The cornea is a delicate structure and the most sensitive part of the eye. That transparent dome of tissue at the front surface of your eye, the cornea is responsible for bending, or refracting, light to provide clear vision. There is a myriad of conditions that can affect the cornea, with effects ranging from no noticeable symptoms to significantly debilitating pain and permanent loss of vision. Recurrent corneal erosion syndrome is a disease that can cause real distress for some patients, leading to corneal surgery, while for others is only a mild irritation that can be easily managed with over-the-counter lubricant eye drops.
As mentioned earlier, the cornea is a very sensitive part of the eye. The lightest touch from a speck of dust can cause irritation and reflexive tearing, an important reflex response designed to protect the eye. It’s no wonder that a more significant injury, such as the severely-named “recurrent corneal erosion”, can have a real impact on quality of life.
The cornea is made up of five layers:
- The epithelium at the front surface of the eye; the epithelial cells are adhered to a basement membrane
- Bowman’s membrane underneath the epithelial basement membrane
- The corneal stroma, which makes up the bulk of the cornea
- Descemet’s membrane, immediately behind the stroma
- And the corneal endothelium, which is comprised of cells responsible for controlling the water content of the cornea
Recurrent Corneal Erosion Syndrome
Recurrent corneal erosion syndrome is a corneal condition that involves the epithelium and its basement membrane. In this disease, the epithelial cells are poorly adhered to the basement membrane in certain patches across the cornea, resulting in these cells separating from each other in what is known as a recurrent corneal erosion. A recurrent corneal erosion is basically a defect at the level of the corneal epithelium. They are most common in people in their 30s and 40s, with a slight bias towards females.
A recurrent corneal erosion is typically characterised by a sudden sharp pain in the eye upon waking in the morning. The theory behind this presentation is that overnight, the corneal epithelial cells stick to the inside of the upper eyelid as the eye’s surface dries. Combined with mild superficial swelling of the epithelium due to the lids being closed during sleep which leads to weakened anchoring of the epithelium to its basement membrane, as the eyelids open in the morning this can mechanically erode, or pull, the epithelium from the basement membrane. Other symptoms associated with this condition include tearing, redness, and light sensitivity in the affected eye. There may also be some disturbance to the vision, whether from the corneal defect itself or from the excessive tearing. As the name suggests, recurrent corneal erosion tends to happen again and again, often in the same area of the cornea.
It is not always understood why a patient may have a weakened epithelial adhesion to the corneal basement membrane. However, in up to about 65% of cases, a history of previous corneal trauma can be identified, such as a scratch from a tree branch, fingernail, or piece of paper. Another predisposing factor for recurrent corneal erosion syndrome is the presence of an epithelial basement membrane dystrophy, which is a genetic corneal condition. Epithelial basement membrane dystrophies account for up to 29% of cases of recurrent corneal erosions. Patients who have dry eye syndrome, diabetes, ocular rosacea, or blepharitis also tend to be at a higher risk of experiencing a recurrent corneal erosion.
Recurrent Corneal Erosion Treatment
Recurrent corneal erosion syndrome can be difficult to treat, leading some patients to get quite frustrated at the lack of relief. Many eyecare practitioners will begin with conservative therapy before escalating to corneal surgery in very severe, stubborn cases.
First line therapy is generally lubricant eye drops or eye ointment. Typically, this involves frequent use of preservative-free artificial tears during the day plus a thicker, more viscous eye ointment at night before bed to discourage the corneal epithelium from sticking to the underside of the eyelid. This should be considered as a preventative measure to avoid an attack from occurring. During an active episode of a corneal erosion, the optometrist or ophthalmologist may prescribe a preventative antibiotic to avoid a bacterial infection from taking advantage of the epithelial defect, as well as pain relief tablets as needed. Large corneal defects may benefit from having a contact lens inserted on the eye to provide some protection from the environment. If these treatments are ineffective, you may be referred for corneal surgery with an anterior eye specialist.
Corneal surgery options for recurrent corneal erosion syndrome include:
- Anterior stromal micropuncture – this involves using a fine needle to prick through the superficial layers of the cornea. The basis of this treatment is that the micro punctures stimulate the cornea to fortify the basement membrane
- Debridement and superficial keratectomy – using a burr or scalpel, loose epithelium is removed from the eye, allowing new, healthy epithelium to regrow
- Phototherapeutic keratectomy – this may be considered the last option for corneal surgery where other treatments have failed. After removing loose epithelium with debridement, a laser is used to vaporise several micrometres of Bowman’s membrane, allowing re-epithelisation with healthy cells.
If you think you may be experiencing recurrent corneal erosions, it is important to be examined by an experienced optometrist or ophthalmologist. Call us today at (03) 9070 5753 for a consultation.
Note: Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second opinion from an appropriately qualified health practitioner.