As an increasingly prevalent condition, glaucoma affects millions around the globe, posing a significant risk of vision loss. While the primary focus often lies on IOP reduction to safeguard the optic nerve, an equally pressing issue in glaucoma management is the emergence and exacerbation of ocular surface disease (OSD). As with any chronic disease, effective treatment depends on minimizing the adverse effects of therapy and maximizing patient compliance.
This article explores the connection between glaucoma medications and ocular surface health, emphasizing the importance of patient-doctor dialogue and adherence to prescribed treatment regimens. As vision care professionals, it is crucial to educate glaucoma patients about this relationship, the importance of compliance and proactive strategies to maintain ocular health.
Understanding glaucoma medications and their impact
The primary purpose of glaucoma medications is to reduce IOP, but they can also have side effects that impact the ocular surface. Here’s a brief overview of the main classes of glaucoma medications and their effects:
Prostaglandin Analogs
(eg, latanoprost)
These medications are the first-line treatment for many glaucoma patients. While effective in lowering IOP by increasing aqueous outflow, they can cause side effects like conjunctival hyperemia and hypertrichosis, which may create irritation for some users. Damage to the ocular surface, including reduced tear break-up time and superficial punctate keratopathy, may occur due to the preservative used (benzalkonium chloride).1
Beta-blockers
(eg, timolol maleate)
These drugs reduce IOP by decreasing aqueous humor production. Side effects may include dryness and discomfort on the surface of the eye, especially among patients with pre-existing OSD.2
Alpha Agonists
(eg, brimonidine tartrate, apraclonidine)
These medications can lower IOP by both decreasing aqueous production and increasing outflow. Common side effects include allergic conjunctivitis and a sensation of dryness, leading to further complications for the ocular surface.3
Carbonic Anhydrase Inhibitors
(eg, dorzolamide hydrochloride, acetezolamide, methazolamide, brinzolamide)
Available in both oral and topical forms, these medications work by decreasing aqueous humor production but can lead to stinging, eyelid edema, conjunctivitis and contact dermatitis.4
Rho Kinase Inhibitors
(eg, netarsudil)
These newer agents help increase aqueous outflow via the trabecular meshwork, decrease episcleral venous pressure and reduce aqueous humor production. They have been associated with conjunctival hyperemia, erythema and corneal edema.5
Understanding how these medications work and their side effects helps patients recognize the connection between their glaucoma treatment and potential ocular surface issues.
The link between glaucoma and OSD
OSD refers to a spectrum of disorders affecting the cornea, conjunctiva, and tear film, exhibiting symptoms like dryness, discomfort, and blurred vision. Its prevalence among glaucoma patients is not coincidental but rather a complex interplay of various factors, which I will discuss below.
Medication side effects.Topical glaucoma medications, particularly those containing preservatives like benzalkonium chloride (BAK), can cause significant ocular surface toxicity. BAK is notorious for its ability to disrupt the epithelial cells of the cornea and conjunctiva, leading to inflammation, cellular apoptosis (cell death), and a deterioration of the tear film stability.6 As many glaucoma patients require lifelong treatment, the cumulative impact of these medications can be detrimental.
Increased tear film evaporation. Many patients with glaucoma may already have a compromised tear film due to underlying conditions or age-related changes. The burden of managing their IOP with various topical medications, combined with the natural progression of their ocular health, can lead to an increase in ocular surface issues.
Frequent dosing. Glaucoma therapies often necessitate multiple daily doses (sometimes exceeding three medications). The repetitive application increases the likelihood of developing OSD due to both the medication and the act of instilling drops itself, which can disturb the tear film.
Existing dry eye conditions. Many glaucoma patients already have baseline ocular surface issues — whether age-related, hormonal or environmental. Meibomian gland dysfunction, superficial punctate keratitis and chronic allergic conjunctivitis are common issues the aging population face. The addition of glaucoma medications can exacerbate these conditions, creating a vicious cycle of discomfort and non-compliance.
Surgical interventions. For patients who undergo surgical procedures for glaucoma management, such as trabeculectomy or tube shunt placement, the manipulation of ocular tissues and the subsequent healing process can cause temporary or permanent alterations in ocular surface integrity, contributing to OSD.
The value of medication compliance
Adherence to prescribed glaucoma medications is essential for several reasons:
Pressure control. Consistency in medication usage directly correlates with IOP control. Fluctuations in IOP can lead to irreversible optic nerve damage and vision loss.
Enhanced outcomes. Studies show that patients who adhere to their medication regimens experience better visual outcomes. Interruption in treatment, even briefly, can result in unintended spikes in IOP.
Minimizing surgical interventions. Effective medication adherence can delay or eliminate the need for surgical interventions, which carry their own risks and complications.
The importance of clear communication with healthcare providers
Given the potential for OSD in glaucoma patients, it is crucial for individuals to maintain open lines of communication with their eyecare specialists about any and all ocular symptoms they experience. Here are several reasons why this dialogue is essential:
Symptom recognition. If a patient does not voice their discomfort, the doctor may presume the treatment is effective, potentially delaying changes that could enhance the patient’s quality of life. Patients may not recognize that symptoms such as dryness, redness, itching or burning sensations are associated with their glaucoma management. By discussing these symptoms, healthcare providers can assess whether they stem from medication side effects or other underlying conditions.
Tailored treatment options. Open discussions allow for a more tailored approach to treatment. There are multiple classes of glaucoma medications available. By discussing side effects, patients and doctors can explore alternatives — such as preservative-free formulations or different delivery systems — that may minimize OSD.
Monitoring and management. Regularly discussing symptoms enables practitioners to monitor the patient’s ocular health more effectively. If OSD is identified, physicians may adjust medication regimens, or integrate artificial tears and other therapies to alleviate symptoms. This monitoring can facilitate timely interventions, helping to prevent further complications that could compromise vision.
Holistic approach to care. Addressing OSD should be an integral aspect of glaucoma management. Patients may benefit from an overall approach that includes artificial tears or punctal plugs to relieve symptoms of OSD, making adherence to glaucoma medications more bearable. Open communication fosters a comprehensive approach to care that enhances both the physiological and emotional well-being of the patient.
Proactive approaches to OSD management
Patients can be proactive in managing OSD, even if they are not currently experiencing symptoms. Awareness and action play a key role in preserving eye health. Here are five strategies:
1. Maintain consistent eyelid hygiene. Routine eyelid hygiene can help reduce OSD symptoms and maintain ocular surface health by removing residual medication from the skin surface. Patients are encouraged to wash their eyelids daily with an approved cleanser. There are several commercial eyelid scrub pads and cleansers on the market to safely remove debris, oils and allergens.
2. Use artificial tears. Patients should consider using preservative-free artificial tears to combat dryness and discomfort. Offering a lubricant before medication application can mitigate irritation caused by glaucoma drops. Avoid drops designed for allergies or redness unless specifically instructed by the provider.
3. Follow-up appointments. Regular check-ups with an eyecare provider ensure that both IOP and OSD symptoms are monitored. This open line of communication allows the doctor to adjust treatments as needed, whether changing medications or adding supportive therapies.
4. Consider omega-3 supplements. Omega-3 fatty acids may promote tear production and overall ocular surface health. Consultation with a healthcare provider can determine if these supplements are appropriate.7
5. Surgical options. In some cases, surgical glaucoma treatments may be considered to reduce dependence on topical medications, thereby minimizing the risk of OSD.
Conclusion
While the primary goal in managing glaucoma is to lower IOP, simultaneous attention to ocular surface health is equally essential. The potential for OSD to complicate treatment and negatively impact the quality of life for glaucoma patients cannot be underestimated. By fostering an environment of open communication with healthcare providers, patients can ensure their ocular symptoms are addressed promptly, paving the way for a more effective and comprehensive strategy in managing both glaucoma and OSD.
In closing, we encourage all patients to discuss their symptoms openly with their eyecare professionals. As we continue to refine treatment paradigms in glaucoma management, patient-practitioner collaboration remains vital, ensuring that ocular health is preserved alongside vision-saving interventions. OP
References
1. Tripathy K, Patel P, Geetha R. Latanoprost. In: StatPearls. Treasure Island (FL): StatPearls Publishing; February 28, 2024. https://www.ncbi.nlm.nih.gov/books/NBK540978/. Accessed October 3, 2024.
2. Barnes J, Moshirfar M. Timolol. In: StatPearls. Treasure Island (FL): StatPearls Publishing; August 17, 2024. https://www.ncbi.nlm.nih.gov/books/NBK545176/. Accessed October 3, 2024.
3. Physicians Total Care, Inc. Brimonidine Tartrate - brimonidine tartrate solution/drops. https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=5316cf97-e38e-4e78-aff2-c6972a666f3d&type=display. Accessed October 4, 2024.
4. Talluto DM, Wyse TB, Krupin T. Topical carbonic anhydrase inhibitors. Curr Opin Ophthalmol. 1997;8(2):2-6. https://pubmed.ncbi.nlm.nih.gov/10168353/. Accessed October 4, 2024.
5. Patel P, Patel BC. Netarsudil Ophthalmic Solution. In: StatPearls. Treasure Island (FL): StatPearls Publishing; February 28, 2024. https://tinyurl.com/233a2nzx. Accessed October 4, 2024.
6. Nagstrup AH. The use of benzalkonium chloride in topical glaucoma treatment: An investigation of the efficacy and safety of benzalkonium chloride-preserved intraocular pressure-lowering eye drops and their effect on conjunctival goblet cells. Acta Ophthalmol. 2023;101 Suppl 278:3-21. https://pubmed.ncbi.nlm.nih.gov/38037546/. Accessed October 3, 2024.
7. Molina-Leyva I, Molina-Leyva A, Bueno-Cavanillas A. Efficacy of nutritional supplementation with omega-3 and omega-6 fatty acids in dry eye syndrome: a systematic review of randomized clinical trials. Acta Ophthalmol. 2017;95(8):e677-e685. https://pubmed.ncbi.nlm.nih.gov/28371493/. Accessed October 4, 2024.
