Bits & Pieces Flashcards
Define Accommodation
Focussing CLOSE UP So: -> Parasympathetic Innervation -> Contraction of ciliary muscle -> Relaxes suspensory ligaments -> Less tension on lens -> Lens shortens and fattens -> Greater bending of light -> Focusses close up
What lens would be used to correct hyperopia vs myopia?
Hyperopia (longsightedness)
- Image focusses behind retina
- > Convex lens to increase bending of light
Myopia (Shortsightedness)
- > Image focusses in front of retina
- Concave Lens to reduce bending
What type of neuron is involved in sight?
Bipolar
Papilloedema
Define [1]
Unilateral or bilateral?
Other signs on fundoscopy [5]
Optic disc swelling caused by increased ICP
Almost always bilateral
Other signs on fundoscopy:
- venous engorgement: usually the first sign
- loss of venous pulsation: although many normal patients do not have normal pulsation
- blurring of the optic disc margin
- elevation of optic disc
loss of the optic cup
- Paton’s lines: concentric/radial retinal lines cascading from the optic disc
Dislocated lens is common in 2 condtions
Marfans
Homocysteinuria
Retinitis pigmentosa associations [3]
- Rare systemic conditions
- Heart block
- Laurence-Moon-Biedl syndrome
Blue sclera is seen in what condition?
Osteogenesis imperfecta
What is Kayser-Fleischer ring seen in?
Wilsons disease
Adverse ocular reactions of drugs
Lid pigmentation
Phenothiazine - antipsychotic, antiemetic`
Adverse ocular reactions of drugs
What is practolol syndrome? [2]
Oculomucocutaneous syndrome
- keratoconjunctivitis sicca
- scarring, fibrosis, metaplasia, and shrinkage of the conjunctiva.
Adverse ocular reactions of drugs
Corneal opacification [3]
- Chloroquine
- Amiodarone
- Indomethacin
Adverse ocular reactions of drugs
What drugs affect pupils and accommodation? [3]
- Atropine
- Tricyclic antidepressants
- Others with anti-cholinergic activity
Adverse ocular reactions of drugs
What drugs can cause cataracts?
- Corticosteroids
* Busulphan
Adverse ocular reactions of drugs
Retina pigment epithelium drug deposits [2]
- Chloroquine
* Thioridizine
Adverse ocular reactions of drugs
Ganglion cell swelling and death [3]
- Digoxin
- Quinine
- Interferon
Adverse ocular reactions of drugs Topiramate
Acute angle closure glaucoma
Adverse ocular reactions of drugs
Oculogyric crisis [2]
- Phenothiazines
* Metoclopramide
Systemic toxicity from ocular treatments
Pilocarpine (cholinergic) [2]
What are allergic reactions from this drug? [2]
• Nausea and malaise if drops used in excess
- Miosis
- Accommodative spasm
Systemic toxicity from ocular treatments
Phospholine (cholinesterase inhibitor) [2]
- Nausea
* Suxamethonium apnoea (beware)
Systemic toxicity from ocular treatments
Phenylephrine (stimulant) [2]
- Hypertension (babies and elderly)
* Beware when concomitant MOAI therapy
Systemic toxicity from ocular treatments
Beta blockers [3]
- Bradycardia
- Bronchospasm, reduced exercise tolerance
- Timolol > Carteolol
Systemic toxicity from ocular treatments
Acetazolamide (carbonic anhydrase inhibitor) [4]
- Depression
- Nausea
- Potassium depletion
- Renal stones
Systemic toxicity from ocular treatments
Chloramphenicol (antibiotic) [2]
Prostaglandins [1] What are allergic reactions from this drug? [1]
- Rare side effects compared with systemic use
- Bone marrow suppression
Prostaglandins can cause abortion. Allergic reaction: • Hyperpigmentation of the conjunctiva and iris and skin around the eyes
Allergic reactions from eye drops: preservatives [3]
- Follicular conjunctivitis
- Corneal epithelial toxicity
- Accumulation in soft contact lenses
Allergic reactions from eye drops: atropine [3]
- Cycloplegia
- Mydriasis
- Angle closure glaucoma
Allergic reactions from eye drops: adrenaline [3]
- Reactive conjunctival deposits in conjunctival sac (adrenochrome)
- Cystoid macular oedema (in aphakia)
- Hyperaemia pigmented conjunctiva
Allergic reactions from eye drops: idoxuridine [2]
- Epithelial toxicity
* Punctual stenosis
Allergic reactions from eye drops: CCS [3]
- Recurrence of herpes simplex keratitis
- Chronic open angle glaucoma
- Lens opacities
Papilloedema definition
Papilloedema describes optic disc swelling that is caused by increased intracranial pressure. It is almost always bilateral.
Signs of papilloedema on fundoscopy [6]
- venous engorgement: usually the first sign
- loss of venous pulsation: although many normal, patients do not have normal pulsation
- blurring of the optic disc margin
- elevation of optic disc
- loss of the optic cup
- Paton’s lines
Patons lines
concentric/radial retinal lines cascading from the optic disc
Causes of papilloedema [5]
- space-occupying lesion: neoplastic, vascular
- malignant hypertension
- idiopathic intracranial hypertension
- hydrocephalus
- hypercapnia
Rare causes of papilloedema [2]
hypoparathyroidism and hypocalcaemia
vitamin A toxicity
