Phototherapeutic keratectomy involves the use of the excimer laser to treat visual impairment or irritative symptoms relating to diseases of the anterior cornea by sequentially ablating uniformly thin layers of corneal tissue. Phototherapeutic keratectomy may be performed in the office setting using topical anesthesia. Phototherapeutic keratectomy must be distinguished from photorefractive keratectomy, which involves the use of the excimer laser to correct refractive errors of the eye (i.e., myopia, astigmatism, hyperopia, and presbyopia). Photorefractive keratectomy is addressed in a separate policy, No. 9.03.02.

Essentially, phototherapeutic keratectomy (PTK) functions by removing anterior stromal opacities or eliminating elevated corneal lesions while maintaining a smooth corneal surface. Complications of PTK include refractive errors, most commonly hyperopia, corneal scarring, and glare. The U.S. Food and Drug Administration (FDA) labeling for the excimer laser identifies the following ophthalmologic therapeutic indications:

• Superficial corneal dystrophies (including granular, lattice, and Reis-Buckler's dystrophies)
• Epithelial basement membrane dystrophy, irregular corneal surfaces (secondary to Salzmann's degeneration, keratoconus nodules, or other irregular surfaces)
• Corneal scars and opacities (i.e., post-traumatic, post-surgical, post-infectious, and secondary to pathology).

Although not included in the FDA labeling, there has been interest in PTK as a treatment of recurrent corneal erosions in patients who have not responded to conservative therapy with patching, cycloplegia, topical antibiotics, and lubricants.

When PTK is used to remove only the epithelial surface of the cornea, the alternative technology is mechanical superficial keratectomy, i.e., corneal scraping. When PTK is used to remove deeper layers of the cornea, i.e., extending into Bowman's layer, competing technologies include lamellar keratoplasty. In addition, candidates for PTK should have exhausted medical approaches. For example, recurrent corneal erosions can be treated conservatively with lubricants, patching, bandage contact lenses, or anterior stromal punctures, while keratoconus can be treated with rigid contact lenses to correct the astigmatism.

Phototherapeutic keratectomy may be considered medically necessary when used as an alternative to a lamellar keratoplasty in the treatment of visual impairment or irritative symptoms related to corneal scars, opacities, or dystrophies extending beyond the epithelial layer.

Phototherapeutic keratectomy is considered not medically necessary when used as an alternative to a superficial mechanical keratectomy in treating patients with superficial corneal dystrophy, epithelial membrane dystrophy, and irregular corneal surfaces due to Salzmann's nodular degeneration or keratoconus nodules.

Investigational applications of phototherapeutic keratectomy include, but are not limited to, treatment of recurrent corneal erosions and infectious keratitis.

There is no specific CPT code for PTK. CPT code 65400 (excision of lesion, cornea [keratectomy, lamellar, partial]) may be used. Superficial mechanical keratectomy may be coded by 65435-65436 (removal of corneal epithelium). CPT code 65710 describes a lamellar keratoplasty. There is an HCPCS code, S0812, that is specific for this procedure.

The following ICD-9 codes describe superficial corneal lesions; PTK for these conditions would be considered not medically necessary.

371.51 Juvenile epithelial corneal dystrophy
 
371.52 Other anterior corneal dystrophy
 
371.53 Granular corneal dystrophy
 
371.54 Lattice corneal dystrophy
 
371.46 Nodular degeneration of cornea (i.e., Salzmann's nodular dystrophy)
 
371.6 Keratoconus code range

The following ICD-9 codes describe corneal scars and opacities and nonepithelial lesions; PTK for these conditions may be considered medically necessary.

371.0 Corneal scar and opacities code range
 
371.56 Stromal corneal dystrophy

The following ICD-9 codes describe recurrent corneal erosions and infectious keratitis, and PTK for these conditions is considered investigational.

371.42 Recurrent corneal erosions
 
017.3 Tuberculosis of the eye
 
053.21 Herpes zoster keratoconjunctivitis
 
054.4 Ophthalmologic herpes simplex code range
 
055.71 Measles keratoconjunctivitis
 
077.1 Epidemic keratoconjunctivitis
 
090.3 Syphilitic interstitial keratitis
 
370.44 Keratitis or keratoconjunctivitis in exanthema

BlueCard/National Account Issues

It is anticipated that PTK may be routinely used as an alternative to superficial mechanical keratectomy, which, according to the above policy, would be considered not medically necessary. Therefore, plans may want to consider actively managing coverage eligibility for PTK, either through precertification or retrospective physician profiling. In the latter approach, retrospective review may be targeted to those physicians or facilities that perform a high volume of PTK procedures. The coverage policy regarding treatment of superficial corneal lesions is based on the lack of data demonstrating that PTK provides additional health benefits compared to the standard treatment of superficial mechanical keratectomy. Therefore, plans may want to consider whether additional reimbursement for PTK compared to superficial mechanical keratectomy is warranted.

No controlled clinical study has directly compared PTK with other forms of treatment, including superficial keratectomy (used to treat superficial lesions), or lamellar keratoplasty (used to treat deeper lesions), or anterior stromal puncture (used to treat recurrent corneal erosions). The FDA approval was based on data from uncontrolled trials of patients with a variety of corneal pathologies. For example, Summit Technology presented data on 398 eyes, including 103 eyes with dystrophy (25.9%), 64 eyes with recurrent erosion (16.1%), and 231 eyes with scars, opacities, or other irregular surfaces (58%). (1) Outcomes included best-corrected visual acuity and/or decrease in irritative symptoms, such as pain and discomfort. Among cases undergoing PTK to increase comfort, 88.5% were considered successes at 1 year. Among those with visual impairment, 63.4% were considered successes. The most common adverse effect was corneal scarring and glare, occurring in 13.7% and 12.2% of cases, respectively. The results of this trial have also been summarized by Maloney and colleagues. (2) Superficial mechanical keratectomy is regarded as a minimally invasive, safe, and effective procedure to remove the superficial layer of the cornea. While PTK offers a more precise and elegant method of epithelial removal, no controlled studies have demonstrated that this technological superiority results in an improved patient health benefit. The precision of PTK may be most significant when deeper corneal lesions involving Bowman's layer are present. In this situation, PTK presents a minimally invasive alternative to lamellar keratoplasty.

There are inadequate data regarding the effectiveness of PTK in treating recurrent corneal erosions and infectious keratitis.

2005 Update
 
A literature review performed for the period of 2003 through November 2004 did not identify any published articles that would prompt reconsideration of the above policy. Therefore the policy statement is unchanged.

References:

1. Summit Technology, Inc., Summary of Safety and Receptiveness Data, ExciMed UV200LA or SVS Apex (formerly the OmniMed) Excimer Laser System for Phototherapeutic Keratectomy (PTK). Waltham, MA: Summit Technology, Inc. 1995.
2. Maloney RK, Thompson, V, Ghiselli G et al. A prospective multicenter trial of excimer laser phototherapeutic keratectomy for corneal vision loss. The Summit Phototherapeutic Keratectomy Study Group. Am J Ophthalmol 1996; 122(2):149-60.

Phototherapeutic keratectomy