Certain risk factors are associated with development of visual field defects in patients with ocular hypertension. Cummins et al developed a risk factor count which measured these factors.
Risk factors:
(1) age
(2) family history
(3) intraocular pressure
(4) cup-to-disc ratio
Parameter |
Finding |
Points |
age |
< 60 years of age |
0 |
|
>= 60 years of age |
1 |
family history |
negative for glaucoma |
0 |
|
positive for glaucoma |
1 |
intraocular pressure |
<= 28 mm Hg |
0 |
|
> 28 mm Hg |
1 |
cup-to-disc ratio |
> 0.5 |
1 |
|
interocular difference > 0.2 |
1 |
|
neither |
0 |
where:
• cup-to-disc ratio = (diameter of optic nerve cup) / (diameter of optic nerve disc)
• interocular difference = ABS((left eye cup-to-disc ratio) – (right eye cup-to-disc ratio))
risk factor count =
= SUM(points for the 4 parameters)
Interpretation:
• minimum count: 0
• maximum count: 4
• The higher the count, the greater the risk for developing visual field defects.
• Patients with risk factors for developing visual field defects should be screened frequently to detect early changes.
Specialty: Ophthalmology