Keratoconus Flashcards
What is keratoconus?
Keratoconus is a progressive eye disease where the cornea thins and begins to bulge into a cone-like shape, causing distorted vision.
What are common symptoms of keratoconus?
Symptoms include blurred or distorted vision, increased sensitivity to light, frequent changes in eyeglass prescriptions, and difficulty seeing at night.
How is keratoconus diagnosed?
Diagnosis is typically made through a comprehensive eye exam that includes corneal topography to map the shape of the cornea.
What are the treatment options for keratoconus?
Treatment options include glasses or soft contact lenses, rigid gas permeable lenses, scleral lenses, corneal cross-linking, and in severe cases, corneal transplant surgery.
What is corneal cross-linking?
Corneal cross-linking is a treatment that strengthens the cornea by using riboflavin (vitamin B2) drops and ultraviolet (UV) light, helping to halt the progression of keratoconus.
What are the management strategies for keratoconus?
Management strategies include regular monitoring of vision changes, using appropriate corrective lenses, and considering surgical options if necessary
How does keratoconus affect vision?
The cone-shaped cornea causes light entering the eye to be focused improperly on the retina, leading to distorted or blurred vision.
What does direct ophthalmoscopy from a distance of half a meter show in keratoconus?
It shows a fairly well-delineated ‘oil droplet’ reflex
What is observed during retinoscopy in a patient with keratoconus?
Retinoscopy shows an irregular ‘scissoring’ reflex
What are Vogt striae, and how are they observed?
Vogt striae are very fine, vertical, deep stromal stress lines seen in keratoconus that disappear with pressure on the globe, observable via slit lamp biomicroscopy.
What is a Fleischer ring, and how is it best seen?
A Fleischer ring consists of epithelial iron deposits surrounding the base of the cone, best seen with a cobalt blue filter.
What is a key feature of progressive corneal protrusion in keratoconus?
Progressive corneal protrusion occurs in a cone configuration, with thinning maximal at the apex.
What is Munson’s sign in keratoconus?
Munson’s sign is the bulging of the lower lid in downgaze.
What causes acute hydrops in keratoconus?
Acute hydrops is caused by a rupture in the stretched Descemet membrane, allowing a sudden influx of aqueous into the cornea, accompanied by pain, photophobia, and decreased vision.
How is acute hydrops initially treated in keratoconus?
Treatment includes cycloplegia, hypertonic (5%) saline ointment, patching, or a soft bandage contact lens. Accelerated resolution may be achieved with intracameral gas injection.
