Age-related macular degeneration (AMD) is a painless, insidious process. In its earliest stages, it is characterized by minimal visual impairment and the presence of large or “soft” drusen, i.e., subretinal accumulations of cellular debris adjacent to the basement membrane of the retinal pigment epithelium.

Large drusen appear as large, pale yellow or pale gray domed elevations and result in thickening of the space between the retinal pigment epithelium and its blood supply, the choriocapillaris. Clinical and epidemiologic studies have shown that the presence of large and/or numerous soft drusen increases the risk of the development of choroidal neovascularization (CNV) in eyes with AMD. For example, in patients with bilateral drusen, the 3-year risk of developing CNV is estimated to be 13%, rising to 18% for those over the age of 65 years. The emergence of CNV greatly increases the risk of subsequent irreversible loss of vision.

Two different kinds of low energy laser therapies, argon and infrared laser, have been investigated as techniques to eliminate drusen by photocoagulation in an effort to prevent the evolution to CNV, ultimately leading to improved preservation of vision. The lasers used are those that are widely used for standard photocoagulation of extrafoveal choroidal neovascularization. Therefore, the treatment of macular drusen represents an additional indication for an existing laser approved by the U.S. Food and Drug Administration (FDA).

Treatments for choroidal neovascularization are addressed in policies 9.03.08 (photodynamic therapy), 9.03.10 (transpupillary thermotherapy) and 9.03.16 (anecortave acetate).

Destruction of macular drusen with laser therapy is considered not medically necessary.

In 2002, a new tracking CPT code was introduced to specifically identify laser therapy of macular drusen:

0017T: Destruction of macular drusen, photocoagulation

Prior to the introduction of the above CPT tracking code, CPT code 67220 (destruction of localized lesion of choroid (e.g., choroidal neovascularization); photocoagulation (e.g., laser) may have been used to describe laser therapy for treatment of macular drusen. Aside from the introduction of the more specific tracking code, macular drusen are technically not choroidal lesions.

BlueCard/National Account Issues

It may be difficult to identify photocoagulation of macular drusen if CPT code 67220 is used, unless it is used in conjunction with ICD-9 code 377.21 (drusen of optic disc). Plans may consider requiring that claims for photocoagulation of macular drusen be submitted with the CPT category III code (0017T).

Some state or federal mandates (e.g., FEP) prohibit plans from denying FDA-approved technologies as investigational. Since the laser used in this procedure is FDA approved (the laser is an adaptation of the laser used for conventional photocoagulation), Plans may have to consider the coverage eligibility on the basis of medical necessity alone for some lines of business.

While studies have shown that laser therapy can induce regression of drusen, not only at the treatment site, but also at sites remote from the laser, (1-3) outcomes of greatest interest are preventing vision loss from atrophy and choroidal neovascularization (CNV). Unfortunately, the biologic rationale has not translated into patient benefit, as demonstrated in multiple trials.

Following initially optimistic results (1) Figueroa and colleagues updated follow-up in 46 patients with confluent soft drusen. (4) A total of 30 patients with bilateral drusen were randomized to receive argon green laser therapy in 1 eye. The remaining 16 patients had CNV in one eye and laser therapy performed on the other eye. Although laser therapy resulted in resolution of the drusen, after 3 years there was no difference between the groups regarding development of CNV.

The Choroidal Neovascular Prevention Trial (CNVPT) randomized eyes with exudative AMD in 1 eye and 10 or more large drusen in the other (Fellow Eye Study, 120 patients, 120 study eyes) or bilateral large drusen without exudative AMD (Bilateral Drusen Study, 156 patients, 312 study eyes) to receive argon green laser therapy or observation. (5) Due to an increased incidence of CNV in laser-treated eyes enrollment and treatment was suspended in December 1996. An earlier report excluding eyes developing CNV found eyes with 50% or more drusen reduction at 1 year had more increases in visual acuity compared to the control group. (6) An updated report from the Fellow Eye Study found no significant differences in visual acuity between photocoagulation or observation eyes during a 4-year follow-up. (7) In addition, the authors noted an increased risk of CNV in treated eyes treated early during follow-up (23% treated eyes vs. 5% observed at 1 year) but diminished over time (33% and 32% at 30 months, respectively. Higher intensity laser treatment was associated with greater risk of developing CNV.

The NEI-sponsored Complications of AMD Prevention Trial (CAPT) enrolled patients with bilateral large drusen ('n= 1,052);1 eye assigned to low-intensity laser treatment and the other to observation. After 5 years, there were no differences between treated and observed eyes in worsening visual acuity (20.5% in both groups lost ≥3 ETDRS [Early Treatment of Diabetic Retinopathy Study] lines), development of CNV (13.3% in both groups) or geographic atrophy. (8)

A pilot study of infrared laser therapy (810 nm) enrolled 152 patients (229 eyes) who had either bilateral drusen or unilateral drusen if CNV was detected in the fellow eye. (9) Eyes were randomized to receive laser therapy or observation. While laser therapy was associated with resolution of drusen and improved visual acuity, the study was not powered to detect an effect on progression to CNV. Based on these results the prophylactic treatment of AMD trial (PTAMD) followed 244 patients with CNV or advanced AMD in 1 eye and ≥ 5 drusen and no CNV in the fellow eye. (10) Treatment consisted of an extrafoveal grid of subthreshold 810-nm laser spots. Enrollment was halted after 47 months due to an excess of CNV in treated eyes. CNV occurred more often in treated eyes (15.8% vs. 1.4% at 1 year); there were no differences in moderate ( ≥ 3 ETDRS lines) visual loss after 6 months, with or without treatment.

The drusen laser study randomized patients with eyes at high risk for AMD. (11) Follow-up was completed over 3 years. A unilateral group ('n=177) in the trial included patients with drusen in the study eye and CNV in the fellow eye; the bilateral group ('n=105) had drusen in both eyes. The treatment protocol was revised and recruitment ultimately halted after 23 months due to concerns over laser-induced CNV in interim analyses. In the unilateral group, prophylactic laser treatment hastened the onset of CNV (29.7% vs. 17.7% observed, p=0.06) and was associated with worsening visual acuity. In the bilateral group, 3-year CNV incidence was 11.6% in laser-treated eyes versus 6.8% without treatment ('p=0.22). In both groups, visual loss paralleled development of CNV.

In summary, evidence from multiple trials indicates that drusen ablation does not prevent visual loss, CNV, or AMD. Furthermore, the evidence from trials indicates that drusen ablation may be accompanied by harm. Given these findings, this approach is considered not medically necessary.

2008 Update
A search of the MEDLINE database for the period of June 2007 through April 2008 did not identify any recent literature on the photocoagulation of macular drusen. Preferred Practice Patterns (practice guidelines) on photodynamic therapy from the American Academy of Ophthalmology (AAO) recommend regular dilated eye exams for the early detection of the intermediate stage of AMD and possible treatment with antioxidants and minerals for patients who have progressed to intermediate or advanced AMD in one eye. (12) No recommendations were made regarding photocoagulation of macular drusen. The guidelines state that “patients with intermediate AMD who are at increased risk of visual loss or of progression to advanced AMD should be educated about methods of detecting new symptoms of CNV and about the need for prompt notification to an ophthalmologist who can confirm if the new symptoms are from CNV and who can begin treatment if indicated.” The literature indicates that photocoagulation of macular drusen procedure is not clinically appropriate; the policy statement is unchanged.

References:

1. Figueroa MS, Regueras A, Bertrand J. Laser photocoagulation to treat macular soft drusen in age-related macular degeneration. Retina 1994; 14(5):391-6.
2. Frennesson IC, Nilsson SE. Effects of argon (green) laser treatment of soft drusen in early age-related maculopathy: a 6 month prospective study. Br J Ophthalmol 1995; 79(10):905-9.
3. Frennesson C, Nilsson SE. Prophylactic laser treatment in early age related maculopathy reduced the incidence of exudative complications. Br J Ophthalmol 1998; 82(10):1169-74.
4. Figueroa MS, Regueras A, Bertrand J et al. Laser photocoagulation for macular soft drusen. Updated results. Retina 1997; 17(5):378-84.
5. Ho AC, Maguire MG, Yoken J et al. Laser-induced drusen reduction improves visual function at 1 year. Choroidal Neovascularization Prevention Trial Research Group. Ophthalmology 1999; 106(7):1367-73.
6. The Choroidal Neovascularization Prevention Trial Research Group. Choroid neovascularization in the Choroidal Neovascular Prevention Trial. Ophthalmology 1998; 105(8):1364-72.
7. The Choroidal Neovascularization Prevention Trial Research Group. Laser treatment in fellow eyes with large drusen: updated findings from a pilot randomized clinical trial. Ophthalmology 2003; 110(5):971-8.
8. Complications of Age-Related Macular Degeneration Prevention Trial Research Group. Laser treatment in patients with bilateral large drusen: the complications of age-related macular degeneration prevention trial. Ophthalmology 2006; 113(11):1974-86.
9. Olk RJ, Friberg TR, Stickney KL et al. Therapeutic benefits of infrared (810-nm) diode laser macular grid photocoagulation in prophylactic treatment of nonexudative age-related macular degeneration: two-year results of a randomized pilot study. Ophthalmology 1999; 106(11):2082-90.
10. Friberg TR, Musch DC, Lim JI et al. Prophylactic treatment of age-related macular degeneration report number 1: 810-nanometer laser to eyes with drusen. Unilaterally eligible patients. Ophthalmology 2006; 113(4):622.e1.
11. Owens SL, Bunce C, Brannon AJ et al. Prophylactic laser treatment hastens choroidal neovascularization in unilateral age-related maculopathy: final results of the drusen laser study. Am J Ophthalmol 2006; 141(2):276-81.
12. American Academy of Ophthalmology. Age-Related Macular Degeneration, Preferred Practice Pattern. San Francisco: American Academy of Ophthalmology, 2006. Available at www.aao.org/ppp.

Drusen, Laser Therapy
Laser Therapy, Macular Drusen
Macular Drusen Destruction
Photocoagulation, Macular Drusen