Hypotony ocular

Anterior uveitis and neutropenia are fairly common side effects of cidofovir therapy. Ocular hypotony and metabolic acidosis are rare. Exposure to therapeutic levels of cidofovir causes cancer in rats therefore, this drug should be considered a potential human carcinogen. Animal studies have also shown cidofovir to produce embryotoxic and teratogenic effects and to impair fertility. 

Serious adverse reactions may include proteinuria (80%), nephrotoxicity (53%), neutropenia (31%), elevated serum creatinine levels (29%), infection (24%), anemia (20%), ocular hypotony (a decrease in intraocular pressure 12%), and pneumonia... 

In the case of ocular hypotony and a positive Seidel s sign with a formed anterior chamber in the early postoperative period, the treatment of choice is to discontinue the steroid to encourage wound closure and avoid secondary infection. The patient should be placed on a third- or fourth-generation topical fluoroquinolone. A topical aqueous suppressant may also be used to ensure secure wound closure.The patient is asked to limit activities and is given an eye shield to wear at night. An alternative treatment may include the use of a topical antibiotic and a 24-hour pressure patch with an eye shield while sleeping. If the wound feils to seal after several days to 1 to 2 weeks, surgical repair should be considered. 

During long-term follow-up of patients with AIDS treated with parenteral cidofovir for CMV retinitis, the median time to discontinuation for intolerance was 6.6 months (11). Cidofovir-associated uveitis occurred in 10 of 58 patients and ocular hypotony (a 50% fall in intraocular pressure from baseline to below 5 mmHg) occurred at a rate of 0.16 per person-year. There were 51 episodes of proteinuria in 30 of the 58 patients and 82% of these episodes resolved on withdrawal (median time to resolution 20 days). No nephrotoxic events required dialysis. 

Nephrotoxicity is the principal dose-limiting side effect of intravenous cidofovir. Proximal tubular dysfunction includes proteinuria, azotemia, glycosuria, and metabolic acidosis. Concomitant oral probenecid and saline prehydration reduce the risk of renal toxicity. On maintenance doses of 5 mg/kg every 2 weeks, up to 5Wo of patients develop proteinuria, 10-15% show an elevated serum creatinine, and 15-20% develop neutropenia. Anterior uveitis that is responsive to topical glucocorticoids and cycloplegia occur commonly and ocular hypotony occurs infrequently with intravenous cidofovir. Administration with food and pretreatment with antiemetics, antihistamines, and/or acetaminophen may improve tolerance. 

Patients experience less discomfort associated with ocular hypotony and the collapse of the anterior chamber together with quickly improved vision. 

Sodium hyaluronate is applied in the treatment of postoperative ocular hypo-tony in glaucoma surgery. Ocular hypotony caused by overfiltration (Fig. 104) is not only relevant in the development of visual acuity (Schwenn et al., 1996) but also subject to numerous complications. Sodium hyaluronate is particularly well suited for treatment of shallowed anterior chambers (Fig. 105) with threatening lentocorneal contact. 

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