Anterior stromal puncture (ASP) is a surgical treatment for recurrent corneal erosion (RCE). It was first reported by McLean in 1986 using a 20-gauge needle 1).
The principle is that puncture wounds from the needle into Bowman’s layer and superficial stroma induce a local fibroblast response, promoting the production of anchoring fibrils and reestablishing the adhesion structure between the epithelium and basement membrane.
Indications include recurrent corneal erosion refractory to conservative treatment, and it may also be used for diabetic keratopathy. It is a relatively simple procedure that can be performed under a slit lamp microscope, but because puncture sites leave permanent punctate opacities, it cannot be performed in the pupillary area.
When a needle punctures from Bowman’s layer into the superficial stroma, a fibroblast response occurs at the puncture site. This response promotes the production of anchoring fibrils, which reestablish the adhesion structure between the corneal epithelium and basement membrane.
Recurrent corneal erosion (RCE) is a disease characterized by abnormal adhesion between the corneal epithelium and basement membrane. It typically presents with the following symptoms.
Recurrence typically occurs weeks to months after the initial erosion.
The causes of RCE are broadly divided into two categories.
Corneal dystrophies associated with RCE include the following:
As a first step, apply eye ointment before bedtime and use artificial tears upon waking for 3 to 6 months. If ineffective, try continuous wear of a bandage contact lens. For refractory cases where these conservative treatments fail, surgical treatments such as anterior stromal puncture are indicated.
The stepwise treatment strategy for RCE is as follows:
The specific steps of the procedure are described below.
Puncture sites leave permanent punctate opacities, so performing the procedure in the pupillary area is contraindicated. For RCE in the pupillary area, superficial keratectomy or phototherapeutic keratectomy (PTK) is chosen.
As an alternative to needle puncture, corneal stromal puncture using Nd:YAG laser has been reported.
Diamond burr
Procedure: Polish with a 3.3 mm diamond burr for about 30 seconds.
Postoperative management: Continue bandage contact lens + antibiotic/steroid eye drops for 3–4 weeks.
Outcomes: Approximately 95% efficacy at 31 months. Recurrence rate about 9%.
Therapeutic laser keratectomy
Procedure: Phototherapeutic keratectomy using an excimer laser.
Indications: Can be performed for RCE involving the pupillary area.
Outcomes: Approximately 90% efficacy. Recurrence rate about 10%. There is a risk of hyperopic shift.
Superficial keratectomy
Procedure: Mechanically remove loose epithelium and abnormal basement membrane.
Combination: Often combined with therapeutic laser keratectomy or diamond burr polishing.
Indications: First-line treatment for erosions in the pupillary area.
Anterior stromal puncture in the pupillary area is contraindicated because it leaves punctate opacities. For RCE in the pupillary area, superficial keratectomy is the first choice, combined with excimer laser phototherapeutic keratectomy or diamond burr polishing.
The treatment outcomes of each procedure are shown below.
| Procedure | Efficacy Rate | Recurrence Rate |
|---|---|---|
| Needle/Laser ASP | Approximately 85% | Approximately 30% |
| Phototherapeutic Keratectomy | Approximately 90% | Approximately 10% |
| Diamond burr | Approximately 95% | Approximately 9% |
For refractory cases with multiple recurrences, oral doxycycline 50 mg has been reported as an adjunctive therapy 3). The mechanism is thought to involve inhibition of matrix metalloproteinase-9 (MMP-9), thereby suppressing basement membrane degradation 3). A Cochrane systematic review indicates that evidence comparing puncture, PTK, and diamond burr polishing is still limited, and larger RCTs are needed 4).
For recurrence after ASP, options include repeat ASP, PTK, or switching to diamond burr polishing. For refractory cases with multiple recurrences, oral doxycycline 50 mg plus topical steroid eye drops has been reported as adjunctive therapy 3).
