Painful Loss of Vision + Glaucoma Flashcards
What causes painful loss of vision
Acute angle close glaucoma
Corneal abrasion
Optic neuritis
GCA
Choroditis / retinitis if immunocompromised
Posterior scleritis - pain > degree of red
Chemical or mechanical injury
What causes acute angle closure glaucoma
Angle is blocked acutely so AH cannot drain through trabecular meshwork
Due to structural change at cornea / iris
Typically in hypermetropia (long eye) so not enough room
Lens get bigger as you age
Iris bulges foreward and blocks trabecular meshwork
Causes rapid rise in IOP
Axonal death occur and optic neuropathy
What are the symptoms
What are complications
Short history Sudden onset pain - headache / ocular Hard red eye N+V Photophobia Vision loss HARD eye on palpation Opaque hazy cornea as IOP drives fluid in = oedema Iris / ciliary / conjunctiva vessels = injected Pupil N+V / abdo pain / headache can occur
Complications
- Visual loss
- Central retinal artery or vein occlusions
What happens to pupil
Mid dilated
Non reactive / sluggish
What is visual loss like
Periphery
Blurring
Halo around eye due to build up of fluid
What are RF
Age Female FH Hypermetropia Mydratic eye drop as dilates eye Pupil dilation Functional block due to large lens
What do you do if suspect
Urgent referral
How do you Dx
Slit lamp = shallow chamber
Tonometry = diagnostic as shows high pressure
Gongioscopy is only way to exclude an occluded angle
Do U+E
How do you Rx initially
Analgesisa Anti-emetic Avoid dark room as encourage further dilation Lie patient supine URGENT OPTHAMOLOGY
What is 1st line Rx
Prostaglandin eye drop (Latanoprost) IV carbonic anhydrase (Azetazolomide) A agonist (Apraclonidine) Mucarinic agonist Mitotic eye drop to constrict and open angle Topical steroid eye drop BB if no CI
What does prostalgnaidn eye drops do
Constrict eye and increase outflow through chamber
What do all the other medications do
Reduce production of AH
What do you do after this
Chek IOP after 1 hour
Consider IV mannitol if not responding as osmotic agent and will draw fluid out
When should you have caution prescribing mannitol
Cardiac function
- draws fluid out = oedema
Renal function
- Should cause diuresis but if impaired = worsens overload
What happens after initial management
Keep on all medcation
Iridiotomy later to bypass (hole in iris)
Do other eye as prophylaxis
Trabeculostomy may be needed if adhesions have formed
What are complications
Visual loss
Central retinal artery or vein occlusion
What is corneal abrasion
Any defect in corneal epithelium
What causes
Trauma FB Grit / contact lenses / finger nails Tear insufficiency Keratconjunctivitis sicca
What are the symptoms
Eye pain - mild / mod Photophobia Decreased acuity Sensation of Fb Conjunctival injection Increased lacrimation
What occurs 2
Bacterial infection / keratitis
How do you Dx
Can usually see with naked eye
Look under eyelid for FB
FLuroscein angiography shows yellow stained abrasion
How do you Rx
Usually heal quick
Topical Ax to prevent bacterial infection
Topical cycloplegia for pain
Remove FB
What Ax
Fluroquinolone = 1st line
Aminoglycoside may be needed but often delays healing but will sort infection
What do you avoid
Topical analgesia as damages cornea
When can you miss abrasion
If chemical burn as no normal epithelium to compare
What is primary open angle glaucoma
Drainage through meshwork blocked Raised IOP Affects drainage of AH Slow and chronic Leads to optic neuropathy as pressure builds up on optic nerve or interrupts blood supply
What is normal IOP range
10-20mmHG
How does it present
Asymptomatic and picked up by screening with optometrist - Elevated eye pressure - ocular HTN - Optic disc changes - Visual field loss pattern - typical Usually bilateral May present with advanced disease as occurs slowly - Gradual visual defect - Pain - Headache
What are the visual defect
Peripheral loss Macular fibres usually preserved until very late which gives central vision Decreased acuity Halo Blurred Eventually all nerve fibres die = blind
What are optic disc changes
Pale and cupped as nerve fibres die
What are RF
Age Genetics FH Black Myopia - short sighted Hypertension DM Steroid Thyroid eye
Who gets screening
Annual from age 40 if FH African Myopia DM Thyroid eye disease
How do you assess visual field
Automated perimetry
How do you measure IOP and what is normal
Application tonometry
Normal = 12-22
What other tests
Slit lamp with pupil dilation to assess optic nerve
Fundoscopy for optic disc
How do you Rx
Prostaglandin eye drops = 1st line Carbonic anhydrase inhibitor BB if no CI Laser trabeculoplasty to allow drainage Trabeculectomy = definitie Rx May need to stop driving
How do you reassess
Exclude progression and visual field loss
SE prostaglandin inhibitor
Eyelash growth
Eyelid pigmentation
Iris pigmentation
SE carbonic anhydrase
Paraesthesia
What causes optic neuritis
MS
DM
Syphillis
How does it present
Unilateral decrease in acuity Poor colour discrmination Red desaturation Pain worse on eye movement Afferent pupil defect
How do you Dx
Always check pupil defect before dilate eye as may be only sign of neuritis
How do you Rx
Steroid
What is a scrotoma
Particular area of blindness in eye surrounding by relatively normal blindness
Occurs due to how retinal axons are arranged
If lower part of nerve affected
Upper part of vision lost
What type of scrotoma in glaucoma
-ve which means patient is not aware
Usually peripheral
Can be very dangerous
In macula disease
+Ve scorotoma so patient is aware of defect
