Fig. 4.37 Peripheral ulcerative keratitis in a patient with rheumatoid arthritis. This slit-lamp photomicrograph illustrates the degree of peripheral corneal ulceration, nearly 80% in depth. The extent, circumferentially, is from 5 to 8 oÕclock. The degree of corneal destruction is much greater than is clinically apparent: exploration of the ulcer with a smooth-tipped tying forcep disclosed undermining of this ulcer, leaving an overhanging lip, with active digestion of the corneal stroma extending approximately 5 mm into the cornea from the area of the obvious active peripheral ulcer

Fig. 4.38 Peripheral ulcerative keratitis, which has progressed centrally and circumferentially in a patient with anterior scleritis associated with rheumatoid arthritis. Like the ulcer shown in Fig. 4.37, this one has an overhanging lip with undermining of the edge of the ulcer and destruction of stroma far in excess of what one would predict as a result of a simple slit-lamp examination. The digestive process has extended into the pupillary zone in this patient

membrane (Fig. 4.37). An intrastromal yellowÐ white blood cell inÞltrate may easily be seen at the advancing edge of the ulcer, which progresses circumferentially and occasionally centrally (Fig. 4.38), in which case vision is lost. In some cases, anterior uveitis may also be present. If no treatment is instituted, spontaneous corneal perforation may easily occur.

Seven percent of our patients had PUK, and the majority of these were associated with necrotizing scleritis (Table 4.4). PUK with or without scleritis is frequently an ocular manifestation of a systemic disease [154Ð156]. PUK was highly associated with the presence of a potentially lethal, often occult, systemic disease in our patients with scleritis. Most of these cases had the necrotizing variety of scleritis. These data show that the presence of PUK-accompanying scleritis should be considered a grave sign: it indicates an extension of the inßammatory process that may cause perforation of the eye, and may signal the presence of a potentially lethal systemic disease.

Differentiation from MoorenÕs ulcer may be difÞcult because both peripheral ulcerations may

be painful and crescent shaped, may follow a circumferential and central progression, and may have an undermined central edge with stromal yellowÐwhite inÞltrates. However, in MoorenÕs ulcer, there is neither adjacent scleritis nor systemic disease association [157].

Treatment for PUK includes cyanoacrylate glue application following keratectomy and conjunctival resection while vigorous systemic treatment is directed at controlling the scleral inßammation [158Ð160].

4.2.6.2 Uveitis

Uveitis is also caused by extension of the scleral inßammation. Fraunfelder and Watson [1] found that 68% of 30 enucleated eyes with a primary histological diagnosis of scleritis had signs of having had uveitis; scleritis with uveitis and glaucoma was the most common combination of complications leading to enucleation. Wilhelmus et al. [6], in another series of 100 enucleated eyes with a primary histological diagnosis of scleritis, found that 63% had had anterior uveitis. These Þndings suggest that scleritis with uveitis, particularly when associated with glaucoma, should be regarded as