaucoma medications) and vision-threatening complications. Secondary outcomes were the presence of complications and the reduction of the number of medications used. RESULTS: IOP was significantly reduced after one procedure (p < 0.05), from a mean pre-operative value of 24.3 ± 2.9 mmHg (n = 2.3 hypotensive medications) to a mean value of 15.9 ± 3.6 mmHg (n = 2.2 hypotensive medications) at 2 years (mean IOP lowering of 33%). Surgical success was achieved in 74% of eyes. Notwithstanding side effects such as transient anterior chamber inflammation, refractive error changes, transient hypotony and macular edema, no major intra or post-operative complications such as phthisis, induced cataract, neovascularization or significant vision loss were observed. CONCLUSIONS: Ultrasound Cyclo Plasty is a valuable, effective and well-tolerated procedure to lower IOP in patients with open-angle glaucoma without previous filtering surgery.

The distribution of relaxin receptors in the anterior segment of primary open-angle glaucoma patients.

Purpose: Relaxin is a polypeptide hormone produced by the corpus luteum and the decidua in females and by the prostate in males. It has vasodilatory and antifibrotic effects. In the past, it has been reported that injection of relaxin hormone has caused a reduction in the intraocular pressure although its mechanism has not yet been fully understood and the expression of relaxin receptors has not yet been evident in the human eye. Therefore, the purpose of this current study was to examine the presence of relaxin receptors in the human eye anterior segment. Methods: This is an interventional non-randomized study. Patients with primary open-angle glaucoma who underwent trabeculectomy were recruited. During the surgery, a punch biopsy (including the cornea, sclera, trabecular meshwork, and Schlemm's canal) was taken and stained with hematoxylin-eosin, and immunohistochemistry staining for relaxin/insulin-like family peptide receptor 1 (RXFP1). Results: A positive staining was noted for RXFP1 in the inner uveal, corneoscleral, and cribriform meshwork and Schlemm's canal's endothelium. Negative staining for RXFP1 was noted in the cornea and sclera. Conclusion: RXFP1 is present in the anterior segment drainage system of the human eye. Therefore, this receptor may have an active role in regulating the outflow facility and in the reduction of intraocular pressure.

The effect of glaucoma treatment using high-intensity focused ultrasound on total and corneal astigmatism: a prospective multicentre study.

PURPOSE: Ultrasound cycloplasty (UCP) acts through the selective coagulation of the ciliary body using high-intensity focused ultrasound (HIFU) technology. The aim of this study was to investigate whether the application of ultrasound beams targeting the ciliary body using an external probe influences astigmatism. METHODS: Multicentre, prospective, single-arm, open-label study in adult patients with primary open-angle glaucoma and moderately uncontrolled intraocular pressure (IOP) under glaucoma medication. The primary outcome was induced corneal astigmatism, calculated from topography, and assessed statistically through vector analysis. Secondary outcomes included induced total astigmatism and mean changes from baseline in best-corrected visual acuity (logMAR) and IOP. Subgroup analysis was performed to assess the impact of device centring on corneal and total induced astigmatism. RESULTS: Fifty eyes were enrolled. Mean age was 69.6 ± 11.3 years. At 1, 3 and 6 months postprocedure, HIFU-induced corneal astigmatism was 0.88 D × 93°, 0.87 D × 106° and 1.16 D × 97°, respectively, while induced total astigmatism was 0.62 D × 103°, 0.42 × 106° and 0.39 × 107°. By the last follow-up, the percentage of patients with <0.50, <1.00, <1.50 and <2.00 D of induced corneal versus total astigmatism was 8.3% versus 46%, 29% versus 66%, 62.5% versus 88% and 79% versus 94%. Visual acuity was statistically significantly impaired at 1 month, but no difference remained by 3 and 6 months postprocedure. CONCLUSION: Ultrasound cycloplasty procedure is associated with increased corneal astigmatism. However, its impact on total refractive astigmatism is less pronounced.

High-intensity Focused Ultrasound Treatment in Moderate Glaucoma Patients: Results of a 2-Year Prospective Clinical Trial.

PRECIS: Ultrasound Cyclo Plasty (UCP) treatment using high-intensity focused ultrasound (HIFU) is an effective and safe therapy to reduce intraocular pressure (IOP) in moderate glaucoma patients as was measured during a 2-year follow-up period. PURPOSE: The purpose of this study was to evaluate the long-term safety and efficacy of the UCP procedure using HIFU in moderate glaucoma patients. PATIENTS AND METHODS: A prospective interventional noncomparative study was carried out. Fifteen patients (15 eyes) with moderate open-angle glaucoma were enrolled. All eyes were treated with UCP-HIFU. A thorough ophthalmic examination and IOP measurements were performed before the UCP-HIFU procedure and at 1 day, 1 week, 4 weeks, 3 months, 6 months, 1 year, and 2 years after the procedure. The primary outcome was defined as a surgical success (IOP reduction of 20% or ≥5 mm Hg) at the last follow-up visit. The secondary outcomes were the mean IOP at each follow-up visit, number of medications used, complications profile, and reinterventions. RESULTS: The mean preoperative IOP at baseline was 26.8±5.0 mm Hg. All patients had a positive response and a lower IOP after treatment, with a relatively stable 31% reduction in IOP during the follow-up period. A significant reduction in IOP was observed at all postprocedure examination points (P<0.01), with a mean 17.6±4.4 mm Hg at 2 years after the procedure (P=0.005). Surgical success was achieved in 87% of the patients at their last follow-up visit. There was a nonsignificant decrease in the mean number of glaucoma medications from 2.5±0.8 to 2.0±1.0 at 2 years (P=0.48). No major intraoperative or postoperative complications were noted. CONCLUSION: UCP-HIFU treatment is an effective, safe, and well-tolerated method to reduce IOP in patients with moderate glaucoma.

Laser-Assisted Techniques for Penetrating and Nonpenetrating Glaucoma Surgery.

The use of lasers is slowly pervading all subspecialties of ophthalmology, especially glaucoma, and lasers are slowly replacing many glaucoma surgeries. Conventional trabeculectomy has so far remained the gold standard for glaucoma surgery and efforts are being made to develop a new surgical approach to overcome the limited success rate and safety issues of this traditional procedure. There is a great interest in using lasers for ab interno and ab externo penetrating and nonpenetrating filtering surgery. Theoretically, laser-assisted surgery offers the potential advantage of improved accuracy, repeatability, and safety, although the main drawback of using lasers for this purpose is the potential collateral damage induced by the scattered energy. Collateral thermal damage adjacent to the sclerostomy site is believed to be detrimental to the long-term success of the filtering procedure. Employing a laser with high water absorbance and low light scattering reduces the extent of collateral thermal damage and improves the long-term surgical success. An increasing number of different radiation sources have been examined for penetrating and nonpenetrating glaucoma surgery with various success rates.

Gold Micro-Shunt Implants Versus Ahmed Glaucoma Valve: Long-term Outcomes of a Prospective Randomized Clinical Trial.

PURPOSE: To compare long-term outcomes of Ahmed glaucoma valve (AGV), 24 µm Gold Micro-Shunt (GMS), and 48 µm GMS implantation for treatment of refractory glaucoma. PATIENTS AND METHODS: This was a 3-armed randomized interventional prospective clinical trial. Within an institutional setting, 29 adults (29 eyes) with refractory glaucoma [mean baseline intraocular pressure (IOP) ≥ 22 mm Hg on maximal medication, status post at least 1 failed trabeculectomy, defined visual field defect, and without recent glaucoma-related surgery] were randomly assigned to AGV, 24 µm GMS, or 48 µm GMS implantation. Exclusion criteria included uveitic, traumatic, or neovascular glaucoma. The 3 groups were comparatively evaluated preoperatively and 1, 2, 3, and 5 years postoperatively for IOP and numbers of glaucoma medications needed. Main outcome measures were implant survival rates. Results of the 24 and 48 µm GMS groups were also compared separately. RESULTS: In all groups the final IOP (in mm Hg) was significantly lower than the preoperative IOP (17.3 ± 2.6 vs. 33.5 ± 6.7, P=0.004; 17.8 ± 2.4 vs. 25.7 ± 0.7, P=0.0001; and 19.6 ± 5.2 vs. 35.6 ± 2.2, P=0.0001 in the AGV, 24 µm GMS, and 48 µm GMS groups, respectively). Differences between initial and final mean numbers of medications were not significant. Cumulative probabilities of success at 5 years were 77.8%, 77.8%, and 72.7%, respectively. CONCLUSIONS: During long-term follow-up, success rates in the 2 GMS groups and the AGV group were similar. Likewise, IOP reduction and the need for continued glaucoma medical therapy remained high and were similar for all devices.

High-intensity focused ultrasound treatment in refractory glaucoma patients: results at 1 year of prospective clinical study.

PURPOSE: To evaluate the safety and efficacy of the ultrasonic circular cyclo-coagulation procedure using high-intensity focused ultrasound by a miniaturized annular device containing 6 piezoceramic transducers in patients with refractory glaucoma. METHODS: This was a prospective interventional noncomparative study of 20 eyes of 20 patients with refractory glaucoma. All eyes were treated with 6 activated transducers operating at 21 MHz. Ultrasound biomicroscopy and a complete ophthalmic examination were performed before the procedure and at 1 day, 1 week, and 1, 3, 6, and 12 months after the procedure. Primary outcomes were surgical success (defined as intraocular pressure (IOP) reduction from baseline ≥20% and IOP >5 mm Hg) at the last follow-up visit. Secondary outcomes were mean IOP at each follow-up visit compared to baseline, medication use, complications, and re-interventions. RESULTS: Intraocular pressure was significantly reduced (p<0.01) from a mean preoperative value of 36.4 ± 5.7 mm Hg to a mean postoperative value of 22.5 ± 10.3 mm Hg at 12 months. Four patients needed to be re-treated. The mean IOP reduction achieved was 38%. Surgical success was achieved in 13 of 20 eyes (65%). No major intraoperative or postoperative complications occurred. CONCLUSIONS: Ultrasonic circular cyclo-coagulation using high-intensity focused ultrasound delivered by a circular miniaturized device containing 6 piezoceramic transducers is an effective and well-tolerated method to reduce IOP in patients with refractory glaucoma.

The effect of oral propranolol on intraocular pressure in infants with Sturge-Weber syndrome glaucoma.

PURPOSE: To report the effect of oral propranolol on intraocular pressure (IOP) in infants newly diagnosed with unilateral Sturge-Weber syndrome (SWS) glaucoma receiving no other treatment. METHODS: This was a prospective, nonrandomized interventional case series. Four infants presenting with unilateral SWS glaucoma with no prior treatment were treated with oral propranolol at a dose of 2 mg/kg and followed thereafter. RESULTS: Propranolol had a temporary IOP-lowering effect in 3 of 4 children after 1 week of treatment. This effect diminished thereafter and 3 of 4 children required additional medical or surgical treatment. CONCLUSIONS: Oral propranolol has a temporary effect on IOP in SWS glaucoma and is not effective as a single treatment in this syndrome, yet can serve to delay surgical treatment for a short period of time. In one case, the glaucoma was well-controlled on this medication.

CO2 laser-assisted deep sclerectomy in glaucoma patients.

PURPOSE: To evaluate the safety and efficacy of CO2 laser-assisted deep sclerectomy surgery (CLASS) in patients with open angle glaucoma. DESIGN: A prospective single-arm, nonrandomized clinical investigation for the evaluation of technology. METHODS: Fifteen eyes of 15 consecutive patients diagnosed with either primary open angle glaucoma or pseudoexfoliation glaucoma who were the candidates for glaucoma filtration surgery were included. Laser-assisted deep sclerectomy using a CO2 laser system was performed in all patients. A half-thickness scleral flap was created, the use of 0.04% mitomycin C for 60 seconds was left at the surgeon's discretion, and a CO2 laser with a beam-manipulating system was used to achieve deep scleral ablation and unroofing of Schlemm's canal zone. Visual acuity, complete ophthalmologic examination, and intraocular pressure (IOP) were measured and documented at baseline, 1, 2, 4, and 6 weeks and at 3, 6, and 12 months, respectively. Complete success was defined as 5≤IOP≤21 mm Hg and 20% IOP reduction with no medication at the 12-month endpoint visit. Qualified success was defined as a similar IOP reduction with medication. RESULTS: The preoperative IOP of 27.3±4.2 mm Hg (mean±SD) dropped to 15.0±3.7 mm Hg at 6 months and 16.6±3.4 mm Hg at 12 months postoperatively, yielding an average IOP reductions at 6 and 12 months of 13.1±4.3 mm Hg (45.1%; 95% CI, 11, 15.3) and 11.5±5.5 mm Hg (39.2%; 95% CI, 8.8, 14.3), respectively (P<0.001). The complete success rate after 12 months was 45.5%, whereas qualified success was 90.9%. Mitomycin C was used in 76.9% of the CLASS subjects.

A novel method for quantifying the amount of trabecular meshwork pigment in glaucomatous and nonglaucomatous eyes.

PURPOSE: To assess the use of a computerized program for evaluating the amount of trabecular meshwork (TM) pigmentation in normal (control), primary open-angle glaucoma (POAG), and pseudoexfoliation glaucoma/pigmentary dispersion glaucoma (PXFG/PDG) patients. METHODS: All included patients were from the Goldschleger Eye Institute glaucoma clinic. After signing an informed consent, each patient's anterior chamber angle was photographed using a single photo-slit under the same conditions. Only one eye per patient was photographed. The superior TM and the inferior TM were documented. Then, the degree of "blackness" (representing melanin pigment) was assessed using the ImageJ program. RESULTS: Of the 43 eyes photographed, 8 were excluded because of low-quality images. Of the remaining 35 patients, 14 were normal, 10 had POAG, and 11 had PXFG/PDG. The amount of pigment was the same in the control and the POAG patients whether the inferior TM (P=0.24), superior TM (P=0.58), or the sum inferior TM+superior TM (P=0.85) was measured. The pigment level was significantly higher in the PXFG/PDG group than in the control group (inferior TM, P<0.01; superior TM, P=0.047; sum, P<0.01). The difference between the inferior and the superior TM pigment levels was found to be statistically insignificant in all the groups (normal, P=0.86; POAG, P=0.10; PXFG/PDG, P=0.22). CONCLUSIONS: The use of ImageJ software might play a role in the quantification of pigment evaluation of the TM.

Pupillometer-based objective chromatic perimetry in normal eyes and patients with retinal photoreceptor dystrophies.

PURPOSE: To evaluate a novel objective perimetry using multifocal chromatic pupil light reflex in normal participants and patients with photoreceptor dysfunction, and to relate this new technique with subjective dark-adapted chromatic Goldmann perimetry. METHODS: Thirty-two eyes of 17 retinitis pigmentosa (RP) or cone-rod dystrophy patients and 20 eyes of 12 healthy individuals were tested. A computerized infrared video pupillometer was used to record changes in pupil diameter in response to short- and long-wavelength stimuli (peak 485 and 640 nm, respectively; light intensity 40 cd/m(2)) at 13 different points of the 30° visual field (VF), under background illumination of 2.7 cd/m(2). The pupillary response (PR) of patients was compared with PR obtained from normal control participants. In 11 patients, the pupillary responses were also compared with their findings on dark-adapted chromatic Goldmann perimetry. RESULTS: Significantly reduced pupillary responses were obtained in RP patients in response to the short-wavelength stimulus in nearly all perimetric locations (P < 0.03). By contrast, in response to the long-wavelength stimulus, RP patients demonstrated significantly reduced PR mostly in peripheral locations (P ≤ 0.02). In a cone-rod dystrophy patient, the PR to both long- and short-wavelength stimuli was significantly lower in the scotoma area identified by the dark-adapted chromatic Goldmann perimetry. In all patients that were tested by the chromatic Goldmann, minimal PR was recorded in areas that were nondetected in the chromatic Goldmann perimetry. CONCLUSIONS: This study demonstrates the potential feasibility of using pupillometer-based chromatic perimetry for objectively assessing VF defects and retinal function in patients with retinal dystrophies. (ClinicalTrials.gov number, NCT01021982.).

Laser-assisted techniques for penetrating and nonpenetrating glaucoma surgery.

The use of lasers is slowly pervading all sub-specialties of Ophthalmology, especially glaucoma, and lasers are slowly replacing many glaucoma surgeries. Conventional trabeculectomy has so far remained the gold standard for glaucoma surgery, and efforts are being made to develop a new surgical approach to overcome the limited success rate and safety issues of the traditional trabeculectomy. There is a great interest in using lasers to create an ab interno and ab externo penetrating and nonpenetrating filtering surgery. Theoretically, laser-assisted surgery offers the potential advantage of improved accuracy, repeatability, and safety, although the main drawback of using lasers for this purpose is the potential collateral damage induced by the scattered energy. Collateral thermal damage adjacent to the sclerostomy site is believed to be detrimental to the long-term success of the filtering procedure. Employing a laser with high water absorbance and low light scattering reduces the extent of collateral thermal damage and improves the long-term surgical success. An increasing number of different radiation sources were examined for penetrating and nonpenetrating glaucoma surgery with various success rates.

Selective laser trabeculoplasty in uncontrolled pseudoexfoliation glaucoma.

BACKGROUND AND OBJECTIVE: To assess the efficacy and safety of selective laser trabeculoplasty (SLT) in uncontrolled pseudoexfoliation glaucoma (PEXG). PATIENTS AND METHODS: Fifty-seven eyes (57 patients) with uncontrolled PEXG and intra-ocular pressure (IOP) greater than 23 mm Hg underwent SLT. All received ophthalmic evaluation preoperatively and at intervals postoperatively. IOP was measured at 1 hour, 1 day, 1 week, and 1, 3, 6, and 12 months postoperatively. During follow-up, patients were treated with topical anti-glaucoma medications as necessary. RESULTS: One year postoperatively, mean IOP in all patients decreased from 26.01 ± 2.5 to 17.8 ± 2.8 mm Hg (31.5%; P < .001). Mean medications per patient decreased from 2.8 to 2.3. Complications included conjunctival redness and infection within 1 day postoperatively in 30 eyes (67%). One hour after SLT treatment, an increase in IOP greater than 5 mm Hg was detected in two eyes (3.5%) and resolved within 24 hours with topical medication. CONCLUSION: SLT is safe and effective in patients with PEXG.

Intraocular pressure measurements and biomechanical properties of the cornea in eyes after penetrating keratoplasty.

PURPOSE: To compare intraocular pressure (IOP) measurements obtained using the Goldmann applanation tonometer (GAT; Haag-Streit), the Tono-Pen XL (Reichert, Inc), and the ocular response analyzer (ORA; Reichert Ophthalmic Instruments), and to determine the influence of corneal factors on IOP measurements in eyes that had undergone penetrating keratoplasty (PK). DESIGN: Consecutive, prospective study. METHODS: Study population. Sixty-one eyes that underwent PK were enrolled in this study. Intervention. IOP was measured using the GAT, Tono-Pen, and ORA. Corneal hysteresis and corneal resistance factor as provided by the ORA were recorded. Central corneal thickness was measured using an ultrasound pachymeter. Main outcome measures. IOP and corneal biomechanical factors. RESULTS: IOP measurements were obtained in an average of 65 months (range, 6 to 209 months) after PK surgery. ORA-derived IOP measurements (corneal-compensated IOP and Goldmann-correlated IOP) and Tono-Pen XL IOP all correlated in a significant manner to GAT IOP measurements. Corneal-compensated IOP and Tono-Pen XL IOP values were higher than GAT IOP (P < .001 and P = .001, respectively), whereas Goldmann-correlated IOP readings did not differ from GAT IOP readings (P = .054). Central corneal thickness did not correlate to any tonometry technique. In a regression analysis, corneal hysteresis and corneal resistance factor were found to play a role in IOP prediction. CONCLUSIONS: Central corneal thickness may be of less importance than corneal hysteresis and corneal resistance factor in IOP determination in eyes that have undergone PK, perhaps because of the lower modulus of elasticity in these eyes. GAT IOP seems to be lower than other tonometry techniques in eyes that have undergone PK.

Rasagiline-induced delay of retinal ganglion cell death in experimental glaucoma in rats.

PURPOSE: To evaluate the neuroprotective effect of rasagiline (N-propargyl-1 (R)-aminoindan), a selective monoamine oxidase inhibitor, on the survival of retinal ganglion cells (RGCs) in glaucomatous rat eyes. Rasagiline is an FDA approved anti-Parkinson disease drug with neuroprotective capabilities that were shown in many models of brain damage. MATERIALS AND METHODS: The neuroprotective effect of daily intraperitoneal (IP) injections of rasagiline (0.5 mg/kg and 3 mg/kg) was evaluated and compared with saline injections using the translimbal photocoagulation model of experimental glaucoma in Wistar rats. Intraocular pressure (IOP) was measured before and immediately after the laser treatment, and then weekly. Seven weeks after the induction of glaucoma, the animals were killed, the eyes were enucleated and the retinas were prepared as whole mounts. Fluoro-gold had been injected into the superior colliculus 10 days before enucleation, and RGC survival was evaluated by counting the surviving labeled RGCs in a masked way. RESULTS: All rats (n=29) displayed significant IOP elevation and RGC damage. Seven weeks after the induction of glaucoma, the mean RGC survival was 43±8% in the rasagiline 3 mg/kg-treated group and 43±9% in the rasagiline 0.5 mg/kg-treated group compared with 23%±4% in the saline-treated (control) group (P=0.01 and P=0.02, respectively). CONCLUSION: Systemic treatment with rasagiline significantly enhances the survival of RGCs in experimental glaucoma.

Intravitreal injections of neurotrophic factors secreting mesenchymal stem cells are neuroprotective in rat eyes following optic nerve transection.

PURPOSE: To evaluate the neuroprotective effect of intravitreal injections of neurotrophic factors secreting mesenchymal stem cells (NTF-SCs) on the survival of retinal ganglion cells (RGCs) in rat eyes after optic nerve transection (ONT). METHODS: Rat and human bone marrow-derived mesenchymal stem cells (MSCs) were induced to secrete high levels of NTF. The neuroprotective effect from intravitreally injected untreated MSCs or NTF-SCs was compared with that from PBS injections using an ONT model in 146 rats. RGCs were labeled by applying rhodamine dextran to the orbital optic nerve or by injecting Fluorogold into the superior colliculus. Cell- and saline-treated eyes were compared 8 days after ONT. For tracking, MSCs and NTF-SCs were labeled with PKH26 and analyzed at 2 hours and at 10, 17, and 24 days using immunohistochemistry and RT-PCR. RESULTS: Mean RGC survival at 8 days after transection increased significantly after intravitreal injections of human NTF-SCs (69% ± 3%) or of untreated human MSCs (66% ± 5%) versus PBS (46% ± 3%; P = 0.0005 and P = 0.03, respectively). In an additional set of experiments, human NTF-SCs versus PBS were significantly neuroprotective, but bone marrow-derived rat NTF-SCs were not (P = 0.001 and P = 0.1, respectively). Immunohistochemistry demonstrated that human-derived MSCs, human NTF-SCs, and rat-derived NTF-SCs survived at least 24 days after intravitreal injection. CONCLUSIONS: Bone marrow-derived MSCs can deliver NTFs by intravitreal injection and can be neuroprotective after ONT. This approach might be further studied to deliver NTFs by autotransplantation in glaucomatous eyes.

Twenty-four-hour intraocular pressure control with bimatoprost and the bimatoprost/timolol fixed combination administered in the morning, or evening in exfoliative glaucoma.

AIM: To compare 24 h intraocular pressure (IOP) control of morning and evening administered bimatoprost/timolol fixed combination (BTFC) and evening administered bimatoprost in exfoliative glaucoma (XFG). METHODS: One eye of 60 XFG patients was included in this prospective, observer-masked, crossover comparison. Following wash-out, all patients received bimatoprost monotherapy for 6 weeks. They were then randomised to morning, or evening, administered BTFC for 3 months and then switched to the opposite therapy. RESULTS: At baseline, mean 24 h pressure was 29.0 mm Hg. Bimatoprost reduced the mean IOP by 8.1 mm Hg (27.8%, p<0.001). The evening administration of BTFC reduced 24 h IOP to a statistically lower level than morning administration (10.2 mm Hg (35.3%) vs 9.8 mm Hg (33.8%); p=0.005). Both dosing regimens reduced IOP significantly more than bimatoprost (p < or = 0.006, for all time points). A 24 h IOP reduction > or = 30% was seen in 43 patients (72%) with evening BTFC compared with 39 patients (65%) with morning BTFC (p=0.344) and only 24 patients (40%) with bimatoprost monotherapy (p<0.001 vs both BTFC regimens). CONCLUSION: Both BTFC dosing regimens significantly reduce 24 h IOP in XFG compared with bimatoprost monotherapy. The evening dosing gives rise to statistically better 24 h IOP control and could be considered in these patients.