Contralateral effect of topical beta-adrenergic antagonists in initial one-eyed trials in the ocular hypertension treatment study

Phase 3 Randomized Clinical Trial of the Safety and Efficacy of Travoprost Intraocular Implant in Patients with Open-Angle Glaucoma or Ocular Hypertension

PURPOSE

To evaluate the safety and intraocular pressure (IOP)-lowering efficacy of 2 models of the travoprost intraocular implant (fast-eluting [FE] and slow-eluting [SE] types) from 1 of 2 phase 3 trials (the GC-010 trial).

DESIGN

Multicenter, randomized, double-masked, sham-controlled, noninferiority trial.

PARTICIPANTS

Patients with open-angle glaucoma or ocular hypertension having an unmedicated baseline mean diurnal IOP (average of 8 am, 10 am, and 4 pm time points) of ≥ 21 mmHg, and IOP of ≤ 36 mmHg at each of the 8 am, 10 am, and 4 pm timepoints at baseline.

METHODS

Study eyes were randomized to the travoprost intraocular implant (FE implant [n = 200] or SE implant [n = 197] model) or to timolol ophthalmic solution 0.5% twice daily (n = 193).

MAIN OUTCOME MEASURES

The primary outcome was mean change from baseline IOP in the study eye at 8 am and 10 am, at each of day 10, week 6, and month 3. Safety outcomes included adverse events (AEs) and ophthalmic assessments.

RESULTS

Mean IOP reduction from baseline over the 6 time points ranged from 6.6 to 8.4 mmHg for the FE implant group, from 6.6 to 8.5 mmHg for the SE implant group, and from 6.5 to 7.7 mmHg for the timolol group. The primary efficacy end point was met; the upper limit of the 95% confidence interval of the difference between the implant groups and the timolol group was < 1 mmHg at all 6 time points. Study eye AEs, most of mild or moderate severity, were reported in 21.5%, 27.2%, and 10.8% of patients in the FE implant, SE implant, and timolol groups, respectively. The most common AEs included iritis (FE implant, 0.5%; SE implant, 5.1%), ocular hyperemia (FE implant, 3.0%; SE implant, 2.6%), reduced visual acuity (FE implant, 1.0%; SE implant, 4.1%; timolol, 0.5%), and IOP increased (FE implant, 3.5%; SE implant, 2.6%; timolol, 2.1%). One serious study eye AE occurred (endophthalmitis).

CONCLUSIONS

The travoprost intraocular implant demonstrated robust IOP reduction over the 3-month primary efficacy evaluation period after a single administration. The IOP-lowering efficacy in both implant groups was statistically and clinically noninferior to that in the timolol group, with a favorable safety profile.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Short-Term Effect of Micropulse Transscleral Laser Therapy on Intraocular Pressure in Untreated Fellow Eyes of Glaucoma Patients: Preliminary Results

It has been observed that an intraocular pressure (IOP) altering intervention in one eye is followed by a consensual response in the untreated fellow eye. The underlying mechanisms remain unclear. Involvement of neuronal, cytokine, and hormonal regulation of aqueous humor dynamics, as well as improved treatment adherence or systemic absorption of topically administered medical compounds, have been suggested. Our aim was to investigate the short-term effects of unilateral micropulse transscleral laser therapy on IOP in the fellow eye. All medical records of glaucoma patients who underwent micropulse transscleral laser therapy in a tertiary referral center between May 2019 and February 2023 were collected and analyzed. We found a significant reduction in IOP in the treated eyes, indicating successful treatment. In the fellow eyes, despite not having changed any of the pharmacological IOP-reducing therapies, a significant reduction in IOP from 17.0 ± 5.1 mmHg to 13.5 ± 4.4 mmHg (p < 0.01) was observed. This reduction was, however, short-term and reached statistical significance on the first postoperative day only. Our findings support the concept of consensual inter-eye responses to unilateral IOP changes. Further research is warranted to elucidate the mechanisms underlying this phenomenon.

Cannabidiol Loaded Topical Ophthalmic Nanoemulsion Lowers Intraocular Pressure in Normotensive Dutch-Belted Rabbits

Cannabidiol (CBD) is the major non-psychoactive and most widely studied of the cannabinoid constituents and has great therapeutic potential in a variety of diseases. However, contradictory reports in the literature with respect to CBD's effect on intraocular pressure (IOP) have raised concerns and halted research exploring its use in ocular therapeutics. Therefore, the current investigation aimed to further evaluate CBD's impact on the IOP in the rabbit model. CBD nanoemulsions, containing Carbopol^® 940 NF as a mucoadhesive agent (CBD-NEC), were prepared using hot-homogenization followed by probe sonication. The stability of the formulations post-moist-heat sterilization, in terms of physical and chemical characteristics, was studied for three different storage conditions. The effect of the formulation on the intraocular pressure (IOP) profile in normotensive Dutch Belted male rabbits was then examined. The lead CBD-NEC formulation (1% w/v CBD) exhibited a globule size of 259 ± 2.0 nm, 0.27 ± 0.01 PDI, and 23.2 ± 0.4 cP viscosity, and was physically and chemically stable for one month (last time point tested) at 4 °C, 25 °C, and 40 °C. CBD-NEC significantly lowered the IOP in the treated eyes for up to 360 min, with a peak drop in IOP of 4.5 mmHg observed at the 150 min time point, post-topical application. The IOP of the contralateral eye (untreated) was also observed to be lowered significantly, but the effect lasted up to the 180 min time point only. Overall, topically administered CBD, formulated in a mucoadhesive nanoemulsion formulation, reduced the IOP in the animal model studied. The results support further exploration of CBD as a therapeutic option for various inflammation-based ocular diseases.

Intraocular Pressure Changes in the Contralateral Eye After Glaucoma Surgery

PRCIS

Glaucoma surgery in 1 eye can result in significant intraocular pressure (IOP) elevation in the fellow eye in a significant percentage of subjects. This effect is more pronounced following glaucoma drainage device implantation and in subjects developing postoperative hypotony in the first eye.

PURPOSE

The aim was to investigate the course and magnitude of IOP changes in contralateral eyes following glaucoma surgery.

PATIENTS AND METHODS

We studied 131 glaucoma patients undergoing surgery. IOP changes in fellow eyes and the number of glaucoma medications were recorded for 6 months. Both normal and glaucomatous fellow eyes were included. Patients on preoperative acetazolamide were analyzed separately. IOP change ≥4 mm Hg or 20% increase from baseline values was considered significant.

RESULTS

Baseline IOP in fellow eyes was 13.1±3.3 mm Hg which increased significantly at all-time points with a peak at 1 week (mean increase: 3.1±3.2 mm Hg) gradually decreasing up to 6 months (mean increase 0.9±2.1 mm Hg). The number of fellow eyes with clinically significant IOP elevation at 1 day, 1 week, and 1, 3. and 6 months was 47, 76, 47, 31, and 37 showing mean IOP rise of 4.5±2.3 (38.5%), 5.4±1.8 (48.5%), 4.8±1.6 (44.2%), 3.7±1.3 (36.5%), and 3.2±1.3 (32.6%) mm Hg, respectively. Medications were added to 18 fellow eyes (including 10 initially "normal" eyes) while 7 other fellow eyes required surgery.Significant IOP elevation in fellow eyes was associated with tube shunt surgery (P<0.008 at all-time points), a diagnosis of glaucoma following cataract surgery, IOP ≤5 mm Hg on the first postoperative day (P=0.002) and use of preoperative acetazolamide.

CONCLUSION

Glaucoma surgery was associated with IOP elevation in fellow eyes in a significant number of subjects and suggests that IOP in the unoperated eye should also be checked at postoperative visits.

Incidence of presumed steroid response in contralateral eye of patients who underwent glaucoma filtration surgery

PURPOSE

The aim of this study was to report the incidence of presumed steroid response in contralateral eye of patients who underwent glaucoma filtration surgery.

METHODS

We reviewed records of 298 glaucoma patients (147 PACG [primary angle-closure glaucoma], 129 POAG [primary open-angle glaucoma], and 22 JOAG [juvenile open-angle glaucoma]) who underwent either trabeculectomy alone or trabeculectomy with cataract extraction. All patients received prednisolone acetate 1% eye drop postoperatively in the operated eye for up to 6 to 8 weeks. The contralateral eye received the same antiglaucoma medications as before. Information collected included age, sex, number of antiglaucoma medications in the fellow eye preoperatively, and VFI (visual field index). The preoperative intraocular pressure (IOP) in the contralateral eye was taken as the baseline. The maximum IOP recorded postoperatively up to a follow-up period of 6 to 8 weeks was noted. A steroid response was defined as rise in the IOP by ≥6 mmHg.

RESULTS

In this study, 298 eyes of 298 glaucoma patients were included. The mean age of patients was 60.1 ± 13.7 years. The mean number of antiglaucoma medications in the fellow eye pre-operatively was 2.4 ± 1.2. Mean preoperative and postoperative IOP in the fellow eye were 17.46 ± 7 and 19.37 ± 7.1 mmHg, respectively. Sixty-three eyes out of 298 eyes (21.14%) showed a rise in IOP by 6 mmHg. The maximum IOP difference noted was 15 mmHg. The average time interval to the defined steroid response was 16.13 days. The majority showed a steroid response within 19 days.

CONCLUSION

Steroid response is a significant factor leading to elevated IOP postoperatively in the contralateral eye as well.

Magnesium Hydroxide Nanoparticles Improve the Ocular Hypotensive Effect of Twice Daily Topical Timolol Maleate in Healthy Dogs

Timolol maleate (TM), a beta-adrenergic receptor antagonist, is widely used for canine antiglaucoma eye drops; however, its bioavailability is <5%. Our previous study revealed that magnesium hydroxide nanoparticles (nMH) have potency in improving the bioavailability of fixed-combined TM in rodent models. This study aimed to investigate whether the fixed combination with nMH improves the ocular hypotensive effect of TM and affects pupil size (PS), heart rate (HR), and mean arterial pressure (MAP) in clinically healthy dogs. Five clinically healthy dogs were administered topical saline, commercial 0.5% TM, and a 0.01% or 0.1% nMH–0.5% TM fixed combination (0.01% or 0.1% nMH–TM) twice daily in one eye for 7 days with at least a 28-day interval. The changes from baseline were calculated and were statistically analyzed for each drug. IOP was significantly reduced in both 0.01% and 0.1% nMH–TM-treated-dogs compared with saline- and TM-treated dogs. Meanwhile, 0.01% and 0.1% nMH did not exacerbate the side effects of TM. From these results, nMH improved the ocular hypotensive effect of TM without enhancing side effects. Topical nMH–TM is potentially more effective for canine ocular hypotensive eye drops than TM.

The Effect of Medical Lowering of Intraocular Pressure on Peripapillary and Macular Blood Flow as Measured by Optical Coherence Tomography Angiography in Treatment-naive Eyes

PRCIS

Reduction of intraocular pressure (IOP) by latanoprost in treatment-naive eyes is significantly correlated to an increase in vessel density (VD) at the optic nerve head (ONH).

PURPOSE

To evaluate the effect of topical latanoprost on ocular microvasculature using optical coherence tomography angiography (OCTA).

PATIENTS AND METHODS

In this prospective case-control study, 26 eyes from 18 treatment-naive subjects in whom prostaglandin analogue (PGA) latanoprost 0.005% was initiated were included as cases. In 10 out of the 18 subjects, medication was initiated in only 1 eye; their contralateral untreated eyes were used as controls. OCTA (AngioVue, Optovue Inc., Fremont, CA) was performed at baseline and ≥3 weeks after commencing treatment. Main outcome measures were change in flow area and VD at the ONH, radial peripapillary capillaries (RPC), and macula. Comparison between the 2 visits was performed using a linear mixed model adjusted for intereye correlation and mean ocular perfusion pressure.

RESULTS

IOP decreased by 26.1%±11.3% (P<0.001) in the cases and 0.18%±12.2% (P=0.63) in controls. Significant correlations between change in IOP and change in ONH VD (correlation coefficient [r]=-0.42, P=0.04), and between change in IOP and change in RPC VD (r=-0.48, P=0.02) were observed in the cases, whereas none were observed in the controls. When multiple testing was considered, no significant changes in flow area and VD were observed in cases and controls.

CONCLUSIONS

The reduction of IOP by a PGA in treatment-naive eyes was significantly correlated to the increase in ONH VD and RPC VD. This may indicate a mechanism by which IOP reduction modulates the risk of glaucoma progression by improving ocular microperfusion.

Ab interno supraciliary microstent surgery for open-angle glaucoma

BACKGROUND

Glaucoma is the leading cause of global irreversible blindness, often associated with raised intraocular pressure (IOP). Where medical or laser treatment has failed or is not tolerated, surgery is often required. Minimally-invasive surgical approaches have been developed in recent years to reduce IOP with lower surgical risks. Supraciliary microstent surgery for the treatment of open-angle glaucoma (OAG) is one such approach.

OBJECTIVES

To evaluate the efficacy and safety of supraciliary microstent surgery for the treatment of OAG, and to compare with standard medical, laser or surgical treatments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2020, Issue 8); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 27 August 2020.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of supraciliary microstent surgery, alone or with cataract surgery, compared to other surgical treatments (cataract surgery alone, other minimally invasive glaucoma device techniques, trabeculectomy), laser treatment or medical treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts from the database search to identify studies that met the selection criteria. Data extraction, analysis, and evaluation of risk of bias from selected studies was performed independently and according to standard Cochrane methodology.

MAIN RESULTS

One study met the inclusion criteria of this review, evaluating the efficacy and safety of the Cypass supraciliary microstent surgery for the treatment of OAG, comparing phacoemulsification + supraciliary microstent surgery with phacoemulsification alone over 24 months. This study comprised 505 eyes of 505 participants with both OAG and cataract, 374 randomised to the phacoemulsification + microstent group.  In this study, the perceived risk of bias from random sequence generation, allocation concealment and selective reporting was low. However, we considered the study to be at high risk of performance bias as surgeons/investigators were unmasked. Attrition bias was unclear, with 448/505 participants contributing to per protocol analysis. Insertion of a Cypass supraciliary microstent combined with phacoemulsification probably increases the proportion of participants who are medication-free (not using eye-drops) at 24 months compared with phacoemulsification alone (85% versus 59%, risk ratio (RR) 1.27, 95% confidence interval (CI) 1.09 to 1.49, moderate-certainty evidence). There is high-certainty evidence that a greater improvement in mean IOP occurs in the phacoemulsification + microstent group - mean (SD) change in IOP from baseline of -5.4 (3.9) mmHg in the phacoemulsification group, compared to -7.4 (4.4) mmHg in the phacoemulsification + microstent group at 24 months (mean difference -2.0 mmHg, 95% CI -2.85 to -1.15). There is moderate-certainty evidence that insertion of a microstent is probably associated with a greater reduction in use of IOP-lowering drops (mean reduction of 0.7 medications in the phacoemulsification group, compared to a mean reduction of 1.2 medications in the phacoemulsification + microstent group). Insertion of a microstent during phacoemulsification may reduce the requirement for further glaucoma intervention to control IOP at a later stage compared to phacoemulsification alone (RR 0.26, 95% CI 0.07 to 1.04, low-certainty evidence). There is no evidence relating to the rate of visual field progression, or proportion of participants whose visual field loss progressed in this study. There is moderate-certainty evidence showing little or no difference in the proportion of participants experiencing postoperative complications over 24 months between participants in the microstent group compared to those who received phacoemulsification alone (RR 1.1, 95% CI 0.8 to 1.4). Five year post-approval data regarding the safety of the Cypass supraciliary microstent showed increased endothelial cell loss, associated with the position of the microstent in the anterior chamber. There were no reported health-related quality of life (HRQoL) outcomes in the included study.

AUTHORS' CONCLUSIONS

Data from this single RCT show superiority of supraciliary microstent surgery when combined with phacoemulsification compared to phacoemulsification alone in achieving medication-free control of OAG. However, there are long-term safety concerns with the device used in this trial, relating to the observed significant loss of corneal endothelial cells at five years following device implantation. At the time of this review, this device has been withdrawn from the market. This review has found that few high-quality studies exist comparing supraciliary microstent surgery to standard medical, laser or surgical glaucoma treatments. This should be addressed by further appropriately designed RCTs with sufficient long-term follow-up to ensure robust safety data are obtained. Consideration of health-related quality of life outcomes should also feature in trial design.

Inter-eye relationship of intraocular pressure change after unilateral trabeculectomy, filtering canaloplasty, or PreserFlo™ microshunt implantation

PURPOSE

This study assesses short-term intraocular pressure (IOP) change in the fellow eye of glaucoma patients after mitomycin C-augmented trabeculectomy, filtering canaloplasty, or PreserFlo™ microshunt implantation in the treated eye.

MATERIALS AND METHODS

Retrospective chart review of 235 glaucoma patients (235 eyes) was performed. Patients underwent initial trabeculectomy (187 patients), filtering canaloplasty (25 patients), or PreserFlo™ microshunt implantation (23 patients) in one eye, while the fellow eye was naïve to any previous glaucoma surgery. IOP was evaluated before and on the 1st and 2nd days and at 1 week after surgery. Main outcome measure was IOP change in the fellow eye. Secondary outcomes were proportion of clinically significant IOP elevation in the fellow eye and evaluation of potential risk factors associated with postoperative IOP fluctuation.

RESULTS

IOP in the fellow eye at 1 week after trabeculectomy was statistically significantly lower than preoperatively (p < 0.0001), while the IOP did not change significantly in the fellow eyes in filtering canaloplasty or PreserFlo groups. The higher the preoperative IOP was in the fellow eye, the larger was the intraocular pressure-lowering effect at 1 week after trabeculectomy (p < 0.0001). A clinically significant IOP elevation was noted in 14.2%, 9.5%, and 5% of fellow eyes after trabeculectomy, filtering canaloplasty, or PreserFlo™ microshunt implantation, respectively.

CONCLUSIONS

This study shows an IOP-lowering effect in the fellow eye of glaucoma patients after trabeculectomy. Significant IOP rise might occur in the fellow eye of some glaucoma patients after different types of glaucoma surgery.

Ab interno trabecular bypass surgery with Trabectome for open-angle glaucoma

BACKGROUND

Glaucoma is the leading cause of irreversible blindness. Minimally invasive surgical techniques, such as ab interno trabecular bypass surgery, have been introduced to prevent glaucoma from progressing.   OBJECTIVES: In light of the potential benefits for people with open-angle glaucoma and the widespread uptake of the technique, it is important to critically evaluate the evidence for whether treatment with ab interno trabecular bypass surgery with Trabectome is both efficacious and safe.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2020, Issue 7); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 17 July 2020.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of ab interno trabecular bypass surgery with Trabectome compared to other surgical treatments (other minimally invasive glaucoma device techniques, trabeculectomy), laser treatment, or medical treatment. We also included trials in which these devices were combined with phacoemulsification compared to phacoemulsification in combination with other glaucoma surgery or alone.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. Our primary outcome was proportion of participants who were medication-free (not using eye drops). Secondary outcomes included mean change in intraocular pressure (IOP), proportion of participants who required further glaucoma surgery, mean change in quality of life, proportion of participants who achieved an IOP of 21 mmHg or less, 17 mmHg or less, or 14 mmHg or less and rate of visual field progression. Adverse effects were the proportion of participants experiencing intra- and postoperative complications. All outcomes were measured in the short term (6 to 18 months), medium term (18 to 36 months), and long term (36 months or longer).

MAIN RESULTS

In this update, we included one RCT which had previously been identified as an ongoing study in our 2016 publication. This trial was a single-centre, single-surgeon RCT set in Canada with 19 participants. Participants were adults who had open-angle glaucoma, open angles, and had inadequately controlled IOP that required surgical intervention. The study was terminated before the intended sample size was reached 'due to slow recruitment and increasing lack of clinical equipoise over time'. This reduced the power of the study to detect clinically important effects. We assessed the trial as being at high risk of attrition, reporting, and other potential sources of biases. The risks of performance and detection bias are unclear. The intervention group of 10 people had Trabectome ab interno trabeculotomy combined with cataract extraction (phaco-AIT) and the comparator group of 9 people had trabeculectomy with mitomycin C combined with cataract extraction (phaco-Trab), one of whom was lost to follow-up. Seven of 10 participants in the phaco-AIT group and 4 of 8 in the phaco-Trab group were medication-free (not using drops) at 12 months (odds ratio (OR) 2.33, 95% confidence interval (CI) 0.34 to 16.2; very low-certainty evidence). At 12 months, the mean change in IOP was worse for phaco-AIT than for phaco-Trab, but this evidence was very uncertain (mean difference (MD) 3.70 mmHg, 95% CI -1.44 to 8.84; very low-certainty evidence) in the phaco-AIT group, as was the difference in the mean number of IOP-lowering drops taken per day (MD -0.41, 95% CI -1.22 to 0.40; very low-certainty evidence). Only one participant in the phaco-AIT group required further glaucoma surgery. The study protocol declared that quality of life and visual field progression were measured, but they were not reported All 8 participants with complete data in the phaco-Trab group and 8 of 10 in the phaco-AIT had at least one early or late postoperative complication (e.g. day 1 IOP spike, hypotony, choroidal effusion, bleb leak or encapsulation, uveitis, or peripheral anterior synechiae). The evidence was very low-certainty due to high risk of bias for several domains for this study and for large imprecision of all estimates. We also identified one ongoing study, identified from the International Clinical Trials Registry Platform (ICTRP): a multicentre, open, RCT comparing Trabectome to ab interno trabeculectomy using microhook. The study investigators plan to recruit 120 adults between 20 and 90 years of age. The primary outcome is duration of treatment success. Secondary outcomes include postoperative IOP, number of anti-glaucoma medications, and adverse events.

AUTHORS' CONCLUSIONS

There is currently no high-quality evidence for the outcomes of ab interno trabecular bypass surgery with Trabectome for open-angle glaucoma. Properly designed RCTs are needed to assess the long-term efficacy and safety of this technique.

Intraocular pressure change with face-down positioning after macular hole surgery

This study evaluated changes in intraocular pressure (IOP) with face-down positioning (FDP) following surgical treatment of idiopathic macular hole. We retrospectively reviewed the records of 130 patients diagnosed with idiopathic macular hole who underwent pars plana vitrectomy (PPV) with intravitreal gas injection after fluid-gas exchange. We analyzed IOP changes in both eyes following FDP over the course of 7 days. The mean IOP of the operated eyes was 14.98±2.95 mmHg preoperatively and 16.82±3.12 and 15.57±6.10 mmHg on postoperative days 2 and 7, respectively. In contralateral eyes, the mean IOP changed from 14.78±3.15 mmHg preoperatively to 16.27±1.87 and 14.40±4.14 mmHg on postoperative days 2 and 7, respectively. On postoperative day 2, the IOP increased in both eyes compared to the preoperative values, but the increase was significant only in operated eyes (p = 0.039). In contralateral eyes, the IOP on postoperative day 7 was significantly decreased compared with that on postoperative day 2 (p = 0.021) and in eyes with an axial length ≥ 23.0 mm, compared with the preoperative values (p = 0.042). The IOP of the operated eyes on postoperative day 7 was higher than that of the contralateral eyes (p = 0.039). Based on a short-term follow-up, FDP after PPV with intravitreal gas tamponade for the treatment of idiopathic macular hole may cause IOP elevation not only in the operated, but also in the contralateral eyes; the IOP increase in contralateral eyes was not as significant as that in operated eyes and was not maintained over 7 days after surgery; the IOP change seems to be affected by axial length and lens status.

Longitudinal assessment of optic nerve head changes using optical coherence tomography in a primate microbead model of ocular hypertension

In humans, the longitudinal characterisation of early optic nerve head (ONH) damage in ocular hypertension (OHT) is difficult as patients with glaucoma usually have structural ONH damage at the time of diagnosis. Previous studies assessed glaucomatous ONH cupping by measuring the anterior lamina cribrosa depth (LCD) and minimal rim width (MRW) using optical coherence tomography (OCT). In this study, we induced OHT by repeated intracameral microbead injections in 16 cynomolgus primates (10 unilateral; 6 bilateral) and assessed the structural changes of the ONH longitudinally to observe early changes. Elevated intraocular pressure (IOP) in OHT eyes was maintained for 7 months and serial OCT measurements were performed during this period. The mean IOP was significantly elevated in OHT eyes when compared to baseline and compared to the control eyes. Thinner MRW and deeper LCD values from baseline were observed in OHT eyes with the greatest changes seen between month 1 and month 2 of OHT. Both the mean and maximum IOP values were significant predictors of MRW and LCD changes, although the maximum IOP was a slightly better predictor. We believe that this model could be useful to study IOP-induced early ONH structural damage which is important for understanding glaucoma pathogenesis.

Glaucoma conversion of the contralateral eye in unilateral normal-tension glaucoma patients: a 5-year follow-up study

BACKGROUND/AIMS

To investigate clinical characteristics and risk factors for glaucoma conversion of the contralateral eye in unilateral normal-tension glaucoma (NTG) patients.

METHODS

A retrospective observational cohort study was conducted on a total of 76 subjects who had been diagnosed with unilateral NTG at the baseline and followed up for more than 5 years. Glaucoma conversion in the contralateral eye was defined as increased thinning of neuro-retinal rim, development of retinal nerve fibre layer defect and/or development of glaucomatous visual field defect.

RESULTS

During the mean follow-up period of 7.3±2.4 years, 21 of 76 (27.6%) subjects were confirmed to have developed glaucoma in the non-glaucomatous contralateral eye. The 5-year rate of glaucoma conversion in contralateral eyes was 19.7%. The maximum width of β-zone parapapillary atrophy (MWβPPA)-disc diameter (DD) ratio at the baseline and the presence rate of disc haemorrhage during follow-up period were significantly greater in the contralateral eyes of the conversion group than in those of the non-conversion group (p=0.011, <0.001, respectively). A multivariate Cox-proportional hazard model revealed intraocular pressure (IOP) over 17 mm Hg (HR 5.05, p=0.031), central corneal thickness (CCT) under 491 μm (HR 4.25, p=0.025) and MWβPPA-DD ratio over 0.32 (HR 6.25, p=0.003) in contralateral eye at the baseline as the independent risk factors for glaucoma conversion.

CONCLUSIONS

Among unilateral NTG patients, those with low CCT and high MWβPPA-DD ratio as well as high IOP in the contralateral eye are more likely to develop glaucoma in that eye during long-term follow-up.

Intereye Symmetry of 24-Hour Intraocular Pressure-related Patterns in Untreated Glaucoma Patients Using a Contact Lens Sensor

PURPOSE

Scarce data are available on the symmetry of 24-hour intraocular pressure (IOP) variations between fellow eyes of glaucoma patients, and such evidence could have profound consequences on the interpretation of monocular therapeutic trials. The objective is to evaluate the intereye correlation of continuously measured circadian IOP-related patterns in untreated glaucoma patients.

METHODS

In this single-center prospective study, a total of 29 untreated patients with open-angle glaucoma underwent bilateral ambulatory 24-hour monitoring of IOP-related patterns using a contact lens sensor (CLS; SENSIMED Triggerfish). IOP was measured before and after CLS monitoring using Goldmann applanation tonometry. Intereye agreement of 24-hour patterns was calculated using Spearman correlation (r) of raw data and after cosinor rhythmometry modeling.

RESULTS

Complete bilateral CLS data could be obtained in 20 patients (mean age: 55.5±15.7 y; 51.7% women). On average, intereye correlation was r=0.76±0.19 (range: 0.16 to 0.95) and r=0.77±0.15 (range: 0.49 to 0.91), after excluding 8 patients with lower quality recordings. Cosine rhythmometry modeling showed mean acrophases occurring at 4:21±2:20 AM in left eyes and 3:39±1:50 AM in right eyes (r=0.48; P=0.034). Mean acrophase amplitude was 110.9±51.9 for left eyes and 107.8±46.2 for right eyes (r=0.79; P<0.001). No serious adverse events related to CLS monitoring were recorded. Transient conjunctival hyperemia (13 patients) and blurred vision (11 patients) were the most frequent adverse events.

CONCLUSIONS

In this group of untreated glaucoma patients, there was good intereye agreement for circadian IOP-related patterns using the CLS. These results show a higher degree of intereye symmetry, in terms of IOP peak timings and amplitudes, than previously reported with standard tonometry.

Ab interno trabecular bypass surgery with Schlemm´s canal microstent (Hydrus) for open angle glaucoma

BACKGROUND

Glaucoma is a leading cause of irreversible blindness. A number of minimally-invasive surgical techniques have been introduced as a treatment to prevent glaucoma from progressing; ab interno trabecular bypass surgery with the Schlemm's canal Hydrus microstent is one of them.

OBJECTIVES

To evaluate the efficacy and safety of ab interno trabecular bypass surgery with the Hydrus microstent in treating people with open angle glaucoma (OAG).

SEARCH METHODS

On 7 May 2019, we searched CENTRAL (2019, Issue 5), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov; and the WHO ICTRP.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of the Hydrus microstent, alone or with cataract surgery, compared to other surgical treatments (cataract surgery alone, other minimally-invasive glaucoma device techniques, trabeculectomy), laser treatment, or medical treatment.

DATA COLLECTION AND ANALYSIS

A minimum of three authors independently extracted data from reports of included studies, using a data collection form and analysed data, based on standard Cochrane methods.

MAIN RESULTS

We included three published studies, with 808 people randomised. Two studies had multiple international recruitment centres in the USA and other countries. The third study had several sites based in Europe. All three studies were sponsored by the Hydrus manufacturer Ivantis Inc. All studies included participants with mainly mild or moderate OAG (mean deviation between -3.6 dB (decibel) and -8.4 dB in all study arms), which was controlled with medication in many participants (mean medicated intraocular pressure (IOP) 17.9 mmHg to 19.1 mmHg). There were no concerns regarding allocation concealment bias, but masking of outcome assessors was high or unclear risk in all studies; masking of participants was achieved, and losses to follow-up were not a concern. Two studies compared the Hydrus microstent combined with cataract surgery to cataract surgery alone, in participants with visually significant cataracts and OAG. We found moderate-certainty evidence that adding the Hydrus microstent to cataract surgery increased the proportion of participants who were medication-free from about half to more than three quarters at 12-month, short-term follow-up (risk ratio (RR) 1.59, 95% confidence interval (CI) 1.39 to 1.83; 2 studies, 639 participants; I² = 0%; and 24-month, medium-term follow-up (RR 1.63, 95% CI 1.40 to 1.88; 2 studies, 619 participants; I² = 0%). The Hydrus microstent combined with cataract surgery reduced the medium-term mean change in unmedicated IOP (after washout) by 2 mmHg more compared to cataract surgery alone (mean difference (MD) -2.00, 95% CI -2.69 to -1.31; 2 studies, 619 participants; I² = 0%; moderate-certainty evidence), and the mean change in IOP-lowering drops (MD -0.41, 95% CI -0.56 to -0.27; 2 studies, 619 participants; I² = 0%; low-certainty evidence). We also found low-certainty evidence that adding a Hydrus microstent to cataract surgery reduced the need for secondary glaucoma surgery from about 2.5% to less than 1% (RR 0.17, 95% CI 0.03 to 0.86; 2 studies, 653 participants; I² = 27%; low-certainty evidence). Intraocular bleeding, loss of 2 or more visual acuity (VA) lines, and IOP spikes of 10 mmHg or more were rare in both groups; estimates were imprecise, and included both beneficial and harmful effects. There were no cases of endophthalmitis in either group. No data were available on the proportion of participants achieving IOP less than 21 mmHg, 17 mmHg, or 14 mmHg; health-related quality of life (HRQOL), or visual field progression. One study provided short-term data for the Hydrus microstent compared with the iStent trabecular micro-bypass stent (iStent: implantation of two devices in a single procedure) in 152 participants with OAG (148 in analyses). Use of the Hydrus increased the proportion of medication-free participants from about a quarter to about half compared to those who received iStent, but this estimate was imprecise (RR 1.94, 95% CI 1.21 to 3.11; low-certainty evidence). Use of the Hydrus microstent reduced unmedicated IOP (after washout) by about 3 mmHg more than the iStent (MD -3.10, 95% CI -4.17 to -2.03; moderate-certainty evidence), and the use of IOP-lowering medication (MD -0.60, 95% CI -0.99 to -0.21; low-certainty evidence). Both devices achieved a final IOP < 21 mmHg in most participants (Hydrus microstent: 91.8%; iStent: 84%; RR 1.09, 95% CI 0.97 to 1.23; low-certainty evidence). None of the participants who received the Hydrus microstent (N = 74) required additional glaucoma surgery; two participants who received the iStent (N = 76) did. Few adverse events were found in either group. No data were available on the proportion of participants achieving IOP less than 17 mmHg or 14 mmHg, or on HRQOL.

AUTHORS' CONCLUSIONS

In people with cataracts and generally mild to moderate OAG, there is moderate-certainty evidence that the Hydrus microstent with cataract surgery compared to cataract surgery alone, likely increases the proportion of participants who do not require IOP lowering medication, and may further reduce IOP at short- and medium-term follow-up. There is moderate-certainty evidence that the Hydrus microstent is probably more effective than the iStent in lowering IOP of people with OAG in the short-term. Few studies were available on the effects of the Hydrus microstent, therefore the results of this review may not be applicable to all people with OAG, particularly in selected people with medically uncontrolled glaucoma, since IOP was controlled with medication in many participants in the included studies. Complications may be rare using the Hydrus microstent, as well as the comparator iStent, but larger studies are needed to investigate its safety.

The penetration and distribution of topical atropine in animal ocular tissues

PURPOSE

To conduct a multi-tissue investigation on the penetration and distribution of topical atropine in myopia treatment, and determine if atropine is detectable in the untreated contralateral eye after uniocular instillation.

METHODS

Nine mature New Zealand white rabbits were evenly divided into three groups. Each group was killed at 5, 24 and 72 hr, respectively, following uniocular instillation of 0.05 ml of 1% atropine. Tissues were sampled after enucleation: conjunctiva, sclera, cornea, iris, ciliary body, lens, retina, aqueous, and vitreous humors. The assay for atropine was performed using liquid chromatography-mass spectrometry (LC-MS), and molecular tissue distribution was illustrated using matrix-assisted laser desorption ionization-imaging mass spectrometry (MALDI-IMS) via an independent experiment on murine eyes.

RESULTS

At 5 hr, the highest (mean ± SEM) concentration of atropine was detected in the conjunctiva (19.05 ± 5.57 ng/mg, p < 0.05) with a concentration gradient established anteriorly to posteriorly, as supported by MALDI-IMS. At 24 hr, preferential binding of atropine to posterior ocular tissues occurred, demonstrating a reversal of the initial concentration gradient. Atropine has good ocular bioavailability with concentrations of two magnitudes higher than its binding affinity in most tissues at 3 days. Crossing-over of atropine to the untreated eye occurred within 5 hr post-administration.

CONCLUSION

Both transcorneal and transconjunctival-scleral routes are key in atropine absorption. Posterior ocular tissues could be important sites of action by atropine in myopic reduction. In uniocular atropine trials, cross-over effects on the placebo eye should be adjusted to enhance results reliability. Combining the use of LC-MS and MALDI-IMS can be a viable approach in the study of the ocular pharmacokinetics of atropine.

Endoscopic cyclophotocoagulation (ECP) for open angle glaucoma and primary angle closure

BACKGROUND

Glaucoma is a leading cause of irreversible blindness. A number of minimally invasive surgical techniques have been introduced as a treatment to prevent glaucoma progressing. Among them, endoscopic cyclophotocoagulation (ECP) is a cyclodestructive procedure developed by Martin Uram in 1992.

OBJECTIVES

To evaluate the efficacy and safety of ECP in people with open angle glaucoma (OAG) and primary angle closure whose condition is inadequately controlled with drops.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 12 July 2018.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of ECP compared to other surgical treatments (other minimally invasive glaucoma device techniques, trabeculectomy), laser treatment or medical treatment. We also planned to include trials where these devices were combined with phacoemulsification compared to phacoemulsification alone.

DATA COLLECTION AND ANALYSIS

Two review authors planned to independently extract data from reports of included studies using a data collection form and analyse data based on methods expected by Cochrane. Our primary outcome was proportion of participants who were drop-free (not using eye drops). Secondary outcomes included mean change in IOP; proportion of participants who achieved an IOP of 21 mmHg or less, 17 mmHg or less or 14 mmHg or less; and proportion of participants experiencing intra- and postoperative complications, We planned to measure all outcomes in the short-term (six to 18 months), medium-term (18 to 36 months), and long-term (36 months onwards).

MAIN RESULTS

We found one ongoing study that met our inclusion criteria (ChiCTR-TRC-14004233). The study compares combined phacoemulsification with ECP to phacoemulsification alone in people with primary angle closure glaucoma. The primary outcome is intraocular pressure (IOP) and number of IOP-lowering drugs. A total of 50 people have been enrolled. The study started in February 2014 and the trialists have completed recruitment and are in the process of collecting data.

AUTHORS' CONCLUSIONS

There is currently no high-quality evidence for the effects of ECP for OAG and primary angle closure. Properly designed RCTs are needed to assess the medium and long-term efficacy and safety of this technique.

Efficacy and safety of preservative-free timolol 0.1% gel in open-angle glaucoma and ocular hypertension in treatment-naïve patients and patients intolerant to other hypotensive medications

GOALS

To assess the efficacy and safety of preservative-free timolol 0.1% gel in patients with primary open-angle glaucoma (POAG) and ocular hypertension (OHT).

METHODS

In this multicenter, open-label, non-controlled clinical trial in Algeria, treatment-naïve patients with intraocular pressure (IOP)>20mmHg and<31mmHg (treatment-naïve patients, group 1) and patients with IOP controlled by current ocular monotherapy but presenting with local intolerance in at least one eye (intolerant patients; group 2) were eligible. Timolol gel was administered once daily in the morning for 84 days. The primary efficacy criteria were reduction in IOP (group 1) and maintenance of baseline IOP (group 2).

RESULTS

Overall, 93 patients were included (53 in group 1, 40 in group 2). All patients in group 2 had been previously treated with preserved eye drops. In group 1, patients showed a significant reduction in IOP with mean changes in the worse eye of -10.3±3.0mmHg at D28 and -10.8±2.5mmHg at D84 (P<0.0001). In group 2, the maintenance of efficacy on IOP at D84 was satisfactory in 91.7% of patients (worse eye). Preservative-free timolol gel was well tolerated in both groups. In group 2, the overall symptom score was significantly reduced from 8.6±5.1 to 0.9±1.6 at D28 and 0.7±1.2 at D84 (P<0.0001), and the overall ocular sign score from 3.7±2.1 to 0.8±1.0 at D28 and 0.6±0.8 at D84 (P<0.0001).

CONCLUSIONS

This preservative-free timolol 0.1% gel was effective in decreasing IOP in treatment-naïve patients and in controlling IOP and reducing ocular signs and symptoms in patients intolerant to their previous preserved medications.

Absence of a secondary glucocorticoid response in C57BL/6J mice treated with topical dexamethasone

Glucocorticoids such as dexamethasone can cause an increase in intraocular pressure (IOP) in some of the population, but not all. In this paper we used a mouse model of glucocorticoid induced ocular hypertension to examine the changes in the anterior segment of the eye in mice that failed to respond to glucocorticoid treatment with a sustained increase in IOP. C57BL/6J mice were treated with either 0.1% dexamethasone sodium phosphate ophthalmic solution or sterile PBS 3 times daily for up to 5 weeks. IOP was measured weekly at approximately the same time of the day. After 3–5 weeks of treatment, eyes were enucleated and evaluated for changes associated with steroid induced glaucoma. These studies showed that IOP was significantly elevated in dexamethasone (DEX) treated mice compared to PBS treated mice after 3 weeks of treatment, but IOP in DEX treated mice returned to baseline levels after 5 weeks of treatment. All the mice demonstrated a response to the glucocorticoid treatments and showed an elevation in FKBP5 expression after both 3 and 5 weeks of DEX treatment (primary glucocorticoid response protein) and a weight loss. Western blot analysis of anterior segments from treated mice, however, did not show an increase in secondary glucocorticoid response proteins such as β3 integrin or myocilin. Fibronectin levels were also not statistically different. The data suggest that in mice, which do not exhibit a prolonged increase in IOP in response to the DEX treatment, there is a compensatory mechanism that can prevent or turn off the secondary glucocorticoid response.

Randomized Prospective Study of the Use of Anti-Inflammatory Drops After Selective Laser Trabeculoplasty

PURPOSE

Evaluating the use of Indomethacin, Dexamethasone, and no anti-inflammatory treatment immediately after selective laser trabeculoplasty (SLT).

MATERIALS AND METHODS

Prospective randomized clinical trial of 132 eyes. Both eyes of the patient underwent SLT. One of the eyes was treated with Indomethacin 0.1% or Dexamethasone 0.1% 3 times daily for 1 week; the other eye did not receive any anti-inflammatory treatment. Intraocular pressure (IOP) and inflammatory parameters were recorded at 1 hour, 1 week, 1, 3, and 6 months.

RESULTS

Cells in the anterior chamber were present in 57% to 71% of the patients after 1 hour. About 16% to 37% of the patients reported pain/discomfort after 1 hour. Redness was present before SLT in 29% to 34% of the patients, probably due to antiglaucoma medication. After 1 hour, the amount of redness recorded raised to 32% to 42%, but the amount of patients with redness returned to pretreatment levels after 1 week. An IOP peak of >5 mm Hg above baseline IOP 1 hour after laser was present in 3% to 9% of the patients. IOP lowered 11% to 21% compared with IOP at baseline. The number of medications needed changed from 1.45 to 1.49 before, to 0.23 to 0.45 six months after SLT.No differential effects based on the kind of anti-inflammatory treatment or no treatment were found for any of the parameters.

CONCLUSIONS

SLT induces little inflammation: anti-inflammatory drops do not make a significant difference in pain, redness, cells in anterior chamber, or peak IOP following SLT.The IOP-lowering effect of the SLT is not influenced by the use of Indomethacin or Dexamethasone.

Selective Laser Trabeculoplasty vs. Fixed Combinations with Timolol in Practice: A Replacement Study in Primary Open Angle Glaucoma

OBJECTIVES

To evaluate the potential of selective laser trabeculoplasty (SLT) in two arms (360˚ vs. 180˚) as a replacement for fixed combinations (FCs) with timolol in primary open angle glaucoma over 6 months.

MATERIALS AND METHODS

Of 40 patients in a prospective, comparative, interventional case series, 18 eyes and 22 eyes were randomized to SLT 180º and SLT 360º groups, respectively, along with 40 fellow-control eyes. FC with timolol was discontinued on the day of treatment for the eye to be operated on, while ongoing therapy was not interrupted for the contralateral eye. Eyes were examined for intraocular pressure (IOP) elevation 1 hour and 1 day after SLT. The follow-up visits were then scheduled for 1 week, 1 month, 3 months, and 6 months after, during the which the IOP of both eyes and any possible complications were evaluated.

RESULTS

There were no statistically significant differences in mean IOPs through 6 months among the groups with exception of postlaser 1 hour and postlaser 1 day (p<0.001 and p=0.010, respectively). Multiple comparison analysis showed significantly higher IOP in both SLT 180º and SLT 360º subgroups compared to their controls at postlaser 1 hour (p=0.007, p<0.001) but significantly lower IOP only in SLT 360º subgroup compared to the controls at postlaser day 1 (p=0.013).

CONCLUSION

SLT offers promising potential as a substitute equivalent to efficacy of FCs with timolol. However, SLT 360˚ may not achieve additional IOP reduction.

Ab interno trabecular bypass surgery with Trabectome for open angle glaucoma

BACKGROUND

Glaucoma is the leading cause of irreversible blindness. Minimally invasive surgical techniques, such as ab interno trabecular bypass surgery, have been introduced to prevent glaucoma progressing.

OBJECTIVES

The main objective was to assess the results at two years of ab interno trabecular bypass surgery with Trabectome for open angle glaucoma in comparison to conventional medical, laser, or surgical treatment in terms of efficacy and safety. A secondary objective was to examine the effects of Trabectome surgery in people who have concomitant phacoemulsification in comparison to those who do not have concomitant phacoemulsification.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to May 2016), EMBASE (January 1980 to May 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 12 May 2016.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) of ab interno trabecular bypass surgery with Trabectome.

DATA COLLECTION AND ANALYSIS

We planned to have two review authors independently extract data from reports of included studies using a data collection form.

MAIN RESULTS

One randomised controlled trial identified from ClinicalTrials.gov, NCT00901108, met the criteria for inclusion. This study has subsequently been terminated. The ClinicalTrials.gov record indicates that the investigators plan to complete 12 months of follow-up and analysis on 19 participants already recruited into the trial.

AUTHORS' CONCLUSIONS

There is currently no high-quality evidence for the outcomes of ab interno trabecular bypass surgery with Trabectome for open angle glaucoma. Properly designed RCTs are needed to assess the long-term efficacy and safety of this technique.

Change in Intraocular Pressure in the Fellow Eye After Glaucoma Surgery in 1 Eye

PURPOSE

To measure the change in intraocular pressure (IOP) of the fellow eye after glaucoma surgery in 1 eye.

PATIENTS AND METHODS

In this prospective interventional study, 71 patients with primary and secondary glaucoma, undergoing glaucoma surgery in 1 eye were included. The IOP in the fellow eye following glaucoma surgery in 1 eye from the first postoperative week till 6 months following surgery was studied. Both normal and glaucomatous fellow eyes were included. IOP change from preoperative IOP levels in the fellow eye was analyzed. Patients treated with acetazolamide preoperatively were analyzed separately.

RESULTS

The mean baseline IOP of the operated and fellow eyes was 28.14±9.4 and 16.5±6.1 mm Hg, respectively. IOP of fellow eyes significantly increased compared with baseline at all timepoints (P<0.001), with a maximum rise 6 weeks postoperatively (4.8±3.3 mm Hg). There was no significant difference in the consensual rise between glaucomatous and nonglaucomatous fellow eyes, or between patients treated with or without acetazolamide before surgery. Regression analysis showed no baseline factor associated with the rise in IOP. By the sixth postoperative month, 24 patients required surgery or needed an increase in medications in the fellow eye for IOP control.

CONCLUSIONS

Glaucoma surgery in eye is associated with a rise in IOP of the fellow eye, regardless of whether the fellow eye is normal or glaucomatous, or had been previously treated with acetazolamide. Fellow eyes of all patients scheduled for glaucoma surgery require careful monitoring of the IOP.

Consensual ophthalmotonic reaction in Chinese patients following augmented trabeculectomy or ExPRESS shunt implantation

INTRODUCTION

Consensual ophthalmotonic reaction (COR) was first described in 1924. Studies following monocular application of glaucoma drops and laser trabeculoplasty showed a drop in fellow eye intraocular pressure (IOP). However, studies following monocular surgery showed heterogeneous results. The purpose of this study was to investigate the COR in Chinese patients who have received monocular filtration surgery.

METHODS

A noncomparative retrospective study of 65 eyes undergoing filtration surgery in Queen Mary Hospital was conducted. The IOP was obtained at baseline and postoperative days 1, 3, 7 and 14. Patient's age, sex, type of glaucoma and surgery, preoperative medications, postoperative bleb status, and number of interventions were tabulated. The postoperative IOP measurements over both eyes were obtained, and the readings were averaged to decrease the chances of extreme readings being a one-off event and allow for regression to the mean bias.

RESULTS

COR was observed in the unoperated fellow eye. The mean preoperative IOP and averaged postoperative IOP were 17.2 ± 5.2 mm Hg and 20.1 ± 8.9 mm Hg, respectively (P < 0.04). All medications were continued in the fellow eye or even stepped up. Twenty-three percent of patients demonstrated fellow eye IOP rise >30% from baseline, while none showed IOP drop >30% from baseline.

DISCUSSION

Following monocular penetrating filtration surgery, our Chinese population demonstrated a significant fellow eye IOP increase in the early postoperative period. We should bear in mind the influence of COR and take care to measure the fellow eye IOP following monocular surgery.

Fluctuations of the Intraocular Pressure in One Eye Influence the Intraocular Pressure in the Fellow Eye

PURPOSE

To investigate the ophthalmotonic consensual reaction (OCR) in healthy individuals.

METHODS

This was a cohort study of 59 pairs of eyes of patients who underwent cataract surgery in one eye and had no other ocular pathology than cataract. Main outcome measure was change of intraocular pressure (IOP) in the untreated fellow eye. The IOP was measured 1 hour before, 1 hour after, and 1 day after surgery.

RESULTS

One hour after surgery, IOP decreased in 24 (41%) operated eyes (group A). In the corresponding untreated fellow eyes (group Af), the mean IOP (±standard deviation [SD]) did not change (14.1 ± 3.0 mmHg preoperatively to 14.2 ± 3.1 mmHg postoperatively, p = 0.8). Only two operated eyes showed unchanged IOP (group B). In 33 (56%) operated eyes, the IOP increased (group C). In the untreated fellow eyes (group Cf), the mean IOP decreased significantly from 15.1 ± 2.9 to 13.7 ± 2.6 mmHg (p = 0.0012). One day after surgery, the mean IOP of group Af decreased significantly from 14.2 ± 3.1 (postoperative IOP) to 12.7 ± 3.2 mmHg (p = 0.007). In group Cf, the mean IOP revealed no changes from 13.7 ± 2.6 to 13.5 ± 2.4 mmHg (p = 0.69).

CONCLUSIONS

Our results showed some evidence for the existence of the OCR in healthy individuals. Significant IOP elevation in one eye resulted in IOP reduction in the fellow eye. Interestingly, this phenomenon did not exist vice versa.

Contralateral intraocular pressure lowering effect of prostaglandin analogues

Background:

Though the use of prostaglandin analogues (PGA) for reduction of intraocular pressure (IOP) has shown a marked increase, studies evaluating the contralateral effects of PGA are limited.

Aims:

To evaluate if PGA treatment in one eye has an effect on the IOP of the untreated fellow eye.

Design:

Retrospective study.

Materials and Methods:

Thirty patients of open-angle glaucoma with no previous antiglaucoma treatment underwent 24-hour diurnal IOP phasing. They subsequently were started on a uniocular trial with PGA, and had office diurnal IOP measurements 6 weeks later. Twenty-four hour diurnal consisted of 8 IOP readings over 24 hours and office diurnal consisted of 4 IOP readings between 8 AM and 6 PM at 3 hourly intervals.

Statistical Analysis:

IOPs of the fellow eye during the office diurnal were compared with IOPs at similar time points during the 24-hour diurnal using paired t-tests.

Results:

Mean (± standard deviation) IOP in the treated eye reduced (P < 0.001) from 17.17 ± 3.2 mm Hg at baseline to 13.7 ± 2.4 mm Hg at 6 weeks, while that in the untreated eye reduced from 16.4 ± 3.1 mm Hg to 14.8 ± 2.7 mm Hg (P = 0.01). The decrease in IOP in the untreated fellow eye was statistically significant at 8 AM (2.7 mm Hg, P = 0.003) and 11 AM (2.3 mm Hg, P = 0.01) but not so at 2 PM (1.2 mm Hg, P = 0.10) and 5 PM (0.9 mm Hg, P = 0.19). The amount of IOP reduction in the untreated eye was significantly associated with the magnitude of IOP reduction in the treated eye (β = 0.69, P = 0.008).

Conclusion:

Uniocular PGA treatment tends to reduce the IOP of the untreated fellow eye.

The impact of timolol maleate on the ocular tolerability of fixed-combination glaucoma therapies

Glaucomatous optic atrophy is the second most common cause of blindness worldwide, and lowering intraocular pressure (IOP) is the only proven method to slow or stop the progression of the disease. Approximately 40% of patients with elevated IOP will require more than one medication to obtain a modest 20% reduction in IOP, and as a result, some patients may require two medications, provided in either two separate bottles or in one bottle with the use of fixed-combination therapies. Each therapy has its own unique safety and efficacy profile. Topical beta-blockers have a particularly favorable ocular-tolerability profile, and several studies of fixed-combination medications containing the beta-blocker timolol maleate have shown a lower prevalence of some ocular adverse events for the fixed-combination therapy compared to the non-beta-blocker individual component. In this review, we examined clinical data pertaining to the ocular surface tolerability of fixed-combination medications containing timolol maleate in comparison to the individual components. In particular, preference was given to prospective, randomized, multicenter trials of 3 months in duration or longer that compared a fixed-combination therapy to monotherapy with the individual components. A review of the literature revealed that some fixed-combination therapies can provide a reduced risk of common side effects compared to their individual components, with conjunctival hyperemia and ocular allergy being less frequent in some timolol-containing fixed-combination therapies. This effect appears to be most significant for latanoprost 0.005%, bimatoprost 0.03%, and brimonidine 0.2%.

Diurnal intraocular pressure with bimatoprost/timolol fixed combination versus latanoprost/timolol fixed combination in healthy subjects

PURPOSE

To evaluate the effects of a bimatoprost/timolol fixed combination (BTFC) and a latanoprost/timolol fixed combination (LTFC) on diurnal intraocular pressure (IOP) and anterior ocular parameters in healthy subjects.

METHODS

We enrolled 58 healthy subjects in this prospective clinical study. Thirty subjects were treated with BTFC and 28 subjects were treated with LTFC. IOP was measured every 2 hours except from 01:00 and 05:00. Axial length, corneal curvature, and anterior chamber depth were obtained using the IOL master at baseline and 24 hours later. Adverse events were assessed by patient interview and by slit lamp examination.

RESULTS

The largest difference in IOP between treated and untreated eyes 8 hours after instillation was 1.67 mmHg in the BTFC group (p < 0.001). The largest difference in IOP between treated and untreated eyes 10 hours after instillation was 1.93 mmHg in the LTFC group (p < 0.001). For anterior ocular parameters such as axial length, corneal curvature, anterior chamber depth at baseline and 24 hours after instillation, there were no significant differences between the baseline and 24-hour values in either the BTFC or LTFC group. The most frequently occurring adverse event was conjunctival hyperemia, which was found in 33.3% (n = 10) of the BTFC group and 25.0% (n = 7) of the LTFC group (p = 0.486).

CONCLUSIONS

BTFC and LTFC provided a significant reduction in IOP from baseline without changing any anterior ocular parameters. Our results provide a reference for monocular trials to assess the effect of eye drops in a clinical condition.

Personalized Medicine in Ophthalmology: From Pharmacogenetic Biomarkers to Therapeutic and Dosage Optimization

Rapid progress in genomics and nanotechnology continue to advance our approach to patient care, from diagnosis and prognosis, to targeting and personalization of therapeutics. However, the clinical application of molecular diagnostics in ophthalmology has been limited even though there have been demonstrations of disease risk and pharmacogenetic associations. There is a high clinical need for therapeutic personalization and dosage optimization in ophthalmology and may be the focus of individualized medicine in this specialty. In several retinal conditions, such as age-related macular degeneration, diabetic macular edema, retinal vein occlusion and pre-threshold retinopathy of prematurity, anti-vascular endothelial growth factor therapeutics have resulted in enhanced outcomes. In glaucoma, recent advances in cytoskeletal agents and prostaglandin molecules that affect outflow and remodel the trabecular meshwork have demonstrated improved intraocular pressure control. Application of recent developments in nanoemulsion and polymeric micelle for targeted delivery and drug release are models of dosage optimization, increasing efficacy and improving outcomes in these major eye diseases.

The efficacy of a monocular drug trial in normal-tension glaucoma

Purpose

To evaluate the efficacy of a monocular drug trial in eyes with normal-tension glaucoma (NTG).

Methods

This prospective study enrolled 74 patients with NTG. The monocular drug trial was started using latanoprost 0.005% for one week. If the intraocular pressure (IOP) reduction was greater than 15%, the same medication was administered to both eyes for one month. The unadjusted change and adjusted change (the change in the treated eye minus the change in the contralateral eye) in IOP were evaluated, and the predictors of IOP response were analyzed by multivariate linear regression.

Results

Among the initial 74 patients, 31 (41.9%) were included; others were excluded because they did not meet the requisite conditions. The most significant predictors of IOP response in the initial eye and subsequent eye were the baseline IOPs in both eyes (β = 0.907, 0.771, respectively). The adjusted change in IOP of the initial eye had greater association (β = 0.589) with the IOP after monocular trial in the initial eye than that of unadjusted IOP change (β = 0.279). The adjusted change in IOP also had greater predictability (β = 0.348) for IOP after monocular trial in the subsequent eye than that of the unadjusted IOP change (β = 0.090).

Conclusions

Although the monocular trial in NTG patients had limited efficacy due to its stringent conditions, it was useful for evaluating the IOP response in the initial eye and for predicting the IOP response in the subsequent eye.

1α,25-Dihydroxyvitamin D(3) and its analog, 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D(3) (2MD), suppress intraocular pressure in non-human primates

Ocular hypertension is the greatest known risk factor for glaucoma that affects an estimated 70 million people worldwide. Lowering intraocular pressure (IOP) remains the mainstay of therapy in the management of glaucoma. By means of microarray analysis, we have discovered that 1α,25-dihydroxyvitamin D(3) (1α,25-(OH)(2)D(3)) regulates genes that are known to be involved in the determination of intraocular pressure (IOP). Topical administration of 1α,25-(OH)(2)D(3) or its analog, 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D(3) (2MD), markedly reduces IOP in non-human primates. The reduction in IOP is not the result of reduced aqueous humor formation, while a 35% increase in aqueous humor drainage by 1α,25-(OH)(2)D(3) was found but this increase did not achieve significance. Nevertheless, our results suggest that 1α,25-(OH)(2)D(3), or an analog thereof, may present a new approach to the treatment of glaucoma.

Rational use of the fixed combination of dorzolamide - timolol in the management of raised intraocular pressure and glaucoma

Glaucoma is a multifactorial optic neuropathy in which the main therapeutic target is lowering of intraocular pressure (IOP) in order to retard the progression of existing structural and functional damage. The three mainstays of treatment are pharmacologic, laser, and surgical. The primary standard therapy in patients with open-angle glaucoma or ocular hypertension is topical medication. When monotherapy does not adequately lower the intraocular pressure, one or more agents are added or substituted. Combination pharmacotherapy such as Cosopt^® is available to improve efficacy and simplify medication regimen. A fixed combination of two ocular hypotensive drugs (the carbonic anhydrase inhibitor dorzolamide and the beta-adrenoceptor antagonist timolol), Cosopt^® is indicated for the treatment of elevated IOP in patients with open-angle glaucoma or ocular hypertension insufficiently responsive to topical beta-adrenoceptor antagonist monotherapy. Compared with concomitant therapy with the individual components, the primary advantage of fixed combination dorzolamide – timolol is convenience, which may also improve compliance. Clinical trials have demonstrated that the fixed combination dorzolamide – timolol is safe, effective and generally well tolerated in lowering IOP in patients with open angle glaucoma or ocular hypertension, including individuals uncontrolled on beta-adrenoceptor antagonist or other monotherapy.

Asymmetry of 24-hour intraocular pressure reduction by topical ocular hypotensive medications in fellow eyes

PURPOSE

A core assumption for the 1-eye therapeutic trial of ocular hypotensive medications is the symmetrical reduction of intraocular pressure (IOP) in paired eyes. This assumption was evaluated for 24-hour IOP reduction in patients who underwent monotherapy or adjunctive therapy.

DESIGN

Database study.

PARTICIPANTS

Patients 41 to 79 years of age with primary open-angle glaucoma or ocular hypertension.

METHODS

Twenty-four-hour IOP data from the paired eyes of patients undergoing bilateral monotherapy (n = 66) of latanoprost, travoprost, timolol, or brimonidine or bilateral adjunctive therapy (n = 52) with brinzolamide or timolol added to latanoprost monotherapy were analyzed retrospectively. Measurements of IOP were obtained every 2 hours in a sleep laboratory before and after at least 4-week drug treatments. Strengths of association for single-pair IOP reductions and average IOP reductions in the paired eyes during the office-hour, diurnal, nocturnal, and 24-hour periods and in different body positions were analyzed.

MAIN OUTCOME MEASURES

Variance for the difference, percentage distribution of large absolute difference, and coefficient of determination (r(2)) in the paired IOP reductions.

RESULTS

The standard deviations for the differences in single-pair IOP reductions from the means were larger than 2.5 mmHg for all periods and body positions under monotherapy and adjunctive therapy. Absolute differences in single-pair IOP reductions of the cutoff thresholds of 3 and 2 mmHg or more occurred in more than 20% and 36% cases, respectively. Corresponding coefficients of determination were 0.240 to 0.374 with monotherapy and 0.215 to 0.381 with adjunctive therapy. When the average differences in the paired IOP reductions were analyzed for a specific period and posture, the standard deviations for the differences in the paired IOP reductions and the percentage distributions of large absolute differences were reduced, and most coefficients of determination were improved.

CONCLUSIONS

There is only a weak association between the right- and left-eye responses to IOP-lowering monotherapy or adjunctive therapy during a 24-hour period when single-pair IOP data are considered. Considering the averages of multiple paired IOP responses can improve the strength of the association.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Effects of brimonidine 0.2%-timolol 0.5% fixed-combination therapy for glaucoma

PURPOSE

To evaluate the effects of brimonidine 0.2%-timolol 0.5% fixed-combination therapy in the treatment of patients with glaucoma.

METHODS

To measure the main treatment effects of a fixed combination of brimonidine 0.2%-timolol 0.5%, we conducted three small studies: (1) a comparison of diurnal intraocular pressure (IOP) at baseline and at 6 months after brimonidine/timolol fixed-combination therapy (n = 81); (2) an assessment of the effects of one drop of the brimonidine/timolol fixed combination on diurnal IOP (n = 25); and (3) the effects of brimonidine/timolol fixed-combination therapy on the anterior ocular segment over time (n = 64).

RESULTS

(1) After 6 months of treatment with the brimonidine/timolol fixed combination, the mean diurnal IOP in primary open-angle glaucoma (POAG) decreased from 21.4 ± 2.0 to 14.5 ± 3.1 mmHg (32.2%, P < 0.001), and the mean diurnal IOP in normal-tension glaucoma (NTG) decreased from 13.5 ± 2.8 to 10.9 ± 2.0 mmHg (19.3%, P < 0.001). (2) After instillation with one drop of the brimonidine/timolol fixed combination, the IOP in the instilled eye was lowest at 9:00 p.m. and had decreased by 1.7 mmHg compared with the baseline IOP in the instilled eye. The difference in IOP between the instilled eye and untreated fellow eye was largest at 3:00 p.m., measuring 1.7 mmHg (P = 0.011). (3) Brimonidine/timolol fixed-combination therapy caused significant miosis over time (P = 0.003).

CONCLUSIONS

The results of this study suggest that brimonidine/timolol fixed-combination therapy has beneficial IOP-lowering effects and significant effects on pupil size.

The utility of the monocular trial: data from the ocular hypertension treatment study

OBJECTIVE

To determine whether adjusting the intraocular pressure (IOP) change of the trial eye for the IOP change of the fellow eye (i.e., monocular trial) is a better assessment of medication response than testing each eye independently.

DESIGN

Analysis of data from a prospective, randomized, clinical trial.

PARTICIPANTS

Two hundred six participants with ocular hypertension randomized to the observation group and later started on a topical prostaglandin analog (PGA).

METHODS

Participants were started on a topical PGA in 1 eye and returned in approximately 1 month to determine medication response. The IOP response of the trial eye was determined by the IOP change between baseline and 1 month in the trial eye alone (unadjusted method) and by adjusting for the IOP change in the fellow eye between the same visits (adjusted method). Our "gold standard" for medication response was the IOP change in the trial eye between up to 3 pre- and 3 posttreatment visits on the same medication. Pearson correlation was used to compare the gold standard with the unadjusted and adjusted methods. In addition, symmetry of IOP response between trial and fellow eyes to the same medication was determined by correlating the trial eye IOP change between up to 3 pre- and 3 posttreatment visits to the fellow eye IOP change between the same visits.

MAIN OUTCOME MEASURES

Correlations of IOP change of the trial eye using the gold standard to the IOP change of the trial eye using the unadjusted and adjusted methods.

RESULTS

The correlations of IOP change using the gold standard to the IOP change using the unadjusted and adjusted methods were r = 0.40 and r = 0.41, respectively. The correlation of IOP change of both eyes between the same pre- and posttreatment visits was r = 0.81.

CONCLUSIONS

The monocular trial (i.e., adjusted method) appears equivalent to testing each eye independently (i.e., unadjusted method); however, neither method is adequate to determine medication response to topical PGAs. Both eyes have a similar IOP response to the same PGA. Further studies to understand IOP fluctuation are necessary to improve current methods of assessing medication response.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

The effect of trabeculectomy on intraocular pressure of the untreated fellow eye in the collaborative initial glaucoma treatment study

PURPOSE

To describe the intraocular pressure (IOP) of the untreated fellow eye after unilateral trabeculectomy in the Collaborative Initial Glaucoma Treatment Study (CIGTS).

DESIGN

Data collected from a prospective, multicenter, randomized clinical trial.

PARTICIPANTS

Three hundred patients with newly diagnosed open-angle glaucoma enrolled at 14 centers in the United States who were randomized to initial trabeculectomy.

METHODS

After baseline evaluation and randomization to initial trabeculectomy in the study eye, patients were evaluated at 3 and 6 months and at 6-month intervals thereafter. The IOP was measured by Goldmann applanation tonometry. All eyes included in the analysis were untreated fellow eyes, and the data were censored for potential IOP-lowering events in the fellow eye, including trabeculectomy, argon laser trabeculoplasty, or cataract extraction. Predictive factors for IOP response in the fellow eye to initial trabeculectomy in the study eye were analyzed using a linear mixed model.

MAIN OUTCOME MEASURES

Intraocular pressure in the untreated fellow eye during follow-up.

RESULTS

Although the IOP in the fellow eye was lower than baseline at 3, 6, 12, 18, and 24 months after trabeculectomy in the study eye, this decrease was statistically significant only at month 12 (mean decrease from baseline, 0.73 ± 3.37 mmHg; P = 0.0134). Predictive associations with higher IOP in the fellow eye during follow-up included higher baseline IOP (P < 0.0001), lower level of education (P = 0.0129), time (P = 0.0005), and the presence of other vascular disease (P = 0.0069). Patients who ultimately required fellow eye trabeculectomy (P < 0.0001) or argon laser trabeculoplasty (P<0.0001), but not cataract extraction (P = 0.4597) in the fellow eye, had lower IOPs during follow-up after these procedures.

CONCLUSIONS

There was no evidence of a substantial effect of trabeculectomy on the IOP of the untreated fellow eye during follow-up. Trabeculectomy does not seem to decrease the mean IOP of the fellow eye, as suggested by some previous studies.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

The monocular trial controversy: a critical review

PURPOSE OF REVIEW

The utility of the monocular trial to determine the response to topical ocular hypotensive medications has been recently debated. This review provides a critical evaluation of recent studies and discusses factors that affect the accurate determination of medication response.

RECENT FINDINGS

Recent concerns about the validity of the monocular trial arise from studies reporting a low-to-moderate correlation of intraocular pressure (IOP) response between the first and second eyes to the same topical ocular hypotensive medication. Few studies, however, have addressed the classic monocular trial that adjusts IOP in the trial eye based on IOP change in the fellow eye. Conflicting results from prior studies are due to differences in study question, study design, and method of analysis. Factors such as variability of IOP, diurnal variation, and regression to the mean further complicate the understanding of whether monocular trials or binocular simultaneous trials (i.e. testing each eye separately) are better for determining medication effect.

SUMMARY

The issue of whether or not to use the monocular trial remains controversial. A more clear understanding of factors such as nontherapeutic variability of IOP within the same eye and between eyes may elucidate the answer to this question. Further studies of monocular and binocular trials are needed to clarify which method better estimates medication response.

A pilot study of topical treatment with an alpha2-agonist in patients with retinal dystrophies

PURPOSE

The aim of this study was to assess the neuroprotective effect of a topical alpha2-agonist in patients with retinal dystrophies.

METHODS

This study was a prospective, placebo-controlled, double-masked, randomized clinical trial. A total of 26 patients with retinal dystrophies were included. One (1) randomly selected eye was treated with brimonidine tartrate 0.2% twice-daily, while the fellow eye received artificial tears. Disease progression parameters tested at 6-8-month intervals throughout the study included Goldmann visual fields, contrast sensitivity, color vision, and fullfield electroretinography.

RESULTS

Seventeen (17) of the 26 recruited patients completed the study. Except for 1 patient with an 18-month follow-up, all patients were followed up for 24-36 months (mean, 29). At the conclusion of the study, there were no differences detected in visual acuity, color vision, and contrast sensitivity between the treated and control eyes. There was a trend, however, toward a lesser degree of visual field loss in the brimonidine-treated eyes. There was also a delay in the time required to reach a 25% visual field loss in the treated eyes. These differences were more pronounced in a subgroup of patients diagnosed as retinitis pigmentosa and with visual fields of 5 cm2 or more at baseline.

CONCLUSIONS

The findings of this pilot study suggest a trend for slower progression in the eyes of patients with retinal dystrophy when treated with brimonidine, according to one of the parameters that was studied (visual field loss). Further studies that include a larger number of patients and a longer follow-up period are needed to clarify and confirm the potential neuroprotective effect of alpha2-agonists in human retinal dystrophies.