Subthreshold laser treatment for reticular pseudodrusen secondary to age-related macular degeneration

Abstract

There is a lack of treatment aimed at the regression of reticular pseudodrusen (RPD) secondary to age-related macular degeneration (AMD). The aim of this prospective, pilot study is to evaluate the safety and short-term efficacy of subthreshold laser treatment (SLT) in patients affected by RPD secondary to dry AMD (dAMD). Twenty eyes of 20 patients (mean age 78.4 ± 6.8 years) with RPD secondary to dAMD were prospectively enrolled. All patients were treated in an extrafoveal area of 1.27 mm2 using end-point management yellow subthreshold laser and followed for 3 months. Best-corrected visual acuity was 0.140 ± 0.09 LogMAR at the baseline and no changes were observed during the follow-up (p = 0.232). No significant worsening was disclosed before and after the treatment analyzing the macular sensitivity of the treated area (p = 0.152). No topical and/or systemic side effects were disclosed during the 3-month follow-up. The distribution among the RPD stages changed after the treatment (p < 0.001). In detail, in the treated area, we observed a significant increase in the number of Stage 1 RPD during the follow-up (p = 0.002), associated with a significant decrease of Stage 3 RPD (p = 0.020). Outer nuclear layer (ONL) thickness analysis showed a significant increase after the treatment associated with RPD regression (p = 0.001). End-point management SLT appears a safe treatment for RPD secondary to dAMD, showing short-term safety outcomes. Our results suggest that SLT could be effective in inducing a RPD regression in terms of RPD stage and ONL thickening.

Conflict of interest statement

Giuseppe Querques is a consultant for: Alimera Sciences (Alpharetta, Georgia, USA), Allergan Inc (Irvine, California, USA), Bayer Shering-Pharma (Berlin, Germany), Heidelberg (Germany), Novartis (Basel, Switzerland), Sandoz (Berlin, Germany), Zeiss (Dublin, USA). Riccardo Sacconi, Francesco Gelormini, Enrico Borrelli, Francesco Prascina, Ilaria Zucchiatti, Lea Querques: none. Francesco Bandello is a consultant for: Alcon (Fort Worth,Texas,USA), Alimera Sciences (Alpharetta, Georgia, USA), Allergan Inc (Irvine, California,USA), Farmila-Thea (Clermont-Ferrand, France), Bayer Shering-Pharma (Berlin, Germany), Bausch And Lomb (Rochester, New York, USA), Genentech (San Francisco, California, USA), Hoffmann-La-Roche (Basel, Switzerland), Novagali Pharma (Évry, France), Novartis (Basel, Switzerland), Sanofi-Aventis (Paris, France), Thrombogenics (Heverlee,Belgium), Zeiss (Dublin, USA).

Figures

Figure 1

A representative case of an included patient affected by reticular pseudodrusen in the left eye. An extrafoveal area of 1.27 mm2 (½ of a disk area, disk area = 2.54 mm2) was selected and treated using yellow subthreshold laser (Pascal Synthesis 577 system, Topcon Corporation, Tokyo, Japan). The treatment was performed using the Endpoint Management (~ 30% of the power of the barely visible burn) with a pattern of 5 × 3 spots (area of 1.27 mm2).

Figure 2

Results of microperimetry in terms of macular sensitivity of the whole macular area, of the treated area, and of the control area during the follow-up. *Analysis of Variance (ANOVA) for paired samples.

Figure 3

Number of reticular pseudodrusen (RPD) in the treated area according to the stage before and after subthreshold laser treatment. Stage 1 RPD significantly increased after the subthreshold laser treatment (first histogram) due to the significant regression of stage 3 RPD (third histogram). No significant differences were disclosed after the treatment in stage 2 and stage 4 RPD (second and fourth histograms, respectively).

Figure 4

Structural optical coherence tomography (OCT) changes in the morphology of the outer nuclear layer (ONL) before and after subthreshold laser treatment. (A) Combined infrared reflectance (IR) and structural OCT showing the presence of 4 reticular pseudodrusen (RPD) in the treated area at the baseline (magnification). (B, C) Combined IR and structural OCT showing the partial regression of RPD with increased ONL thickness at 1-month (B) and 3-month follow-up (C) (magnifications).