How to prevent common eye problems

There are more than 200 eye conditions, ranging from common problems (e.g. dry eye disease [DED], cataracts and glaucoma) to rarer diseases (e.g. ocular melanoma and vernal keratoconjunctivitis). Some of these have no symptoms and can cause loss of sight before patients even realise what is happening. There are 1.8 million people in the UK who are living with significant sight loss, 50% of which is avoidable^[1]
. As such, the government’s Public Health Outcomes Framework has highlighted preventable sight loss as a health priority^[2]
.

There are many services that pharmacists and healthcare professionals can signpost patients to that support the aim of reducing the incidence of preventable sight loss. This article describes how to identify patients in at-risk groups and counsel them on lifestyle changes and the treatments that are available. It also outlines the ‘red flag’ symptoms as well as when and where to refer patients.

1. Reduce alcohol consumption

In addition to increasing the risk of heart disease, liver disease and certain cancers, persistent alcohol misuse can also affect long-term eye health. Alcohol use has been shown to exacerbate the signs and symptoms of DED (also known as keratoconjunctivitis sicca)^[3]
, a condition where the eyes do not make enough tears or the tears evaporate too quickly, leading to the eyes drying out and becoming red, swollen and irritated (see Box 1). A case–control study in ten patients following ethanol ingestion demonstrated that ethanol was detected in the person’s tears and was associated with a decreased tear break-up time (through ethanol acting as a solvent), increasing tear osmolarity and disturbing cytokine production^[4]
.

Heavy alcohol consumption has also been associated with known causes of blindness, including age-related macular degeneration (AMD; when the cells in the central part of the retina become damaged and central vision is impacted as a result). A meta-analysis of five published studies found that heavy alcohol consumption, defined as an intake of ≥30g of alcohol/day, was associated with an increased risk of early AMD^[7]
. Alcohol is thought to increase oxidative stress by modifying the mechanisms that protect against it, resulting in AMD^[7]
. The link with cataracts (clouding of the lens in the eye) is less clear, but an increased prevalence of cataracts has been reported in patients with heavy alcohol consumption^[8]
.

Pharmacists should counsel patients in accordance with current NHS guidance: people should not drink more than 14 units of alcohol (a unit of alcohol is defined as 10mL of pure alcohol, roughly equivalent to 8g) per week and alcohol consumption should be evenly spread over three or more days, with several alcohol-free days each week^[9]
. Patients can be signposted to organisations that can help provide support alongside the NHS, including Alcohol Concern, Alcoholics Anonymous and Drinkaware.

2. Quit smoking

A history of cigarette smoking has been associated with an increased risk of AMD and is related to both its incidence and progression^[10]
. Current smokers have been shown to be at an increased risk of developing AMD, compared with ex-smokers and non-smokers who are exposed to second-hand smoke^[11]
. Cigarette smoke has also been shown to have a dose-related relationship with the formation of cataracts^[12]
. It has also been linked to diabetic retinopathy (the blockage of blood vessels at the back of the eye), DED and glaucoma (a condition affecting the optic nerve).

A cross-sectional survey of 260 teenagers found that fear of blindness was just as compelling a motivation for smoking cessation as fear of lung cancer, heart disease and stroke^[13]
. Discussions relating to eye care could, therefore, help motivate patients to quit smoking.

Pharmacists and healthcare professionals should enquire on the smoking status of all patients at least once per year and should discuss it during routine consultations. They can even provide advice to patients outside of smoking cessation services or the provision of nicotine replacement therapy, including during the purchase of over-the-counter (OTC) medicines, through medicines use reviews or during local or national campaigns (e.g. No Smoking Day). 

3. Protect eyes from the sun

High levels of exposure to ultraviolet (UV) A and B light are known risk factors for numerous eye conditions, including cataracts and cancer^[14]
. Most brands of prescription glasses now contain a UV filter, but not all sunglasses provide adequate protection. Patients should be counselled to ensure their sunglasses are either CE or BS marked (i.e. proof of conformity with European or British standards, respectively), and are the appropriate filter category for their use (filter categories range from 0 to 4, where 4 is the darkest lens). For further advice, see Box 2.

4. Reduce screen time

Increasing reliance on digital devices has led to a rapid increase in computer-related eye symptoms, known as computer vision syndrome (CVS)^[15]
. Symptoms of CVS can be divided into four categories:

• Eye strain (asthenopia);
• Dry or painful eyes relating to the ocular surface^[3],[16]
  ;
• Difficulty focusing (visual blur);
• Other non-ocular symptoms^[15]
  .

For patients experiencing CVS, a range of pharmacy medicines are available over the counter, along with environmental management options, such as:

• For symptoms of fatigue, everyone using screens should be advised to follow the 20:20:20 rule (every 20 minutes individuals take a 20-second break and focus on an object 20 feet away)
  • Modify the screen environment, taking into account lighting and glare, airflow, screen and seating configuration and blue light.
• Refering patients with blurred vision to an optometrist
  • If difficulty focusing is a problem, patients should be advised of the Health and Safety Executive guidance (i.e. that employers have to provide an eye test if an employee habitually uses display screen equipment as a significant part of their normal day-to-day work).
• Following advice for mild aqueous-deficient DED
  • Treat with artificial tears and ocular lubricants;
  • Although hydroxypropyl methylcellulose (hypromellose) is commonly recommended, a more viscous product, such as carbomer 980, may be helpful for patients with CVS because they can increase the time that moisture is retained;
  • Moderate-to-severe symptoms may require prescribed topical anti-inflammatory medications (e.g. ciclosporin, non-steroidal anti-inflammatory eye drops or corticosteroid eye drops);
  • Sodium hyaluronate is often recommended for treatment of more advanced DED.
• Following advice for evaporative DED
  • Ocular lubricants may ease symptoms.
• Modifying the screen environment, taking into account the following factors
  • Lighting and glare;
  • Airflow;
  • Screen and seating configuration;
  • Exposure to blue light.
• For patients with double vision, refer to an orthoptist^[15]
  .

OTC treatments for eye conditions are available in a range of formulations, including sprays, drops, gels and ointments. Patients should be advised of the various products, their potential modes of action and administration methods, to allow them to make an informed decision. For further advice, see Barai and Hammond’s ‘Computer vision syndrome: causes, symptoms and management in the pharmacy’^[15]
.

5. Have regular sight tests

Pharmacists can reinforce the importance of regular sight tests; for the majority of adults, the recommended interval is every two years^[17]
. However, some higher risk patient groups are recommended to have more frequent sight tests (see Box 3). Some patient groups also have additional risk factors for glaucoma (e.g. Afro–Caribbean or Asian patients, or patients who are aged 40 years and over with a family history, are living with diabetes or high blood pressure, or are taking systemic or topical corticosteroids). These patients should be signposted to their local optician if they have not had a recent sight test or have any vision concerns.

Similarly to exemptions from NHS prescription charges, some patient groups are exempt from paying for sight tests. It is worth checking with patients to see if they qualify^[18]
.

6. Follow contact lens hygiene advice

Owing to the nature of introducing a foreign item onto the surface of the eye, and the warm and moist environment in the eye, improper use of contact lenses can lead to problems. Pharmacists should be aware of The Association of Optometrists’s advice for contact lens wearers in order to counsel patients effectively:

• Hands should be washed and dried before handling contact lenses;
• Tap water should never be used to clean lenses (Acanthamoeba is found in tap water, which can lead to sight-threatening infections);
• A specific type of contact lens solution should be used, as advised by an optometrist;
• Contact lens cases should be cleaned weekly with lens solution and replaced monthly when a new bottle of lens solution is opened. The solution in the case should be changed after each lens wear;
• Never swim or bathe while wearing contact lenses unless advised by an optometrist or eye care practitioner that it is safe to do so;
• Never share or swap lenses;
• Apply makeup after putting in lenses and remove once lenses removed;
• Never wear lenses for longer than recommended (maximum 16 hours/day) as this increases the risk of microbial keratitis and DED;
• Never sleep in lenses unless they are specifically designed for overnight wear;
• Go to regular aftercare appointments (at least annually);
• Consult an optometrist in the event of redness, pain or loss of vision;
• If in doubt, take them out^[19]
  . 

7. Attend screening

All patients taking hydroxychloroquine and chloroquine should receive regular eye screening owing to the risk of hydroxychloroquine retinopathy, as stipulated by the Royal College of Ophthalmologists^[20]
. At least 7.5% of patients taking hydroxychloroquine for more than five years will have some retinal damage. Hydroxychloroquine screening schemes are still being developed across the UK; however, it is still important to remind patients about the importance of regular eye screening. The rule of five is a helpful reminder: if patients are taking more than 5mg/kg/day for more than five years, then annual eye screening is required^[20]
. 

8. Practise good eye drop compliance and technique

Around 50% of patients with glaucoma are non-compliant with treatment^[21]
. Given the consequences of treatment failure, pharmacists should consider reasons for this and assist patients to overcome any barriers they may have; this will help prevent poor clinical outcomes and potentially unnecessary polypharmacy. The case study in Box 4 demonstrates how to do this.

When to refer

OTC treatment of common eye problems in the pharmacy is often limited to management of red, sticky, gritty and sore eyes. However, pharmacists should have a good awareness of how to treat DED and bacterial conjunctivitis^[6],[24]
, and recognise red flag symptoms (e.g. visual loss; pain; flashing lights, floaters or halos; headaches; and co-existing diabetes or hypertension).

Where established, minor eye condition schemes (MECS) involve local accredited opticians or optometrists who offer urgent appointments (see Table 1 for an overview). Patients can self-refer or be referred by a pharmacist, GP or NHS 111. Those participating in the MECS can refer patients to eye casualty or hospital eye services if required^[25]
. Pharmacists are advised to check the details of MECS in their area for a definite list of referral criteria.