The one-eye trial and fellow eye response to prostaglandin analogues

The Japan Glaucoma Society guidelines for glaucoma 5th edition

We are pleased to bring you the 5th edition of the Glaucoma Clinical Practice Guidelines. Clinical practice guidelines are based on evidence (scientific grounds). It is a document that presents the treatment that is the most appropriate for the patient. "Glaucoma Clinical Guidelines" was first published in 2003. This was the first guideline for glaucoma treatment in Japan. The principle of glaucoma treatment is to lower intraocular pressure. Means for lowering intraocular pressure includes drugs, lasers, and surgery; Glaucoma is a disease that should be considered as a complex syndrome rather than a single condition. Therefore, the actual medical treatment is not as simple as one word. This time we set the Clinical Questionnaire with a focus on glaucoma treatment. We hope that you will take advantage of the 5th edition.

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.

Incidence of deepening of the upper eyelid sulcus on treatment with a tafluprost ophthalmic solution

PURPOSE

Deepening of the upper eyelid sulcus (DUES), one symptom of prostaglandin-associated periorbitopathy, was recently found to be an additional side effect of prostaglandin-related ophthalmic solutions. Here, we prospectively investigated the incidence and factors associated with DUES in Japanese open-angle glaucoma patients initially treated with benzalkonium chloride (BAK)-preserved tafluprost (TAF).

METHODS

In this open-label prospective study instilling TAF in one eye, mean deviation (MD) and intraocular pressure (IOP) were measured, and facial photographs and subjective reports of DUES were obtained at intervals over 6 months. Three ophthalmologists independently assessed the photographs of DUES and reached consensus. Relationships between demographic and ocular/systemic factors (age, sex, MD, refraction and IOP reduction) and DUES occurrence were evaluated.

RESULTS

Forty-three eyes of 43 glaucoma patients (24 men and 19 women) were evaluated. Mean IOP before treatment was 16.6 ± 2.7 and after treatment, 14.1 ± 2.3 mmHg (P < 0.001). The objective rate of DUES was 9 % (4/43) at 2 months, 14 % (6/43) at 4 months and 14 % (6/43) at 6 months. During this period, only one patient self-reported an occurrence of DUES. No significant association was found between DUES occurrence and any of the demographic, ocular, or systemic factors.

CONCLUSIONS

Physicians should inform patients about DUES as a minor side effect when prescribing TAF for IOP control.

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.

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.

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 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.