Glaucoma: Low Tension Glaucoma (Guest Lecture)

Question 1

1. Low Tension Glaucoma: What is it?
   a. Genetics?
   b. IOP Dependent Factors? (2) (Patho)
   c. IOP Independent Factors? (5)
   d. ON BF: MOPP: = ?

Answer 1

1. Optic neuropathy: Optic Disc Cupping, w/VF loss, Open Angle, and Normal IOPs (21 mmHg or LESS)
   a. Rare: <1%: OPTN
   b. Sensitive ON and Diurnal Fluctuation
   c. Vascular, Rheologic, Immune, Neurodegenerative, Nutritional/Toxic
   d. 2/3 (diastolic + 1/3(systolic - diastolic) - IOP

Question 2

Risks for Glaucoma

1. Neurodegenerative (NTG)
2. Nutritional/Toxic

Answer 2

1. No risk of developing Dementia or Alz’s Disease w/NTG

2. ANY Nutritional Deficiency or Toxic Insult can cause INCREASED SUSCEPTIBILITY to GLAUCOMATOUS DAMAGE

Question 3

When should you image?

Answer 3

Age, RAPD, Bitemporal/Homonymous VF Defects; Disc Pallor; Dyschromotopsia; VF defect > than Optic Disc Cupping; unexplained VA loss; Vertically Aligned VFs

Question 4

Typical Clinical Findings w/Low Tension Glaucoma?

Answer 4

Open Angle, Optic Disc Cupping, Disc Hemorrhage, Peripapillary Atrophy

Question 5

Disc Hemorrhage: More common w/what?

Answer 5

1. In NTG
   * Normal IOP: More blood is Extravasated (allows visualization)
   * Elevated IOP: Tamponade of Blood Occurs: Prevents clinically visible Hemorrhage

Question 6

Sleep Apnea:

1. What is it?
   a. Increased Prevalence of what?
2. VF: What is normally seen?

Answer 6

1. Increased CO2 Levels, Hypoxia, fragmented sleep.
   a. of NTG in pts w/OSA
2. Early Paracentral Defects

Question 7

Study: He talked about study on NTG where they followed 140 eyes of 140 Pts to see if IOP played a role in the progressiveness of NTG. What did they find?

Answer 7

Cataracts more common in Surgical Treatment Group, and Duration to progression for those treated about almost twice as LONG as those who had nothing done.

*Goal was 30% IOP reduction

Question 8

1. Goals of Treatment?

Answer 8

1. Reduce Peak Pressure 30%; REDUCE DIURNAL FLUCTUATION; Improve ocular BF; maybe Neuroprotection…?

Question 9

Medical Tx

1. 1st Line
2. 2nd Line
3. 3rd Line

Answer 9

1. Prostaglandin Analogues
2. Alphagan P (best w/PGA); Dorzolamide (Improves Ocular Circulation)
3. Beta-Blocker (AM Dosing ONLY!) ***DONT REDUCE NIGHT TIME HYPERTENSIVE MEDS!!

Question 10

Treatment: Lasers

1. Less effective for what 2 things?

Answer 10

1. for LOW PRESSURES and those WITHOUT PIGMENT!

Question 11

Surgical GOALS
1. 5 Things

2. RISK? (1)

Answer 11

1. REDUCE IOP to LOW TEENS: Remove Fluctuation, Reduce Med Dependence; STOP PROGRESSION
2. HYPOTONY

Question 12

TRABECULECTOMY

1. What is it?

Answer 12

1. Augmented w/Antimetabolites; Addition of EXPRESS SHUNT

* GOLD STANDARD (BEST OPTION for ACHIEVING LOW IOP!!!