Pathology of Endophthalmitis


Endophthalmitis

Acute onset

Delayed onset

Glaucoma filtration surgery

Common microorganisms

Coagulase negative Staphylococci

Propionibacterium acnes

Haemophilus influenzae

Staphylococcus aureus

Coagulase negative Staphylococci

Staphylococcus species

Gram-negative bacteria

Fungi
 


Post-traumatic endophthalmitis—Acute or delayed onset endophthalmitis is an important complication of open globe injury, and these are more often associated with a poorer visual outcome [7].

Endogenous (metastatic) endophthalmitis—It is a condition where the infectious agent travels via bloodstream and multiplies in the choroid, eventually infiltrating the retina and spreading at the vitreous [8].



Specimen for Study of Pathology of Endophthalmitis





  1. 1.


    Aqueous

     

  2. 2.


    Vitreous

     

  3. 3.


    Lens capsule/intraocular lens (IOL)

     

  4. 4.


    Eviscerated tissue

     

  5. 5.


    Enucleated eyeball

     


Pathology of Involved Tissue in Endophthalmitis


The primary site of involvement is vitreous; retina and choroid show inflammatory cell deposit due to release of inflammatory mediators and autolytic enzymes from leukocytes. The predominant cell type in acute inflammation is the polymorphonuclear leukocyte; it is lymphocyte (white arrow) and the plasma cell in chronic inflammation. These cells are commonly seen in hematoxylin and eosin (H&E) (Fig. 28.1).

A427662_1_En_28_Fig1_HTML.jpg


Fig. 28.1
Photomicrograph showing polymorphonuclear leukocyte and lymphocytic infiltration in eviscerated tissue of endophthalmitis (H&E ×100)


Pathology of Cornea


The cellular migration into the anterior chamber may plaster in the endothelial surface and later may invade the corneal tissue (Fig. 28.2). Disorganization and edematous stoma may be visible if associated with raised intraocular pressure. A marked polymorphonuclear migration into cornea with corneal ring abscess formation in response to the bacterial invasion or locally produced inflammatory mediators is hallmark of Bacillus cereus [9]. Besides, hyphae of fungus may also be observed within the corneal stroma in case of fungal endophthalmitis.

A427662_1_En_28_Fig2_HTML.jpg


Fig. 28.2
Photomicrograph showing dense polymorphonuclear infiltration in all layers of cornea with areas of hemorrhage in corneal tissue (white arrow) along with plastered exudates behind the endothelium of cornea and in anterior chamber (green arrow) (H&E ×40)


Pathology of Anterior Chamber


Exudation of polymorphonuclear leukocytes with or without macrophage is seen in aqueous humor. The rupture of anterior vitreous face with disruption of blood–aqueous barrier is the cause of exudates in anterior chamber (Fig. 28.2). Sometimes, there can be necrotic leukocytes admixed with a large amount of uveal pigment leading to brown hypopyon due to Streptococcus bovis endogenous endophthalmitis [10].


Pathology of Lens


Clustering of microorganisms like Pseudomonas aeruginosa and Paecilomyces lilacinus may occur within the lens capsule following accidental trauma causing the rupture of capsule or after the cataract surgery creating a localized infection within the lens capsular sac [9]. Sometimes, residual lens cortex, phacotoxic reaction, and phacoanaphylaxis reaction can lead to sterile granulomatous endophthalmitis [11]. It is characterized histologically by a zonal granulomatous inflammatory reaction to the lens capsular remnants with central polymorphonuclear reaction.

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Mar 1, 2018 | Posted by in OPHTHALMOLOGY | Comments Off on Pathology of Endophthalmitis
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