The Dry Eye Report

… and it is not just a pain in the eye

by Hazlin Hassan

While dry eye disease (DED) may seem like a minor inconvenience, the condition is becoming more and more common — and it is not just a pain in the eye.

A Global Dry Eye Treatment Devices Market Report 20221 released in November 2022 revealed that the market size is expected to reach US $348.8 million by 2028. This is an increase in the market growth of 7.4% compound annual growth rate (CAGR) during the forecast period.

The rise underlines the demand for cutting-edge treatments and the need for treatments to be customized to each patient by focusing on the distinct mechanisms linked to their condition, depending on the various presentations and pathophysiology.

Prevalence and pain

Dry eye is an extremely prevalent and underdiagnosed ocular condition. It is a growing health problem worldwide with a global prevalence of 11.59%.2 In the US alone, DED has been diagnosed in about 16.4 million adults, and 6 million more experience DED symptoms without a formal diagnosis.3 It is also more prevalent in older individuals and women.

Patients who have dry eyes experience uncomfortable symptoms, including burning, stinging, grittiness, soft tissue sensation, tearing, ocular fatigue, and dryness — because their tear film is unstable and unable to maintain the protective qualities required for its structure and function.

According to the report, DED is considered untreatable and needs constant care to restore and keep the ocular surface system's equilibrium.

Treatments, signs, and symptoms

Treatments for DED currently include broadband light (BBL), intense pulsed light (IPL), meibomian gland expression (MGX), and combination (MGX+IPL).

The report shared that the IPL segment garnered a significant revenue share in the dry eye treatment devices market in 2021.

Slit-lamp examinations with and without various stains, such as fluorescein, are used in diagnosing a patient. Further tests include the Schirmer test, tear break-up time, tear function index, and functional visual acuity.

People with dry eyes can experience itchiness, watery eyes, a sensation of foreign bodies, redness, and eye pain. Uncontrolled screen time using smartphones, laptops or tablets can lead to an increase in dry eye symptoms.

Other symptoms of DED include hyperemia, low tear lakes, a quick tear break-up period, and meibomian gland disease. DED symptoms are usually exacerbated by diseases such as blepharitis, diabetes, thyroid problems, rheumatoid arthritis, systemic lupus, and Sjogren's syndrome.

Who are at risk?

At the Hava Optique eyewear company in Cyberjaya, Malaysia, fluorescein tests conducted on patients with complaints of DED symptoms found that 70% were women with low tear break-up time. It also found a higher prevalence in older patients, with all patients aged 40 years and above recording low tear break-up time.

While DED is common among both contact lenses wearers and nonwearers, the symptoms can be more severe for the previous. “In Malaysia, an online survey of Contact Lens Dry Eye Questionnaire (CLDEQ-8) was distributed through social media. A total of 140 contact lens wearers completed the online survey, and 98.6% of them were soft contact lens wearers,” shared Ms. Nur Marsya Sabrina Mohamad Sahrizal, an optometrist at Hava Optique.

Some 93.6% of contact lens wearers complained of dry eye symptoms, she noted. Environmental factors include low humidity, wind, air conditioning, prolonged near-work — including reading, screen time, driving, and exposure to second-hand smoke.

Medications also play a role in the increased risk of DED. Some of the medications that can cause dry eyes include diuretic agents, betablockers, antihypertensive agents, antihistamines, decongestants, antidepressants, oral contraceptives, herbal supplements, and isotretinoin.

The OSDI questionnaire…

The Ocular Surface Disease Index (OSDI) questionnaire is often used for patients experiencing ocular surface discomfort, with questions regarding visual functions, social activity, and environmental influences.

One of the signs observed in dry eye patients is their tear break-up time. “At Hava Optique, we determine dry eye disease when tear break-up time is less than five seconds. Using the Schirmer test, patients with less than 5 mm in five minutes are also considered to have dry eye disease,” said Ms. Nur Marsya Sabrina.

The Schirmer's test determines whether the eye produces enough tears to keep it moist. It works by placing a strip of filter paper in the lower eyelid pouch. A normal test result would see more than 10 mm of moisture on the filter paper in five minutes.

The Meibomian glands are also checked for any blockages. Lastly, the tear meniscus height measurement is taken. "If it is less than or equal to 0.3 mm, it is classified as abnormal using the variable beam height on the slit lamp,” Ms. Nur Marsya Sabrina noted.

…versus the SPEED questionnaire

Another questionnaire, known as the Standard Patient Evaluation of Eye Dryness (SPEED), has been shown to be a repeatable and valid metric with the needed psychometric properties for the identification of a patient’s dry eye symptoms using a clinic-based sample.

The two questionnaires differ, but they both aim to accurately capture a patient’s dry eye symptoms and also monitor the efficacy of various dry eye treatments.

The SPEED questionnaire is both a frequency- and severity-based questionnaire designed to track diurnal and long-term symptom changes over a period of three months.

The composite score of the SPEED questionnaire is obtained by summing the scores from the frequency and severity parts of the questionnaire.

The symptoms include dryness or grittiness or scratchiness, soreness or irritation, burning or watering, as well as eye fatigue reported and scored as sometimes, often, and constant — and whether these symptoms posed no problems, were tolerable, uncomfortable, bothersome, or intolerable.

Ms. Nur Marsya Sabrina said she finds the OSDI questionnaire easier for her to use in patients compared to the SPEED, as patients can better understand it — both in the English and Malay versions — and the symptoms are more relatable to her patients.

References

1. Global Dry Eye Treatment Devices Market Report 2022: High Incidence & Prevalence of Dry Eye Diseases Boosting Sector. Available at: https://www.globenewswire.com/en/newsrelease/2022/11/08/2550646/28124/en/ Global-Dry-Eye-Treatment-Devices-MarketReport-2022-High-Incidence-Prevalenceof-Dry-Eye-Diseases-Boosting-Sector.html. Accessed on December 28, 2022.

2. Papas EB. The global prevalence of dry eye disease: A Bayesian view. Ophthalmic Physiol Opt. 2021;41(6):1254-1266.

3. Aggarwal S, Galor A. What's new in dry eye disease diagnosis? Current advances and challenges. Review. 2018;7:F1000 Faculty Rev-1952.

Contributing Doctor

Ms. Nur Marsya Sabrina Mohamad Sahrizal is currently an optometrist at the Hava Optique eyewear company in Cyberjaya, Malaysia. She graduated in optometry from the National University of Malaysia (UKM). She has conducted research studies on dry eye diseases, and her passion lies in issues concerning contact lenses. She has conducted several community services for eye health screening offline as well as online. During her leisure time, she enjoys dancing on her own and watching horror movies.

marsyaams@gmail.com