Uveitis part 3

This presentation gives a brief notes about Uveal tract inflammation and its treatment in this first part presentation.

1. Uveitis. Part 3 By Dr . Amr Mounir.MD Lecturer of Ophthalmology Sohag University

2. PARASITIC UVEITIS

3. PARASITIC UVEITIS 1-Toxoplasmosis 2-Toxocariasis 3- Onchocerciasis 4- Cysticercosis

4. Toxoplasmosis

5. Toxoplasmosis Toxoplasmosis is caused by Toxoplasma gondii , an obligate intracellular protozoan. The cat is the definitive host, with intermediate hosts including mice, livestock, birds and humans. Oocysts are excreted in cat faeces and then ingested by intermediate hosts including via contaminated water supplies . Occasionally ; infection may be transmitted via organ transplantation or blood transfusion

6. Systemic features: 1) Congenital toxoplasmosis Neurological and visceral involvement may be very severe , Retinochoroiditis may occur in over 75% 2) Postnatal childhood acquisition 50% of cases of childhood toxoplasmosis 3) Acquired toxoplasmosis in immunocompetent adults subclinical in 80–90 %, early retinitis may occur in up to 20% 4) Toxoplasmosis in immunocompromised patients meningoencephalitis , pneumonitis, retinochoroiditis

7. Ocular features: Toxoplasmosis constitutes 20–60% of all posterior uveitis Reactivation at previously inactive cyst-containing scars is the rule in the immunocompetent Recurrent episodes of inflammation are common and occur when the cysts rupture and release hundreds of tachyzoites into normal retinal cells Ocular involvement from congenital infection may only be detected later in life with the incidental discovery of typical retinochoroidal scars, though occasionally macular or optic nerve damage may impair vision in childhood.

8. C/P: Symptoms : Unilateral acute or subacute onset of floaters, blurring and photophobia . Signs : - ‘ Spill-over’ anterior uveitis is common - A single inflammatory focus of fluffy white retinitis or retinochoroiditis associated with a pigmented scar (‘satellite lesion’) is typical. - De novo foci not associated with an old scar, and multiple lesions - Vitritis may be severe and impair fundus visualization. ‘Headlight in the fog ’ - Vasculitis

9. - Optic disc oedema - Extensive and fulminant retinal involvement - Retinochoroiditis may be absent - Neuroretinitis - Punctate outer retinal toxoplasmosis - Visual loss: Causes of permanently reduced vision ( around 25% of eyes) include macular inflammatory lesions and oedema , optic nerve involvement , vascular occlusion , serous , rhegmatogenous and tractional retinal detachment and late secondary choroidal neovascularization

10. Healing: in immunocompetent hosts usually occurs spontaneously within 6–8 weeks, although vitreous opacities take longer to clear . The inflammatory focus is replaced by a sharply demarcated atrophic scar that develops a pigmented border Recurrence: The average number of recurrent attacks per patient

11. Investigation: Serology: Toxoplasma IgG antibodies are detectable in the serum within 1–2 weeks of initial infection. Positivity to IgM antibodies usually means that infection has been acquired within the last year. PCR testing of intraocular fluid is variably sensitive (16–67%) but highly specific. Ocular fluid antibody assessment . Calculating the ratio ( Goldmann – Witmer coefficient) of specific IgG in aqueous humour to that in serum seems to be a reasonably sensitive (48–90%) investigation.

12. Treatment : -Evidence for the efficacy of current regimens is limited. -Eradication of the parasite has not been demonstrated but parasite activity and multiplication may be reduced. - Spontaneous resolution generally occurs, treatment is not administered in every case.

13. Indications for treatment: Sight-threatening lesion involving the macula, papillomacular bundle, optic nerve head or a major blood vessel, for severe vitritis and in the immunocompromised. Prednisolone (1 mg/kg) is given initially and tapered according to clinical response , Should always be used in conjunction with a specific anti- Toxoplasma agent, most frequently pyrimethamine combined with sulfadiazine (‘classic’ or ‘triple’ therapy, sometimes supplemented with clindamycin ). Intravitreal therapy with clindamycin (1 mg) and dexamethasone (400 μg ) may be as effective as triple therapy in reactivated infection; two to three injections (two-weekly intervals) may be required. It may be preferred in recurrent infection in pregnancy

14. Other lines of therapy: Azithromycin 250–500 mg daily shows evidence of reducing the rate of recurrence of retinochoroiditis and its use in combination with pyrimethamine , folinic acid and prednisolone is a promising newer regimen. Clarithromycin may be a good alternative to azithromycin. Co- trimoxazole (trimethoprim 160 mg/ sulfamethoxazole 800 mg) twice daily in combination with prednisolone is a lower-cost and better-tolerated option that might not be quite as effective as classic therapy. Clindamycin 300 mg four times daily may be added to triple therapy (see above) or used instead of pyrimethamine . Pseudomembranous colitis is a potential adverse effect. Atovaquone 750 mg two to four times daily. Topical steroid and mydriatic may be given for anterior uveitis. Antimicrobial maintenance therapy is used in immunocompromised patients.

15. Toxocariasis

16. Toxocariasis is caused by infestation with a common intestinal ascarid (roundworm) of dogs, Toxocara canis ; puppies are more commonly infected than adult dogs, and are also more likely to spread the organism. Human infestation is by ingestion of soil or food contaminated with ova shed in canine faeces; young children are at particular risk from the soil of parks and playgrounds. Once ingested, ova develop into larvae, which penetrate the intestinal wall and travel to various organs such as the liver, lungs, skin, brain and eyes, with resultant inflammation

17. C/P: - Asymptomatic infestation is common . - Visceral toxocariasis (VT), also known as visceral larva migrans (VLM) is systemic infection of variable severity that usually occurs in a child aged 2–7 years. Fever, abdominal pain, pneumonitis, lymphadenopathy, hepatomegaly and myocarditis are some of the possible features . - Covert toxocariasis : mild systemic form

18. Ocular toxocariasis : (ocular larva migrans – OLM) generally occurs independently of VLM, and is associated with a lower parasitic load. It is typically unilateral, and in around two-thirds causes some degree of permanent visual impairment . a) Chronic endophthalmitis typically presents with leukocoria , strabismus, floaters or unilateral visual loss. Features may include anterior uveitis, vitritis, chorioretinitis , papillitis and a fundus granuloma. b) Posterior pole or peripheral granuloma without Inflammation c) Chorioretinal scar d) Diffuse unilateral subacute neuroretinitis (DUSN).

19. Investigations: It is particularly important to distinguish a Toxocara granuloma from retinoblastoma. Full blood count. Eosinophilia may be present, particularly in VLM, and can become chronic Hypergammaglobulinaemia especially IgE . • Serology. Antibodies to Toxocara canis are detectable in only about 50% of ocular cases. Positivity is common in the general population (14% overall in the USA). • Ultrasonography may be useful if the media are hazy. • Aqueous or vitreous sampling for eosinophilia, antibody detection and PCR. • Biopsy of a granuloma of the skin or elsewhere for larvae is sometimes possible.

20. Ocular treatment - Prevention by good hygiene practices and deworming of pets. - Steroids. Topical, regional and systemic as indicated. - Anthelmintic agents such as mebendazole and thiabendazole can be considered in OT, noting that worm death may promote inflammation. - Vitrectomy for sight-threatening tractional sequelae

21. Onchocerciasis

22. Onchocerciasis, which affects the eyes and skin, is the second most common cause of infectious blindness in the world. It is endemic in areas of Africa and other regions. The parasitic helminth Onchocerca volvulus is causative; the vector is the Simulium blackfly, which breeds in fast-flowing water, hence the colloquial term “river blindness” Larvae are transmitted when the fly bites to obtain blood; they migrate to subcutaneous sites to form onchocercomas , where microfilariae are produced by adult worms. Degenerating microfilariae excite an intense inflammatory reaction accounting for most of the clinical manifestations of the disease.

23. C/P: Systemic features are principally dermatological and include pruritus, a maculopapular rash ( onchodermatitis ) involving the buttocks and extremities, and areas of hypo- and hyperpigmentation on the shins (‘leopard skin)

24. Eye manifestations : Live microfilariae may be seen in the cornea, vitreous and suspended in the anterior chamber after the patient has postured face-down for a few minutes followed by immediate slit lamp examination. Anterior uveitis is an early feature. Pear-shaped pupillary dilatation may be seen, and is due to posterior synechiae . Keratitis. Punctate keratitis (snowflake opacities) affects a third of patients and consists of infiltrates surrounding dead microfilariae; initial lesions are most commonly located at 3 and 9 o’clock in the anterior third of the stroma Slowly progressing sclerosing keratitis may eventually involve the entire cornea. Chorioretinitis is usually bilateral and predominantly involves the temporal fundus, sparing the macula until late .

25. Treatment Ivermectin (supplied in many countries by Merck at no charge) kills microfilariae (but not adult worms) and is given at least annually for many years. Ivermectin occasionally precipitates inflammation , so prophylactic prednisolone may be considered in patients with visible anterior chamber. Moxidectin is a newer drug that may be superior to ivermectin . Doxycycline 100–200 mg per day for six weeks targets Suramin is effective against adult worms. It is given intravenously. Steroids . Anterior uveitis is responsive

26. Cysticercosis Cysticercosis refers to infection by Cysticercus cellulosae , the larval form of the pork tapeworm Taenia solium . Ingesting cysts of T. solium in undercooked pork leads to intestinal tapeworm development ( taeniasis ); the infested human then sheds eggs that lead to larval infection ( cysticercosis ) when ingested by the same or another individual. Inflammation develops in response to antigens released by dead organisms.

27. Clinical features Systemic disease may involve the lungs, muscle and CNS ( neurocysticercosis ). MRI and CT imaging are effective at demonstrating cysts; plain X-rays may show calcified cysts. Serology and stool analysis are useful for diagnosis. Ocular features include cysts of the conjunctiva and occasionally the orbit and eyelids. The anterior chamber may show a free-floating cyst . Larvae entering the subretinal space can cause exudative retinal detachment They can also pass into the vitreous where released toxins can incite an intense vision-threatening inflammatory reaction.

28. Treatment Systemic steroids to control inflammation are combined with Surgical removal of the larvae from the anterior chamber, vitreous and subretinal space. Anthelmintic agents such as albendazole may be appropriate in systemic disease, but should be used with caution under specialist guidance, and often with steroid co-administration.

29. Diffuse unilateral subacute neuroretinitis (DUSN) DUSN is a clinical syndrome due to the presence of a single motile subretinal nematode such as Toxocara canis , Baylisascaris procyonis and Ancylostoma caninum Misdiagnosis (e.g. multifocal choroiditis ) is common as the worm is often small and may be overlooked.

30. Clinical features Presentation is with insidious monocular visual decrease; diagnosis is essentially clinical. Electroretinography (ERG) is subnormal , even in early disease. Acute disease. Crops of grey–white outer retinal lesions vitritis , papillitis and retinal vasculitis . End-stage disease. Optic atrophy, retinal vascular attenuation and diffuse RPE degeneration

31. Treatment Photocoagulation (200 μm , 0.2–0.5 s, 150–300 mW ) is the treatment of choice when a worm can be visualized (<50%); if necessary a slit beam or very light laser burns are first used to shepherd (sometimes lure) the photosensitive nematode away from the fovea . Systemic albendazole (400 mg for 30 days) or vitrectomy may be appropriate in some cases. Steroid cover may be prudent with all treatment modalities.

32. VIRAL UVEITIS

33. Uveitis in human immunodeficiency virus infection Human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) is transmitted by unprotected sexual intercourse (heterosexual contact overall globally but sex between men in wealthier countries), via contaminated blood or needles, and vertically from mother to child transplacentally , during birth or breastfeeding. HIV depletes CD4+ T cells, which are vital to the initiation of the immune response to pathogens

34. Systemic features: Ocular features: Eyelid: Blepharitis, Kaposi sarcoma, multiple molluscum lesions and herpes zoster ophthalmicus . Orbit: Cellulitis (e.g. aspergillosis , contiguous sinus infection), B-cell lymphoma. Conjunctiva: Kaposi sarcoma, squamous cell carcinoma and microvasculopathy (up to 80%). Cornea: Keratoconjunctivitis sicca and an increased incidence of keratitis, e.g. herpes simplex and zoster, and fungal. Anterior uveitis: associated with ocular infections, or (commonly) with drug toxicity, e.g. rifabutin , cidofovir .

35. HIV-related retinal microangiopathy : Retinal microangiopathy is the most frequent retinopathy in patients with AIDS, developing in up to 70% of patients. HIV infection of the retinal vascular endothelium, and abnormalities of flow. It manifests with cotton-wool spots and/or retinal haemorrhages , In contrast to CMV retinitis , lesions are usually asymptomatic and almost invariably disappear spontaneously after several weeks

36. Other viral retinitis: cytomegalovirus retinitis (most common), progressive retinal necrosis, acute retinal necrosis. Protozoal : toxoplasmic retinochoroiditis , often atypical. Fungal : Pneumocystis choroiditis , Histoplasma chorioretinitis , cryptococcal choroiditis , candidiasis. Bacterial : syphilis, tuberculosis. Neoplastic : B-cell intraocular lymphoma. Neuro -ophthalmological . Usually secondary to meningitis or encephalopathy due to an opportunistic infection (e.g. toxoplasmosis, cryptococcosis , neurosyphilis ) or neoplastic process (e.g. CNS lymphoma).

37. Cytomegalovirus retinitis Infection with cytomegalovirus (CMV), a herpes virus , is very common in the general population, causing no or minimal constitutional symptoms in most healthy individuals. CMV retinitis is seen in patients immunocompromised from a variety of causes; it is a common opportunistic ocular infection in patients with AIDS, in whom it may represent reactivation of latent infection. Without treatment, severe visual loss is essentially inevitable

38. Ocular features Presentation is with reduced vision from macular involvement or with floaters from vitritis. - Anterior uveitis can occur but is usually mild with little or no injection; it is considered separately later in this chapter. - Cataract is a common later-stage finding. - Vitritis is typically mild, except in immune recovery - Retinitis. The characteristic appearance is of one or two areas of dense white retinal infiltration associated prominently with flame-shaped retinal hemorrhages (‘pizza pie’ or ‘ Margherita pizza’), beginning peripherally (centrally in 10%) and extending along the course of the vascular arcades

39. Optic neuritis may result from direct spread or from primary involvement. Retinal necrosis is evident in areas where active inflammation has settled, leaving irregular pigmentation, atrophy and holes frequently leading to retinal detachment a major cause of visual morbidity (up to 50%). Frosted branch angiitis (FBA) describes marked vascular sheathing that occurs in about 6% this appearance is seen in other conditions, and the term is also used for a distinct idiopathic disorder (primary FBA)

40. Immune recovery uveitis (IRU ). This is a cause of limited visual outcome in CMV retinitis, thought to be due to a rejuvenated immune response against residual viral antigen following immune reconstitution with HAART. Manifestations can be severe, progressing to phthisis in some cases.

41. Treatment Highly active antiretroviral therapy (HAART) is also sometimes called combination antiretroviral therapy, or antiretroviral therapy is the mainstay of management, restoring the patient’s innate ability to suppress CMV activity . • Valganciclovir . • Ganciclovir , foscarnet and cidofovir given intravenously were formerly key therapeutic agents, but substantial side effects have largely led to their relegation to reserve status. • Ganciclovir slow-release intravitreal implant. • Vitrectomy with endolaser demarcation and silicone oil tamponade is successful in around 75% of CMV-related retinal detachments. • Steroids may be required for IRU, though intravitreal and systemic administration should be used with caution.

42. Rubella: Latent rubella virus may cause chronic anterior uveitis relatively unresponsive to steroids, and has been implicated in the causation of Fuchs uveitis syndrome. Reported ocular features of congenital rubella include cataract, anterior uveitis, (salt and pepper) pigmentary retinopathy glaucoma and microphthalmos . Measles: Infection acquired in childhood typically features conjunctivitis and epithelial keratitis; occasionally retinitis with macular and disc oedema can occur. Subacute sclerosing panencephalitis (SSPE) is a late complication of measles infection, manifesting with chronic progressive neurodegenerative and usually fatal disease of childhood caused by the measles virus. Posterior uveitis is common, and may be the presenting feature.

43. FUNGAL UVEITIS

44. Presumed ocular histoplasmosis syndrome (POHS) Histoplasma capsulatum infection occurs following inhalation of the yeast form of this dimorphic fungus, and can lead to the systemic mycosis histoplasmosis – pulmonary involvement is the most common feature. It is common in AIDS. POHS is relatively common in areas of endemic histoplasmosis (e.g. the Mississippi river valley in the USA), implicating H. capsulatum in its aetiology

45. Ocular features Sixty per cent have bilateral signs. Presentation: POHS is usually asymptomatic unless macular choroidal neovascularization supervenes; signs may be discovered at a routine eye examination . Classic triad : ( i) multiple white atrophic chorioretinal ‘ histo ’ spots about 200 μ m in diameter ( ii) peripapillary atrophy ( iii) vitritis is absent. Linear midperipheral scars also occur (5%).

46. Choroidal neovascularization (CNV) is a late manifestation occurring in less than 5% of affected eyes. It is usually associated with a pre-existing macular histo spot. Associated subretinal fluid and haemorrhage lead to a fall in vision. Acute chorioretinitis is almost always asymptomatic and rarely identified, but discrete oval–round whitish lesions <400 μm in diameter that may develop into classic punchedout histo spots have been described.

47. Investigation HLA testing: POHS is associated with HLA-B7 and DRw2. Serological testing: is helpful if positive, but is usually negative in the absence of systemic mycosis. FA and OCT when CNV is suspected.

48. Treatment Spontaneous regression of CNV may occasionally occur, but without treatment 60% of eyes with CNV have a final visual acuity of less than 6/60. Intravitreal anti-vascular endothelial growth factor (VEGF) injection for CNV. Amsler grid testing of the fellow eye at least weekly, particularly if a macular histospot is present (25% risk of CNV).

49. Pneumocystis choroiditis The fungus Pneumocystis jirovecii , a pulmonary commensal, is a major cause of mortality in uncontrolled AIDS. Systemic antimicrobial prophylaxis has replaced pulmonary-only preventative treatment with inhaled pentamidine , and along with immune reconstitution has dramatically reduced the incidence of Pneumocystis choroiditis . Multiple slowly progressing deep round yellow– orange lesions commonly bilateral, are characteristic. There is minimal vitritis, and visual loss is often negligible.

50. Cryptococcal choroiditis Cryptococcus neoformans , a dimorphic yeast, enters the body through inhalation, and can spread to the eye in the bloodstream or from the CNS via the optic nerve. As with pneumocystosis , cryptococcosis was formerly responsible for much morbidity

51. Endogenous Candida endophthalmitis Candida (usually the commensal C. albicans) can be introduced into the eye from the external environment by trauma or surgery or can spread from fungal keratitis, but endogenous infection is an important alternative route . Risk factors for metastatic spread include intravenous drug abuse, a septic focus associated with an indwelling catheter, chronic lung disease such as cystic fibrosis, general debilitation and diabetes

52. Clinical features Systemic candidiasis may already have been diagnosed; up to a third of patients with untreated candidaemia will develop ocular involvement. Peripheral fundus lesions may cause little or no visual disturbance while central lesions or severe vitritis will manifest earlier . Bilateral involvement is common. Anterior uveitis is uncommon or mild in early disease but may become prominent later.

53. Vitritis: May be marked with fluffy ‘cotton ball’ or ‘string of pearls’ colonies, sometimes progressing to abscess formation. Chorioretinitis : one or more small creamy white lesions with overlying vitritis . Retinal necrosis: may lead to retinal detachment, with severe proliferative vitreoretinopathy .

54. Investigation Vitreous biopsy (preferably using a vitreous cutter rather than a needle) to identify the organism (PCR and culture) and identify sensitivities. Systemic investigation, e.g. blood and urine cultures

55. Treatment : Antifungal treatment: Intravenous amphotericin-B in combination with oral flucytosine , but resistance is a concern. Voriconazole orally or intravenously has a broad spectrum of antifungal action with low reported resistance and high ocular penetration; adjunctive ( intravitreal treatment may be given (100 μg in 0.1 ml Pars plana vitrectomy should be considered at an early stage, especially for severe or unresponsive disease

56. Aspergillus endophthalmitis Aspergillus species are common environmental fungi, but cause disease in humans less commonly than Candida . Spores undergo airborne spread, and risk factors for infection include intravenous drug abuse, chronic lung disease, organ transplantation, and blood disorders; neutropenia may be of particular importance. Iridocyclitis and vitritis are common . Yellowish retinal and subretinal infiltrates tend towards macular involvement at an earlier stage than Candida infection. Occlusive retinal vasculitis is common

57. Coccidioidomycosis Coccidioides immitis acquired by inhalation usually causes a mild pulmonary infection, but wider systemic involvement can occur and reinfection can lead to chronic lung disease . Ocular features include severe granulomatous anterior uveitis and multifocal choroiditis .

58. BACTERIAL UVEITIS

59. Tuberculosis Tuberculosis (TB) is a chronic granulomatous infection usually caused in humans by Mycobacterium tuberculosis . TB is primarily a pulmonary disease but may spread by the bloodstream to other sites; ocular involvement commonly occurs without clinically overt systemic disease . Immune deficiency is a risk factor

60. Ocular features Anterior uveitis Vitritis is very common Choroidal granuloma : A very large abscess-like tubercle is termed a tuberculoma . Choroiditis independent of tubercles, typically multifocal and in a centrifugally spreading serpiginous pattern ( serpiginoid ), has increasingly been recognized. Choroiditis that tracks retinal vessels may have reasonably specificity for TB. Retinal vasculitis Other manifestations include reddish-brown eyelid nodules (lupus vulgaris), conjunctivitis, phlyctenulosis , interstitial keratitis, scleritis , exudative retinal detachment and optic neuropathy including neuroretinitis .

61. Choroidal granuloma

62. Serpiginous pattern

63. Occlusive vasculitis

64. Investigation Systemic assessment Ocular: Aqueous or vitreous sampling

65. Acquired syphilis Syphilis is caused by the spirochaete bacterium Treponema pallidum . In adults the disease is usually sexually acquired when organisms enter through a skin or mucous membrane abrasion.

66. Ocular features Anterior uveitis occurs in about 4% of patients with secondary syphilis Chorioretinitis is often multifocal Acute syphilitic posterior placoid chorioretinopathy (ASPPC) is characterized by large pale-yellowish subretinal lesions in the posterior pole Retinitis has a ‘ground glass’ appearance; associated vasculitis may be occlusive Optic neuritis and neuroretinitis Other features include conjunctivitis, episcleritis and scleritis , intermediate uveitis, glaucoma, cataract and miscellaneous neuro -ophthalmic features related to CNS involvement including Argyll Robertson pupils

67. Investigation Serology is the mainstay and is discussed under ‘Anterior uveitis’ earlier in this chapter. Systemic assessment by an appropriate specialist, including lumbar puncture to rule out neurosyphilis . HIV status should be established. Aqueous and/or vitreous sampling for PCR

68. Endogenous bacterial endophthalmitis A wide range of organisms can be responsible – Gram-positives predominate in North America and Europe and Gram-negatives in eastern Asian. Risk factors include debilitating disease of many types as well as other factors such as intravenous drug abuse; spread can occur from any potential focus such as an indwelling catheter or septic joint . Ocular features: similar to those of postoperative endophthalmitis

69. Lyme disease Lyme disease ( borreliosis ), like syphilis, is caused by a spirochaete . The responsible organism, Borrelia burgdorferi , is transmitted through tick bites; deer are important vectors. The disease is endemic in regions of North America, Europe and Asia, but can be difficult to diagnose. Several days after a bite an annular skin lesion, erythema chronicum migrans .

70. Ocular features Uveitis is relatively uncommon but can be anterior (granulomatous or non-granulomatous. Other manifestations include early transient conjunctivitis, bilateral stromal keratitis, episcleritis , scleritis , orbital myositis, optic neuritis, papilloedema and ocular motor and facial nerve palsy. Investigations: Serology should be performed at least a month after infection

71. Cat-scratch disease Cat-scratch disease ( bartonellosis ) is caused by Bartonella henselae , a Gram-negative rod. Infection is usually mediated transmitted by the scratch (or bite) of an apparently healthy cat. Ocular features: The eyes are affected in 5–10%: neuroretinitis is the most common manifestation and consists of disc oedema with macular exudate in a star conformation; intermediate uveitis, focal retinochoroiditis , vasculitis , and conjunctivitis with a 2–4 mm conjunctival granuloma

72. Leprosy Leprosy (Hansen disease) is a chronic granulomatous infection caused by Mycobacterium leprae and M. lepromatosis . Ocular features: Ocular signs are principally due to direct bacterial invasion. Anterior uveitis : chronic and low-grade; classically ‘ plasmoid ’ (prominent fibrin). Iris pearls (pathognomonic): usually under 0.5 mm in diameter . Keratitis : thickened, beaded corneal nerves, punctate subepithelial lesions, pannus and vascularization

73. MISCELLANEOUS IDIOPATHIC CHORIORETINOPATHIES Multiple evanescent white dot syndrome (MEWDS ) Acute idiopathic blind spot enlargement syndrome (AIBSE ) Acute posterior multifocal placoid pigment epitheliopathy (APMPPE ) Serpiginous choroidopathy Relentless placoid chorioretinitis (RPC ) Persistent placoid maculopathy (PPM ) Acute macular neuroretinopathy (AMN ) Acute zonal occult outer retinopathy (AZOOR ) Punctate inner choroidopathy (PIC ) Multifocal choroiditis and panuveitis Progressive subretinal fibrosis and uveitis syndrome (SFU ) Birdshot retinochoroidopathy Acute retinal pigment epitheliitis (Unilateral) acute idiopathic maculopathy (AIM ) Acute multifocal retinitis Frosted branch angiitis (FBA ) Idiopathic retinal vasculitis , aneurysms and neuroretinitis syndrome (IRVAN)

74. Thank You