STAPHYLOMA

Posterior staphyloma, the posterior outpouching of the wall of the eye, is an important component of the diagnosis of pathologic myopia; indeed, it is one of the hallmarks of pathologic myopia.

 With the exception of inferior staphyloma related to tilted disc syndrome, it does not occur in pathologies other than pathologic myopia.

Thus, the presence of staphyloma is specific to pathologic myopia and critically important in differentiating simple school myopia with good best corrected visual acuity (BCVA) and pathologic myopia that could cause the loss of BCVA.

• Anterior staphylomas can be caused by smallpox, keratomalacia, sloughing corneal ulcer and trauma.
• intercalary staphylomas occur due to a penetrating wound at the limbus.
• Ciliary staphylomas occur due to buphthalmos, long standing absolute glaucoma, scleritis, scleromalacia, rhinosporidiosis, traumatic and idiopathic reasons.
• equatorial staphylomas are often congenital in origin.

Ans. Episcleritis

Ciliary staphyloma:

• As the name implies, it is the bulge of weak sclera lined by the ciliary body, which occurs about 2–3 mm away from the limbus.
• Ciliary staphyloma is due to scleritis. 
• Its common causes are thinning of sclera following perforating injury, scleritis & absolute glaucoma.

   

Ans. A: Myopia

Staphyloma is the term given to an eye whose sclero-uveal coats are stretched (also known as ectasia). This most commonly occurs posteriorly, athough anterior staphyloma also is recognised.

Posterior staphyloma

• Progressive myopia (or mega myope) most common cause.
• Glaucoma
• Scleritis
• Necrotizing infection
• Surgery/trauma
• Radiotherapy

Posterior staphyloma affects the posterior pole of the eye and is lined by the choroid.

The ectatic portion is not visible externally but can be detected by fundoscopy and B-scan USG.

Anterior staphyloma

The most common cause for anterior staphyloma is sloughing corneal ulcer winch perforates and heals with the formation of a pseudocornea by the organization of exudates and laying down of fibrous tissue.

Differential diagnoses

• Buphthalmos (congenital glaucoma)
• Axial myopia
• Macrophthalmos: seen in neurofibromatosis typel (NF1)
• Coloboma

Ans. D: High myopia

Degenerative high axial myopia is the most common cause of posterior staphyloma

Staphyloma

• It is an abnormal protrusion of the uveal tissue through a weak point in the eyeball.
  The protrusion is generally black in colour, due to the inner layers of the eye.
• It occurs due to weakening of outer layer of eye (cornea or sclera) by an inflammatory or degenerative condition.
• It may be of 5 types, depending on the location on the eye ball (bulbus oculi).

Anterior (corneal) staphyloma

• In the anterior segment of the eye, involving the cornea and the nearby sclera.

Intercalary staphyloma

• It is the name given to the localised bulge in limbal area, lined by the root of the iris.
• It results due to ectasia of weak scar tissue formed at the limbus, following healing of a perforating injury or a peripheral corneal ulcer.
• There may be associated secondary angle closure glaucoma, may cause progression of the bulge if not treated.
• Defective vision occurs due to marked corneal astigmatism.
• Treatment consists of localised staphylectomy under heavy doses of oral steroids.

Ciliary staphyloma

• It is the bulge of weak sclera lined by ciliary body, which occurs about 2-3 mm away from the limbus.
• Its common causes are thinning of sclera following perforating injury, scleritis and absolute glaucoma.

Equatorial staphyloma

• Seen on the equator of the eye (region circumferencing the largest diameter orthogonal to the visual axis).
• Its causes are scleritis and degeneration of sclera in pathological myopia.
• It occurs more commonly in the regions of sclera which are perforated by vortex veins.
• Posterior staphyloma
• It is seen in the posterior segment of the eye, typically diagnosed at the region of the macula, deforming the eye in a way that the eye-length is extended associated with myopia (nearsightedness).
• It is diagnosed by ophthalmoscopy, which shows an area of retinal excavation in the region of the staphvloma

Ans. is ‘c’ i.e., Degenerative axial myopia

Ans. is ‘c’ i.e., Corneal ulcer

Staphyloma

• Staphyloma is an abnormal protrusion of uveal tissue through a weak and thin portion of cornea or sclera.
• So, a staphyloma is lined internally by uveal tissue and externally by weak cornea or sclera.
• Staphyloma is divided anatomically into : ‑

1. Anterior staphyloma : – Protrusion and adhesion of iris to ectatic cornea. The most common cause is a sloughing corneal ulcer which perforates and heals with the      formation of pseudocornea by the organization of exudates and laying down of fibrous tissue. It is lined internally by iris.

2.  Intercalary staphyloma : – It occurs at the limbus. It is lined internally by the root of iris and the anterior

most portion of the ciliary body. The causes are perforating injuries to limbus, marginal corneal ulcer,

anterior scleritis, Scleromalacia perforans, Complicated cataract surgery, secondary angle closure

glaucoma.

3.  Ciliary staphyloma : – This affects the ciliary zone that includes the region upto 8 mm behind the limbus. The ciliary body is incarcerated in the region of scleral ectasia. Causes are Developmental glaucoma, Primary or secondary glaucoma end stage, scleritis, trauma to ciliary region.

4. Equatorial staphyloma : – This occurs at the equatorial region of the eye with incarceration of the choroid. Causes are scleritis, degenerative myopia and chronic      uncontrolled glaucoma.

5.   Posterior staphyloma : – Occurs at posterior pole and is lined internally by choroid. Degenerative high axial myopia is the most common cause