This document provides an overview of ocular parasites, including Toxocara canis, Cysticercus cellulosae, Gnathostoma spinigerum, and Histoplasma capsulatum. It discusses the organisms, clinical presentations, diagnosis, and treatment of each parasite. Key points include that Toxocara canis causes ocular inflammation and granulomas, Cysticercus cellulosae causes cysts in eye tissues leading to uveitis, and Gnathostoma spinigerum and Histoplasma capsulatum can spread from the lungs to the eyes and cause vision changes. Diagnosis involves clinical examination, imaging, and serology testing, while treatment consists of ant

2. Ocular parasite
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Introduction
Organisms
Clinical presentations
Clinical findings
Complications
Treatment

3. Ocular parasite
Introduction
• Ocular inflammation as a result of
infection with a helminthic parasite.
• The three most common are Toxocara
canis, Cysticercus cellulosae, and
microfilariae of Onchocerca volvulus.

4. Toxocariasis
• Organism : Toxocara canis
• Common round worm of
Dogs
• Easily infected, by ingest
the eggs, especially who
exposed to puppies,
lactating bitches or who
have a history of ingesting
contaminated soil.

5. Toxocariasis
• The eggs hatch in the small
intestine and the larvar
enter the bloodstream, and
migrate in to the tissue.

6. Toxocariasis
Ocular manifestration
• Form of a dense white
granuloma in the
posterior pole or retinal
periphery, which occurs
when the organism
enters the eye and
encysts.

7. Toxocariasis
• Typical toxocara
granuloma located
over the optic
nerve. Note how
the surrounding
retina is drawn
toward the lesion.

8. Toxocariasis
• Vision may markedly decrease if the
granuloma affects the optic nerve or
posterior pole
• May develop RRD if the holes occur
• May cause endophthalmitis

9. Toxocariasis
• Another presentation consists of the
identification of living, mobile larvae within
the eye.
• In the subritinal space or lens.
• More unusual presentations include optic
neuritis and neuroretinitis.

10. Toxocariasis
Diagnosis
• The classic presentation of a whitish
granuloma and surrounding vitreoretinal
traction
• Confirm by ELISA

11. Toxocariasis
Treatment
• Systemic or periocular
corticosteroids
• Thiabendazole
• Vitrectomy

12. Toxocariasis
Prognosis
• A poor outcome associated with
a large fold in the macular region
• Destroy the larvae with minimal
inflammatory reaction is important

14. GNATHOSTOMIASIS
Organism: Gnathostoma
spinigerum

15. GNATHOSTOMIASIS
Life cycle
• Definite Host : Cat ,Dog ,Tiger ,Leopard
• First Intermediate Host : Cyclops (water)
• Second Intermediate Host : Reptile,
Birds, Mammals, Fish, Amphibians
• Accidental Host : Human

16. GNATHOSTOMIASIS
Epidemiology
• Widely found in far east
• Most cases occur in
Thailand and Japan

17. GNATHOSTOMIASIS
Pathogenesis and
Pathology
• Third-stage lavare and
sexually immature worms
migrate through tissues
• Cause local necrosis,
acute inflammation and
hemorrhage

18. GNATHOSTOMIASIS
Clinical Manifestation
• Dark spot in field of
vision
• Decreased vision
• Redness
• Pain in the eye
• Photophobia
• Hypopyon
• Uveitis
• Chorioretinal
hemorrhage
• Secondary glaucoma

19. GNATHOSTOMIASIS
Diagnosis
• History
• Clinical manifestations
• Discovery of the
organism

20. GNATHOSTOMIASIS
Treatment
• No specific treatment
• Supportive care : analgesics,
systemic corticosteriods
• Medical therapy : Mebendazole ,
Albendazole
• Surgical removal is the treatment
of choice

21. GNATHOSTOMIASIS
Prognosis
• Mortality 10-15% by CNS
Gnathostomiasis
• 2/3 of survivors recover fully , the
remainder have permanent or long-term
sequelae

23. OCULAR CYSTICERCOSIS

24. Cysticercosis
SITE OF INFECTION
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EXTRAOCULAR MUSCLE
EYE LIDS
SUBCONJUNCTIVA
OPTIC NERVE
INTRAOCULAR
ANTERIOR CHAMBER
VITREOUS CAVITY
SUBRETINA SPACE

25. Cysticercosis
SYMPTOM AND SIGN
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EYES PAIN
PROPTOSIS
EYE LIDS SWELLING
CONJUNCTIVAL
INJECTION
• CHEMOSIS
• DIPLOPIA
• OPTHALMOPARESIS

26. Cysticercosis
• EXTRAOCULAR MUSCLE
– OCULAR PAIN
– DIPLOPIA
• ANTERIOR CHAMBER
– OCULAR PAIN
– CATARACT
– IMPAIR VISUAL
ACUITY

27. Cysticercosis
PATHOPHYSIOLOGY
• HEMATOGENOUS - POSTERIOR CILIARY
ARTERY
• SUBRETINAL SPACE
• VITREOUS CAVITY
• ANTERIOR CHAMBER

28. Cysticercosis
• CYSTICERCOSIS LARVAE ENCYST
WITH IN 2 MONTH
• ORGANISM DEAD – INFLAMATION
– UVEITIS
– IRITIS
– RETINITIS
– ENDOPHTHALMITIS
– PANOPHTHALMITIS
• IMPAIR VISUAL ACUITY

29. Cysticercosis
Diagnosis
• CLINICAL
• IMAGING
• SEROLOGY

30. Cysticercosis
• CLINICAL
Suspected in patient
who diagnosis
cysticercosis

31. Cysticercosis
• IMAGING
– Ultrasound
– CT
non enhance oval cystic lesion with
hyperdense rim
– MRI
INTRAOCULAR CYSTICERCOSIS
Suspected by slit lamp biomicroscopy
and indirect ophthalmoscopy

32. Cysticercosis
• SEROLOGY – cysticercosis antibody
– ELISA
– IMMUNOFLUORESCENCE
– HEMAGGLUTINATION
– ASSAY ENZYME LIKED
IMMUNOELECTROTRANSFER BLOT

33. Cysticercosis
TREATMENT
– MEDICAL
• PRAZIQUANTEL
• ALBENDAZOLE
– COMPLICATION = CEREBRAL EDEMA /
INFLAMATION FROM DEAD CYST
– SURGICAL
• TOTAL SURGICAL EXCISION WHEN POSSIBLE
• AVOID TO ASPIRATION OR OPEN OF CYST

35. HISTOPLASMOSIS
- Airborne spores of the
fungus inhaled into the
lungs
- Spread from the lungs to
the eyes by lodging in the
choroid caused ocular
histoplasmosis syndrome

36. HISTOPLASMOSIS
Mechanism
- Fragile,abnormal blood vessels grow
underneath the retina choroidal
neovascularization (CNV) untreated scar
tissue replace the normal retinal tissue in
the macula.

37. HISTOPLASMOSIS
Symptom & Sign
- Early stage : intial OHS infection subsides
with out treatment
tiny scars called
“histo spots” associated with the growth of
the abnormal blood vessels
- Later stage : abnormal vessels cause vision
change Ex ; straight lines
crooked,
wavy, blind spot

38. HISTOPLASMOSIS
Diagnosis
• The presence of histo spot.
• Swelling of the retina
,which signals the growth
of new,abnormal blood
vessels.
Diagnostic procedure“
Fluorescein agiography”

39. HISTOPLASMOSIS
“ Histo spots ”

40. HISTOPLASMOSIS
Treatment
-LASER surgery
“photocoagulation”

42. Paragonimiasis

43. Paragonimiasis