Eyes and Vision Flashcards
Retinoblastoma
✓ Retinoblastoma is a rare type of cancer (develops in immature cells of the retina).
✓ It is the most common primary intraocular cancer and almost exclusively affects children with 50% of cases being genetic. Most cases present before the age of 2.
✓ It can present with leukocoria (a white reflex or white pupil), strabismus or less commonly heterochromia, hyphaemia, glaucoma or orbital cellulitis. Orbital swelling and proptosis are presenting signs in more advanced disease.
✓ NICE suggests: Consider urgent referral for an appointment within 2 weeks for ophthalmological assessment for Retinoblastoma in children with an absent red reflex.
✓ Treatment depends on the size of the Retinoblastoma and includes enucleation, external-beam radiation therapy, brachytherapy, thermotherapy, cryotherapy, laser photocoagulation and chemotherapy.
Corneal Abrasion
✓ Superficial corneal abrasions are a result of mild trauma to the surface of the eye.
✓ It presents with pain, watery eye and foreign body sensation and fluorescein drops should stain the abraded area.
✓ If diagnosis is clear then provide information about condition and Chloramphenicol ointment QDS for 5 days.
✓ Review 24 hours after starting treatment and if concerns to consider discussion with ophthalmology.
✓ There is no good evidence for padding of the eye.
Disorders of visual acuity
He has myopia. Far away objects appear blurred and near objects appear clearly. With myopia, the eyeball is too long, or the cornea is too steep, so images are focused in the vitreous inside the eye rather than on the retina. The near point is reduced. It will appear in young people during periods of growth.
Astigmatism - difference in degree of curvature refraction of the two different meridians (i.e. the eye has different focal points in different planes). £ causes difficulties in seeing fine detail, and in some cases vertical lines (e.g. walls) may appear to the patient to be tilted.
Amblyopia - no transmission or poor transmission of the visual stimulation through the optic nerve to the brain for a sustained period or during early childhood, resulting in poor or dim vision. Amblyopia normally only affects one eye.
Hypermetropia - eyeball is too short, or the lens cannot become round enough, causing difficulty focusing on near objects.
Presbyopia - progressively diminished ability to focus on near objects with age (~ 40–50 yrs)
