Table 1.
Examples of ocular infections causing sight loss.
| Classification | Diagnostic category | Organisms involved |
|---|---|---|
| Viruses | Keratitis | Measles virus, herpesviruses, adenovirus |
| Cicatrising conjunctivitis | Adenovirus, herpes simplex | |
| Uveitis | Herpesviruses, rubella, HIV, Ebola, Chikungunya, Zika | |
| Retinitis | Herpesviruses, Rift Valley Fever virus, Zika virus, Chikungunya, measles | |
| Foveolitis | Dengue | |
| Chorioretinitis | West Nile virus, Ebolavirus | |
| Orbital apex syndrome, optic neuritis, scleritis | Varicella zoster virus | |
| Post-infectious maculopathies | Influenza, Coxsackie, SARS-CoV2 | |
| Retinal vascular occlusion | Dengue, SARS-CoV2 | |
| Congenital retinopathy and/or retinal lesions | Rubella, Zika, HSV-2 | |
| Bacteria and fungi | Trachoma | Chlamydia trachomatis |
| Keratitis | Various e.g., Staphylococcus aureus, Fusarium spp. | |
| Endophthalmitis | Various e.g., coagulase-negative staphylococci, Candida albicans, Klebsiella spp. | |
| Orbital cellulitis | Various e.g., Streptococcus pneumoniae, Haemophilus influenzae | |
| Neuroretinitis | Spirochaetes (e.g., tick-borne borrelioses, leptospirosis), Bartonella spp., rickettsioses | |
| Ocular syphilis (placoid chorioretinitis, optic neuritis, multifocal retinitis, vitritis, granulomatous uveitis) | Treponema pallidum | |
| Hypopyon uveitis | Leptospirosis (Weil’s disease) | |
| Multifocal retinitis | Rickettsioses, Bartonella spp. | |
| Ocular tuberculosis (granulomatous uveitis, occlusive retinal vasculitis, serpiginous-like and ampiginous choroiditis, choroidal granulomas, and/or optic nerve granuloma) | Mycobacterium tuberculosis | |
| Ocular leprosy, erythema nodosum leprosum, iris leproma | Mycobacterium leprae | |
| Choroidal granuloma | Brucella spp., TB | |
| Multifocal choroiditis | Nocardia spp., paracoccidioidomycosis, coccidioidomycosis, presumed ocular histoplasmosis syndrome | |
| Post-streptococcal uveitis | β-haemolytic (Group A) streptococci | |
| Optic disc oedema | Tropheryma whipplei | |
| Parasites and arthropods | Onchocerciasis | Onchocerca volvulus |
| Ocular toxoplasmosis (chorioretinitis) | Toxoplasma gondii | |
| Keratitis | Acanthamoeba spp., microsporidia spp. | |
| Post-kala azar ocular leishmaniasis | Leishmania donovani, Leishmania infantum | |
| Ocular toxocariasis | Toxocara spp. | |
| Diffuse subacute neuroretinitis | Various, e.g., Toxocara spp., Baylisascaris procyonis, soil-transmitted helminths, non-human hookworms | |
| Orbital and ocular tapeworm infections | Cysticercosis (Taenia solium), Echinococcus granulosus, Spirometra spp. | |
| Presumed trematode-induced granuloma | Schistosoma spp., Procerovum varium | |
| Orbital and ocular roundworm infections | Trichinella spp., Dirofilaria spp., Angiostrongylus spp., Gnathostoma spp. | |
| Ocular pentastomiasis | Armillifer armillatus, Linguatula serrata | |
| Ophthalmomyiasis | Various, e.g., sheep bot fly Oestrus ovis |