An Examination of the Presbyopic Patient With Dry Eye

It is estimated that 2 billion of the nearly 7.8 billion people on the planet are presbyopic.¹ An estimated 16 million US adults have been diagnosed with dry eye disease,² but some reports indicate that nearly half of all US adults experience dry eye signs and symptoms.³

The prevalence of dry eye increases with each passing decade of life starting at age 40,⁴ and the prevalence of dry eye symptoms in women increases from 14% at 50 years of age to 22% for those 80 and older. In men, the prevalence of dry eye symptoms increases from 7% between 60 and 69 years of age to 13% for those 80 and older.⁵ Although literature reviews have not suggested a positive correlation between presbyopia and dry eye disease, the aging population primarily constitutes the majority of patients who report symptoms consistent with those of dry eye.

What factors should practitioners consider when they treat presbyopic patients with dry eye, and why does this age group differ from others? I’ll tackle these questions here.

THE EFFECTS OF DEVICE USE

Blinking helps our eyelids to mechanically discharge the meibomian glands. Blink rate reduction with near work is well documented. Multiple studies have come to the conclusion that spontaneous eye blink rates are reduced irrespective of type of reading platform.^6,7 It is hypothesized that blink inhibition with near work may arise from high cognitive demand or from a low-legibility condition that requires us to perform prolonged fixation while acquiring visual information.⁸

A recent study in which I was involved as a researcher identified a negative correlation between time spent on digital devices and meibomian gland function and structure and the symptomatology of dry eye disease. Researchers from five clinics across the United States and Canada used members of Old Order Amish populations as a control group because of their limited exposure to digital devices. This multicenter study of 64 patients found that digital device use for more than 2 hours per day resulted in statistically significant morphologic changes in meibomian glands (gland atrophy) and increased symptoms of dry eye disease (Figure).⁹ We also found that meibum quality and expressibility were both negatively affected with more than 2 hours per day of digital device use, and we demonstrated a negative correlation between the amount of digital device use per day and the quality of expressible meibum.⁹

ACCOMMODATIVE DEMAND AND OCULAR ALIGNMENT

Some consumers spend more than 50% of their days—more than 12 hours—connected to media, according to The Nielsen Total Audience Report.¹⁰ Specifically, adults between ages 50 and 64 years spend an average of 13 hours, 50 minutes connected to media, which is twice the amount spent by adults between ages 35 and 49 years.¹⁰

The average American has approximately eight networked devices, and with 5G on the verge of being the next mainstream normal that number is expected to climb to 13.6 networked devices per person by 2022.¹¹ With an array of digital devices and the diverse nature of a person’s visual demands, it is important to remember the role that accommodation can play in one’s visual comfort.

Some patients do not fixate accurately at the point of interest, and their vergence angle may correspond with a point slightly closer or farther away. In today’s digital workplace, accommodative demand is an ever-changing carousel. One study of 23 patients found that their mean viewing distance while using their smartphones was 20.3 cm when seated and 16.4 cm when lying down.¹² The average viewing distance for an iPad or tablet is around 38 cm, a laptop 50 cm, and a desktop monitor around 70 cm. Another study of 3,314 patients found that the prevalence of any phoria (distance or near) was 28.37% and that the prevalence of phoria significantly increased with age. The prevalence of near exophoria and near esophoria was 25.96% and 0.47%, respectively.¹³

Clinical research has shown that 90% of ocular misalignments are greater at near than distance.¹⁴ Fifty percent of patients who have unresolved dry eye symptoms, despite all proper dry eye treatment protocols, have at least three symptoms that could be related to ocular misalignment.¹⁵ Furthermore, in patients whose primary complaint is late-day dry eye, symptoms seem to lessen when they are prescribed prismatic correction in spectacle lenses (neurolenses, eyeBrain Medical).¹⁶ In a study of 360 patients who were prescribed contour prism for 90 days, 93% had a reduction in symptoms of computer vision syndrome.¹⁵

Presbyopic adults spend a majority of their waking hours viewing digital media, and they should undergo a thorough assessment of their ocular alignment and refractive demands in addition to a standard dry eye workup.

THE ROLE OF HORMONES

Sex hormones are constantly changing in the presbyopic adult. Both estrogens and androgens influence the synthesis and components of the tear film, including the lipid, aqueous, and mucin layers. The meibomian glands have androgen-binding receptors that play a part in the synthesis and secretion of lipids. Estrogen actually causes a decrease in lipid production, and increased levels of estradiol are believed to be a risk factor for dry eye.^17,18 However, the relationship between sex hormone levels and dry eye treatments remains controversial, as the effects of estrogen and androgen therapy to treat dry eye are not well understood.

Hormone replacement therapy (HRT) has shown mixed results in its effect on dry eye symptoms across a number of studies.^19,20 In women with abnormally low testosterone levels, men on androgen blockers, and patients with androgen insensitivity syndrome, topical androgen treatments are widely considered beneficial.²¹ A systematic literature review of HRT showed significant improvement of dry eye (tear production and tear breakup time) at 1 month, but a nonsignificant impact at 3 and 6 month follow-ups).¹⁹

BE PREPARED TO IDENTIFY AND MANAGE DRY EYE

Dry eye is increasingly prevalent as the average person is consumed by digital device use during the majority of his or her waking hours. It is crucial to perform a comprehensive evaluation of any patient who presents with dry eye symptoms, including both a refractive and a binocular assessment of the patient’s vision system. Primary eye care providers should be equipped with the ability to diagnose and treat dry eye for the presbyope while instituting interventions using a comprehensive ophthalmologic approach.