Glaucoma Flashcards
Inheritance of juvenile open-angle glaucoma
Autosomal dominant (myocilin/TIGR gene)
When no other family history of primary congenital glaucoma exists, what is the chance that an affected parent will have an affected child?
<5% (usually sporadic, but can be inherited in autosomal recessive fashion)
Only selective beta-1 antagonist
Betaxolol
UBM versus B-scan:
- wavelength
- scleral penetration
- resolution
Shorter wavelength
Less scleral penetration
Increased resolution
Mechanism of iris color change with topical prostaglandin use
Increased number of melanosomes within melanocytes
What conditions lower IOP? (4)
Aerobic exercise
Pregnancy
Alcohol use
Marijuana use
Optic disc findings suggestive of glaucomatous optic neuropathy
Vertical cup elongation, rim notching, cupping to rim margin Exposed lamina cribrosa Nasal vessel displacement Baring of circumlinear blood vessels Beta zone peripapillary atrophy
What IOP lowering agent may precipitate keto acidosis in patients?
Glycerol
In the TVT 5-year follow-up study, eyes with previous intraocular surgery had highest success rate with what glaucoma surgery?
Baerveldt (both trab and Baerveldt lowered IOP similarly, but Baerveldt required fewer additional surgical procedures)
Elevation of IOP associated with uveitis can be related to what? (4)
Elevation of IOP associated with uveitis can be related to trabecular inflammation, cellular trabecular obstruction, corticosteroid-induced ocular hypertension, and occlusio pupillae with synechial angle closure.
What class of glaucoma medications should be avoided during pregnancy?
Prostaglandin analogs (induce uterine smooth muscle contraction)
How is uveoscleral outflow affected by age, pressure, and cycloplegia?
Decreases with age and in glaucoma patients
Pressure-insensitive
Increased by cycloplegia (also adrenergic agents, prostaglandin analogs)
Miotics decrease uveoscleral outflow
What parameter of the modified Goldmann equation cannot be directly measured clinically and must be calculated? How are the other parameters measured? (4)
Uveoscleral flow rate
Intraocular pressure: tonometry
Outflow facility: tonography
Aqueous humor formation: fluorophotometry
Episcleral venous pressure: venomanometry
What is the prevalence of glaucoma among siblings of glaucoma patients?
10%
What mode of tonometry is less influenced by CCT? e.g. post-LASIK changes
Dynamic contour tonometry (contours to cornea instead of applanating it)
Goldmann more affected
Rebound (e.g. iCare) most affected
Direct gonioscopy lenses (5)
Koeppe, Barkan, Wurst, Swan-Jacob, Richardson
Indirect gonioscopy lenses (4)
Goldmann, Posner, Sussman, Zeiss
Imbert-Fick principle for application tonometry
Pressure inside dry, thin-walled sphere related to force required to flatten specific area
What iris color is least likely to darken with chronic prostaglandin use? Most likely?
Blue irides least likely (8%)
Green-brown/hazel most likely (85%)
How does aqueous humor formation during sleep compare to during waking hours?
Decreases by 50% (waking hours 2-3 uL/min )
What was most common cause of decreased vision in surgical arm of CIGTS?
Cataract formation
What type of primary angle closure occurs independently of pupillary block?
Plateau iris syndrome
What anesthetic has least effect on IOP? Increases IOP? Decreases IOP?
Chloral hydrate
Increase IOP: ketamine, succinylcholine (skeletal muscle relaxant)
Decrease IOP: sevoflurane
