Eye Conditions

Age Related Macular Degeneration (AMD)

What is it?

Age-related macular degeneration (AMD) is a progressive eye disease affecting the macula—the central region of the retina responsible for sharp, detailed vision. AMD primarily forms when the retinal pigment epithelium (RPE) undergoes damage and deterioration, often due to accumulated deposits known as drusen. These tiny yellow deposits build up between the retina and the choroid over time, leading to the gradual loss of retinal cells. As the disease advances, it typically manifests in one of two forms:

Dry AMD: Characterized by the slow atrophy of the macula and the gradual accumulation of drusen, leading to diminished central vision.
Wet AMD: Involves the formation of abnormal, fragile blood vessels beneath the retina that leak fluid or blood, often resulting in rapid vision deterioration

Prevalence

Age-related macular degeneration (AMD) is a leading cause of vision loss, particularly among older adults. Globally, it affects approximately 196 million people, with projections estimating this number will rise to 288 million by 2040 due to the aging population.

In the United States, an estimated 19.8 million individuals aged 40 and older had AMD in 2019, with 1.49 million experiencing vision-threatening forms of the disease. The prevalence increases significantly with age, from about 2% among those aged 40–44 to nearly 47% among individuals aged 85 and older

Further Reading

Cataracts

What is it?

Cataracts form when the eye’s natural lens becomes clouded due to changes in the delicate crystallin proteins—often as a result of aging, oxidative stress, or UV exposure. Over time, these proteins aggregate and precipitate, causing the lens to lose its clarity and leading to impaired vision. This process, commonly known as age-related cataract formation, is also influenced by factors such as genetics, diabetes, and environmental exposures, making it a multifactorial condition that experts continue to study for better prevention and treatment strategies.

Prevalence

Globally, cataracts are the leading cause of blindness, impacting an estimated 20 million people, with the condition becoming increasingly prevalent as populations age. Regional studies, such as those focusing on the burden in South and Southeast Asia where prevalence can exceed 40%, underline the significant public health challenge that cataracts present.

Further Reading

Cataract as viewed through the Aston Vision Sciences Lumio device under dilation

Cataract Under Dilation with Lumio device

Dry Eye Disease

What is it?

Dry eye Disease (DED), also known as Keratoconjunctivitis sicca (KCS) is a global health issue affecting compromised tear film production which can manifest itself as a number of co- dependent symptoms ranging from minor discomfort, visual compromise right through to persistent pain severely on the anterior eye, interfering with daily activities. Patients experiencing long term DED risk worsening progression which can lead to serious visual complications involving corneal epithelial defects, superficial punctate erosions, conjunctival and corneal scarring, and chronic pain. Furthermore, dry eye patients often exhibit measurable shortages of tear film defensive compounds such as lysozyme and lactoferrin which increase the risk of acute and chronic infections such as acne rosacea and blepharitis.

The hotly anticipated Tear Film and Ocular Society report entitled Dry Eye Workshop III is due to be released in the first half of 2025 and will offer updated information on the subject of Dry Eye Disease.

Prevalence

Estimates suggest that DED affects approximately 10–20% of individuals over the age of 40, with the condition becoming increasingly prevalent due to lifestyle and environmental changes. New evidence put forward by the Vision council 2016 Digital eye strain report shows 73% of US patients below the age of 30 demonstrating symptoms of digital eye strain, higher than any other age group (1).

Further Reading

Placido rings created by the Mobile Eye Examiner (MOBEE) from Aston Vision Sciences showing tear film breakup on a patient's eye — Tear break up time measurement to assess tear stability

Glaucoma

What is it?

Glaucoma is a progressive neurodegenerative eye disease primarily characterized by optic nerve damage, which is often—but not always—associated with elevated intraocular pressure (IOP). This increase in IOP typically results from impaired drainage of the aqueous humor, leading to the gradual death of retinal ganglion cells and irreversible vision loss. In some cases, even with normal IOP, patients can develop “normal-tension glaucoma,” suggesting that other factors such as vascular dysregulation and genetic predisposition also play a crucial role in its formation.

Prevalence

Glaucoma is a leading cause of irreversible blindness worldwide, affecting approximately 3.54% of individuals aged 40 to 80 years. The most common form, Primary Open-Angle Glaucoma (POAG), has a global prevalence of around 3.05%, while the more severe Primary Angle-Closure Glaucoma (PACG) affects about 0.50%. Regional differences are notable, with Africa experiencing the highest prevalence at 4.0%, followed by Asia (3.0%), Europe (2.0%), and North America (1.5%). The global number of glaucoma cases is expected to rise from 64.3 million in 2013 to an estimated 111.8 million by 2040. In the UK alone, over 2 million people are at risk of vision loss due to glaucoma, many of whom are unaware they have the condition.

Further Reading

Presbyopia

What is it?

Presbyopia is an age-related refractive condition that arises primarily due to the gradual loss of elasticity in the crystalline lens along with weakening of the ciliary muscles. As people age, the lens becomes stiffer and less capable of changing shape to focus on near objects. This diminished accommodative ability causes difficulty in performing near-vision tasks such as reading, writing, or using digital devices, and is a natural part of the aging process.

Prevalence

Globally, presbyopia affects an estimated 1.09 billion people, with prevalence rates reaching up to 90% in adults aged 35 and older in some regions. The condition significantly impacts quality of life by reducing near-vision clarity, which in turn can hinder daily activities and work productivity. Uncorrected presbyopia not only affects individual lifestyles but also has broader socioeconomic implications, leading to substantial global productivity losses.

Further Reading

Tachoma

What is it?

Trachoma is a chronic, infectious eye disease caused by the bacterium Chlamydia trachomatis. It typically begins in childhood through repeated bacterial infections that cause persistent inflammation of the conjunctiva and lead to scarring of the inner eyelid. Over time, the scarring can cause the eyelid to turn inward (a condition known as entropion), resulting in misdirected eyelashes that scratch the cornea (trichiasis). This repeated irritation and damage to the ocular surface ultimately may lead to irreversible vision loss or blindness if left untreated.

Prevalence

Globally, trachoma remains the leading infectious cause of blindness, with an estimated 1.4 million people affected and hundreds of millions more at risk, particularly in rural and underdeveloped regions with limited access to clean water and sanitation. The disease disproportionately impacts impoverished communities in Africa, Asia, and parts of the Middle East, where the World Health Organization (WHO) has spearheaded large-scale elimination initiatives such as the SAFE strategy—Surgery, Antibiotics, Facial cleanliness, and Environmental improvements—that aim to reduce both incidence and the overall burden of the disease.

Further Reading