Ocular Syphilis

Ocular syphilis is infection of the eye or optic nerve by Treponema pallidum at any stage of syphilis. It is managed as a form of neurosyphilis and can cause permanent vision loss within weeks.

• Occurs more often in men who have sex with men, people with HIV, and in the period of rising cases.
• It may be the only manifestation of syphilis.

Blurred vision, floaters, photophobia, eye pain and redness, visual field defects, or sudden vision loss, unilateral or bilateral.

• Forms: anterior, intermediate or posterior uveitis, panuveitis, posterior placoid chorioretinitis, retinal vasculitis, retinal necrosis, optic neuritis and papillitis, interstitial keratitis, scleritis.
• Differential diagnosis: tuberculous uveitis, sarcoidosis, toxoplasmosis, cytomegalovirus retinitis, acute retinal necrosis, Behcet disease, HLA B27 uveitis, multiple sclerosis optic neuritis, lymphoma, endophthalmitis, ocular lymphoma.
• Complications: permanent visual loss, optic atrophy, retinal detachment, glaucoma, cataract, cystoid macular oedema, blindness.

Ophthalmic examination plus syphilis serology.

• Slit lamp and dilated fundus examination, visual acuity, visual fields, optical coherence tomography, fluorescein angiography.
• Serum treponemal and non treponemal tests; HIV test; CSF examination (cells, protein, VDRL) for possible neurosyphilis (do not delay treatment while awaiting the result).
• MRI brain and orbits when neurological signs are present; test for tuberculosis, toxoplasma, CMV and sarcoid where indicated.

Urgent treatment with high dose intravenous penicillin, with ophthalmology.

• Supportive: urgent ophthalmology referral, protect the eye, analgesia (paracetamol 1 g), partner notification and treatment, HIV and STI screening, counselling on adherence.
• Pharmacological: benzylpenicillin 18 to 24 million units daily IV (3 to 4 million units every 4 hours, or continuous infusion) for 10 to 14 days, optionally followed by benzathine benzylpenicillin 2.4 million units IM weekly for 3 doses; alternative ceftriaxone 2 g IV daily for 10 to 14 days. Anti inflammatory treatment: topical prednisolone acetate 1 percent hourly while awake for anterior uveitis and cycloplegic cyclopentolate 1 percent three times daily; oral prednisolone 1 mg/kg daily started 24 to 48 hours after antibiotics for posterior or optic nerve disease, tapered over 2 to 4 weeks. Jarisch Herxheimer reaction: monitor.
• Procedures: lumbar puncture; intravitreal or retinal surgery for detachment; glaucoma surgery.
• Special groups: pregnancy, penicillin (desensitise if allergic); HIV, give the full penicillin course and start antiretroviral therapy early; penicillin allergy, ceftriaxone; contact lens wearers, stop contact lens use.
• Red flags: sudden vision loss, afferent pupillary defect, optic disc swelling, retinal necrosis, headache or neurological signs, pregnancy.
• Follow-up: ophthalmology review at 1 week and monthly for 3 months; RPR at 3, 6, 12 and 24 months; CSF repeat if abnormal at 6 months.