Gradual Loss Of Vision Flashcards
List the causes of gradual loss of vision
Cataract
Glaucoma
Age related macular degeneration
Trauma
Optic atrophy
Diabetic retinopathy
Corneal opacity
Refractive errors
Drugs and nutritional deficiencies
Ocular tumors
Retinitis pigmentosa
What is cataract?
Cataract is opacity of the lens and its capsule
What is the classification of cataract?
BASED ON AETIOLOGY
1.Congenital
(a) Heredity
(b) Maternal causes; Infections, Radiation, Drugs
(c) Foetal; Birth trauma, prematurity, Metabolic Diseases (galactosemia, hypoglycaemia), associated with other congenital anomalies (e.g. Lowe syndrome, Trisomy)
- Acquired
(a) Senile cataract
(b) Traumatic cataract
(c) Complicated cataract; uveitic, Acute congestive angle closure glaucoma
(d) Metabolic cataract; diabetes, galactosaemia, ↓Ca
(e) Electric cataract
(f) Radiational cataract; infra-red, x or γ-ray, ultraviolet ray
(g) Toxic cataract e.g. corticosteroid-induced cataract, copper (in chalcosis) and iron (in siderosis) induced cataract.
(h) Cataract associated with skin diseases – Dermatogenic cataract
BASED ON MORPHOLOGY
•Cortical
•Nuclear
•Capsular – anterior or posterior
•Subcapsular – anterior or posterior
•Polar – anterior or posterior
•Lamella
•Coronary
•Blue dot
•Membranous
BASED ON MATURITY
•Immature
•Mature
•Hypermature
•Morgagnian
What are the clinical features of cataract?
•Loss of vision (blurred, cloudy)
•Glare
•Coloured haloes
•Uniocular polyopia (double vision)
•Reduced VA
What are the management options for cataract?
•Treat any Underlying cause
•Medical management with eye drops that dilate the eyes
•Surgery
1.intracapsular cataract extraction (uncommon)
2.extracapsular cataract extraction
i) conventional
ii)manual small incision cataract surgery
3.phacoemulsification
NB:- Introduction of intraocular lens; There are 4 places where it can be attached-: Anterior chamber, Posterior chamber, Iris fixation, Sclera fixation.
What are the intraop complications of cataract surgery
1.Iris prolapse
2.Suprachoroidal haemorrhage (space between the choroid and sclera)
3.Zonular dehiscence (weakness or rupture of the zonules or suspensory ligament of the lens)
4.Posterior capsule rupture
5.Vitreous loss
6.Nucleus drop (a part of the lens that is cut off in cataract surgery)
7.Hyphaema (presence of blood in the aqueous humor/anterior chamber of the eye)
What are the postop complications of cataract surgery?
Early
1) Hyphema
2) Corneal edema
3) Acute endolphthalmitis
4) Shallow anterior chamber
5) Striae keratopathy
6) Iris prolapse
Late
1) Endolphthalmitis (inflammation of the inner coat of the eye from infection)
2) Lens subluxation
3) Bullous keratopathy (blister-like swelling of the cornea) from corneal edema
4) Dislocation of lens
5) Retinal detachment
6) Pseudophakic glaucoma
7) Posterior capsular opacity
What is glaucoma
A group of eye disorders that is characterized by progressive and characteristic optic neuropathy.
NB:- IOP may or may not be elevated
What is the classification of glaucoma?
Congenital and developmental glaucomas
1. Primary congenital glaucoma (without associated anomalies).
2. Developmental glaucoma (with associated anomalies).
Primary adult glaucomas
1. Primary open angle glaucomas (POAG)
2. Primary angle closure glaucoma (PACG)
3. Primary mixed mechanism glaucoma
Secondary glaucomas
List some glaucomatous changes in optic disc
- Generalized or focalized increase in optic cup size
- Increase in cup-disc ratio
What are the risk factors for primary open angle glaucoma?
Age
Family history
Myopia
Vascular disease - HTN migraine
Race
What are the clinical features of primary open angle glaucoma
•May be symptomless initially
•Visual disturbances
•Elevated IOP
•Corneal haziness in very high IOP
•Pupillary light reflex – normal → RAPD → APD
Which investigations are done for suspected POAG
•Slit lamp exam. to exclude causes of secondary glaucoma and Optic disc assessment – enlarged cupping
•Pachymetry (measures corneal thickness)
•Gonioscopy - (measures angle between iris and cornea)
•Visual field defects
•Optic disc or peripapillary RNFL imaging - Confocal scanning laser tomography, Scanning laser polarimetry and Optical coherence tomography
What are the treatment options for POAG
Medical – Pressure lowering drugs
• beta-blockers e.g. timolol, betaxolol
•Alpha-2 agonist e.g. brimonidine, Apraclonidine
•Miotics e.g. pilocarpine, carbachol
•Prostanglandin analogues e.g. latanoprost, travoprost
•Topical carbonic anhydrase inhibitors CAI e.g. Dorzolamide, brinzolamide
•Systemic CAI e.g acetazolamide, dichlorphenamide
•Osmotic agents e.g. mannitol, glycerol, isosorbide
Surgical
TRABECULECTOMY
Artificial drainage shunts
Laser trabeculoplasty
i) Argon laser trabeculoplasty
ii) Selective laser trabeculoplasty
What is normal variant glaucoma?
It is a variant of POAG. The IOP is usually normal.
Risk factors include female gender, family history, mutations in the OPTN gene.
There is also History of migraine, Raynaud phenomenon, Obstructive sleep apnoea syndrome
