Association between meibomian gland dysfunction and compliance of topical prostaglandin analogs in patients with normal tension glaucoma

Expert Consensus Recommendations for the Management of Ocular Surface Inflammation in Patients With Glaucoma

PRCIS

We have developed through a consensus process 24 clinical recommendations for the comprehensive management of ocular surface inflammation in glaucoma patients, including diagnostic criteria, prevention measures, and treatment strategies according to ocular surface disease severity.

PURPOSE

To obtain expert consensus on the diagnosis, prevention, and management of ocular surface inflammation (OSI) in patients with glaucoma.

METHODS

An international steering committee of glaucoma and/or ocular surface disease (OSD) experts and a wider faculty of members from the Educational Club of Ocular Surface and Glaucoma (ECOS-G) collaborated to develop clinical recommendations on best practice in the management of OSI in glaucoma patients using a nonanonymous interactive quasi-Delphi process. Clinical recommendations were formulated by the steering committee based on an analysis of the recent literature to determine unmet needs, together with a web-based interactive survey of faculty members' opinion in seven identified areas of OSI management in glaucoma. Topics included (1) diagnosis of OSD, (2) diagnosis of OSI, (3) causes of OSI, (4) impact of OSD/OSI, (5) prevention of OSI, (6) treatment of OSI, and (7) inflammation and the deep structures of the eye. Faculty members were invited to vote on the clinical recommendations, and the steering committee then determined whether consensus had been achieved.

RESULTS

Consensus was obtained on 24 clinical recommendations by 80%-100% of faculty members. There was consensus that OSI should be investigated in all glaucoma patients. The main prevention measure in glaucoma patients with pre-existing OSD was the elimination/minimisation of preserved medications, especially BAK-preserved eye drops. A subtractive treatment strategy rather than an additive strategy is recommended according to OSI/OSD severity to improve the ocular health and/or before glaucoma surgery.

CONCLUSION

These recommendations for the management of OSI in glaucoma should be useful to guide decision-making in clinical practice.

Topical glaucoma medications - Possible implications on the meibomian glands

One of the most common causes of blindness on a global scale is glaucoma. There is a strong association between glaucoma and increased intraocular pressure (IOP). Because of this, adequate IOP-lowering is the most important treatment strategy, mostly through topical eyedrops. Well-functioning meibomian glands are paramount for maintaining a stable tear film, and their dysfunction is the most common cause of dry eye disease. There is a growing concern that both topical glaucoma medications themselves and their added preservatives damage the meibomian glands, and consequently, the ocular surface. Preserved topical glaucoma medications appear to cause dysfunction and atrophy of the meibomian glands. Upon comparison, preserved formulations caused more symptoms of dry eye, tear film instability, inflammatory changes and meibomian gland dropout than the preservative-free counterpart. However, although seemingly less detrimental, unpreserved alternatives may diminish glandular efficacy, and, depending on the active ingredient, lead to glandular death. This negatively impacts quality of life, adherence to treatment regimens and prognosis. In this review, we explore the available evidence regarding the effects of IOP-lowering eye drops on the meibomian glands.

[Three-component tear substitute as preoperative support in glaucoma surgery]

PURPOSE

This study investigates the effect of preoperative preparation with the three-component tear substitute Stillavit on the outcomes of glaucoma surgery in patients on long-term topical glaucoma therapy.

MATERIAL AND METHODS

The study included 63 patients (63 eyes) with glaucoma, among them 30 (30 eyes) were women and 33 (33 eyes) were men. Group 1 consisted of 33 patients (33 eyes) receiving long-term topical antihypertensive therapy with preservatives and tear substitute Stillavit 3 times a day for 1 month as preoperative preparation. Group 2 included 30 patients (30 eyes) receiving similar antihypertensive therapy who were not prescribed preoperative medications. All patients underwent a comprehensive ophthalmological examination and computer tomography of the filtering blebs (FB) on Visante system (Carl Zeiss Meditec, Germany) before surgery, as well as 1 week, 1, 3, and 6 months after surgery.

RESULTS

Mean intraocular pressure (IOP) elevation at 6 months postoperatively was significantly higher in the group that did not undergo preoperative preparation with a tear substitute, compared to the group of patients who received the tear substitute Stillavit preoperatively. According to anterior segment optical coherence tomography, a greater number of favorable diffuse FB were noted in the group that received the tear substitute Stillavit in preparation for surgery - 87.9%, while in group 2 (without preparation) - 66.7%. Odds ratio calculation between the two groups revealed that preoperative preparation with the tear substitute Stillavit reduced the odds of IOP elevation to 20 mm Hg or higher at 3 months postoperatively by more than 10 times.

CONCLUSION

The use of tear substitute Stillavit in preparation for anti-glaucoma surgery reduces the chances of IOP elevation in the early postoperative period by more than 10 times, which may indicate a reduction in the rate of FB scarring due to the beneficial effect of the drug's components on the precorneal tear film.

Glaucoma and Dry Eye Disease: Opportunity to Assess and Treat

Dry eye disease (DED) has been found to occur at a higher prevalence in individuals with glaucoma than in individuals without glaucoma. The relationship between glaucoma and DED may be, in part, a result of glaucoma therapy. Greater number of antiglaucoma medications used and greater number of antiglaucoma eyedrops instilled per day have been associated with ocular surface disease in patients with glaucoma. Use of antiglaucoma medication has also been associated with higher levels of ocular surface inflammatory markers and ocular surface alterations. There is evidence to suggest that antiglaucoma medications with preservatives and, to some extent, antiglaucoma medication formulations without preservatives may contribute to ocular surface signs and symptoms. Trabeculectomy for glaucoma has also been associated with ocular surface signs related to DED; however, there may be benefits of trabeculectomy and other procedures for glaucoma due to reduced use of antiglaucoma medications. Patients with glaucoma with ocular surface disease have been found to have greater ocular surface symptoms, poorer vision-related quality of life, and poorer antiglaucoma medication adherence compared with patients with glaucoma without ocular surface disease. Because of the potential negative impact of DED on patients with glaucoma, patients with glaucoma may benefit from evaluation for DED. Management of DED in patients with glaucoma may include modifications to antiglaucoma medications and use of treatments for DED.

Ocular Surface Disease in Glaucoma Patients Randomized to Benzalkonium Chloride-Containing Latanoprost and Preservative-Free Bimatoprost

Purpose: To investigate the influence of benzalkonium chloride (BAK) on ocular surface disease (OSD) in glaucoma patients receiving ocular-hypotensive agent. Methods: Patients were randomized to receive BAK-containing latanoprost (Xalatan) or preservative-free bimatoprost (Lumigan PF). Intraocular pressure (IOP), basal Schirmer's test, noninvasive keratograph tear-breakup time (TBUT), conjunctival redness score (R score), OSD index (OSDI), and corneal Oxford staining were recorded and compared between the 2 groups at 1-month and 4-month visits. The influence of BAK was analyzed by a generalized estimating equation model. Results: We enrolled 74 and 76 eyes treated with latanoprost and bimatoprost, respectively. The IOP decreased in both groups, although greater reduction was observed for latanoprost (13.95 vs. 15.42 mmHg, P = 0.0264). There was a significantly negative association between tear flow and latanoprost use (β = -0.763, P = 0.0243). The first and average TBUT did not show intergroup differences, but the area with unstable tear film increased with latanoprost use and showed marginal significance at 4-month visit (9.33% vs. 5.94% P = 0.055). In both groups, OSDI decreased, whereas Oxford stain increased over time, and R scores showed improvement after transient increase in the first month. The bimatoprost group had significantly worse conjunctival hyperemia, whereas a negative association with conjunctival hyperemia was revealed for latanoprost use (R score-bulbar nasal: β = -0.045, P = 0.0423). Conclusions: BAK-containing latanoprost was associated with decreased tear secretion and may be associated with tear-film instability, whereas bimatoprost was associated with worse conjunctival hyperemia. Ocular surface side effects should be considered when prescribing BAK-containing medication to glaucoma patients.

Meibomian Gland Changes in Open-angle Glaucoma Users Treated with Topical Medication

SIGNIFICANCE

Glaucoma patients treated with topical hypotensive eye drops often experience changes in the ocular surface, including the lid margin and the meibomian glands. In this study, the clinical parameters of the ocular surface have been analyzed to detect the presence of meibomian gland dysfunction-related dry eye disease.

PURPOSE

This study aimed to evaluate the meibomian gland dysfunction in glaucoma patients secondary to topical antiglaucomatous treatment.

METHODS

A total of 131 eyes from different patients with open-angle glaucoma treated with topical medication and 92 eyes from different patients with untreated ocular hypertension were consecutively and prospectively enrolled. The structure of the meibomian glands was assessed using noncontact meibography (Keratograph 5M; Oculus, Wetzlar, Germany), and their function was evaluated by measurement of meibomian glands expressibility, the duct appearance, and the Marx line location. Moreover, tear osmolarity measurement, corneal staining score (Oxford scale), and ocular symptom assessment (Ocular Surface Disease Index questionnaire) were performed. We also compared these variables in the glaucoma group according to the presence (or not) of preservative in topical treatment.

RESULTS

Meibomian gland depletion was higher in glaucoma patients with topical medication (P < .001). Furthermore, the quantity of meibomian glands and expressibility of meibum in these patients were altered compared with the control group (P < .001 in both cases). In addition, the glaucoma group presented a higher degree of corneal staining as measured with the Oxford scale (P < .001). The Marx line location score was higher (P < .001 in central Marx line and P < .003 in temporal Marx line) in patients using drugs containing preservative than in those having preservative-free treatment. Logistical regression found that Marx line central, Marx line temporal, quantity of meibum expression, and quality of meibum expression have predictive ability to detect meibomian gland dysfunction-related dry eye disease.

CONCLUSIONS

Glaucoma topical treatments produce meibomian gland dysfunction altering their structure and function, and this condition can be worsened using topical treatments containing preservative.

Revisiting the Safety of Prostaglandin Analog Eyelash Growth Products

BACKGROUND

The FDA approved bimatoprost ophthalmic solution 0.03% for treatment of eyelash hypotrichosis in 2008. Consumer concern persists regarding potential side effects of this product.

OBJECTIVE

To identify gaps in the safety information associated with the use of prostaglandin eyelash growth products.

MATERIALS AND METHODS

Literature searches were performed using PubMed, Embase, and Nexis Uni databases without restriction to publication date, language, or study setting.

RESULTS

The literature pertaining to bimatoprost for treatment of eyelash hypotrichosis is dominated by industry-sponsored clinical trials. Study design choices create gaps in our understanding of the clinical safety of these products.

CONCLUSION

Because of study design choice, clinical trials of bimatoprost for eyelash growth may have systematically underreported the incidence of drug application discomfort and prostaglandin-associated periorbitopathy. The risk of increased iris pigmentation remains inadequately investigated. Consequently, there is an ongoing need to educate and monitor patients who choose to use these products.

Evaluation of Meibomian Gland Loss and Ocular Surface Changes in Patients with Mild and Moderate-to-Severe Graves' Ophthalmopathy

OBJECTIVES

To evaluate the association of Graves' Ophthalmopathy (GO) with the meibomian glands and investigate the relation of ocular surface changes with meibomian gland parameters in patients with GO.

METHODS

This prospective study included 44 eyes of 44 mild and moderate-to-severe GO patients and 38 eyes of 38 control subjects. After a complete ophthalmologic examination, patients were assessed according to the Clinical Activity Score (CAS). The area of meibomian gland loss and meibography score was evaluated using meibography (Sirius; CSO, Florence, Italy). Schirmer test, tear break-up time (TBUT) and Ocular Surface Disease Index (OSDI) scores were evaluated.

RESULTS

Mean meibomian gland dropout area was 26.29 ± 1.58% in the GO group and 14.46 ± 1.52% in the healthy controls (p < .001). Mean meibography score in the GO group was 2.61 ± 0.15 while it was 1.32 ± 0.25 in the healthy controls (p < .001). Meibomian gland dropout area was positively correlated with CAS and OSDI questionnaire results (p = .015, r = 0.391; p < .001, r = 0.662, respectively) and negatively correlated with TBUT and Schirmer test scores (p < .001, r = -0.635; p = .003, r = -0.474, respectively). Meibography score was positively correlated with CAS and OSDI questionnaire results (p = .012, r = 0.383; p = .007, r = 0.419, respectively) and negatively correlated with TBUT and Schirmer test scores (p = .002, r = -0.467; p = .023, r = -0.359, respectively).

CONCLUSION

Meibomian glands are quantitatively decreased in patients with GO. The decrease of meibomian glands is correlated with objective and subjective dry eye findings. Dry eye treatment in GO patients should include meibomian gland deficiency as well.

A novel EyePhone© App for improving adherence to glaucoma therapy

PURPOSE

Despite advances in glaucoma treatment options, patient adherence and compliance remain very low. The EyePhone© App is a free non-commercial reminder application designed specifically for the needs of glaucoma patients. In this study, we evaluated its usefulness in improving adherence to medical treatment among glaucoma patients.

METHODS

This is a prospective multicenter interventional study. Glaucoma patients were recruited from a tertiary center and a large community glaucoma service center. After a short explanation, the EyePhone© App was installed on their smartphone device, and the notifications for the current medical treatment were entered. After enrollment and at 1-month follow-up, subjects completed the Morisky Medication Adherence Scale (MMAS-8) and the Quality of Life and Glaucoma 17-item (GlauQOL-17) questionnaires for evaluation of adherence and QOL, respectively.

RESULTS

In the study, 133 patients (71 men and 62 women) aged 62±15.5 years and using 2.0±0.9 IOP-lowering drugs participated. The proportion of highly adherent subjects improved from 29.3% (39/133) at baseline to 42.1% (56/133) at follow-up (P < 0.001), and the proportion of poorly adherent subjects decreased from 29.3 (39/133) to 20.3% (27/133) at follow-up (P = 0.012). QOL also improved, as evidenced by a significant increase in the GlauQOL-17 score (P < 0.05). In a subgroup of patients for whom IOP measurements were available, IOP reduced by 0.92 mmHg (P = 0.069).

CONCLUSIONS

Significant improvements in glaucoma adherence and QOL were achieved among poorly adherent glaucoma patients after 1 month of using the EyePhone© App.

Understanding the Dual Dilemma of Dry Eye and Glaucoma: An International Review

Glaucoma-related ocular surface disease (G-OSD) is a significant, yet often underdiagnosed, ocular co-morbidity affecting 40% to 59% of glaucoma patients worldwide. Although the use of topical glaucoma medications represents a proven strategy to control the untoward effects of high intraocular pressure, this treatment can profoundly disrupt the homeostasis of the tear film. The cumulative effect of medications, preservatives, and excipients alter underlying cellular structures which results in tear film abnormalities and instability of the ocular surface. Furthermore, these chronic inflammatory changes have been shown to impact efficacy of glaucoma treatment, patient compliance with therapy and overall quality of life. The pathogenesis of G-OSD is multifactorial and involves a vicious self-perpetuating cycle of inflammatory cytokines and proteins. The diagnosis of such disease is based on similar tests used in assessing traditional dry eye, taking into consideration findings specific to this patient population. The hallmark of treatment for these patients is to minimize the ocular surface inflammatory response by choosing glaucoma therapies that spare the ocular surface such as preservative free formulations and initiating dry eye treatment early in the course of care. In summary, glaucoma affects millions of patients around the world and chronic use of topical glaucoma medications may negatively impact the patient's ocular surface, symptoms, and vision. Understanding the pathogenesis of G-OSD, recognizing its risk factors and incorporating diagnostic and therapeutic strategies that restore and maintain ocular surface homeostasis will result in improved care for our patients.

The protective effect of 3% diquafosol on meibomian gland morphology in glaucoma patients treated with prostaglandin analogs: a 12-month follow-up study

Background

To determine if 3% diquafosol (DQS) can preserve the meibomian gland morphology in glaucoma patients treated with prostaglandin analogs (PGA) for a 12-month follow-up period.

Methods

This study included 84 eyes of 46 normal tension glaucoma (NTG) patients who were treated with either preservative-containing PGA (PC-PGA; 16 patients, 28 eyes), preservative-free PGA (PF-PGA; 21 patients, 39 eyes), or a combination of PC-PGA and 3% DQS (PC-PGA + DQS; 9 patients, 17 eyes). The meibography of the upper eyelid was acquired using Keratograph® 5 M at baseline and at each follow-up (1, 3, 6, 9, and 12 months). Meibomian gland loss (MGL) was quantitatively analyzed by using ImageJ software.

Results

In the PC-PGA group, MGL increased significantly from baseline to month 9 and month 12, whereas no significant changes were observed in the PF-PGA and PC-PGA + DQS groups during the entire 12 months. All groups showed similar MGL at each follow-up time from baseline to six months. However, MGL in the PC-PGA group was significantly higher than those in the PF-PGA and PC-PGA + DQS groups at the 9 and 12 months.

Conclusions

Combining 3% DQS with PC-PGA was as effective as PF-PGA in preserving the meibomian gland morphology for at least 12 months. Our results suggest that 3% DQS may be a promising strategy for managing glaucoma patients with a high risk of developing meibomian gland dysfunction due to preservative-containing topical medications.

Prospective, Multicenter, Cross-Sectional Survey on Dry Eye Disease in Japan

INTRODUCTION

Dry eye disease (DED) is commonly encountered in eye clinics and hospitals, and it is therefore very important to understand DED prevalence in outpatients.

METHODS

A multicenter, hospital-based cross-sectional study was conducted among outpatients in Japan to ascertain DED prevalence and relationships between DED and patient profiles, including eye disease, DED diagnosis history, and surgical history. DED was diagnosed according to diagnostic criteria of the Asia Dry Eye Society. Patient self-assessment of DED-related subjective symptoms was conducted using the 5-Item Dry Eye Questionnaire (DEQ-5). Tear break-up time was evaluated in subjective symptom-positive patients.

RESULTS

The prevalence of DED was 55.7% in 990 patients (mean age 69.1 ± 13.4 years), DED was commonly experienced in combination with other ocular diseases. In revisiting patients, 15.2% had not previously been diagnosed as DED, and their total DEQ-5 scores were higher than those of patients who had undergone DED treatment.

CONCLUSION

This study revealed that more than half of the outpatients had DED. Among revisiting patients, there were many "hidden" DED patients who had not been diagnosed with DED in the past. There is a high likelihood of finding DED comorbidity in patients with other eye diseases in eye clinics and hospitals.

FUNDING

Santen Pharmaceutical Co., Ltd.

TRIAL REGISTRATION

UMIN Clinical Trials Registry Identifier, UMIN000035506.

Effect of topical glaucoma medication on tear lipid layer thickness in patients with unilateral glaucoma

Purpose:

To compare the lipid layer thickness (LLT) using the LipiView® ocular surface interferometer (TearScience® Inc, Morrisville, NC) between the eye treated with glaucoma medication and untreated normal eye in the unilateral glaucoma patients, and evaluate the effect of topical glaucoma medication on the LLT parameters in glaucoma eyes.

Methods:

The participants in this cross-sectional comparative study were unilateral glaucoma patients treated with topical glaucoma medications for more than 12 months. Three LLT parameters (average, minimum, and maximum) obtained by the LipiView® were compared between the glaucomatous eye and normal eye. The factors associated with LLT parameters in the eyes treated with glaucoma medication were investigated with multiple regression analysis.

Results:

Thirty patients with unilateral normal tension glaucoma were enrolled in the present study. Lipid layer average, minimum, and maximum were 64.83 ± 16.50, 51.63 ± 16.73, and 82.53 ± 20.62 in glaucomatous eyes, 77.26 ± 17.81, 62.83 ± 20.99, and 86.13 ± 15.42 in normal eyes. Lipid layer average and minimum were significantly thinner than those in normal eyes (P < 0.001, P < 0.001, respectively). Longer duration of glaucoma eye drops and a greater number of glaucoma medications were associated with the lower LLT average (β = −0.456, P < 0.001, β = −8.517, P = 0.003, respectively), and increasing glaucoma medications have a significant correlation with lower LLT minimum in glaucoma eyes (β = −8.814, P = 0.026).

Conclusion:

The present study highlights that patients with long-term glaucoma medications need to be assessed for LLT parameters objectively evaluate their ocular surface health.

Effects of Preservative on the Meibomian Gland in Glaucoma Patients Treated with Prostaglandin Analogues

This study compared the effect of preservative-containing (PC) and preservative-free (PF) prostaglandin analogue (PGA) formulations on the ocular surface, especially on the meibomian gland (MG) in patients with open-angle glaucoma (OAG). This is a retrospective study of treatment-naïve patients with OAG (n=80) and healthy controls (n=40). OAG patients were randomized into groups using either PC-PGA or PF-PGA for 12 months. All participants underwent ocular surface and MG examinations including their meibum score, meiboscore, and lid margin abnormality score (LAS). Eighty OAG patients were randomized into two groups (n=42 in PC, n=38 in PF). All PGA and control groups showed similar ocular surface and MG parameters at the baseline. Both PC- and PF-PGA groups showed increased meibum scores, meiboscores, and LASs at 12 months compared to the baseline (all p<0.05). At the 12-months visit, PC-PGA group showed severe OSDI, shorter TBUT, greater OSS, and worse MG parameters than those of the other two groups (all p<0.05). In addition, PF-PGA group showed worse meiboscores, meibum scores, and severe OSS scores than those of the control group (all p<0.05). Both PC and PF formulations can cause damage to the MG in patients using PGA. However, PC formulations induced more ocular discomfort, poorer ocular surface, and more severe MG loss compared to PF formulations. Therefore, it would be advisable to use PF formulations in patients with a preexisting or concomitant ocular surface disease or MGD.

Meibomian gland dropout rate as a method to assess meibomian gland morphologic changes during use of preservative-containing or preservative-free topical prostaglandin analogues

PURPOSE

To investigate the usefulness of meibomian gland (MG) dropout rate in the evaluation of MG morphological change associated with the use of prostaglandin for glaucoma treatment through the association between MG and the ocular surface parameters and medication duration and presence of preservative.

METHODS

This cross-sectional study was conducted on 88 eyes of 88 patients who were diagnosed with glaucoma and used only Tafluprost as treatment. The patients were divided into four "user" groups: 1) 23 patients used preservative-free (PF) Tafluprost for 6 months; 2) 21 patients used preservative-containing (PC) Tafluprost for 6 months; 3) 23 patients used PF-Tafluprost for 24 months; 4) 21 patients used PC-Tafluprost for 24 months. Ocular surface parameters and the MG condition, including MG dropout rate and meiboscale, were evaluated. Multiple regression was used to identify associations.

RESULTS

There were significant differences in age (p = 0.003), tear breakup time (p = 0.016), lid margin abnormality (p = 0.016), expressibility (p = 0.039), meiboscale (p<0.001), and MG dropout rate (p<0.001) among the 4 groups. MG dropout rate and meiboscale showed significant differences in all post hoc analyses, except for the comparison between the PF-Tafluprost and PC-Tafluprost 6-month user groups. Medication duration, preservative status, and meiboscale were significantly correlated with MG dropout rate (p<0.001, p = 0.024, p<0.001, respectively). In the 6-month user group, preservative status significantly correlated with MG dropout rate (p = 0.015). However, in the 24-month user group, meiboscale was the only parameter significantly associated with MG dropout rate (p<0.001).

CONCLUSION

MG dropout rate in patients using Tafluprost showed a significant correlation with medication duration and preservative status. This result indicates MG dropout rate reflects MG morphologic change associated with prostaglandin.

[Influence of treatment adherence on the progression of primary open-angle glaucoma in clinical setting]

According to various studies, treatment adherence of patients with primary open-angle glaucoma ranges from 5% to 80% and significantly influences the effectiveness of the therapy. Some authors report higher levels of adherence in patients receiving preservative-free medications.

PURPOSE

To study the influence of treatment adherence in patients receiving preservative-free and preserved medications on the progression of primary open-angle glaucoma (POAG).

MATERIAL AND METHODS

This prospective multicenter non-interventional study was conducted in clinical setting and included 504 patients with primary open-angle glaucoma receiving drug therapy; 51 ophthalmologist was involved in the management of patients' diaries.

RESULTS

The percentage of patients who did not reach target IOP was three times lower in the group with high adherence, in comparison to patients with medium and low adherence (7% against 22%, respectively). Development of side effects was one of the factors influencing treatment adherence, their rates and expressiveness were much lower in the preservative-free group compared with the group receiving preserved medication (13.9% against 35.4%). The rate of patients who did not reach target IOP was two times lower in the group of preservative-free medication (10% against 21%).

CONCLUSION

The study confirms that preservative-free glaucoma medication promotes higher adherence to treatment in clinical setting predominantly due to the reduction of quantity and severity of side effects leading to treatment gaps, which results in increased effectiveness and better stabilization of glaucoma.

The impact of topical intraocular pressure lowering medications on the ocular surface of glaucoma patients: A review

Purpose

To assess the literature on the effects of topical intraocular pressure (IOP)-lowering medications on the ocular surface. Ocular surface assessment in these patients is seldom a priority for most clinicians since the ultimate goal of management is to preserve vision.

Methods

A literature search of articles (English only) on the subject matter was conducted and their findings summarized.

Results

This review assesses the prevalence of dry eye symptoms in glaucoma patients on topical IOP-lowering medications. We extensively reviewed the effects of the preservatives and active ingredients in these medications on the ocular surface. In particular, the effects of benzalkonium chloride (BAK), a widely used preservative, on meibomian glands are explored. Also mentioned in this review is the association between duration of therapy and severity of dry eye symptoms. The role of the pH of medications in the development of ocular surface disease is also reviewed. Finally, we probed the occurrences of ocular allergic reactions with the use of topical IOP-lowering medications.

Conclusions

The preservatives and active agents in most topical glaucoma medications are implicated in the prevalence of ocular surface discomfort. Whilst clinicians involved in glaucoma care are encouraged to assess the ocular surface routinely, further studies are needed to demonstrate the contributions of other physiochemical properties of these medications to the development of ocular surface disease in these patients.