Why do patients go blind from glaucoma?

Louis B. Cantor, MD

Professor
Indiana University

How many patients go blind from glaucoma?

• RPB: 89,000-120,000 individuals are estimated to be blind from glaucoma in the US. Rate of blindness 93-126/100,000 in the population over 40 y.o. from glaucoma.

Hattenhauer, Johnson, et al (Ophthal 1998)

• 295 residents of Ohmstead County with mean f/u of 15 +/- 8 years (community based)
• At 20 years the K-M probability of glaucoma related blindness (acuity 20/200 or worse and/or VF loss within central 20 degrees) was 27% in one eye and 9% for both eyes
• At diagnosis 15 patients were blind in at least one eye

Chen (Ophthal 2003)

• 168 patients diagnosed in 1975 or later. Mean f/u 10.2 +/- 4.9 y at Univ. of Washington (university based).
• K-M estimate of blindness at 15 y was 14.6% in one eye and 6.4% for both eyes
• Noncompliance, worse initial VF, and nonwhite race were associated with an increased risk of blindness
• 39% of patients with blindness were present at diagnosis

Eid, Spaeth, et al (Ophth 2003)

• 102 patients diagnosed and treated prior to 1982. Mean f/u 19 +/- 3 years.
• 96% Caucasion
• Optic disc and VF graded on a 5 point scale in one eye in each patient
• 19 remained stable, the remainder deteriorated at least one stage or more
• IOP and stage of disease not predictive

Eid, Spaeth, et al (Ophth 2003)

• 17 (17%) deteriorated to 20/200 or worse. 10 (10%) not due to glaucoma (mostly cataract and retinal disease), 7 (7%) glaucoma related
• VF loss within central 20 degrees (Grade IV or V) present in 45 (44%) at last follow-up

Why do patients go blind from glaucoma?

• Glaucoma related factors
• Other eye disease related factors
• Patient factors
• Physician factors

Why do patients go blind from glaucoma: Glaucoma?

• Incomplete understanding of pathophysiology
• Progressive neuropathology
• Diagnostic uncertainty
• Treatment directed at a surrogate endpoint (IOP)
• Extra IOP effects of therapy

Other eye diseases

• Cataract
• AMD
• Diabetes
• Others…
• All the reasons why individuals without glaucoma may become blind

Patient Factors

• Race
• Systemic/ocular conditions
• Understanding
• Compliance
• Family history (pick your parents carefully!)

Physician factors

• Diagnostic delay
• Inadequate patient education
• Inadequate therapy
• Inadequate follow-up
• Inappropriate expectations (from patients)
• Misinterpretation of testing results