Initial Glaucoma Evaluation
The initial glaucoma evaluation may include the tests and procedures of a comprehensive adult eye and vision examination in addition to some procedures specific to the differential diagnosis of glaucoma. Baseline data are established for key clinical parameters that must be evaluated longitudinally in the proper management of glaucoma. Potential components of an initial glaucoma evaluation (discussed in detail in the original guideline document) include:
- Patient history
- Ocular and systemic risk factors and medical history
- Visual acuity
- Corrected and uncorrected visual acuity
- Pupil assessment
- Relative afferent pupillary defect
- Biomicroscopy
- Evaluation of anterior and posterior ocular segment
- Applanation tonometry
- Diurnal variability
- Symmetry
- Gonioscopy
- Open or closed angle
- Primary or secondary glaucoma
- Assessment of optic nerve
- Stereoscopic evaluation through a dilated pupil
- Tomography
- Assessment of nerve fiber layer
- Stereoscopic evaluation through a dilated pupil
- Evaluation with red-free illumination
- Confocal scanning laser polarimetry, optical coherence tomography, confocal scanning laser ophthalmoscopy
- Assessment of peripapillary area (PPA)
- Fundus stereo photography
- Photodocumentation of optic nerve and nerve fiber layer
- Visual Fields
- Standard automated perimetry
- Frequency doubling perimetry
- Short wavelength automated perimetry
Follow-up Glaucoma Evaluation
Individuals with one or more risk factors, who have higher probabilities of developing primary open angle glaucoma (POAG), need more frequent evaluation to rule out the presence of the earliest clinical signs of glaucoma. This evaluation should be done at least yearly in the absence of complicating factors, but perhaps more often, depending on the person's relative risk of developing glaucoma.
Follow-up evaluation of the patient with diagnosed open angle glaucoma (OAG) is similar to the procedure used to make the initial diagnosis of the disease and may include, but is not limited to, the following assessments (further discussed in the original guideline document):
- Patient history
- Visual acuity
- Blood pressure and pulse
- Biomicroscopy
- Tonometry
- Gonioscopy
- Optic nerve assessment
- Nerve fiber layer assessment
- Fundus photography
- Automated perimetry
- Supplemental testing
Available Treatment Options
Traditionally glaucoma treatment has begun with pharmacological intervention, proceeding to laser therapy and surgery, when necessary. This approach was designed to maximize the benefit of the treatment, while minimizing the risk to the patient. Recently, this method has been challenged as less effective than other sequences of therapy. Many glaucoma patients may require all three treatment options. These options should be available because glaucoma is a chronic, progressive disease with no known cure.
In the choice of a specific form of treatment or the decision to alter or provide additional therapy, the risk or benefit to the patient must be the overriding consideration. All forms of treatment for glaucoma have potential side effects or complications. The possible impact of the treatment socially, psychologically, financially, and from a convenience standpoint must be evaluated.
The following three levels of treatment are described in greater detail in the guideline document:
Medical (Pharmaceutical)
The treatment of open angle glaucoma (OAG) includes the use of orally administered or topical agents that enhance aqueous outflow or reduce aqueous production or both. Pharmacological management of OAG includes:
- Cholinergic agonists – miotics (pilocarpine – solution, gel, or membrane-bound wafer; carbachol)
- Adrenergic agonists (nonselective [epinephrine, dipivefrin]; selective [apraclonidine, brimonidine])
- Beta-adrenergic blocking agents (nonselective [carteolol, levobunolol, metipranolol, timolol] selective [betaxolol])
- Carbonic anhydrase inhibitors (systemic –oral [acetazolamide – injection or sustained release, dichlorphenamide, methazolamide], topical [dorzolamide, brinzolamide])
- Prostaglandin analogs (bimatoprost, latanoprost, travoprost, unoprostone isopropyl)
- Combination medications
Laser therapy
The second level of primary open angle glaucoma (POAG) involves the use of systemic medication or laser procedures. As an alternative to drug therapy, argon laser trabeculoplasty (ALT) is a common treatment after topical medication for POAG.
Surgery
Surgical intervention, the third level of treatment for POAG, is required in many moderate or advanced glaucoma patients, to lower the intraocular pressure (IOP) into the target range, especially in normal tension glaucoma (NTG) or eyes resistant to other forms of therapy.
Filtration surgical procedures create alternative pathways for the outflow of aqueous. Among various filtering procedures used to lower IOP are thermal sclerostomy, posterior or anterior lip sclerectomy, trephination, and trabeculectomy. Cyclodestructive procedures, which damage the ciliary body and thereby decrease aqueous production, are less commonly used, being reserved for the most advanced stages of the disease.
Patient Education
The proper management of glaucoma requires full compliance by the patient. Patient education regarding the benefits and risks of the treatment and proper use of medications is critical to ensure maximum compliance. Continual reinforcement of the seriousness of the disease and the importance of following the therapy regimen is essential.
Prognosis and Follow-Up
Once treatment for glaucoma has been initiated, follow-up examinations are required to monitor: stability of the intraocular pressure (IOP), optic nerve (ON), visual field (VF), and peripapillary area (PPA); patient compliance with the therapy; the presence of side effects associated with the treatment; and the effectiveness of patient education. Follow-up also provides an opportunity to reconfirm the diagnosis. Determining whether the disease is progressing may be clinically challenging, due to the difficulty, in some patients, of distinguishing subtle structural or functional changes representing normal fluctuation from changes caused by progressive glaucomatous damage.
The frequency of follow-up evaluations of a glaucoma patient under active treatment depends on the level of intraocular pressure and the stability and severity of the disease. The following table summarizes the frequency and composition of evaluation and management visits for open angle glaucoma.
Frequency and Composition of Evaluation and Management Visits for Open Angle Glaucoma
| Type of Patient |
Frequency of Examination |
Tonometry |
Gonioscopy |
Optic Nerve (ON)/Nerve Fiber Layer (NFL) Assessment |
Stereoscopic ON, NFL, and Peripapillary Area (PPA) Documentation
Confocal scanning laser imaging (CSLI)** |
Perimetry** |
Management Plan |
| New glaucoma patient or new glaucoma suspect |
Weekly or biweekly to achieve target pressure |
Multiple readings may be necessary to establish baseline |
Standard classification and drawing an initial visit |
Dilate; optic nerve drawing at initial visit |
As part of initial glaucoma evaluation |
Repeat to establish baseline |
Prepare problem list with treatment plan |
| Glaucoma suspect |
6 to 12 months, depending on level of risk |
Multiple readings may be necessary to establish baseline |
Annual |
Dilate every other visit |
Every 2 years; CSLI Annual* |
Annual |
Review |
| Stable - mild stage |
4 to 6 months |
Every visit |
Annual |
Dilate every other visit |
Annual |
Annual |
Review |
| Stable - moderate stage |
2 to 4 months |
Every visit |
Annual |
Dilate every other visit |
Annual |
6 to -12 months; depending on prior data |
Review |
| Stable - severe stage |
1 to 3 months |
Every visit |
6 months |
Dilate every other visit |
Annual; CSLI?* |
4 to 8 months, depending on prior data |
Review |
| Unstable - IOP poorly controlled; ON or VF progressing |
Weekly or biweekly until stability is established |
Every visit |
Initial visit and each time other clinical findings warrant a reassessment |
Dilate at initial visit and each time other clinical findings warrant reassessment |
Annual or each time ON or NFL changes |
4 to 6 weeks or as needed to establish new baselines |
Formulate new plan until stable |
| Recently established stability |
1 to 3 months |
Every visit; re-establish baseline |
Depends on severity of the glaucoma |
Dilate every interim visit |
Annual or each time ON or NFL changes |
Depends on severity of the disease |
Review |
*Confocal scanning laser imaging (CSLI) is recommended once annually in glaucoma suspect patients and those with mild to moderate disease who can respond to standard testing. CSLI may be performed up to 2 times per year for patients in whom visual fields or tonometry cannot be assessed or in patients with unstable borderline control and other glaucoma risk factors. CSLI may not be useful for monitoring stable-severe or end-stage disease.
**Threshold automated perimetry is recommended.
