CHAPTER 3

Clinical Evaluation

History and General Examination

Appropriate management of glaucoma depends on the clinician’s ability to diagnose the specific form of glaucoma in a given patient, to determine the severity of the condition, to predict the likelihood of progression, and to detect progression when it occurs. Clinical evaluation of the glaucoma patient should include a history of the current complaint, including symptoms, onset, duration, and severity. Past ocular history (medical and surgical) and a general medical history, including the patient’s current medications and allergies, should be obtained. On physical examination, prior to biomicroscopy, the patient’s pulse and blood pressure should be recorded.

The clinician should inquire about symptoms often associated with glaucoma, such as pain, redness, colored halos around lights, alteration of vision, and loss of vision. Similarly, the general medical history should include specific inquiry about diseases that may have ocular manifestations or that may affect the patient’s ability to tolerate medications. Such conditions include diabetes, cardiac and pulmonary disease, hypertension, hemodynamic shock, systemic hypotension, sleep apnea, Raynaud phenomenon, migraine and other neurologic diseases, and renal stones. The clinician should take note of a history of corticosteroid use. See also BCSC Section 1, Update on General Medicine.

Refraction

Neutralizing any refractive error is crucial for accurate perimetry with most perimeters, and the clinician should understand how the patient’s refractive state could affect the diagnosis. Hyperopic eyes are at increased risk of angle-closure glaucoma and generally have smaller discs. Myopia is associated with disc morphologies that can be clinically confused with glaucoma, and myopic eyes are at increased risk of pigment dispersion.

External Adnexae

Examination and assessment of the external ocular adnexae is useful for determining the presence of a variety of conditions associated with secondary glaucomas as well as external ocular manifestations of glaucoma therapy.

An example of an association between adnexal changes and systemic disease is tuberous sclerosis (Bourneville syndrome), in which glaucoma may occur secondary to vitreous hemorrhage, anterior segment neovascularization, or retinal detachment. Typical external and cutaneous signs of tuberous sclerosis include a hypopigmented lesion termed the “ash-leaf sign” and a red-brown papular rash

(adenoma sebaceum) that is often found on the face and chin.

Glaucoma is commonly associated with neurofibromatosis (von Recklinghausen disease), likely secondary to developmental abnormalities of the anterior chamber angle. Subcutaneous plexiform neuromas are a hallmark of the type 1 variant of neurofibromatosis. When found in the upper eyelid, the plexiform neuroma can produce a classic S-shaped upper eyelid deformity strongly associated with risk of glaucoma.

In juvenile xanthogranuloma, yellow and/or orange papules are commonly found on the skin of the head and neck. Secondary glaucoma may cause acute pain and photophobia and ultimately significant vision loss. Oculodermal melanocytosis (nevus of Ota) presents with the key finding of hyperpigmentation of periocular skin. Intraocular pigmentation is also increased, which contributes to a higher incidence of glaucoma and may possibly increase the risk of melanoma. Axenfeld-Rieger syndrome, an autosomal dominant disorder with variable penetrance, is associated with microdontia (small, peglike incisors), hypodontia (decreased number of teeth), and anodontia (focal absence of teeth). Maxillary hypoplasia may also be present. Glaucoma occurs in 50% of cases in late childhood or adulthood.

Several entities are associated with signs of increased episcleral venous pressure. The presence of a facial cutaneous angioma (nevus flammeus, or port-wine stain) can indicate encephalofacial angiomatosis (Sturge-Weber syndrome). Hemifacial hypertrophy may also be observed. The cutaneous hemangiomas of the Klippel-Trénaunay-Weber syndrome extend over an affected, secondarily hypertrophied limb and may also involve the face.

Orbital varices are associated with secondary glaucoma. Intermittent unilateral proptosis and dilated eyelid veins are key external signs of orbital varices. Carotid cavernous, dural cavernous, and other arteriovenous fistulae can produce orbital bruits, restricted ocular motility, proptosis, and pulsating exophthalmos. Superior vena cava syndrome can cause proptosis and facial and eyelid edema, as well as conjunctival chemosis. Thyroid eye disease and its associated glaucoma are associated with exophthalmos, eyelid retraction, and motility disorders.

Use of prostaglandin analogues may result in trichiasis, hypertrichosis, distichiasis, and growth of facial hair around the eyes, as well as increased skin pigmentation involving the eyelids. Use of glaucoma hypotensive agents may also result in an allergic contact dermatitis. Chapter 7 discusses these agents in detail.

Pupils

Pupil size may be affected by glaucoma therapy, and pupillary responses are one measure of compliance in patients who are on miotic therapy. Testing for a relative afferent pupillary defect may detect asymmetric optic nerve damage. Corectopia, ectropion uveae, and pupillary abnormalities may also be observed in some forms of secondary open-angle glaucoma and angle-closure glaucoma. In some clinical situations, it is not possible to assess the pupils objectively for the presence of a relative afferent defect, and a subjective comparison between the eyes of the perceived brightness of a test light may be helpful. Testing for color vision, extraocular motility, and cranial nerve abnormality may also be indicated.

Biomicroscopy

Biomicroscopy of the anterior segment is performed for signs of underlying or associated ocular disease. BCSC Section 8, External Disease and Cornea, discusses slit-lamp technique and the examination of the external eye in greater depth.

Conjunctiva

Eyes with acutely elevated intraocular pressure (IOP) may show conjunctival hyperemia. The chronic elevation of IOP that can occur with arteriovenous fistulae may produce massive episcleral venous dilation. Long-term use of sympathomimetics and prostaglandin analogues may also cause conjunctival hyperemia, and long-term use of epinephrine derivatives may result in black adrenochrome deposits in the conjunctiva. The use of topical antiglaucoma medication can also cause decreased tear production, allergic and hypersensitivity reactions (papillary and follicular conjunctivitis), foreshortening of the conjunctival fornices, and scarring. Prior to filtering surgery, the presence or absence of subconjunctival scarring or other conjunctival abnormalities should be assessed. The presence or absence of any filtering bleb should be noted. If a bleb is present, its size, height, degree of vascularization, and integrity should be noted, and in the situation of postoperative hypotony, a Seidel test performed.

Episclera and sclera

Dilation of the episcleral vessels may indicate elevated episcleral venous pressure, as seen in the secondary glaucomas associated with Sturge-Weber syndrome, arteriovenous fistulae, or thyroid eye disease. Sentinel vessels may be seen in eyes harboring an intraocular tumor. The clinician should note any thinning or staphylomatous areas.

Cornea

Enlargement of the cornea associated with breaks in the Descemet membrane (Haab striae) is commonly found in developmental glaucoma patients. Glaucomas associated with other anterior segment anomalies are described in the following discussions. Punctate epithelial defects, especially in the inferonasal interpalpebral region, are often indicative of medication toxicity. Microcystic epithelial edema is commonly associated with elevated IOP, particularly when the IOP rise is acute. The following corneal endothelial abnormalities can be important clues to underlying associated secondary glaucoma:

Krukenberg spindle in pigmentary glaucoma

deposition of exfoliative material in exfoliation syndrome keratic precipitates in uveitic glaucoma

irregular and vesicular lesions in posterior polymorphous dystrophy a “beaten bronze” appearance in the iridocorneal endothelial syndrome

An anteriorly displaced Schwalbe line is found in Axenfeld-Rieger syndrome. The clinician should note the presence of traumatic or surgical corneal scars. The central corneal thickness (CCT) of all patients suspected of glaucoma should be assessed by corneal pachymetry, as low central corneal thickness is a risk factor for glaucoma. (See Chapters 2 and 4.)

Anterior chamber

When evaluating the anterior chamber, the examiner should note the uniformity of depth of the chamber and estimate the width of the chamber angle. In the Van Herick method of estimating angle width, the examiner projects a narrow slit beam onto the cornea, just anterior to the limbus. This method may miss narrow angles or angle closure and is not a substitute for gonioscopy, which is discussed in detail later in this chapter (Figs 3-1, 3-2, Table 3-1).

Figure 3-1 Gonioscopic appearance of a normal anterior chamber angle. 2, Peripheral iris: a, insertion; b, curvature; c, angular approach. 3, Ciliary body band. 4, Scleral spur. 5, Trabecular meshwork: a, posterior; b, mid; c, anterior. 6, Schwalbe line. Asterisk, Corneal optical wedge.

Figure 3-2 A, Normal open angle. Gonioscopic photograph shows trace pigmentation of the posterior trabecular meshwork and normal insertion of the iris into a narrow ciliary body band. The Goldmann lens was used. B, Normal open angle. This gonioscopic view using the Goldmann lens shows mild pigmentation of the posterior trabecular meshwork. A wide ciliary body band with posterior insertion of the iris can also be seen. C, Narrow angle. This gonioscopic view using the Zeiss lens without indentation shows pigment in the inferior angle but poor visualization of angle anatomy. D, Narrow angle. Gonioscopy with a Zeiss lens with indentation shows peripheral anterior synechiae in the posterior trabecular meshwork. Pigment deposits on the Schwalbe line can also be seen. This is the same angle as shown in part C. (Courtesy of Elizabeth A. Hodapp, MD.)

Table 3-1

Iris bombé can result in an anterior chamber that is deep centrally and shallow or flat peripherally. Aqueous misdirection and pseudoexfoliation may also be associated with reduced anterior chamber depth and narrow angles. Iris masses, choroidal effusions, or trauma can produce an irregular iris surface contour and nonuniformity or asymmetry in anterior chamber depth. In many circumstances, especially in the assessment of narrow-angle glaucoma, comparing the chamber depth of the 2 eyes is of substantial value. The presence of inflammatory cells, red blood cells, floating pigment, or inflammatory debris (such as fibrin) should be noted. The degree of inflammation (flare and cell) should be determined before instillation of eyedrops.