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Glaucoma

Diagnosis/Definition

Glaucoma refers to a group of diseases that have in common a characteristic optic neuropathy with associated visual field loss for which elevated intraocular pressure (IOP) is a common, but not necessarily required, risk factor.
There are five types of glaucoma: Primary Open Angle, Congenital, Secondary, Developmental or Childhood and Angle-Closure. Glaucoma is one of the leading causes of blindness worldwide.
The diagnosis of glaucoma is usually made by an eye care professional such as an Ophthalmologist.

Initial Diagnosis and Management

Typically, the “at-risk” patient will have at least two of the following three characteristic findings of glaucoma:

elevated intraocular pressure of greater than 21 mmHg on 3 or more separate measurements
characteristic glaucomatous optic neuropathy cupping greater than .5, or
characteristic and reproducible visual field loss.

Risk factors such as family history of glaucoma, race, myopia, diabetes or hypertension may also be taken into consideration by the specialist before labeling a patient as having glaucoma. Once the diagnosis is made, the treatment regimen consists of lowering the intraocular pressure and/or removing the cause of the elevated pressure in cases of secondary glaucoma.

Indications for Specialty Care Referral

Any patient who has been diagnosed as having glaucoma, ocular HTN, or is on medication for either of these conditions, should be referred to Ophthalmology’s general clinic for evaluation and follow-up. Also, any patient in whom the clinician is seeing an enlarged cup to disc ratio of .5 or greater in the optic nerve should be referred.

The following weighted scale, established by the American Academy of Ophthalmology Glaucoma – 2001 Commission, should help in identifying those patients for whom referral is indicated. Consider each variable (age, race, family history, and exam history) and total the assigned weights. All patients with a score of 4 or greater (high risk) should be given a general ophthalmology consultation. A score of 3 is moderate risk, and a score of 2 or less is low glaucoma risk.

Variable	Weight
Age
<50	0
50-64	1
65-74	2
>75	3
Race
Other	0
African-American	2
Family History of Glaucoma
None or positive in non-first degree relatives	0
Positive for parents	1
Positive for siblings	2
Years Since Last Eye Exam
<2	0
2-5	1
>5	2

Other historical variables such as high myopia or hyperopia, systemic hypertension, steroid use, and perhaps diabetes are not strong enough to be assigned a weight, but may be considered in the overall assessment of glaucoma risk.

Criteria for Return to Primary Care

Once identified and diagnosed, the glaucoma patient needs to be followed by an ophthalmologist. Moreover, these patients will most likely be placed on a regimen that could include pharmacologic, laser and/or surgical control of their intraocular pressure.