Ocular toxoplasmosis: a global reassessment. Part II: disease manifestations and management.
OBJECTIVE
To update clinical information about ocular toxoplasmosis. Part II reviews the spectrum of disease manifestations and factors that influence severity of disease. Implications for disease management are discussed.


METHODS
Literature review.


METHODS
Selected articles from the medical literature, information from several recent scientific meetings, and the author's personal experiences were reviewed critically in preparation for the LX Edward Jackson Memorial Lecture.


RESULTS
The appearance of toxoplasmic retinochoroiditis lesions varies with duration of active retinal infection and intensity of inflammation. Severe ocular disease occurs in immunocompromised hosts. Older patients who are recently infected with Toxoplasma gondii may have a higher prevalence of ocular involvement and more severe ocular disease because of altered host defenses. Most disease-producing isolates of T. gondii belong to one of three clonal lineages (types I, II, III); type I has been associated with severe disease in both animals and human beings. Many observational studies suggest a benefit of short-term antimicrobial therapy for toxoplasmic retinochoroiditis in immunocompetent patients, although the efficacy of these treatments has not been proven in randomized clinical trials. Intermittent trimethoprim/sulfamethoxazole treatment was associated with fewer recurrences than placebo during a 20-month randomized clinical trial.


CONCLUSIONS
Variations in disease characteristics may be related to host, parasite, or environmental factors. The genotype of the infecting parasite appears to be an important determinant of disease severity in immunocompetent patients. Secondary prophylaxis may reduce the rate of recurrences in high-risk patients. A better clinical understanding of ocular toxoplasmosis can lead to more effective prevention and treatment strategies.
Holland
Gary N
GN
Ocular Inflammatory Disease Center, Jules Stein Eye Institute and the Department of Ophthalmology, David Geffen School of Medicine at UCLA, University of California, Los Angeles 90095-7003, USA. uveitis@jsei.ucla.edu
D000328:Adult; D017677:Age Distribution; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D002825:Chorioretinitis / Q000175:diagnosis / Q000188:drug therapy / Q000469:parasitology; D004359:Drug Therapy, Combination; D005260:Female; D014943:Global Health; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D008297:Male; D011241:Prednisone / Q000627:therapeutic use; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000517:prevention & control; D011739:Pyrimethamine / Q000627:therapeutic use; D012307:Risk Factors; D013411:Sulfadiazine / Q000627:therapeutic use; D014126:Toxoplasmosis, Ocular / Q000151:congenital / Q000175:diagnosis* / Q000188:drug therapy*; D014481:United States
D000981:Antiprotozoal Agents; D005938:Glucocorticoids; D013411:Sulfadiazine; D011241:Prednisone; D011739:Pyrimethamine