Common causes of Visual Loss Flashcards
3 commonest causes of visual loss
- Cataract
- Glaucoma
- Age related Macular Degeneration
ARMD
Degenerative disorder of the macula affecting those over 50years. Irreversible
Dry ARMD
- Accumulation of pigment epithelial waste products- Drusen
- Atrophy of the retinal pigment epithelium
- Slowly progressing
- Less dramatic symptoms
Wet ARMD
- Accumulation of fluid secondary to neovscularisation from pigment epithelial disruption
- Haemorrhages, scarring, swelling
- Can develop dramatically
ARMD risk factors
Age, smoking, sun exposure, poorly balanced diet, alcohol
ARMD symptoms
Blurring, scotoma, distortion, difficulty reading fine prinet, difficulty recognising faces, difficulty fine detail
AMRD signs
Distortion on Amsler grid testing, fundoscopy: drusen, atrophy, scarring and pigmentation, haemorrhages
Amsler Grid
A diagnostic tool that aids in the detection of visual disturbances cause by macular degeneration. Person looks with each eye separately at the small dot in the center of the grid. Patients with macular disease may see wavy lines or some lines may be missing.
Scotoma
A partial loss of vision or blind spot in an otherwise normal visual field
Treating ARMD
- No Cure
- Lifestyle modification: smoking cessation, minimise prolonged sun exposure, diet
Drug that minimises angiogenesis for Wet ARMD
Lucentis (ranibizumab injection)
Anti-VEGF
Medication that block vascular endothelial growth factor
Cataract
Opacification of the lens
Symptoms of cataracts
gradual onset, blurred hazy vision, glare, haloes, monocular diplopia
Signs of cataracts
Reduced VA, Reduced red flex, poor view of fundus
Treating cataracts
Surgical phacoemulsification and intraocular lens implanation
Glaucoma
Chronic structural optic neuropathy causing typical pattern of field loss
Linked to raised intraocular pressure
Runs in family- first degree relative positive history
Second leading cause of blindness
Glaucoma
Symptoms of Glaucoma
Bumping into things, missing objects, visual acuity unaffected until end stage
Signs of Glaucoma
Optic disc: cupping, pallor, plinter haemorrhages, raised intraocular pressure, confrontation fields, rAPD if asymmetric advanced glaucoma
Investigating Glaucoma
Tonometry - inner eye pressure
Opthalmoscopy - shape and colour of the optic nerve
Perimetry - Complete field of vision
Gonioscopy - angle in the eye where the iris meets the cornea
Pachymetry - thickness of the cornea
Medical treatment for Glaucoma
Topical ocular hypotensive agents
Carbonic anhydrase inhibitors
Laser treatment for Glaucoma
Selective laser trabeculoplasty
Surgical treatment for Glaucoma
Glaucoma filtration surgery
Social treatment for Glaucoma
- Counselling about compliance
- Driving: patient to inform DVLA
- IGA: International Glaucoma Association
When to refer Glaucoma
- non-urgent unless intraocular pressure is raised >30mmHg
- Acute angle closure glaucoma
Acute Angle Closure Glaucoma
Ophthalmological emergency!
Glaucoma medications: Prostaglandins analogue
Latranoprost, Bimatoprost, Travoprost
Increases uveoscleral outflow
Side-effects of Prostaglandin analogues
Pigmentation, increase eyelash length, stinging, conjunctival injection
Beta-blockers for glaucoma
Timolol
Reduces aqueous production
Avoid in Asthma, COPD, heat block
Carbonic Anyhdrase inhibitors
Dorzolamide, Brinzolamide
Reduces aqueous production
Usually combined with Beta-blockers
Selective a2 receptor agonists
Brimonidine, Iopidine
Reduces aqueous production
Avoid with MOI
Side effects of selective a2 receptor agonists
Lethargy, dry mouth and eyes, allergy
Combination therapies for glaucoma
Ganfort, Xalacom, Cospot, Combigan, Azarga
Surgery for Glaucoma
Trabeculectomy +/- antimetabolite impants/shunts
Laser for Glaucoma
Argon laser trabeculoplasty
Selective laser trabeculopasty