Examination of the Patient with Uveitis

Key concepts

•A thorough ophthalmic examination is critical for both diagnosis and assessing response to therapy.

•Use of standardized grading scales for assessing intraocular inflammation can improve patient management.

•Standard grading scales are available for anterior chamber cells and flare and vitreous cells and haze.

•A detailed examination of the peripheral retina can reveal pars plana exudates, signs of retinal vasculitis, Delen–Fuchs nodules, or other lesions suggesting active inflammation or infection.

The ocular examination of patients with uveitis is important not only to diagnose the disease correctly but also to determine the appropriate therapy. The examination will provide information that enables the examiner to generate a differential diagnosis and will allow the patient’s subjective complaints to be placed into the framework of objective clinical findings. In addition, the baseline examination becomes an important yardstick against which treatment success or failure will be measured. Many inflammatory diseases are chronic and require potentially toxic therapy. Therefore, it is critical to accurately assess whether a patient is benefiting from treatment. This includes a thorough review of the patient’s previous medical records and accurate assessment of the disease at each clinic visit. A complete review of the patient’s medical records provides important information for planning new therapeutic approaches and guards against repeating therapies that were unsatisfactory in the past. Because a patient’s medical record is valuable in assessing response to therapy, it is important to accurately record the presence or absence of important physical findings in a reproducible and standardized manner. Furthermore, because many of the ophthalmic findings in inflammatory disease, such as vitreous cells and haze, are evaluated only by subjective means, the examiner should strive to maintain internal consistency in grading the severity of the observations and to standardize these observations whenever possible. Importantly, standard grading scales should be used whenever possible. The use of standard scales provides consistency when different ophthalmologists are involved in the care of the patient over time. This also allows comparison of patients with those reported in the literature.

Scott M. Whitcup

Visual acuity

Several factors can lead to reduced visual acuity in patients with uveitis or retinitis. A combination of corneal opacity, anterior chamber inflammation, cataract, and vitreous haze may exacerbate a disturbance in retinal function caused by retinal edema, necrosis, or scarring. In addition, optic nerve function may be compromised after inflammation or glaucoma. It is important for the clinician to determine the cause of diminished vision because the therapeutic approach will differ according to the cause. For example, it would be inappropriate to increase a patient’s dose of prednisone to treat worsening vision that is due to a progressive posterior subcapsular cataract. Whatever type of visual acuity measurement is used, it must be performed under the same lighting conditions each time, otherwise the fluctuations induced by the testing environment will mask changes in vision caused by worsening disease or response to therapy. A bestcorrected visual acuity measurement should be obtained either by refraction or at the very least with the use of a pinhole occluder. Near-vision measurement is also helpful because we have observed that an improvement in near vision can precede an improvement in distance vision by several weeks in patients with chronic macular edema.

The most common method to measure visual acuity is the Snellen eye chart. Like all eye charts, the Snellen chart tests a patient’s ability to resolve high-contrast letters and is satisfactory if their vision is good. Unfortunately, the chart does not have enough sensitivity for patients with poor vision. There are no lines between 20/100 and 20/200 or between 20/200 and 20/400. In addition, there are too few letters on the lines above 20/100. Although an improvement in visual acuity from 20/200 to 20/125 may not be significant to the patient, the ability to measure this improvement is an important indicator that the current therapeutic approach is working. Because many patients with macular edema have a visual acuity of less than 20/80, initial improvement might be missed with use of a standard Snellen chart.

For these reasons, we have used the ETDRS chart initially developed for the evaluation of patients in the Early Treatment for Diabetic Retinopathy Study (ETDRS) (Fig. 3-1).1 This chart has five letters per line starting with the 20/200 line, and every three lines represent a doubling of the visual angle. Therefore, improving from 20/40 to 20/20 represents the same level of improvement in visual function as 20/80 to 20/40. If patients cannot read the 20/200 line while sitting 4 m from the chart, they are moved to 1 m from the chart and the acuities are recorded as 5 over the appropriate