Clinical aspects of ocular leptospirosis in New Caledonia (South Pacific)

The incidence of leptospirosis is very high in New Caledonia (average annual incidence rate: 180/100 000 of the population). To investigate the role of pathogenic leptospires as an aetiological agent of ocular diseases, we report the results of a 5-year survey in New Caledonia.

We reviewed 13 patients (corresponding to 17 investigated pathologic eyes) retrospectively. The selection of patients was based on epidemiological data, initial clinical examination, biological confirmation of leptospirosis according to reference procedures and a specific polymerase chain reaction assay. The anatomic criteria of uveitis and the criteria describing the evolution of the disease were those recommended by the International Uveitis Study Group.

Consequent rates of optic neuritis (65%), posterior uveitis (35%), secluded pupil (24%), interstitial keratitis (18%) and pars planitis (12%) were found. Our rates of recurrence (46%) and of ophthalmic complications (82%) were substantial; some symptoms indicated brain involvement.The final visual damage was severe in 35% of eyes.

Microagglutination and polymerase chain reaction hybridization are complementary tests for the diagnosis of Leptospira-induced ophthalmic lesions. Before deciding on treatment, one must consider the ability of virulent leptospires to persist in immunologically privileged sites such as aqueous humor, cerebrospinal fluid and eukaryotic cells. Polymerase chain reaction is a useful tool for the diagnosis of Leptospira-induced ocular complications, which are probably misdiagnosed if based only on routine laboratory tests. It enables early diagnosis and early specific treatment that now consists of quinolone and cyclines.