Survey of Common Eye Conditions
Ophthalmic assistants encounter a broad spectrum of conditions every day. This overview covers the most frequently seen conditions -- refractive errors, dry eye, and common anterior and posterior segment diseases -- with enough clinical detail to support your role in patient intake, testing, and education.
Refractive Errors
Refractive errors occur when the eye's optical system does not focus light precisely on the fovea in its resting (non-accommodating) state.
| Condition | Cause | Symptoms | Correction |
|---|---|---|---|
| Myopia (nearsightedness) | Eye too long or cornea too steep; focal point in front of retina | Blurred distance; clear near | Minus (concave) lenses or contacts |
| Hyperopia (farsightedness) | Eye too short or cornea too flat; focal point behind retina | Blurred near (children/young), eye strain; may have good acuity with accommodation | Plus (convex) lenses or contacts |
| Astigmatism | Non-spherical corneal or lenticular curvature; light focuses at two different points | Blurred or distorted vision at all distances; ghosting | Toric lenses (cylindrical correction) or RGP lenses |
| Presbyopia | Age-related loss of lens elasticity; reduced accommodative amplitude | Difficulty reading or near tasks, typically after age 40-45 | Reading glasses, bifocals, progressives, multifocal contacts, monovision |
💡 Clinical Tip: Presbyopia affects everyone eventually. As the crystalline lens stiffens with age, the ciliary muscle's ability to change lens shape decreases. The typical age of onset is 40-45 years, and most patients will eventually need some form of near correction even if they were previously emmetropic (no glasses needed).
Dry Eye Disease
Dry eye disease (DED) is among the most common conditions in eye care. It is a multifactorial disease of the ocular surface characterized by loss of tear film homeostasis. Two main types:
- Aqueous deficient dry eye: insufficient aqueous tear production (lacrimal gland dysfunction, Sjogren's syndrome)
- Evaporative dry eye: adequate aqueous but rapid evaporation due to Meibomian gland dysfunction (MGD)
Symptoms: burning, stinging, foreign body sensation, fluctuating vision, paradoxical tearing (reflex hypersecretion), contact lens intolerance. Treatments range from artificial tears to prescription drops (cyclosporine, lifitegrast), punctal plugs, warm compresses, omega-3 supplementation, and intense pulsed light (IPL) for MGD.
Cataracts (Review)
Lens opacity causing progressive vision loss. Treated with phacoemulsification and IOL implantation. Nuclear cataracts are most common; posterior subcapsular cataracts cause disproportionate symptoms early. PCO (posterior capsule opacification) after surgery is treated with YAG laser.
Glaucoma (Review)
Progressive optic neuropathy primarily caused by elevated IOP. POAG is painless and insidious; acute angle-closure is a painful emergency. Treatment aims to lower IOP with drops, laser, or surgery. Regular visual field testing and OCT monitor progression.
Age-Related Macular Degeneration (Review)
Affects the macula; causes central vision loss. Dry AMD: drusen and RPE atrophy; AREDS2 supplements slow progression. Wet AMD: CNV causes rapid vision loss; treated with anti-VEGF injections. Amsler grid monitors for conversion.
Diabetic Retinopathy (Review)
Damage from chronic hyperglycemia ranges from NPDR (microaneurysms, hemorrhages) to PDR (neovascularization, vitreous hemorrhage). DME is the leading cause of visual morbidity. Anti-VEGF is first-line for center-involving DME; PRP for PDR.
Conjunctivitis (Review)
Bacterial (mucopurulent), viral (adenoviral -- watery, preauricular node, contagious), allergic (bilateral itch). Treatment varies by type. EKC requires strict infection control protocols.
Blepharitis
Chronic eyelid margin inflammation, often from seborrheic dermatitis or MGD. Causes irritation, crusting, and is associated with dry eye. Managed with warm compresses, lid hygiene, omega-3s, and sometimes topical or systemic antibiotics.
Uveitis
Intraocular inflammation. Anterior uveitis (iritis): deep aching pain, photophobia, ciliary flush, cells and flare in the anterior chamber. Associated with HLA-B27 conditions, sarcoidosis, juvenile idiopathic arthritis. Treated with topical steroids and cycloplegics.
Retinal Detachment
Separation of neurosensory retina from RPE. Symptoms: sudden floaters, flashes, curtain. Rhegmatogenous (tear-related) is most common. Surgical emergency if the macula is threatened. Surgery: pneumatic retinopexy, scleral buckle, or vitrectomy.
Key Takeaways
- Myopia = too much power, corrected with minus; hyperopia = too little power, corrected with plus
- Presbyopia is universal after age 40-45; managed with reading glasses, bifocals, or progressive lenses
- Dry eye is most commonly evaporative (Meibomian gland dysfunction); treated with warm compresses + artificial tears as a foundation
- Acute uveitis: pain + photophobia + ciliary flush + cells/flare = iritis; treat urgently to prevent synechiae
- Sudden floaters/flashes/curtain = retinal emergency; macula-on detachments have better prognosis
- Recognizing common conditions helps the CPOA take accurate histories, perform targeted testing, and support patient education