stromal corneal pigmentation

Stromal Corneal Pigmentation Signs and Symptoms

Stromal corneal pigmentation, such as that seen in ochronosis, can result from chronic irritation. The melanin is typically found in the superficial stroma and basal layer of the cornea.

• Loss of Palisades of Vogt: A characteristic sign of limbal stem cell deficiency, which can be associated with stromal corneal pigmentation.
• Dull or Irregular Corneal Reflex: The corneal reflex may appear dull or irregular due to the presence of melanin in the stroma.
• Epithelium of Variable Thickness: The epithelial layer may exhibit variable thickness, which can be a sign of underlying stromal pigmentation.
• Opacification and Haze: Stromal corneal pigmentation can cause opacification and haze in the affected area.

Other Associated Symptoms

• Severe Photophobia: Patients with stromal corneal pigmentation may experience severe photophobia, which is a sudden and intense sensitivity to light.
• Tearing and Lacrimation: Excessive tearing and lacrimation can be associated with stromal corneal pigmentation.
• Corneal Foreign Body Sensation: Some patients may experience a sensation of having a foreign body in their eye due to the presence of melanin in the stroma.

References

• [1] Stromal pigmentation such as that in ochronosis results from chronic irritation. The melanin is in the superficial stroma and the basal layer... (Search Result 1)
• [2] Signs of limbal stem cell deficiency are a loss of palisades of Vogt, dull or irregular corneal reflex, epithelium of variable thickness, and opacification and ... (Search Result 2)
• [5] Epithelial and stromal haze, lacrimation and limbal redness adjacent to the lesion will be noticed initially, followed by anterior chamber flare, iritis, ... (Search Result 5)

Based on the provided context, here are some diagnostic tests that may be relevant for stromal corneal pigmentation:

• Slit lamp biomicroscopy: This test can reveal altered corneal transparency involving the posterior half of the stroma (Search Result 7).
• Fluorescein staining: Fluorescein does not stain intact corneal epithelium but does stain corneal stroma, thus demarcating the area of epithelial loss (Search Result 9). This test may be useful in identifying areas of stromal pigmentation.
• Corneal cytology smears, brushes, or impression cytology: These non-invasive methods can be used to sample cells from the conjunctiva and cornea for suspected OSSN (Search Result 6).
• Retroillumination: This technique can help identify central guttae in Descemet membrane, which may be associated with stromal pigmentation (Search Result 10).

It's worth noting that the diagnosis of stromal corneal pigmentation is often made based on a comprehensive exam and clinical appearance, rather than a single diagnostic test. A careful slit-lamp exam, including retroillumination, can help identify characteristic features of stromal pigmentation.

References:

• Search Result 7: Slit lamp biomicroscopy can reveal bilateral, altered corneal transparency involving the posterior half of the stroma.
• Search Result 9: Fluorescein does not stain intact corneal epithelium but does stain corneal stroma, thus demarcating the area of epithelial loss.
• Search Result 6: Cytology smears, brushes, or impression cytology may be used as noninvasive methods for conjunctival and corneal sampling.
• Search Result 10: A careful slit-lamp exam, including retroillumination, can identify central guttae in Descemet membrane.

Treatment Options for Stromal Corneal Pigmentation

Stromal corneal pigmentation, also known as stromal deposits, is a condition where medications accumulate in the stroma layer of the cornea, causing pigmentation. This can be caused by various drugs, including chlorpromazine, gold, rifabutin, indomethacin, and tyrosine kinase inhibitors (TKIs) such as vandetanib.

Treatment Approaches

While there is no specific treatment for stromal corneal pigmentation, several approaches may help alleviate symptoms:

• Topical corticosteroids: These can be used to reduce inflammation and improve symptoms. However, their effectiveness in treating stromal deposits is limited.
• Laser treatment: Laser therapy may be used to remove or reduce the pigmented areas in the cornea.
• Cautery: This involves using a fine needle diathermy to destroy the affected tissue.
• Fine needle diathermy: This procedure can help reduce inflammation and improve symptoms.

Systemic Treatment

In some cases, systemic treatment may be necessary to address underlying conditions that contribute to stromal corneal pigmentation. For example:

• Prednisone: This corticosteroid can be used systemically to reduce inflammation.
• Cyclosporine: Topical cyclosporine has been shown to cause regression of corneal stromal neovascularization and reduce the risk of graft rejection.

Other Considerations

It's essential to note that stromal corneal pigmentation can resolve on its own after months or years of drug cessation. However, in some cases, the deposits may persist, requiring ongoing treatment.

References:

• [10] Stromal deposits Many drugs can cause deposits in the corneal stroma, such as chlorpromazine, gold, rifabutin, indomethacin and tyrosine kinase inhibitors (TKIs) such as vandetanib.
• [12] Most of these deposits resolve automatically, after months to years of drug cessation.
• [13] The normal anatomy further facilitates the drug to enter into structures such as lens, cornea.

Differential Diagnosis of Stromal Corneal Pigmentation

Stromal corneal pigmentation refers to the deposition of pigment in the stroma of the cornea, which can be caused by various conditions. The differential diagnosis for stromal corneal pigmentation includes:

• Fuchs endothelial dystrophy: This is a condition characterized by the accumulation of guttata (small deposits) on the endothelium of the cornea, leading to corneal swelling and pigmentation [13].
• Pigment dispersion syndrome: This is a condition where pigment from the iris is deposited onto the anterior surface of the lens and cornea, causing pigmentation and other symptoms [13].
• Keratic precipitates from uveitis: Inflammation in the eye can cause the deposition of keratic precipitates on the endothelium of the cornea, leading to pigmentation and other symptoms [13].
• Microsporidia-induced stromal keratitis: This is a rare condition caused by an infection with microsporidia, which can lead to inflammation and pigmentation in the stroma of the cornea [14].

Other Conditions

In addition to these conditions, other factors that may contribute to stromal corneal pigmentation include:

• Trauma: Physical trauma to the eye can cause pigment deposition in the stroma of the cornea.
• Surgery: Surgical procedures on the eye can also lead to pigment deposition in the stroma of the cornea.

References

[13] The differential diagnosis for Fuchs’ endothelial dystrophy includes anything that could induce endothelial deposits and/or corneal swelling: Pigment dispersion syndrome; Keratic precipitates from uveitis; ... [14] Microsporidia-induced stromal keratitis: a new cause of presumed immune stromal (interstitial) keratitis.