In a recent study published by the American Academy of Ophthalmology, researchers reviewed the safety and efficacy of epithelium-off (Epi-off) corneal collagen cross-linking (CXL) for progressive corneal ectasia treatment.
Give me some background first.
CXL is a minimally-invasive procedure most commonly used to stop ectasia. It utilizes riboflavin and ultraviolet (UV) light to strengthen chemical bonds in the cornea, which in turn stiffens it.
Now adding in the “epi-off” component…
Epi-off CXL is one of two main approaches to CXL (the other being Epithelium [Epi]-on) that involves:
- Removing 7-9 mm of epithelium
- Subsequent application of a riboflavin solution at regular interval (2-5 minutes) for 30 minutes
- 30 minutes of UV-A (irradiation with continued concurrent intermittent administration of the riboflavin solution
Following this sequence, the patient is provided with topical antibiotics until:
- Re-epithelialization occurs, followed by
- Corticosteroids for a variable period of time
Now, talk about the study.
Investigators conducted a literature search of the PubMed database in March 2024. The search had no date restrictions and was limited to studies published in English.
They identified:
- 359 citations that were reviewed in abstract form
- 43 of which were reviewed in full text
What articles were included in the analysis?
Included were six prospective, randomized controlled trials (RCTs) that:
- Evaluated the use of Epi-off CXL to treat progressive keratoconus (KC) (five studies)
- Analyzed post–laser refractive surgery ectasia (one study)
- Had a mean postoperative follow-up of 2.4 years (range: 1 to 5 years)
Findings?
- All studies showed a decreased KC progression rate in treated patients compared with controls
- A decrease in corneal thickness was observed in both groups
- This was greater in the CXL group
- Complications were rare between both groups
Tell me more.
The following improvements were observed in the treatment groups compared with control groups:
- Maximum keratometry (Kmax) value
- Corrected distance visual acuity (CDVA)
- Uncorrected distance visual acuity (UDVA)
Expert opinion?
The authors stated that, “According to the results of these studies, epithelium-off CXL should be considered a first-line treatment for patients with progressive KCN and post-laser refractive surgery ectasia.”
Take home.
These findings suggest that epi-off CXL may be effective in reducing KCN progression as well as post-laser refractive surgery ectasia in most treated patients with an acceptable safety profile.