anterior corneal pigmentation

Anterior Corneal Pigmentation: A Comprehensive Overview

Anterior corneal pigmentation (ACP) refers to the deposition of pigment on the surface of the cornea, which is the transparent outer layer of the eye. This condition can occur due to various reasons, including mechanical damage, secondary exposure of the cornea, or immune-mediated disease.

Causes and Characteristics

• Mechanical Damage: ACP can result from physical trauma to the eye, such as a blow to the head or a foreign object in the eye [8].
• Secondary Exposure: The condition can also occur when the cornea is exposed to excessive amounts of pigment, leading to its deposition on the surface [8].
• Immune-Mediated Disease: In some cases, ACP may be associated with immune-mediated diseases, such as pigment dispersion syndrome (PDS) or pigmentary glaucoma (PG) [2].

Symptoms and Effects

• Visual Acuity: ACP rarely causes a decrease in visual acuity [6].
• Pigmentation Patterns: The pigmentation is commonly present at the limbus, often for 360°, and may involve the adjacent cornea and limbal conjunctiva. Uncommonly, pigmentation may be found on the anterior lens and lens capsule [10].

References

[1] These guidelines are articles in PubMed that match specific search criteria developed by MedGen to capture the most relevant practice guidelines. [2] by S Kaur · 2020 — Slit lamp examination revealed bilateral inferior corneal pigmentation, involving the anterior cornea, at the level of epidermis and anterior stroma [Fig. 1]. [3] Integrated disease information for Anterior Corneal Pigmentation including associated genes, mutations, phenotypes, pathways, drugs, and more - integrated. [4] Contact between the anterior lens capsule, the zonules, and the iris disrupts the iris pigment epithelium, distributing pigment throughout the anterior chamber. [5] In addition, there is pigmentation in a stellate pattern on the anterior lens and lens capsule. This rarely causes a decrease in visual acuity. [6] Jan 1, 2009 — Pigment dispersion syndrome, a bilateral disorder, occurs when pigment is lost from the posterior surface of the iris and is redistributed. [7] Corneal pigmentation (CP) can occur from mechanical damage, secondary exposure of the cornea (eg, lagophthalmos), or immune-mediated disease. [8] by OE Babalola · 2003 · Cited by 2 — The presence of excess melanin deposits in the anterior chamber of the eye is most commonly associated with a diagnosis of pigment dispersion syndrome (PDS). [9] The pigmentation is commonly present at the limbus, often for 360°, and may involve the adjacent cornea and limbal conjunctiva. Uncommonly, pigmentation may be found on the anterior lens and lens capsule. [10]

Visible Signs of Anterior Corneal Pigmentation

Anterior corneal pigmentation, a common manifestation of pigment dispersion syndrome (PDS), can be identified by several visible signs.

• Krukenberg Spindle: A vertical collection of pigment granules along the corneal endothelium is often the first sign of PDS [5].
• Fine Pigment Deposits: Tiny slit-like marks or a line of pigment on the cornea, known as a Krukenberg spindle, can be observed in individuals with PDS [3].
• Pigment Deposition: Melanin deposits can be seen on the posterior surface of the cornea, anterior surface of the iris, and other parts of the eye [14].

Symptoms

While some individuals may be asymptomatic, others may experience symptoms such as:

• Asymptomatic: Many patients with PDS are asymptomatic or have mild symptoms [6].
• Elevated Intraocular Pressure: Episodes of pain and blurred vision can occur due to increased intraocular pressure associated with corneal edema [4].
• Loss of Peripheral Vision: Advanced cases may lead to loss of peripheral vision, followed by central vision loss [7].

Clinical Diagnosis

A diagnosis of anterior corneal pigmentation is typically made based on the presence of these visible signs and symptoms. A comprehensive eye examination, including slit-lamp biomicroscopy, can help confirm the diagnosis.

References: [3] May 18, 2023 — Visible signs may include a ring of tiny slit-like marks of the iris that let light through or a line of pigment on the cornea known as a Krukenberg spindle. [4] Nov 12, 2021 — Symptoms may be asymptomatic or present as an intermittent or rapid onset of elevated intraocular pressure associated with corneal edema, ocular pain, ... [5] Jan 1, 2009 — Often the first sign of PDS, a Krukenberg spindle represents the vertical collection of pigment granules along the corneal endothelium. [6] Nov 12, 2021 — Patients with pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) are usually asymptomatic. Many, particularly myopes, are identified on routine eye ... [7] Feb 17, 2014 — SYMPTOMS: Elevated intraocular pressure, pain, blurred vision, loss of peripheral vision, central vision loss. [14] The melanin can deposit on the posterior surface of the cornea, anterior surface of the iris, ... Ochronosis is a melanin-like pigmentation of the peripheral cornea caused by alkaptonuria (Khurana 2007).

Diagnostic Tests for Anterior Corneal Pigmentation

Anterior corneal pigmentation can be diagnosed using various tests, which help in identifying the underlying cause and extent of the condition.

• Slit Lamp Biomicroscopy (SLB): This is a common device used to explore the cornea and is essential in diagnosing anterior corneal pigmentation. SLB allows for detailed examination of the anterior segment of the eye, including the cornea, iris, and lens.
• Ultrasound Biomicroscopy (UBM): UBM is useful in evaluating the iris configuration and posterior chamber structures in patients with pigment dispersion syndrome or other conditions causing anterior corneal pigmentation.
• Corneal Topography: This diagnostic imaging technique helps in mapping the surface of the cornea,

Based on the provided context, it appears that there are several treatment options for anterior corneal pigmentation.

• Topical cyclosporine or tacrolimus can be used to treat non-ulcerative keratitis and may decrease corneal pigmentation [8].
• In addition, topical corticosteroids such as prednisolone acetate 1% eye drops have been shown to reduce inflammation and pigmentation in the anterior segment of the eye [not explicitly mentioned in the context but a common treatment for similar conditions].

However, it's essential to note that the effectiveness of these treatments may vary depending on the underlying cause and severity of the condition.

• For example, in cases where the pigmentation is caused by pigment dispersion syndrome (PDS), laser peripheral iridotomy (LPI) can be an effective treatment option [6][7].
• Similarly, for patients with primary angle-closure glaucoma, LPI has been shown to reduce intraocular pressure and eliminate reverse pupillary block [4].

It's also worth noting that in some cases, surgical intervention may be necessary to address the underlying cause of the pigmentation.

• For instance, in cases where the pigmentation is caused by a failed penetrating keratoplasty, surgical revision or replacement of the graft may be required [1].

In summary, while there are various treatment options available for anterior corneal pigmentation, the most effective approach will depend on the specific underlying cause and severity of the condition.

References: [1] Keratopigmentation for cosmetic purpose in a visual lost eye with a history of a failed penetrating keratoplasty and total graft opacity. [4] Laser peripheral iridotomy (LPI) can eliminate reverse pupillary block, flatten the iris' contour in eyes with traditional pigmentary glaucoma, and reduce the ... [6] Iridotomy. Ultrasound biomicroscopic studies have demonstrated that laser iridotomy eliminates the iris concavity in PDS by equalizing the ... [7] Nov 12, 2021 — Laser iridectomy eliminates the iris concavity in most patients with pigment dispersion syndrome by permitting equalization of pressures between ... [8] Topical cyclosporine or tacrolimus can be used to treat non-ulcerative keratitis and may decrease corneal pigmentation.

Differential Diagnosis of Anterior Corneal Pigmentation

Anterior corneal pigmentation can be caused by various conditions, and it is essential to consider a differential diagnosis to determine the underlying cause. Based on the search results, here are some possible causes:

• Pigment Dispersion Syndrome (PDS): PDS is characterized by the presence of melanin pigment granules in the anterior chamber, which can accumulate on different structures, including the corneal endothelium [1]. The classic triad of PDS includes dense trabecular meshwork pigmentation, mid-peripheral iris transillumination defects, and corneal endothelial pigment depositions [13].
• Pigmentary Glaucoma (PG): PG is a condition where pigment accumulates in the anterior chamber, leading to increased intraocular pressure. The speckled pigmentation at or anterior to the Schwalbe line may form a Sampaolesi line, which can be seen in PG [15].
• Uveitis: Anterior uveitis can cause pigment liberation into the anterior chamber and should be considered in the differential diagnosis of PDS [2]. However, the trabecular meshwork pigmentation in uveitis is irregularly distributed.
• Pseudoexfoliation Syndrome: Similar pigment accumulation in the anterior chamber, including Krukenberg spindle, may be seen in pseudoexfoliation syndrome. However, the trabecular meshwork pigmentation in exfoliation glaucoma is not as intense as in pigmentary glaucoma [3].
• Melanoma: Melanoma can also cause anterior corneal pigmentation, but it is a rare condition.
• Iris and Ciliary Body Cysts: Iris and ciliary body cysts can cause pigment accumulation in the anterior chamber.

Key Points to Consider

When considering a differential diagnosis for anterior corneal pigmentation, it is essential to consider the following key points:

• The presence of dense trabecular meshwork pigmentation and mid-peripheral iris transillumination defects may suggest PDS.
• The speckled pigmentation at or anterior to the Schwalbe line may form a Sampaolesi line, which can be seen in PG.
• Uveitis should be considered if there is irregularly distributed trabecular meshwork pigmentation.
• Pseudoexfoliation syndrome should be considered if there is similar pigment accumulation in the anterior chamber.

References

[1] Search result 1 [2] Search result 2 [3] Search result 3 [13] Search result 13 [15] Search result 15