What’s in the web for family physicians – common eye problems

Wilbert WB Wong 王維斌，Alfred KY Tang 鄧權恩

Eye conditions are commonly encountered in primary care. Early identification of acute eye injuries and infection and of acute and progressive visual loss are essential roles for general practitioners.

Identification of individuals at risk of common conditions such as diabetic retinopathy, glaucoma and age-related macular degeneration are also important to ensure early institution of appropriate screening and prevention strategies.

General practitioners are indispensable in the co-ordination of care of individuals with visual impairment to ensure access to appropriate community supports and necessary services.

Differentiating Urgent and Emergent Causes of Acute Red Eye for the Emergency Physician

Acute red eye refers to conjunctival or scleral redness. Differential diagnoses can range from subconjunctival haemorrhage to immediately sight-threatening conditions such as acute angle closure glaucoma (AACG) or endophthalmitis. A good history and a detailed ocular examination will help to distinguish the more emergent and urgent cases from those who require only as-needed follow up arrangements. This article covers in detail the management of red eyes with particular emphasis on those urgent conditions when specialist care is needed.

Pain is the most important distinguishing feature for the acute red eye. Bacterial or viral keratitis, uveitis, AACG, corneal abrasion, or scleritis should be considered in patients with more than minimal pain or irritation. A patient’s pain will generally improve after instillation of topical anaesthetics to the cornea, such as corneal abrasion and early viral or bacterial keratitis.

Patients with bacterial, viral keratitis, corneal abrasion and foreign body injury will usually show uptake on fluorescein examination. To summarise, patients with moderate or severe pain, photophobia, elevated intraocular pressure, anterior chamber inflammation, corneal epithelial defects with associated infiltrate, or decreased visual acuity should be referred urgently or emergently to ophthalmologists without delay.

Vision Loss in Older Adults

Vision loss in older adults is associated with increased risk of fall, loss of independence, depression, and increased all-cause mortality. Conditions which may lead to vision loss in older patients are usually age-related macular degeneration, glaucoma, ocular complications of diabetes mellitus, and age-related cataracts.

Visual impairment (VI) refers to a functional loss of vision. Significant VI refers to loss of visual acuity (VA) and/or loss of visual field that makes it impossible to cope with daily tasks without specialised adaptations. VI is usually classified according to the VA of the better eye and to visual field defects. Different definitions and classifications have been used in different contexts. In Hong Kong, with reference to Rehabilitation Programme Plan (2007), VI is defined as:

Visual Impairment

Severe low vision ― persons with VA of 6/120 or worse and persons with constricted visual field in which the widest field diameter subtends an angular subtense of 20 degrees or less, irrespective of the VA;

Moderate low vision ― persons with VA from 6/60 to better than 6/120;

Mild low vision ― persons with VA from 6/18 to better than 6/60

Total blindness: persons with no visual function, i.e. no light perception.

Medicated eye drops help to reduce intraocular pressure, and may delay the progression of vision loss in patients with glaucoma. Tight glycaemic control in adults with diabetes slows the progression of diabetic retinopathy. The article covers the management protocols of the above in order to prevent elderly blindness.

Update and guidance on management of myopia. European Society of Ophthalmology in cooperation with International Myopia Institute

Prevalence studies have shown that the number of individuals with high myopia is increasing and pathological myopia is becoming the most common cause of blindness worldwide. Myopia control interventions, which aim to delay onset of myopia and to slow down myopia progression, are important to reduce the burden of myopia. The International Myopia Institute (IMI) has recently published a series of white papers on the pathogenesis of myopia based on results of randomised controlled trials on experimental and genetics studies.

The prevalence of myopia increases markedly from approximately 6 years of age. There is strong evidence that less near work and more outdoor activity provide protection against myopia development in the human eye. Under correction of myopia is not recommended as it increased myopia progression slightly and did not slow myopia progression as previously thought.

There is evidence of myopia control with soft multifocal contact lenses (low-certainty evidence), specific myopia control soft lens designs (moderate-certainty evidence) and orthokeratology (moderate-certainty evidence). Atropine is reported to stimulate extracellular matrix biosynthesis in scleral fibroblast cells, and decrease extracellular matrix biosynthesis in other tissues such as choroidal fibroblasts, slowing down myopia progression. Atropine has been reported to have a dose dependent inhibitory effect on myopia progression. Myopia progression was slower in children treated with combinations of atropine eye drops and multifocal spectacles than in children treated with placebo eye drops and single vision lenses.

Chalazion Management: Evidence and Questions

As the most common inflammatory lesion of the eyelid, chalazion occurs when lipid breakdown by-products, possibly from bacterial enzymes or retained meibomian secretions, leak into the surrounding tarsal plate stroma and incite a granulomatous inflammatory response.

Patients presenting to the clinic for the first time can usually be given a trial period conservative management like hot pad and topical antibiotics eye gel.

A course of oral tetracycline may be considered (for example, doxycycline 50-100 mg once daily or lymecycline 408 mg once daily) when severe blepharitis or blepharitis associated with rosacea. However, tetracyclines should be avoided in children and pregnant women because they can affect tooth and bone development; erythromycin or azithromycin is a possible alternative for these patients.

Eyelid ptosis: physical examination

This video, prepared by the University of Manitoba, is a good and useful demonstration on examination for eyelid ptosis. Ptosis is most commonly the result of age-related stretching and dehiscence of the levator aponeurosis. Other causes of ptosis may be neurogenic (e.g., third-nerve palsy, myasthenia gravis, Horner syndrome), traumatic, congenital, mechanical (e.g., eyelid tumours;) or myogenic. Pseudoptosis can be caused by dermatochalasis (excess eyelid skin that may hang over the margin). The underlying cause will affect the type and urgency of referral. Surgical treatment is highly effective in specific cases.

Ptosis Correction

The term “ptosis” is derived from the Greek word falling and refers to drooping of a body part.

Blepharoptosis is upper eyelid drooping with the eyes in the primary position of gaze. This article describes in detail the different causes of ptosis like aponeurotic ptosis, third nerve palsy, Horner syndrome, myogenic ptosis, myasthenia gravis, congenital causes and psuedoptosis when ptosis is due to abnormalities in structures other than the levator muscle. The article also covers how history taking, physical examination and specific tests can help to differentiate different types of ptosis.

ICO Guidelines for Glaucoma Eye Care

The International Council of Ophthalmology (ICO) Guidelines for Glaucoma Eye Care have been developed as a supportive and educational resource for ophthalmologists and eye care providers worldwide.

Glaucoma is the leading cause of world blindness after cataract. Glaucoma refers to a group of diseases, in which optic nerve damage is the common pathology that leads to vision loss. The most common types of glaucoma are open angle and closed angle forms, each accounting for about half of all glaucoma cases. High intraocular pressure (IOP) is a major risk factor for loss of sight from both open and closed angle glaucoma, and it is the only risk factor that is modifiable. The risk of blindness depends on the height of the intraocular pressure, severity of disease, age of onset, and other determinants of susceptibility, such as family history of glaucoma. Pupils should be tested for reactivity and afferent pupillary defect. An afferent defect may signal asymmetrical moderate to advanced glaucoma. IOP should be measured in each eye.

The Royal College of Ophthalmologists (RCOphth) - Age Related Macular Degeneration Commissioning Guidance June 2021

Age related macular degeneration (AMD) is a chronic progressive degenerative disease of the macula typically affecting people over the age of 50 years. There are two types of advanced forms of the disease, commonly called dry and wet AMD. Whilst the dry form is a slowly deteriorating condition with no treatment at present, the wet form presents acutely and needs both urgent and chronic treatment over years. This guideline is developed by the Royal College of Ophthalmologist in the United Kingdom. It covers materials ranging from diagnosis and treatment to referral of the age-related macular degeneration. Patients with medium or high-risk AMD should be advised to stop smoking, encouraged to have a healthy diet, with plenty of greens and monitor themselves for any central visual disturbances, and most important, report if they experience any visual symptoms.