Detecting and Monitoring Health Conditions and Risks with Ocular Exams

Comprehensive Eye Exams

Although many people confuse routine eye exams for comprehensive eye exams, there is a distinct difference between the two.

A routine eye exam is often done in an optometry office once a year to monitor vision and identify any visual changes. However, a comprehensive eye exam does not need to be done annually.

According to an article by the American Academy of Ophthalmology (AAO), healthy people with normal vision do not need a complete eye exam yearly. Instead, they should get a comprehensive eye exam once in their 20s and twice in their 30s for baseline assessments and early disease detection.

“Annual or biannual examinations are not recommended until age 65 years unless the individual is known to have an eye condition or a medical condition which warrants more frequent examination (such as diabetes, pre-glaucoma, or early macular degeneration) or if they are at higher risk due to family history,” revealed Sandra Brown, MD, ophthalmologist, and medical advisor for the Dry Eye Foundation, in an interview with LifeSciencesIntelligence.

The 2015 Frequency of Ocular Examination Clinical Guidelines from the AAO note that patients who have yet to have a comprehensive eye exam should have one by age 40.

The components of a comprehensive eye exam may vary slightly based on the provider, patient age, and reason for the visit. However, providers generally start by taking a medical history, testing visual acuity, and checking or providing a new prescription.

After that, they will likely check pupil response, eye movement, peripheral vision, and intraocular eye pressure. Additionally, providers will examine each eye's eyelids, cornea, iris, and lens. The last component of these in-depth exams involves assessing retinal health and the optic nerve in the back of the eye.

Some ophthalmologists may incorporate additional specialized imaging to detect eye diseases, including optical coherence tomography (OCT), fundus photos, fluorescein angiography (FA), topography, and automated visual field tests.

This initial assessment will help the provider determine the appropriate schedule for future eye exams based on a patient’s ocular health and disease history. Some patients with chronic health problems may be required to get more frequent exams, depending on the type or severity of the disease.

“It is not essential for every patient with chronic illnesses to get regular eye exams. Only those diseases which might negatively affect the structure or function of the eye warrant annual eye examinations.  Of these, the critical diagnosis is diabetes,” explained Brown. “Adults with type 1 or type 2 diabetes who do not have diabetic eye damage should generally have an annual eye examination.  Once the diabetic damage starts, the examination frequency may be increased to twice a year or more, depending on severity.”

Diseases Detected and Assessed Through Eye Exams

As indicated by the AAO and many public health experts, a host of chronic diseases can be detected or assessed through ocular exams, providing additional insight into patient health.

“One unique feature of the eye is that the doctor can examine blood vessels in the retina (the nerve tissue that transforms light signals into electrical signals). This is the only part of the human body where arteries and veins are directly visible. Eye doctors can therefore diagnose unsuspected conditions that affect blood vessels, like diabetes,” said Brown.

“Several eye conditions, which do not cause perceptible vision loss until advanced, can be detected by routine eye examination, including glaucoma and macular degeneration,” she added.

A 2022 article published by the AAO revealed 20 different conditions that can be detected or assessed through eye exams, including aneurysms, brain tumors, cancer — such as blood, tissue, or skin cancers — diabetes, heart disease, high blood pressure, high cholesterol, multiple sclerosis, rheumatoid arthritis, vascular disease, thyroid disease, and many more. Although each disease provides different insights into human health, this article will focus on diabetes, heart disease, high blood pressure, high cholesterol, and neurological conditions.

Diabetes

Diabetes can be detected and monitored through comprehensive eye exams. According to the NIH, high blood glucose may cause tissues to retain fluid, leading to blurred vision. Long-term elevated blood glucose levels can cause damage to tiny blood vessels in the eye, which may leak and damage the eye.

Although diabetic ocular damage requires persistently high blood glucose over time, the damage can begin during the prediabetes stage, when a patient has not been diagnosed with diabetes yet.

As a result of the damage, patients may develop diabetic retinopathy, diabetic macular edema, glaucoma, or cataracts. Evidence of these conditions may indicate to providers that a patient should be assessed for diabetes or that their diabetes is not well controlled.

Heart Disease and Related Conditions

In addition to diabetes, heart disease may be detected through ophthalmic exams. According to the AAO, patients with heart disease may present with an eye stroke due to limited oxygen and blood flow to the eye. These strokes are usually detected using OCT imaging.

Another condition linked to heart disease that may cause stroke is high cholesterol. High cholesterol may present as a yellow or blue ring around the cornea. High cholesterol detected through an eye exam can be fatal depending on the patient's age and overall health.

Additionally, high blood pressure, known to cause glaucoma, diabetic retinopathy, and macular degeneration, may present as kinks in blood vessels or bleeding in the back of the eye.

Neurological Conditions and Nervous System Disorders

Recently, researchers published an article in Acta Neuropathologica identifying ophthalmic biomarkers for Alzheimer’s disease. Investigators implied that higher levels of amyloid β-protein (Aβ42) forms and novel intraneuronal Aβ oligomers (AβOi) and packed astrocytes and microglia around the plaques identified in an eye examination of the retina could be indicative of Alzheimer’s.

“While several articles have been published over the past several years regarding the detection of Alzheimer’s through the eyes, these findings are still preliminary, and there is still much research to be done to solidify this connection,” stated Brown.

“We do know, however, that eye examinations can detect neurological conditions such as brain tumors, brain aneurysms, increased brain fluid pressure, and small strokes that cause double vision but no other symptoms that the patient would understand to be a stroke,” she added.

Ophthalmic Education and Patient Protection

While ophthalmic exams may provide insight into eye health, overall health, and managing health conditions, patients must receive proper education to minimize the risk of severe health issues.

Beyond routine eye exams to detect early stages of the disease, patients must be cognizant of how over-the-counter eyedrops may impact their health outcomes.

“A major risk to patients is the proliferation of over-the-counter eye drops available through e-commerce. The FDA does not approve or even review OTC products,” said Brown. 

Recently, there has been a flurry of recalls on over-the-counter eyedrops, starting with a recall of the Global Pharma Healthcare artificial tears contaminated with Pseudomonas Aeruginosa. Shortly after that initial recall, multiple other companies, including Apotex Corp and Pharmedica USA LLC, issued additional recalls due to similar contamination.

“Low-cost eye drops may be manufactured incorrectly and imported and distributed by companies with no background in eye pharmaceuticals. This can lead to improper product formulation and bacterial contamination leading to blindness and even death,” she noted.

In the most recent recalls, multiple patients reported adverse events such as vision loss, blurred vision, eye pain, enucleation, and more.

“Eye care providers have learned that they must pay more attention to their patients’ OTC eye drops, which may be the source of persistent eye irritation or repeated infection which is otherwise inexplicable,” explained Brown.

In addition to vigilance surrounding over-the-counter eyedrops, providers must also be on the lookout for false advertising,

“Ophthalmologists and optometrists must also learn to be more skeptical of the unproven claims of manufacturers of unique-seeming eye drops, such as amniotic fluid eye drops,” noted Brown. “These manufacturers may use the same marketing channels as legitimate manufacturers of FDA-approved prescription products, or FDA-compliant OTC products, effectively fooling eye care providers into believing that the eye drops are safe and effective or otherwise comply with FDA regulations.”

In addition to vigilance by eye care providers, patients, and the public must also take the initiative and protect themselves from ocular infections or injury. The Dry Eye Foundation has developed a website to educate patients on the appropriate use of eye drops and highlight the critical alerts on eye drops.

Beyond using the resources provided by the Dry Eye Foundation, FDA, and CDC, Brown notes, “Patients using e-commerce can protect themselves by primarily purchasing products that are available in drugstores and by ensuring that the online retailer is not a ‘reseller’ who sells a variety of unrelated products.”

She revealed that a telltale sign of an unreliable vendor is exclusive online availability, saying, “There are a few eye drops available only through e-commerce, which are distributed by reputable smaller companies dedicated to the eye care space.”

With so many health risks being tied to eyes and ocular care, it is critical that providers and public health experts emphasize proper eye care.