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

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.

Topical anti-glaucoma medications effects on meibomian glands: systematic review and meta-analysis

Meibomian gland (MG) dysfunction and glaucoma are very prevalent ocular conditions that significantly impact patients' quality of life. A growing number of clinical and experimental studies have reported an association between the use of topical eye drops to reduce intraocular pressure and the development or exacerbation of MG dysfunction. Studies investigating the impact of glaucoma eyedrops on MG diagnostic parameters have shown variable results, particularly regarding the morphology and function of MG and tear film instability. Herein, we corroborated the findings of greater changes in morphological and functional variables related to MG in patients treated with antiglaucoma eye drops through a systematic review and meta-analysis.

Management of Glaucoma-Related Dry Eye Disease with Intense Pulsed Light: A Randomized Control Study

Purpose

The objective of this study was to assess the effectiveness of intense pulsed light (IPL) therapy in individuals diagnosed with glaucoma and dry eye disease (DED).

Methods

This randomized control study recruited 22 individuals diagnosed with glaucoma, ranging in age from 33 to 82 years. These participants were undergoing treatment with hypotensive eyedrops and had clinical indications and subjective complaints associated with dry eye. Each patient underwent three sessions of IPL therapy in one eye, while the contralateral eye served as the control eye (CT). The following parameters were assessed at three time points: baseline, week-2, and week-4. These parameters include non-invasive breakup time (NITBUT), tear meniscus height (TMH), conjunctivocorneal epithelial staining score (CS), tear film lipid layer (TFLL), meibomian gland expressibility score (MGEx), Schirmer I test, ocular bulbar redness score (OBRS), and ocular surface disease index (OSDI). Intraocular pressure (IOP), best-corrected visual acuity (BCVA), and corneal endothelial cell count (ECC) were assessed for safety. The clinical trial was registered on 25/12/2023 at ClinicalTrials.gov website (NCT06158984).

Results

Comparing baseline and 4-week measurements revealed that the IPL group found significant improvements in NITBUT (IPL: 8.74±2.60 sec. vs CT: 5.76±1.75 sec. p<0.01), TMH (IPL: 0.23±0.05mm vs CT: 0.19±0.06mm, p=0.011), C.S. (IPL: 1.14±0.56 vs CT: 1.95±1.17, p=0.005), TFLL (IPL: 2.91±2.91 vs CT:3.36±0.58, p=0.047), MGEx score (IPL: 1.14±0.35 vs CT: 1.45±0.51, p=0.020) and OSDI scores (IPL: 31.77±15.59 vs 50.59±21.55, p=0.002) significantly improved. Conversely, other parameters showed no significant improvements (p>0.05).

Conclusion

The progression of ocular surface disease in individuals using topical anti-glaucoma medication may worsen if the condition is not addressed. Nevertheless, IPL therapy has the potential to result in significant improvements in both objective and subjective measures of dry eye. Best-corrected visual acuity, endothelial cell count, and intraocular pressure were determined to be within the permitted limits. No adverse events were reported during the course of the study.

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.

The molecular aspect of anti-glaucomatous eye drops - are we harming our patients?

Glaucoma is one of the leading causes of irreversible blindness. Progression is halted with a reduction in intraocular pressure (IOP), which is most often achieved with eye drops. A major challenge in the topical treatment of glaucoma patients is the many side effects and the resulting reduced adherence. Side effects may of course be due to the molecular properties of the active pharmaceutical ingredients (APIs). There are currently six different APIs available: prostaglandin analogues, β-adrenergic inhibitors, α-adrenergic agonists, carbonic anhydrase inhibitors, rho-kinase inhibitors and muscarinic 3 agonists. But the additives used in eye drops are also known to cause damage to the ocular surface and to some extent also to the deeper tissues. Said additives are considered inactive molecular components and are added to secure for instance viscosity and pH value, and to prevent contamination. There has been an increasing focus on the harmful effects of preservatives, with the most commonly used preservative benzalkonium chloride (BAK) being particularly controversial. BAK has long been recognized as a toxin that increases the risk of ocular discomfort. This can affect the adherence and ultimately result in lack of disease control. Other issues include the addition of certain buffers, such as phosphates, and varying pH values. This review will address the different molecular components of the IOP-lowering eye drops and what to be aware of when prescribing topical glaucoma treatment.

Case report: Medical treatment for limbal epithelial stem cell deficiency in patients treated for glaucoma

Limbal epithelial stem cell deficiency (LSCD) is an abnormal corneal epithelial lesion with several causes. The patient was diagnosed using fluorescein staining. Bullous keratopathy, multiple surgeries, and drug-related damage can cause LSCD in glaucoma patients. We evaluated the medical treatment course for LSCD in patients with glaucoma. We retrospectively reviewed the electronic medical records of patients diagnosed with LSCD and investigated their background, course of treatment, and classification stages of LSCD before and after treatment. The global consensus classification system (stages IA-C, IIA-B, and III) proposed by Deng et al. (Cornea 2020) was used. Seven patients (two males) and eight eyes were studied. The median age of the patients was 82 years, and the mean duration of glaucoma treatment was 8 years. The patients had open-angle glaucoma (four eyes), exfoliation glaucoma (one eye), neovascular glaucoma (one eye), normal tension glaucoma (one eye), and uveitic glaucoma (one eye). Stage classifications at diagnosis were stage IA in four eyes and stages IC, IIA, IIB, and III in one eye each. All treatments were carried out with dry eye drops, steroid eye drops, and antibiotics. The mean duration of treatment was 1.4 years. The classifications at the time of the final visit were normal corneal epithelium (three eyes), stage IA (two eyes), IIA (one eye), and III (two eyes). Three eyes (37%) improved by more than one stage and one eye deteriorated by more than one stage. LSCD is long-lasting and difficult to treat in a short period; thus, it requires careful medical attention.

Ocular Surface Disease in Glaucoma Patients

PURPOSE

To review the most recent studies in the literature regarding the ocular surface in glaucoma patients and treatment options aimed to reduce ocular surface disease in this population.

METHODS

We performed a literature search in the electronic databases of PubMed CENT RAL, Google Scholar, EMBASE the Register of Controlled Trials, and Ovid MEDLINE using the following terms: "ocular surface", "dry eye", "glaucoma", "selective laser trabeculoplasty", "glaucoma surgery", "preservatives", "preservative free", "ocular surface disease index", "tear break up time", "MMP-9" and "conjunctival hyperemia".

RESULTS

Over the last several years, several studies have demonstrated the changes to the ocular surface in the setting of glaucoma, the best tests for markers of dry eye, and how management can be altered to help address ocular surface disease routinely or in preparation for glaucoma surgery.

CONCLUSION

Ocular surface disease in the glaucoma patient population is widely recognized. It should be addressed to maximize patient compliance and quality of life.