CryptococcosisSoil contaminated with pigeon droppings contains anencapsulated yeast. Cryptococcus IlcojiJr/Il(/lls. which entersthe body through inhalation (see Chapter 24). Cryptococcalinfection is usually limited to patients with cell-mediatedimmune dysfunction and occurs in )-10% of patients withAIDS. Ocular involvement is present in approximately 6% ofpatients with cryptococcalmeningitis. The most likely routeof infection is via direct extension from the optic nerve or byhaematogenous spread to the choroid and retina.I. Signs. J'vleningitis-associated manifestations are the mostcommon and include papilloedema. ophthalmoplegia.ptosis. optic neuropathy and sixth nerve palsy... Nlultilocal choroiditis (Fig. 14.44). Iris infiltration. keratitis and conjunctival granulomahm'e been reported.2. Treatment of sight-threatening lesions is with intravenousamphotericin. oral l'Iuconazole and itraconazole.Fig. 14.44Multifocal cryptococcal choroiditis (Courtesy of A Curi)Endogenous fungal endophthalmitisPathogenesisThe major source of fungal infection within the eye ismetastatic spread from a septic focus associated withcatheters. intravenous drug abuse. parenteral nutrition andchronic lung disease such as cystic fibrosis. Neutropeniafollowing immunosuppression and AIDS are also major riskfactors. Approximately 75% of isolates are ClIlldidllspp.; otherpathogens include CryplococcllS spp.. Sporoll1ri.r Sclll'llCkiiandBlllslomyces spp.DiagnosisI. Presentation is dependent on the location of theinl1ammatory focus. Peripheral lesions may cause few orno visual symptoms while central lesions or thoseresulting in severe vitritis will manifest earlier. Theprogression is. however. much slower than in bacterialendophthalmitis and bilateral involvement is common.

2. Signs · Anterior uveitis is uncommon in the early stages but

may become prominent later. · Creamy white chorioretinal lesions with overlying

vitritis (Fig. 14.45a). · Extension into the vitreous (Fig. 14.45b). · Vitritis and floating 'cotton-ball' colonies (Fig. ] 4,45c).

· Chronic endophthalmitis characterized by severe

vitreous infiltration and abscess formation (Fig. 14.45d).14. Uveitis 4853. Course is relatively chronic and may result in thedevelopment of retinal necrosis and retinal detachmentassociated with severe proliferative vitreoretinopathy.4. Investigations involving vitreous biopsy and smears andcultures may be required to confirm the diagnosis and testsensitivity of the organisms to antifungal agents.TreatmentI. Medical treatment is indicated for systemic disease and

ocular disease without vitreous involvement. · Intravenous amphotericin 5'X,dextrose; the initial dose

is 5mg and arter a few days can be increased to 20mg. · Oral fluconazole ltJO-200mg/day (400-800mg for

disseminated disease) for 3-6 weeks. lt can be used inconjunction with flucytosine (I OOmg/kg/day).· Oral voriconazole to treat cases resistant to [1uconazole.NB Systemic steroids are contraindicated in fungalinfections.2. Pars plana vitrectomy combined with intravitrealinjection of amphotericin 5-1 O~g in 0.1 ml is indicated in

the presence of vitreous involvement.

(clinical ophtalmology edisi 6 )