Ian Conner, MD, PhD; Joel S. Schuman, MD, FACS; Malik Y. Kahook, MD; and David L. Epstein, MD, MMM
It is important to routinely perform a complete ophthalmological examination including dilated slit-lamp examination and peripheral retinal examination, in addition to the specific glaucoma evaluation in all patients with glaucoma. In primary open-angle glaucoma (POAG), there are few ocular signs; therefore, a diagnosis of POAG is really a diagnosis of exclusion. Ophthalmologists should view themselves as diagnostic sleuths, evaluating for unusual causes and considering new insights into mechanisms of the disease, including in patients with apparent POAG. Because the glaucomas involve multiple pathogenic mechanisms, the observant and inquisitive clinician is able to make important discoveries about known as well as new forms of glaucoma. This can only happen as a result of a complete and meticulously documented full ophthalmological examination.
Historically, many glaucoma physicians have found it useful to document the initial full comprehensive examination in an easily accessible location for constant reference. One frequently wants to know what the patient’s examination showed at baseline.
One should develop a routine for approaching the patient. One approach is as follows.
REFRACTION
Patients should be refracted first for their best distant and near acuity. As detailed, measurement and assessment of best corrected visual acuity (which can be degraded by glaucoma, especially in more advanced stages of the disease) are critical in the glaucoma patient evaluation. The proper refraction should be determined, and this information should be used for visual field testing, which is best performed before any ocular diagnostic manipulation.
PENLIGHT EXAMINATION
There is a tendency to hone in right away on the slit-lamp examination and optic nerve evaluation, especially in the follow-up of patients with glaucoma in continuing care. However, patients with glaucoma can develop other ocular and periocular disease, as much as any other patient. It is useful, therefore, to first approach the patient with a penlight or transilluminator and examine the lids and conjunctiva grossly. Topical allergies to glaucoma medications and diseases of the conjunctiva are often more apparent on penlight examination than on slit-lamp examination, especially if high magnification for the latter is routinely chosen. Note the position of the upper lids. This can be very important in planning where to perform a laser iridotomy or a filtration procedure in the future, so that the lid will naturally cover the manipulated site. (Even slight exposure of such sites can produce monocular diplopia and unrelenting patient unhappiness.) In addition, ptosis can develop after filtration or cataract surgery due to even mild surgical trauma, and needs to be discriminated from neurological causes.
Next, the pupils should be examined both for size and reactivity with the penlight. The swinging flashlight test should be performed, looking for a relative afferent pupillary defect (rAPD). It is common to detect an rAPD in asymmetric glaucoma, especially if the glaucomatous optic neuropathy is sufficiently advanced. However, a large rAPD in the presence of relatively symmetric optic nerve cupping should prompt a work-up for nonglaucomatous neuropathy.
David L. Epstein, MD, MMM
Some may think that this emphasis on compulsive thorough ocular examination in patients with glaucoma is not that necessary. Although likely less true in glaucoma than other ocular conditions, the eye is a wonderful self-healing and self-correcting organ. In fact, I teach ophthalmic residents that, for most issues, things turn out satisfactorily 95% of the time, even if nonoptimal methods or treatments are used. But the whole point of a residency or fellowship training, or even a book such as this, is to learn what to do for that other 5% of patients who will truly suffer if imprecise methods of understanding are implemented. In treating the glaucomas, we must aim for 100% (realizing that even 100% today, with so little true understanding, will not be satisfactory in the future).
For example, about 90% of the time, slit-lamp examination alone can identify narrow occludable angles. Because in POAG one sees nothing definitely abnormal in the angle and causes of secondary open-angle glaucoma are rare, then why do gonioscopy? The answer is that 90% is not good enough, especially for skilled professionals who have undergone years of ophthalmologic training. One can only hope that, with ever-expanding managed care health systems, we still will not be satisfied with less than 100%.
Heterochromia (eg, in Fuchs’ heterochromic iridocyclitis) can often be best appreciated on penlight examination (or even better with bright room light or sunlight).
Binocular eye position (cover test) and extraocular movements should also be routinely evaluated. Although one may argue that ocular alignment is uncommonly related to glaucoma, many patients with glaucoma will see their glaucoma specialist for their primary eye care, and patients with glaucoma may develop other ocular and systemic diseases in the course of their routine glaucoma follow-up. Examples of these include exophorias and tropias in patients who lose their ability to fixate as a consequence of advanced glaucoma or progressive cataracts, ocular motility restrictions following filtering procedures, nerve palsies secondary to microvascular disease, and ocular myasthenia.
Finally, although less common in the modern treatment era, assessing the actual size of the pupils in patients on cholinergic therapy may help the clinician gain insight into issues of medication compliance over time.
SLIT-LAMP EXAMINATION
One should always use at least 2 levels of magnification on slit-lamp examination. Some observations are actually easier to make with lower magnification (eg, conjunctival disease and iris transillumination defects). Start with low power, and examine the lids and conjunctiva. Note whether the punctum is in proper position, and whether it has been previously occluded as treatment for dry eye disease. Many patients with glaucoma complain of epiphora, which may be a sign of topical medication intolerance or allergy, but more commonly results from nonrelated abnormalities of lid position, meibomianitis, punctal stenosis, or dry eyes. Patients with underlying external ocular disease may complain of excessive stinging and irritation (and thus intolerance) of antiglaucoma agents. Early treatment of coincident external ocular disease will often improve acceptance of topical glaucoma medication (or at least a more accurate assessment of the side effects of the latter).
Figure 5-1. Conjunctival follicles from apraclonidine allergy.
Note palpebral conjunctival injection or follicle formation (Figure 5-1). The latter are common side effects from adrenergic agonists, such as apraclonidine and brimonidine, and the redness from these agents is often incorrectly interpreted by the patient because it is often delayed after instillation. In fact, the initial conjunctival response is commonly vasoconstriction followed later by vasodilation and redness, so many patients do not inform their ophthalmologist about their red eye, attributing it instead to general allergies. Thus, the incurious ophthalmologist may not easily detect the patient’s problem. Furthermore, patients may develop conjunctival follicles secondary to other causes (eg, benign lymphoid hyperplasia or lymphoma), and such entities are usually best appreciated under lower magnification.
Always pull down the lower lid and look for symblepharon formation, which could indicate pemphigoid-type disease (Figure 5-2). Although uncommon, miotics can cause a pemphigoid-type syndrome,1 which can be progressive and indicate the need to discontinue the medication. Of course, patients with primary ocular pemphigoid can develop POAG as a separate unrelated entity,2 emphasizing the importance of the thorough baseline exam in aiding the proper interpretation of this ocular finding.
As a routine, it is quite helpful to test conjunctival mobility superiorly, in case filtration surgery is required in the future. The presence of conjunctival scarring from previous ocular surgery, from early yet undiagnosed pemphigoid syndromes, or from previous other periocular inflammatory disease is important for one’s therapeutic plan, prognosis, and discussions with the patient.
Figure 5-2. Fornix shortening and fibrosis in ocular cicatricial pemphigoid.
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