PDS Flashcards
What is PDS
Common in young (30/40) male, myopic, caucasian patients. It is usually bialteral alright can be asymmetric. Recall that PDS is due to excessive bowing of the iris psoteirorly, resulting in contact between the iris and lens zonules, and the release of pigment from the posterior pigmented iris epithelium.
Signs of PDS
K spindle
TIDS
Pigment on anterior capsule of the lens and iris surface
Hyperpigmentation of TM
Pigment release in PDS
Often increased with jarring exercise to with dilation resulting in a temporal block of aqueous humor outflow throuh the TM with subsequent increase in IOP and corneal edema; pts may complain of temporary blurred vision and halos around lights during these epidsode. Less pigment release over time may occur as the lens thickens , resulting in less contact between the post pigment epithelial of iris and the lens zonules
Hallmark of PDS
K spindle
RIDS
Sampaolesi line
PXF
Age related systemic condition that is most common in elderly caucasian (Scandinavian). Characterized by breakdown of basement membranes thrghouout the body, including ocular structures
Ocular signs of PDX
May be unilateral or bilateral
- abnormal, white, flaky deposits on pupillary margin, the anterior lens capsule (in a bulls eye pattern, the lens zonules, and the TM)
- the PXF material on the lens zonules often results in the release of pigment form the posterior pigmented iris epithelium, leading to an accumulation of pigment within the TM (similar to PDS)
Sampoalesi line
Characterized by increased pigmentation anterior to Schwalbes line in the anterior chambe angel, it is associated with PDS and PXF
Risk of glaucoma in PXF
15% within 10 years; PXF is the most common identifiable cause of elevated IOP and resulting secondary open angle glaucoma
Fuchs heterochromic iridocyclitis
Chronic, nongran low grade anterior uveitis with stellate KPs; May also present with heterochromia of iris (due to chronic inflammation) and iris and/or angle neo in the affected eye. At an increased risk of glaucoma (due to chronic damage to TM) and cataracts (due to chronic inflammation).
Posner schlossman syndrome
Characterized by acute trabeculitis that causes an acute elevation in IOP (40-60), resulting in blurred vision. Patients will have an open angle on gonio and very few cells in the AC, the condition is characterized by recurrent unilateral episodes.
POAG
Most common optic neuropathy characterized by excavation of the optic nerve with corresponding VF defects (often bialteral and asymmetric), with an open angle on Gino and elevated IOP.
MS and blurred vision
Uhtoffs phenomenon. After exercise
What test should always be performed on patients with elevated IOP
Gonio
IOP elevation occurs in what ways due to PDS
Physical blockage of the TM pores by released iris pigment
Toxicity to the endothelial cells and the TM fibers due to accumulated iris pigment
Risk of glaucoma in PDS
109% at 5 years
15% at 15 years
What percent of RNFL fibers need to be damaged in order to have a VF defect
50%
OHTS and pachs
Thinner pachs have incereased risk of glaucoma
GDx
Evans the thickness of the RNFL
Order of angle structures on gonio
Iris CB Scleral spur TM Schlemms Schwalbes
MOA of pilo
Cholinergic agonist that causes ciliary contraction, which pulls the scleral spur posterior and opens up the pores of the TM. This allows for increased AH flow through the TM.
Can also cause miosis
MOA of prostaglandin
Increase in AH outflow through uveoscleral meshwork
Xalatan, latanaprost, lumigan
MOA of docosanoid compound (rescula)
Increases AH outflow through the TM
BBlockers MOA
Timolol, istaolol, timoptoc, betimol, betagan, betoptic
Decreases AH production
A agonist MOA
Decrease AH production and increases US outflow
Iopidine, alphagan
Cholinergic agonists MOA
Increase AH outflow through TM
CAI MOA
Inhibits CA, an enzyme involved in AH production
What drugs should not be RXed to a patient with sulfa allergies
CAIs
When should you not give someone pilocarpine for glaucoma
If they have lattice
TX for PDS
Not treated until there is an increase in IOP and/or optic nerve damage.
Treated the same as POAG, although this is often more aggressive and diffcicult to control
