Subconjunctival Hemorrhage in Leptospirosis
A previously healthy 18-year-old guy arrived at the ER with a 2-day history of fever, vomiting, and diarrhoea. He had fallen into a canal three weeks before to his presentation. The temperature was 38.4°C, and his heart rate was 110 beats per minute. Scleral icterus and subconjunctival haemorrhage were found in both eyes (Panels A and B), as well as mild stomach pain without hepatosplenomegaly. Laboratory tests revealed acute renal damage as well as increases in aminotransferase and total bilirubin levels. The patient’s characteristic appearance (including subconjunctival hemorrhage) and exposure to water contaminated with mouse urine raised the possibility of a severe form of leptospirosis manifesting as fever, jaundice, renal failure, and haemorrhage.
An experimental treatment with intravenous penicillin was started. The titer for IgM antibodies against leptospira species was 1:320 (reference value, negative). Testing for leptospira species in serum was positive, and microscopic agglutination later confirmed Icterohaemorrhagiae as the infectious serogroup. After a one-week hospital stay, the patient was discharged. His symptoms, subconjunctival haemorrhage, and liver and renal damage were resolved three weeks later.
Ophthalmological features of leptospirosis
Leptospirosis (Weil disease) is caused by a gram-negative, water-borne spirochete belonging to the Leptospira genus of the Leptospiraceae family. This tropical disease is the most frequent zoonotic disease in the world. The majority of patients appear with self-limiting clinical signs such as rapid fever, myalgia, headache, scleral icterus, chemosis, nausea, anorexia, and stomach pain during the acute (anicteric) phase. Weil disease is the late icteric phase of interstitial nephritis, uremia, oliguria, renal lesions, vascular damage, meningitis, jaundice, psychosis, confusion, and delirium. Leptospirosis can cause both anterior and posterior segment ophthalmic signs, and this Eyewiki focuses on these ocular findings.
Direct or indirect contact with infected animals (e.g., cattle, pigs, horses, racoons, porcupines, domesticated dogs) or their body fluids (particularly urine) via water or soil contamination is the predominant mechanism of human transmission.
With an estimated 500,000 high-risk cases each year and a 30% fatality rate, leptospirosis is the most frequent zoonotic sickness in the world. Infection rates are ten times higher in tropical and subtropical regions than in temperate settings. Furthermore, leptospiral uveitis is more common in young to middle-aged men, most likely due to their greater involvement in agricultural activity.
The aetiology of leptospirosis ocular characteristics has been proposed as a host immune response and/or toxin generation. Endotoxin as a possible causative factor for leptospiral uveitis is indicated by the presence of serovar-specific lipopolysaccharide (LPS) with an increase in Interleukin-6 (IL-6), IL-8, IL-10, IL-12p70, and tumour necrosis factor (TNF) cytokines and selective neutrophil infiltration in aqueous humour.
Ocular manifestations
Sub-conjunctival haemorrhage, scleral icterus, circum-corneal congestion without conjunctival discharge, conjunctival suffusion, and chemosis are all ocular symptoms in the leptospiremic acute phase of the illness. Nongranulomatous uveitis, interstitial keratitis, conjunctival suffusion, cranial nerve palsies (third, fourth, sixth, or seventh cranial nerves), retinal vasculitis and haemorrhages, and optic neuropathy are ophthalmic symptoms of the late immunological phase (Weil disease) of infection.
Unilateral or bilateral uveitis (anterior or diffuse, acute or recurrent) typically develops 6 months after a systemic infection, though clinical signs of iridocyclitis, iritis, hypopyon, vitreous inflammatory reaction, cataract, retinal vasculitis, and papillitis can appear as early as 2 weeks. Panuveitis can be severe and relapsing, whereas anterior uveitis is usually mild and self-limiting.
Optic nerve involvement can appear as papillitis, optic neuritis, neuroretinitis, and optic disc hyperemia (seen in 3%-64% of case presentations). Optic neuropathy in leptospirosis can be detected by disc leakage on fluorescein angiography and a delayed response on visual-evoked potential testing. In neuroretinitis, inflammation of the peripapillary retinal layers and the optic nerve can cause a macular star. Finally, in leptospirosis, field abnormalities or colour vision defects may be symptoms of retrobulbar optic neuropathy or optic neuritis.
Source: NEJM
