Subthreshold Laser Treatment for Reticular Pseudodrusen and Geographic Atrophy Secondary to AMD


To evaluate the effectiveness of subthreshold laser treatment on retinal sensitivity in patients with reticular pseudodrusen and incipient Geographic Atrophy (GA) secondary to Age-Related Macular Degeneration (AMD). Secondary objective is to investigate changes in best-corrected visual acuity, atrophy progression and safety.

Full Title of Study: “Subthreshold Laser Treatment for Reticular Pseudodrusen and Incipient Geographic Atrophy Secondary to Age – Related Macular Degeneration: a Pilot Study”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Non-Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: None (Open Label)
  • Study Primary Completion Date: September 1, 2019


  • Procedure: Subthreshold 577 nm yellow wavelength laser photo-coagulator
    • Subthreshold photocoagulation is a method in which the burn spots (treated areas) cannot be seen with biomicroscopy, on color fundus photograph, on Optical Coherence Tomography or Fluorescein Angiography when the subthreshold level is adequately set. Subthreshold photocoagulation can be considered to be truly minimally invasive or non-damaging photocoagulation. A term sometimes used is photo-thermal stimulation since the Retinal Pigment Epithelium (RPE) layer is heated and stimulated, but not destroyed. The threshold level output power is set to obtain barely visible burn at approximately 200 mW to 250 mW using the titration mode, and irradiation is conducted after switching over to Endpoint Management.

Arms, Groups and Cohorts

  • Experimental: Pseudodrusen
    • Subthreshold 577 nm yellow wavelength laser photo-coagulator
  • Experimental: Geographic atrophy
    • Subthreshold 577 nm yellow wavelength laser photo-coagulator

Clinical Trial Outcome Measures

Primary Measures

  • Retinal Sensitivity
    • Time Frame: Baseline, 4 weeks and 12 weeks
    • Change in retinal sensitivity on customized microperimetry (treated area).

Secondary Measures

  • Visual Acuity
    • Time Frame: Baseline, 4 weeks and 12 weeks
    • Change in mean Visual Acuity
  • The Thickness of the Outer Nuclear Layer in the Treated Area
    • Time Frame: Baseline, 4 weeks and 12 weeks
    • The thickness of the outer nuclear layer in the treated area was measured using structural OCT
  • Adverse and Serious Adverse Events
    • Time Frame: 4 weeks and 12 weeks
    • Adverse and Serious Adverse Events were recorded
  • Presence of Haemorrhage, Photocoagulation Spots, Ischemic Areas
    • Time Frame: 4 weeks and 12 weeks
    • Fundus examination by using slit-lamp was performed in order to assess the presence of hemorrhage, photocoagulation spots, ischemic areas
  • Intraocular Pressure
    • Time Frame: 4 weeks and 12 weeks
    • Intraocular pressure was recorded.

Participating in This Clinical Trial

Inclusion Criteria

  • GA < 0.5 disk areas secondary to AMD and/or Reticular pseudodrusen
  • 50 years or older
  • The periphery of the atrophic lesions must demonstrate increased autofluorescence
  • Best corrected visual acuity between 20/20 and 20/400 inclusive
  • Clear ocular media
  • Ability to provide informed consent and attend all study visits

Exclusion Criteria

  • GA secondary to other causes aside from AMD
  • Evidence of choroidal neovascularization in either eye
  • Any prior treatment for AMD, aside from antioxidants
  • Any other ocular condition that would progress in the study period and confound visual acuity assessment
  • Any ocular or systemic medication known to be toxic to the lens, retina or optic nerve
  • Presence of idiopathic or autoimmune-associated uveitis
  • Any intraocular surgery 3 months of entry
  • Any prior thermal laser in the macula
  • History of vitrectomy, filtering surgery, corneal transplant or retinal detachment surgery
  • Previous therapeutic radiation in the ocular region in either eye
  • Any treatment with an investigational agent in the previous 60 days before study entry
  • Women of child-bearing potential, defined as all women less than 1 year postmenopausal or less than 6 weeks since sterilization at Baseline, unless they are using highly effective methods of contraception during dosing of study treatment
  • Participation in an investigational drug, biologic, or device study within 6 Months prior to Baseline [Note: observational clinical studies solely involving over-the-counter vitamins, supplements, or diets are not exclusionary

Gender Eligibility: All

Minimum Age: 50 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: No

Investigator Details

  • Lead Sponsor
    • Ospedale San Raffaele
  • Provider of Information About this Clinical Study
    • Principal Investigator: Querques Giuseppe, Head-Medical retina & Imaging unit – Ospedale San Raffaele
  • Overall Official(s)
    • Giuseppe Querques, MD, PhD, Principal Investigator, Ospedale San Raffaele
    • Riccardo Sacconi, MD, Principal Investigator, Ospedale San Raffaele
    • Francesco Gelormini, MDs, Principal Investigator, Ospedale San Raffaele


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