Crash course: Optic Nerve/Neuro-ophthalmic pathways & glaucoma Flashcards
What are drusen made of?
Hyaline bodies
What is the gold standard test for drusen of the optic nerve?
B-scan ultrasonography (hyperreflective lesion)
5 line raster OCT can be used as well
What are B-scans used for?
- Blocked fundus (heme or dense cataract
- nevus vs melanoma
- Drusen
What conditions are associated with drusen?
- Sharp drusens can lead to glaucoma-like visual field defects but does NOT progress over time
- Optic disc edema
- Angioid streaks
- CNVM (can have PPA)
What is the first thing you should test for in a patient swollen optic nerves?
BP > MRI > lumbar puncture
What is an abnormal LP measurement?
> 200 mmH20 in normal non-obese adults
250 mmH20 in obese adults
280 mmH20 in children
Define Malignant HTN
BP > 220/100
An increase pressure can cause which type of palsy?
lateral rectus palsy
Treatment for IIH
Initial treatment: Weight loss & acetazolamide
2nd option: gastric bypass, shunt,
If only ocular issues & no systemic issues: optic nerve sheath decompression
For a pt with IIH, what is the target weight?
6% of their current body weight
Other initial findings for IIH
Visionloss, Bilateral enlarged blind spots on VF (common in papilledema), lateral rectus palsy (high pressure compresses CN on the petrous ridge) - anything high pressure in the brain THINK CN 6
papilledema can occur
Signs of NAION
- Acute sudden vision loss in one eye, older pts with systemic conditions, w/ APD
- Small C/D ratio, <0.2, disc edema
- Systemic (HTN, DM, high cholesterol)
- 50 - 60 yo
- heme confined near the optic nerve
- NAION 10x more common than AAION, Rule out AAION (jaw claudication, HAs, scalp tenderness, polymyalgia rheumatica, transient vision loss)
If you see unilateral disc edema in a 30 yo F, what should you be thinking?
Optic neuritis or lupus
What blood test should you order for AAION
- CBC, ESR, CRP
- Temporal biopsy is the gold standard
What are the norms for CBC, ESR, CRP?
CBC - ?
ESR - age/2 (men) or age + 10/2 (women)
CRP - 0.8 - 1.0 mg/dL or lower is normal
What is the pathophysiology of NAION?
Ischemia of the SPCA
What causes optic nerve edema?
- Compressive (meningioma)
- Ischemia
- Ophthalmic
- Inflammatory - infectious (syphilis or TB) /non-infectious (sarcoid or lupus) /other (optic neuritis)
Tx for NAION
- treat underlying risk factors (HTN, DM, smoking, sleep apnea etc)
What is the pathophysiology of AAION?
occlusion of the posterior ciliary artery
Tx for AAION?
100 mg prednisone PO followed by taper & refer to rheumatology
What is the pathophysiology of an optic nerve pit?
Incomplete closure of the embryonic fissure
What complications can occur with optic pit?
Serous macular detachment
Tx for serous macular detachment
pars plana vitrectomy
What can cause asymmetric IOPs?
- POAG
- Pigment dispersion syndrome
- Uveitis
- NVG
- Cataract surgery
- Angle recession
- Angle closure
- Wrong measurement
Elevated IOP with pseudoexfoliation is due to what?
Toxic accumulation of debris within the TM NOT clog the TM
Psuedoexfoliation risk of developing glaucoma within 10 years?
15%
Tx for psuedoexfoliation syndrome
- treat more aggressively than POAG
Pseudoexfoliation cataract surgery complications?
- lens subluxation due to weak zonules
- poor pupil dfe
What is the pathophysiology of pigment dispersion syndrome?
Pigment releaes from posteiror iris epithelium due to concave iris insertion
What is the primary cause of elevated IOP in PDS?
Toxic damage to the TM due to pigment deposition
What is the risk of developing glaucoma within 5 years in pts with PDS?
10%
What happens in pts with PDS who has cataract sx and age?
Less pigment release and consistent elevated IOP
