Difference between revisions of "Eye"

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===Retina===
===Retina===
Complex multilayered structure:
Simplified structure - eosinophilic material separating:
*Two layers of small round nuclei.
#Intermediate size, round, pale-staining nuclei (ganglion cells).
*Eosinophilic ellipsoid structures (rods/cones).
#Two layers of small round nuclei (inner and outer nuclear layer).
#Eosinophilic ellipsoid structures - rods/cones (photoreceptors).
#Single layer of cuboidal cells (retinal pigment epithelium.
 
Detailed structure - in direction light travels:
#Inner limiting membrane.
#Nerve fibre layer.
#Ganglion layer.
#Inner plexiform layer.
#Inner nuclear layer.
#Outer plexiform layer.
#Outer nuclear layer.
#Layer of rods and cones.
#External limiting membrane.
#Retinal pigment epithelium.


Images:
Images:

Revision as of 03:49, 17 January 2013

The eye is rarely seen by pathologists. Typically, they go to neuropathologists, as the eye is really part of the brain. The article also covers lesions found around the eye. The lacrimal gland is covered in the lacrimal gland article.

An introduction to neuropathology is in the neuropathology article.

Procedures

  • Evisceration - eye muscles left intact.
  • Enucleation.
  • Exenteration - extensive resection.

Anatomy

Anterior to posterior

  1. Cornea.
  2. Iris.
  3. Lens.
  4. Conjunctiva - edge of cornea.
  5. Sclera.
    • Similar to cornea - normally has blood vessels.

Optic nerve

  • Surrounded by CSF.
  • Covered by dura.

Inside to outside

  1. Retina.
  2. Retinal pigment epithelium (RPE).
  3. Choroid.
  4. Sclera.

Anterior angle

  • Angle between cornea and iris.

Histology

Eye muscles

  • The muscles that move the eye have a high nerve:muscle ratio = ~1:4.[1]
    • Other muscles in the body ~1:250.

Conjunctiva

Features:[2]

  • Stratified squamous.
    • May be stratified columnar
  • Goblet cells.

Cornea

Layers:[3]

  1. Epithelium layer.
    • Squamoid cells.
  2. Bowman's layer.
    • Indistinct.
  3. Stroma.
    • Fibrous tissue.
    • No blood vessels.
  4. Descemet’s layer.
    • Indistinct.
    • PAS -ve.
  5. Endothelium.
    • Single layer.

Retina

Simplified structure - eosinophilic material separating:

  1. Intermediate size, round, pale-staining nuclei (ganglion cells).
  2. Two layers of small round nuclei (inner and outer nuclear layer).
  3. Eosinophilic ellipsoid structures - rods/cones (photoreceptors).
  4. Single layer of cuboidal cells (retinal pigment epithelium.

Detailed structure - in direction light travels:

  1. Inner limiting membrane.
  2. Nerve fibre layer.
  3. Ganglion layer.
  4. Inner plexiform layer.
  5. Inner nuclear layer.
  6. Outer plexiform layer.
  7. Outer nuclear layer.
  8. Layer of rods and cones.
  9. External limiting membrane.
  10. Retinal pigment epithelium.

Images:

Eye structures with melanocytes

Melanoma may arise from these sites:

  • Iris.
  • Conjunctiva.
  • Ciliary bodies.
  • Choroid.

Benign entities

Conjunctivitis

General

  • Benign.
  • Never biopsied.
    • It is an incidental finding in a biopsy for something else.

Gross

  • Red eye.

Microscopic

Features:

  • Conjunctival epithelium - stratified squamous epithelium with goblet cells.
  • Inflammatory cells.

Pinguecula

  • Plural Pingueculae.

General

  • Raizada et al.[4] suggest it is an early pterygium; however, this is disputed.
  • Due to ultraviolet light exposure, e.g. sunlight.[5]
  • Tend to be older than individuals afflicted with a pterygium.

Gross

  • Yellow spot.

Microscopic

Features:

  • Similar to pterygium.[5]

Pterygium

  • AKA surfer eye.

General

  • Pronounced: "tuh-rij-ee-uhm".[6]
  • Conjunctiva lesion that covers part of the sclera.
    • Sclera = white part of the eye.[7]
  • Benign.
  • Due to ultraviolet light exposure, i.e. sunlight.[5]

Gross

  • Medial aspect of eye - covers sclera (white part) and part of the iris (coloured part).

Image:

Microscopic

Features:[5]

  • Hyaline material beneath epithelium.
  • Elastic fibres beneath the hyaline material.
  • +/-Inflammation.
  • Solar elastosis.[8]
    • Dense gray/light brown acellular material.
  • Dilated vessels.[8]

DDx:

Images:

Sign out

CONJUNCTIVA ("PTERYGIUM"), RIGHT, EXCISION:
- CONJUNCTIVAL MUCOSA WITH STROMAL ACTINIC CHANGES -- CONSISTENT WITH PTERYGIUM.

CONJUNCTIVA ("PTERYGIUM"), RIGHT, EXCISION:
- CONJUNCTIVAL MUCOSA WITH SOLAR ELASTOSIS AND DILATED SUPERFICIAL BLOOD VESSELS -- CONSISTENT WITH PTERYGIUM.
- NEGATIVE FOR DYSPLASIA.

CONJUNCTIVA ("PTERYGIUM"), RIGHT, EXCISION:
- CONJUNCTIVAL MUCOSA WITH STROMAL ACTINIC CHANGES -- CONSISTENT WITH PTERYGIUM.
- NEGATIVE FOR DYSPLASIA.

Eccrine hidrocystoma

  • Occasionally spelled eccrine hydrocystoma.[10]

General

  • Benign.
  • Eyelid lesion.

Clinical DDx:[10]

Microsopic

Features:

Chalazion

General

  • Benign eye thingy that arises from the special sebaceous gland associated with the eyelid (Meibomian gland).
  • Usually diagnosed based on clinical appearance - accuracy ~94% in one series.[11]

Gross

  • Focal eyelid swelling - typically upper eyelid.

DDx (clinical):[11]

Images:

Microscopic

Features:

Images:

Sign out

EYELID LESION, RIGHT UPPER, BIOPSY:
- LIPOGRANULOMAS.
- LYMPHOPLASMACYTIC RICH INFLAMMATORY INFILTRATE.
- GRANULATION TISSUE.
- REACTIVE SQUAMOUS MUCOSA.

COMMENT:
The findings are consistent with a chalazion.

Special stains (ZN, PASD, GMS) did not demonstrate microorganisms.

Micro

The sections show a reactive squamous mucosa with palisading granulomas that surround clear spaces (lipid). This is accompanied by a lymphoplasmacytic rich inflammatory infiltrate. Granulation tissue is present. Rare multinucleated giant cells are identified. Neutrophils are numerous and seen in association with the histiocytes.

No significant nuclear atypia is apparent.

Retinal hemorrhage

See Traumatic brain injury in infants.

Image:

Glaucoma

General

  • Leading cause of irreversible blindness.

Classification:

  • Open angle - more common.
  • Closed angle.

Microscopic

Features (closed angle):

  • Cornea and iris opposed to one another.

Retinal detachment

General

  • Blindness.

Causes:

  • Trauma (classic) - pathologist doesn't usually see.
  • Tumours - common in pathology specimens.

Microscopic

Features:

  • Retina separated from retinal pigment epithelium.
  • Eosinophilic exudate containing macrophages.

Blepharochalasis

General

  • Rare, benign eyelid disorder.[16]

Clinical:

  • Swelling of eyelids - recurrent.[17]
  • Children and adolescents.
  • Leads to ptosis.

Microscopic

Features:[16]

  • Edema.

DDx:

Stains

  • Elastin stain - shows loss of elastin.[19]

Sign out

EYELID, LEFT UPPER, PTOSIS REPAIR:
- SQUAMOUS EPITHELIUM WITHIN NORMAL LIMITS.
- SUBEPITHELIAL TISSUE WITH MILD EDEMA.
- SOLAR ELASTOSIS.
- NEGATIVE FOR MALIGNANCY.

Malignant entities

Retinoblastoma

General

  • Rare.
  • Malignant.
  • May be familial.[20]

Gross

  • White, solid.
  • Patterns:
    • Endophytic - grow into the vitreous cavity.
    • Exophytic - grow toward choroid.
    • Mixed - components of endophytic and exophytic.

Image:

Note:

  • Tumour is extremely friable.

Microscopic

Features:

  • Small round cell tumour:
    • Scant cytoplasm.
  • Flexner-Wintersteiner rosette - key feature.
    • Rosette with empty centre (donut hole).[21]
  • +/-Homer-Wright rosette.[22]
    • Circular rosette with neuropil at the centre.[21]
  • Mitoses - common.
  • +/-Necrosis.
  • +/-Calcification.

DDx:

  • Retinocytoma (retinoma) - benign counterpart of retinoblastoma.

Notes:

  • DDx of Flexner-Wintersteiner rosette includes:
    • Pineoblastoma.
    • Medulloepithelioma.

Image:

Malignant melanoma

Main article: Malignant melanoma

Common malignancy in the eye in adults.

See also

References

  1. ↑ Bilbao. 24 November 2010.
  2. ↑ URL: http://www.lab.anhb.uwa.edu.au/mb140/corepages/eye/eye.htm. Accessed on: 20 October 2011.
  3. ↑ URL: http://www.ophthobook.com/questions/question-name-the-layers-of-the-cornea-and-their-function. Accessed on: 26 January 2012.
  4. ↑ Raizada, IN.; Bhatnagar, NK. (Jul 1976). "Pinguecula and pterygium (a histopathological study).". Indian J Ophthalmol 24 (2): 16-8. PMID 1031388.
  5. ↑ 5.0 5.1 5.2 5.3 Hill, JC.; Maske, R. (1989). "Pathogenesis of pterygium.". Eye (Lond) 3 ( Pt 2): 218-26. doi:10.1038/eye.1989.31. PMID 2695353.
  6. ↑ URL: http://dictionary.reference.com/browse/pterygium. Accessed on: 20 October 2011
  7. ↑ URL: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002006/. Accessed on: 20 October 2011.
  8. ↑ 8.0 8.1 URL: http://www.uic.edu/depts/mcpt/eyepath/specco4.htm. Accessed on: 25 October 2011.
  9. ↑ Clear, AS.; Chirambo, MC.; Hutt, MS. (Feb 1979). "Solar keratosis, pterygium, and squamous cell carcinoma of the conjunctiva in Malawi.". Br J Ophthalmol 63 (2): 102-9. PMC 1043407. PMID 427069. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1043407/.
  10. ↑ 10.0 10.1 10.2 Adams, SP. (Feb 1999). "Dermacase. Eccrine hydrocystoma.". Can Fam Physician 45: 297, 306. PMC 2328272. PMID 10065300. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2328272/.
  11. ↑ 11.0 11.1 11.2 11.3 Ozdal, PC.; Codère, F.; Callejo, S.; Caissie, AL.; Burnier, MN. (Feb 2004). "Accuracy of the clinical diagnosis of chalazion.". Eye (Lond) 18 (2): 135-8. doi:10.1038/sj.eye.6700603. PMID 14762403. http://www.nature.com/eye/journal/v18/n2/full/6700603a.html.
  12. ↑ D'hermies, F.; Fayet, B.; Meyer, A.; Morel, X.; Halhal, M.; Elmaleh, C.; Azan, F.; Behar-Cohen, F. et al. (Feb 2004). "[Chalazion mimicking an eyelid tumor].". J Fr Ophtalmol 27 (2): 202-5. PMID 15029054.
  13. ↑ URL: http://emedicine.medscape.com/article/1212709-workup. Accessed on: 9 February 2012.
  14. ↑ URL: http://www.surgical-pathology.com/chalazion.htm. Accessed on: 24 January 2012.
  15. ↑ URL: http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/fofrm.html. Accessed on: 6 December 2010.
  16. ↑ 16.0 16.1 Koursh, DM.; Modjtahedi, SP.; Selva, D.; Leibovitch, I.. "The blepharochalasis syndrome.". Surv Ophthalmol 54 (2): 235-44. doi:10.1016/j.survophthal.2008.12.005. PMID 19298902.
  17. ↑ Bergin, DJ.; McCord, CD.; Berger, T.; Friedberg, H.; Waterhouse, W. (Nov 1988). "Blepharochalasis.". Br J Ophthalmol 72 (11): 863-7. PMID 3207663.
  18. ↑ Wang, G.; Li, C.; Gao, T. (Apr 2009). "Blepharochalasis: a rare condition misdiagnosed as recurrent angioedema.". Arch Dermatol 145 (4): 498-9. doi:10.1001/archdermatol.2009.19. PMID 19380685.
  19. ↑ Kaneoya, K.; Momota, Y.; Hatamochi, A.; Matsumoto, F.; Arima, Y.; Miyachi, Y.; Shinkai, H.; Utani, A. (Jan 2005). "Elastin gene expression in blepharochalasis.". J Dermatol 32 (1): 26-9. PMID 15841657.
  20. ↑ Lohmann D (2010). "Retinoblastoma". Adv. Exp. Med. Biol. 685: 220–7. PMID 20687510.
  21. ↑ 21.0 21.1 Wippold FJ, Perry A (March 2006). "Neuropathology for the neuroradiologist: rosettes and pseudorosettes". AJNR Am J Neuroradiol 27 (3): 488–92. PMID 16551982.
  22. ↑ WH. 14 March 2011.
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