Glaucoma: Early Screening and Treatment Are Key

A lack of warning signs can delay detection and treatment of glaucoma.

A patient newly diagnosed with glaucoma may have many concerns and questions about this ophthalmic condition. Although pharmacists are a vital resource for medication information, they can also provide patients with fundamental resources to help them live with and effectively manage glaucoma.

According to the Glaucoma Research Foundation, an estimated 2.2 million individuals in the United States have glaucoma; unfortunately, more than 50% of these individuals are unaware that they have glaucoma because there are typically no warning signs in the initial stages.^1,2 Results of a study published in the January 2014 issue of Ophthalmology show that the risk of blindness related to glaucoma 20 years after diagnosis has decreased by 50% due to early intervention and consistent treatment.^3,4 Although the results of this study are encouraging, health care professionals should continue to educate patients about the importance of undergoing glaucoma screenings and adhering to treatment plans. With an increased awareness of the risk factors and the treatments for glaucoma, many patients may benefit from early screenings and treatments, thus preventing or decreasing complications such as vision impairment, loss of peripheral vision, and blindness.⁴

Ensuring that patients have a thorough understanding of the potentially progressive nature of glaucoma can be essential to effective therapy, because informed patients are more likely to adhere to therapy.⁵ Many studies have reported that patients are more likely to adhere to therapy if they clearly understand the seriousness of glaucoma and the rationale for the selected therapy and if the therapy plan is simple.⁶ Adherence to therapy may decrease the need for surgery, prevent further optic nerve damage and vision loss, and lower overall health care costs.6 For more facts about glaucoma, see Table 1.^1,2

Forms of Glaucoma

The most common forms of glaucoma are open-angle glaucoma and angle-closure glaucoma.^7,8 These forms are marked by an increase in intraocular pressure (IOP).^7,8 Open-angle glaucoma accounts for an estimated 95% of all glaucoma cases.^1,2,7 These forms of glaucoma can be classified as primary or secondary conditions. If the cause is unknown, the glaucoma is considered to be primary; if the cause is known (eg, eye injury, inflammation, advanced cataracts, diabetes), the glaucoma is considered to be secondary.⁷ Other types of glaucoma include normal tension glaucoma and congenital glaucoma.⁷

Risk Factors

Although anyone can be diagnosed with glaucoma, certain patient populations have an increased risk for developing it. Commonly known risk factors include the following^2,5,8,9:

• Being older than 60 years
• Being African American and older than 40 years
• Being of African, Latino, or Asian descent
• Having a family history of glaucoma
• Having uncontrolled diabetes or hypertension
• Using steroids/cortisone long term
• Having a history of myopia
• Having previous eye injuries
• Having a thin central cornea (ie, <0.5 mm thick)

Results of a 2013 study suggest that individuals with sleep apnea are at an increased risk for developing open-angle glaucoma.¹⁰

Glaucoma Treatments

In general, the goals of treating glaucoma include lowering IOP, thus preventing further optic nerve and visual field damage; improving overall quality of life; preserving vision; and selecting a therapy with minimal adverse effects.^11-13 Although there are several treatment options for preserving vision (eg, medication, laser trabeculoplasty, conventional surgery, or a combination of these treatments), they do not improve vision that has already been compromised by glaucoma.^11-13 Generally, the use of pharmacologic agents is the preferred treatment because they are associated with a low incidence of risk and their adverse effects are typically reversible.^11-13

The drug classes used for treating open-angle glaucoma include alpha-agonists, beta- blockers, carbonic anhydrase inhibitors, miotic agents, and prostaglandin analogues.^5,11-13 These agents decrease IOP by decreasing aqueous humor production or increasing aqueous humor outflow.^11-13 Some patients may require more than 1 medication to lower IOP. Some individuals may require a combination of therapies or surgery, especially if medication is insufficient or intolerable.

Patient Adherence

Patient adherence is key to successful therapy, but several reasons for nonadherence have been identified. Some studies suggest that patient adherence continues to be problematic, and multiple studies report that more than 50% of patients with open-angle glaucoma discontinue the prescribed therapy within 1 year.^14,15 A study published in the June 2103 issue of Ophthalmology reported that individuals with severe glaucoma were more likely to adhere to therapy compared with patients with mild to moderate glaucoma.¹⁶

Reasons for nonadherence include medication-related patient factors, provider factors, and environmental factors.^14,15,17 The American Academy of Ophthalmology and clinical studies have identified several factors that may negatively affect patient adherence to therapy (Online Table 2^14,15,17-23). One study estimated that 58% of glaucoma patients do not take their medication as prescribed because they do not understand the serious nature of glaucoma.¹⁸

Table 2: Factors that May Affect Patient Adherence

• Adverse effects
• Lack of understanding about glaucoma
• Physical impairments often related to aging (eg, difficulty administering treatment due to dexterity or vision problems)
• Other chronic health conditions
• Cost of medications
• Complex treatment regimens or number of doses per day
• Difficulties in communication with health care provider
• Lack of a support system or help with medication therapy

Adapted from references 14, 15, 17-23.

Patient Counseling

When patients are counseled about their prescribed medication, it is imperative that they understand the importance of adhering to their treatment plan and taking their medications as directed. Pharmacists should screen patients for potential contraindications or drug interactions and advise patients on how to manage adverse effects. For ophthalmic medications to be effective, patients need to be educated on how to properly instill these medications (Online Table 3²⁴). Patients should be encouraged to discuss any issues with their primary health care provider. Because glaucoma and some of the pharmacologic agents used for treatment can make eyes more sensitive to light and glare, pharmacists can recommend the use of sunglasses to help protect patients’ vision.

Table 3: Counseling Patients on Proper Instillation of Ophthalmic Medications

• Always wash your hands before applying eyedrops.

• If you use eye ointments and eyedrops, always use the eyedrops first.

• Tilt your head back, and with 1 hand, pull down the lower eyelid to form a pocket.

• With the other hand, hold the bottle as close to the eye as possible without touching it. Apply a drop of medication.

• After the drop has been applied, close the eye for at least 1 minute to prevent the drop from draining out.

• If another drop from another medication is needed, wait at least 5 minutes before administering it.

• Wash your hands after administering eyedrops, and store the medication in a proper place

More detailed information on administering eyedrops can be found on the Glaucoma Research Foundation website at www.glaucoma.org/treating/eyedrop_tips_1.php.

Adapted from reference 24.

Pharmacists can remind patients to maintain routine checkups with their eye specialist and to have an eye examination, including dilation, at least every 1 to 2 years or as directed by their health care provider. According to current recommendations by the American Academy of Ophthalmology, individuals with no signs of or risk factors for eye disease should have a baseline eye screening exam at 40 years of age.²⁵

Closing Thoughts

Ongoing research provides hope for glaucoma patients. Research reported this year includes the possibility of using a nanodiamond-embedded contact lens as a drug delivery system, with fewer adverse effects. Researchers have also discovered potential drug targets for early-onset glaucoma.^26,27

Although a diagnosis of glaucoma may seem overwhelming, most glaucoma cases can be effectively managed through patient education, early detection and intervention, proper and consistent treatment, and routine monitoring. In addition, patients should be encouraged to take an active role in their health and discuss the available treatment options with their primary health care provider.

Ms. Terrie is a clinical pharmacist and medical writer based in Haymarket, Virginia.

References

• Glaucoma facts and stats. Glaucoma Research Foundation website. www.glaucoma.org/glaucoma/glaucoma-facts-and-stats.ph. Accessed April 1, 2014.
• Glaucoma facts & statistics. Bright Focus Foundation website. www.brightfocus.org/glaucoma/about/understanding/facts.html. Accessed April 1, 2014.
• Risk of glaucoma blindness drops by half: study. HealthDay website. http://consumer.healthday.com/senior-citizen-information-31/misc-aging-news-10/glaucoma-blindness-risk-ophthalmology-mayo-release-batch-1109-684105.html. Accessed May 12, 2014.
• Malihi M, Moura Filho ER, Hodge DO, Sit AJ. Long-term trends in glaucoma-related blindness in Olmsted County, Minnesota. Ophthalmology. 2014;121(1):134-141.
• Bell J. Primary open-angle glaucoma treatment & management. Medscape website. http://emedicine.medscape.com/article/1206147-treatment. Accessed April 2, 2014.
• Robin A, Grover DS. Compliance and adherence in glaucoma management. Indian J Ophthalmol. 2011;59(suppl):S93-S96.
• Types of glaucoma. The Glaucoma Foundation website. www.glaucomafoundation.org/types_of_glaucoma.htm . Accessed April 1, 2014.
• Glaucoma. American Optometric Association website. www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/glaucoma. Accessed April 1, 2014.
• Are you at risk for glaucoma? Glaucoma Research Foundation website. www.glaucoma.org/glaucoma/are-you-at-risk-for-glaucoma.php. Accessed April 3, 2014.
• Lin CC, Hu CC, Ho JD, Chiu HW, Lin HC. Obstructive sleep apnea and increased risk of glaucoma: a population based matched cohort study. Ophthalmology. 2013;120(8):1559-1564.
• Lee DA, Higginbotham EJ. Glaucoma and its treatment: a review. Am J Health Syst Pharm. 2005;62:691-699.
• Facts about glaucoma. National Institutes of Health National Eye Institute website. www.nei.nih.gov/health/glaucoma/glaucoma_facts.asp. Accessed April 4, 2014.
• Glaucoma medications and their side effects. Glaucoma Research Foundation website. www.glaucoma.org/treatment/glaucoma-medications-and-their-side-effects.php. Accessed April 4, 2014.
• Improving medication adherence in patients with glaucoma. Medscape website. www.medscape.org/viewarticle/713779. Accessed April 3, 2014.
• Improving medication compliance among glaucoma patients. Ocular Surgery News website. www.healio.com/ophthalmology/glaucoma/news/online/%7B4555ce2a-47e3-462e-a947-789e061a6ac9%7D/improving-medication-compliance-among-glaucoma-patients. Accessed April 4, 2014.
• Glaucoma watch: medication adherence better in patients with advanced glaucoma. Pharmacy Times website. www.pharmacytimes.com/publications/issue/2013/September2013/Medication-Adherence-Better-in-Patients-with-Advanced-Glaucoma. Accessed April 3, 2014.
• Tsai JC. A comprehensive perspective on patient adherence to topical glaucoma therapy. Ophthalmology. 2009;116:S30-S36.
• Herdon L. Communication is the cornerstone of glaucoma treatment. Ophthalmology Management website. www.ophthalmologymanagement.com/articleviewer.aspx?articleid=86075. Accessed April 3, 2014.
• Stryker JE, Beck AD, Primo SA, et al. An exploratory study of factors influencing glaucoma treatment adherence. J Glaucoma. 2010;19(1):66-72.
• Tsai JC. A comprehensive perspective on patient adherence to topical glaucoma therapy. Ophthalmology. 2009;116:S30-S36.
• Yeaw J, Benner JS, Walt JG, et al. Comparing adherence and persistence across 6 chronic medication classes. J Manag Care Pharm. 2009;15:728-740.
• Hahn SR. Patient-centered communication to assess and enhance patient adherence to glaucoma medication. Ophthalmology. 2009;116(suppl):S37-S42.
• Budenz DL. A clinician’s guide to the assessment and management of nonadherence in glaucoma. Ophthalmology. 2009;116(suppl):S43-S47. ,
• Eye Drop Tips. Glaucoma Research Foundation website. www.glaucoma.org/treatment/eyedrop-tips.php. Accessed April 4, 2014.
• Glaucoma diagnosis. eyeSmart website. www.geteyesmart.org/eyesmart/diseases/glaucoma/diagnosis.cfm. Accessed April 3, 2014.
• Nanodiamond-embedded contact lenses may improve glaucoma treatment. Bright Focus Foundation website. www.brightfocus.org/glaucoma/newsupdates/nanodiamond-embedded-contacts-to-treat-glaucoma.html. Accessed April 1, 2014.
• Researchers discover potential drug targets for early-onset glaucoma. Bright Focus Foundation website. www.brightfocus.org/glaucoma/newsupdates/researchers-discover-potential-drug-targets-glaucoma.html. Accessed April 1, 2014.