The cornea[1] plays a crucial and vital role in the visual pathway. To maximize the visual potential of the eye, both the clarity of the cornea and the refractive power (curvature) are important. Any disturbance to the clarity or thickness of the cornea will affect its visual potential. The Descemet membrane and endothelial cells play a critical role. See the image below.
View Image | Diffuse illumination showing Descemet membrane folds after surgery. |
The cornea is composed of 5 discrete anatomical components, each with specific functions to achieve the goal of clarity and refractive potential. The outermost component, the epithelium, provides a smooth surface due to the interactions of cytoskeletal components and tear film matrix. It also serves an important protective barrier function. The Bowman layer[2] or membrane, the second layer moving in toward the eye, serves as the smooth adhesion layer for the basement membrane of the epithelial cells. This layer is not crucial for clarity or visual function since removal of the Bowman layer during photorefractive keratectomy does not negatively affect vision.
The corneal stroma makes up the majority of the width of the cornea. It is composed of collagen fibrils arranged in a regular pattern to allow light to enter and pass through without being diffracted or reflected. Inflammation manifesting as stromal infiltrates and/or stromal edema results in the interruption of the regular periodicity of the collagen matrix and decreased corneal clarity. Because the cornea is avascular, nutrients and wastes are delivered and deposited anteriorly via the tear film and external environment, internally via corneal nerves, and posteriorly via the aqueous humor.
The innermost layer of the cornea is the endothelial cell layer, a monolayer of polarized cells. They are arranged with their apical portion toward the aqueous humor in the anterior chamber. The endothelial cells are responsible for maintaining the desiccation of the stroma by actively removing water. The Descemet membrane is the specialized basement membrane of the endothelial cells positioned between the stroma and the endothelial cell layer. Any condition that causes inflammation of the cornea or the anterior chamber can cause Descemet membrane folds.
United States
Descemet membrane folds is common because it is associated with many inflammatory conditions of the eye.
International
The frequency is similar to that in the United States.
Morbidity due to decreased vision and pain exists.
No predisposition to race exists.
Descemet membrane folds affects women and men equally.
Descemet membrane folds affects all age groups with slower resolution of the folds in elderly persons.
History may reveal the following:
Descemet folds are directly visible with slit lamp biomicroscopy using direct focal illumination, specular reflection, and retroillumination.[3]
Descemet folds are associated with corneal edema due to endothelial dysfunction from infections, from infiltrations, or following surgery.
Descemet folds also are associated with corneal inflammation due to infections or infiltrations or following surgery.
Descemet folds also are associated with anterior chamber inflammation visible by direct focal illumination.
The following are potential causes of Descemet folds:
Elucidate and treat the underlying condition causing the inflammation. Most of the ophthalmic evaluation is clinical. Consider herpes simplex for epithelial infection or stromal infiltrations, which may need impression cytology studies.
B-scan ultrasound can be considered if the view to the posterior pole is obscured.
Ultrasound biomicroscopy (UBM) can be helpful to identify foreign bodies in the angle, iris, or anterior sclera, especially after trauma. UBM may be helpful if the view to the anterior chamber angle is obscured.
Gonioscopy may be helpful to reveal retained lens fragments in the anterior chamber angle.
Surgery may be necessary either to replace the cornea if the endothelium is not functional or to treat the underlying cause of inflammation (eg, retinal detachment, retained lens fragments, intraocular foreign body).
Corneal donor button from penetrating keratoplasty shows corneal stromal edema with fixed folds of the Descemet membrane.
Staging is not standardized but can be described as 1 to 4 with 1+ implying mild and 4+ implying severe folds.
Treat the underlying cause of inflammation and reduce the inflammation using steroidal, nonsteroidal, and osmotic agents.
Penetrating keratoplasty is available if the corneal edema overlying the Descemet folds does not resolve.[4]
Posterior lamellar keratoplasty is another technique that may be helpful in eyes with unresponsive corneal edema.
Persistent corneal edema causing painful symptoms in an eye with poor visual function also can be treated with anterior stromal micropuncture, excimer laser phototherapeutic keratectomy (PTK), amniotic membrane graft, or a conjunctival flap.[5] See the image below.
View Image | Descemet membrane folds after surgery. |
A consultation with a cornea specialist can be considered if the patient does not improve with identification and medical treatment of the underlying condition.
Medical treatment of Descemet folds requires the treatment of the underlying cause of ocular inflammation. This includes topical steroidal, nonsteroidal, and osmotic agents, as well as topical antibiotics, as needed, for ocular infection.[6] Once the underlying ocular inflammation is treated, the Descemet folds generally resolve.
Clinical Context: Decreases inflammation and corneal neovascularization. Suppresses migration of polymorphonuclear leukocytes and reverses increased capillary permeability.
In cases of bacterial infections, concomitant use of anti-infective agents is mandatory; if signs and symptoms do not improve after 2 days, re-evaluate patient. Dosing may be reduced, but advise patients not to discontinue therapy prematurely.
Sold under multiple preparations and suspensions.
Clinical Context: Structurally similar to other corticosteroids but with a variation that enhances penetration into cells, transforms into inactive metabolite quickly. This drug is less likely than prednisolone acetate to increase intraocular pressure with prolonged use.
Inhibit edema, fibrin deposition, capillary dilation and proliferation, and deposition of collagen and scar formation.
Clinical Context: Nonsteroidal anti-inflammatory eyedrops, by inhibiting cyclooxygenase and thus prostaglandin synthesis, have analgesic, anti-inflammatory, and antipyretic properties.
Clinical Context: Member of nonsteroidal anti-inflammatory drugs for ophthalmic use. Has analgesic, anti-inflammatory, and antipyretic properties and also inhibits prostaglandin biosynthesis.
Clinical Context: A phenylacetic acid with anti-inflammatory and analgesic properties. Believed to inhibit cyclooxygenase, essential to the synthesis of prostaglandins.
Clinical Context: Used for temporary relief of corneal edema. Available as 2% and 5% ophthalmic solution concentrations and 5% ointment. The 5% drop is typically the concentration used.
The amount of outpatient care needed depends on the underlying cause of inflammation. For instance, inflammation due to corneal infection requires close follow-up care, while Descemet folds from inflammation after routine cataract surgery[7] only need routine follow-up care. If not acute in nature, monthly follow-up care may be warranted.
Descemet membrane folds usually are not associated with a condition that requires inpatient care.
Severe ocular infection with or without pending perforation may require intensive topical medication (every 30 min).
Patients should be treated with appropriate medications to treat the underlying cause of inflammation. If infectious, antibiotics are appropriate. The inflammation causing the Descemet folds should be treated with topical steroidal and nonsteroidal drops, unless a contraindication exists. Hypertonic agents also can be used to decrease corneal edema and to improve Descemet folds.
Since these conditions usually do not warrant hospitalization, transfers are unusual.
Minimizing the length of surgery may help reduce the amount of Descemet folds in the acute postoperative period. Avoid intraoperative complications, such as posterior capsular rupture, corneal burns, retained lens fragments, and posterior dislocation of lens material.
Trauma and ocular injuries, such as chemical splashes, often can be avoided by the use of protective eyewear.
Most of the time, factors that lead to Descemet folds (eg, infections, inflammatory conditions) cannot be prevented.
If corneal inflammation is associated with thinning, then corneal perforation may result. Central corneal scarring also may result depending on the location of the underlying corneal infection or injury.
Usually, the Descemet folds resolve with the resolution of the ocular inflammation. Depending on the duration of the corneal edema and folds, there may be residual corneal scarring after the edema and folds resolve.
Patients usually have a good prognosis unless central corneal scarring results. Once the inflammation is treated, the corneal edema and Descemet folds typically resolve.
Patients usually need reassurance with prolonged use of topical medications. They may find it difficult and tedious to instill the drops as frequently as usually is prescribed. Also, the patient needs to understand that gradual improvement will occur in the inflammation and Descemet folds, which results in gradual improvement of their vision.