Role of Surgery in the Patient with Uveitis

Considerations

In general, the indications for proceeding with surgery need to be more carefully considered in eyes with uveitis. Because of the possible increased risks, surgery is frequently not justified for eyes with slightly reduced, but functional, vision, which are not in danger of visual loss from a surgically repairable problem. However, we have observed many eyes in which surgery was delayed for so long that potentially treatable problems became hidden behind cataract or vitreous haze. Vision was then permanently lost because of the attempt to use surgery conservatively; vision might have been saved if the inflammatory disease and its complications could have been directly viewed and treated. There is a tendency to not operate on an eye with dense opacities and light-perception vision, but unseen and untreated inflammation causes further permanent damage to the retina. In addition to visual rehabilitation, surgical procedures in eyes with uveitis are performed as part of a diagnostic evaluation. The relative risks versus the potential benefits are considered here.

Except for the few situations in which it is necessary to operate on an acutely inflamed eye, surgery should be performed when the inflammation is quiescent. However, in some patients, it is impossible to clear every cell from the anterior chamber or vitreous. Furthermore, in patients with dense cataracts and primarily vitreoretinal inflammation, it is impossible accurately to assess the activity of the disease behind the opacity. Therefore an attempt should be made to reduce the inflammation as much as possible, but surgery should not be delayed while the patient endures a long-term visual handicap because the inflammation never becomes completely quiescent. If the inflammatory activity cannot be fully assessed, the eye may be treated prophylactically as though active inflammation were present.

In our opinion, corticosteroids are still the best drugs for control of inflammation in the perioperative period. In a small study of 20 patients randomly selected to receive prednisone or cyclosporin before cataract surgery, we found that 3 of 10 patients treated with cyclosporin, but none of the steroid-treated patients, had severe postoperative inflammation that necessitated a change in medication to the other drug. Corticosteroids work at multiple points in the inflammatory process, as described in Chapter 8 , and are able to affect inflammation mediated by neutrophils and macrophages and that by lymphocytes. Therefore they may prevent nonspecific postoperative inflammation that may occur in a previously inflamed eye and inhibit the more specific pathways of inflammation. We prefer to begin steroid therapy on the day before or on the day of surgery if the patient is not already receiving the drug, and if there is no evidence of active inflammatory disease. Some practitioners prefer to start steroid therapy several days before the scheduled surgical intervention. If there is no strong contraindication this may not be unreasonable in some patients. Usually, a steroid dose of 1 mg/kg/day or 60 mg/day (whichever is lower) is adequate. Preoperative subconjunctival or intravitreal corticosteroid injection can also be considered as an alternative. If the patient has a history of severe intraocular inflammation, an intravenous dose of corticosteroids, such as 50 to 100 mg of methylprednisolone, can also be given at the time of surgery. The goal is clearly to prevent severe postoperative inflammation.

The surgeon should be aware that with the aforementioned perioperative therapy, the eye may appear relatively quiet for the first few days after surgery, but the inflammation may increase a few days later. It is therefore critical to monitor patients with uveitis closely during the first 5 to 7 days after surgery. It is also important to remember that this perioperative corticosteroid regimen is administered in addition to the immunomodulatory regimen that the patient has already been receiving. In young patients, marked postoperative flares of inflammation, accompanied by significant fibrin and protein within the eye, can occur. Tissue plasminogen activator can be used to clear severe fibrin accumulation in the anterior chamber ( Fig. 9.1 ). After surgery, these eyes frequently have hypotony, and although they appear to be in imminent danger of phthisis, aggressive and continued treatment with steroids and other immunomodulators usually results in marked improvement.

Removal of Band Keratopathy

Calcium hydroxyapatite accumulates in the Bowman membrane of the cornea in some patients with sarcoidosis or juvenile rheumatoid arthritis (JRA) and occasionally in younger patients with chronic uveitis, such as pars planitis. Its location may be related to the local pH of the interpalpebral cornea. It can be removed by chelation if it is located centrally and interferes with vision because of opacity or glare or if it is the cause of recurrent corneal erosions. Although chelation with 1% to 2% ethylenediaminetetraacetic acid (EDTA) can be performed under local anesthesia, the young age of most patients with this condition makes general anesthesia necessary. Our procedure is to use a sterile 1.7% solution of EDTA in water or saline applied to the cornea with cotton or a cellulose applicator. Gentle pressure and movement of the applicator result in removal of the corneal epithelium and gradual solubilization of the calcium deposits. This procedure can take up to 30 minutes and often must be performed before intraocular surgery. Occasionally, resistant deposits must be gently removed with a spatula or a Tooke knife, but this may cause scarring of the Bowman membrane and should be avoided in the visual axis. The eye is then patched until the epithelial defect heals. Band keratopathy has also been removed with the excimer laser ( Fig. 9.2 ). It should be remembered that eyes with uveitis may have recurrences of the band even years after the removal of the calcium. Further, the procedure may very rarely induce a severe inflammatory response, as was reported in one patient.

Corneal Transplantation

Although keratic precipitates involve the corneal endothelial surface, in our experience, endothelial decompensation is rare in patients with chronic uveitis. Thus corneal transplantation is rarely performed in this group because of corneal edema, but it may be necessary in patients with corneoscleral melting in association with systemic inflammatory disease and intraocular inflammation or in patients with herpetic keratouveitis. If the intraocular inflammation has been severe, there may be coexisting glaucoma or cataract. The primary goal before corneal transplantation in these patients is to control the immune process, or the newly grafted tissue will melt as well. The ongoing inflammatory response suggests that the risk for rejection of a cornea transplant in any patient with active uveitis is high because there are already large numbers of cells in the eye that could present corneal antigens to the immune system and participate in the rejection event. Certain severe manifestations of immune-mediated ocular surface disease, such as vernal keratoconjunctivitis, can lead to limbal stem cell deficiency, and before penetrating keratoplasty is considered, the ocular surface environment needs to be addressed. The treating physician should be aware of the drugs being given for other indications that may induce uveitis and risk graft survival. Richards et al. described such a case of a patient receiving alendronate sodium for osteoporosis. The uveitis resolved after cessation of the drug. More recently, advanced endothelial keratoplasty techniques, such as deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), and Descemet membrane endothelial keratoplasty (DMEK), have resulted in improved visual outcomes and reduced rejection.