Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions. Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply. If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.
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 1 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 age-related macular degeneration (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 this diminished over time (33% and 32% at 30 months, respectively). Higher intensity laser treatment was associated with greater risk of developing CNV.
The National Eye Institute-sponsored Complications of AMD Prevention Trial (CAPT) enrolled patients with bilateral large drusen (n=1,052); 1 eye was 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 equal to or greater than 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, respectively; 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 2009, Friberg and colleagues from the PTAMD study group reported 3-year outcomes from 639 participants (1,278 eyes). (12) Treatment consisted of the placement of an annular grid of 48 extrafoveal, subthreshold laser applications in one eye of each participant. Subthreshold laser treatment did not decrease the incidence of CNV in comparison with the other (fellow) eye. A very slight benefit in visual acuity (1.5 letter difference) was found at 24 months, but this effect was not sustained at 3 years. The authors concluded that a single subthreshold 810-nanometer laser treatment to eyes of participants with drusen is not an effective prophylactic strategy against CNV.
A Cochrane review on laser treatment of drusen to prevent progression to advanced AMD was published in 2009. (13) Nine randomized studies with a total of 2,216 patients were included in the systematic review. Two of the studies reported significant drusen disappearance at 2 years, but photocoagulation did not appear to affect the development of CNV at 2 years’ follow-up. The authors concluded that the trials confirmed the clinical observation that laser photocoagulation of drusen leads to their disappearance. However, there is no evidence that this reduces the risk of developing CNV, geographic atrophy, or visual acuity loss.
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. The literature indicates that photocoagulation of macular drusen procedure is not clinically appropriate; this approach is considered not medically necessary.
Practice Guidelines and Position Statements
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 1 eye. (14) 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.”
Disclaimer for coding information on Medical Policies
Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive.
The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers. Only the written coverage position in a medical policy should be used for such determinations.
Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps.