Macular laser picks up speed: The technology accelerating retinal therapies

During the 25th Congress of the European Society of Retina Specialists (EURETINA), held in Paris, France, in September 2025, the session “Macular Laser Treatment: Where Are We, Where Are We Going?” highlighted ongoing advancements in understanding and refining retinal laser therapy. Rather than a routine technical review, the session featured presentations on how the field is moving toward shared standards and smarter technology. Presentations ranged from efforts to standardise laser nomenclature and refine treatment strategies to updates on subthreshold protocols and the latest advances in navigated laser delivery platforms, all pointing to a more coordinated, evidence-driven future for macular laser care.

Defining a language for laser: The RELITE framework

In his talk “Basics and Classification of Regenerative Retinal Laser and Light Therapies,” Claus von der Burchard, MD, introduced the new RELITE classification, a framework designed to bring clarity to the rapidly expanding field of retinal laser therapy.¹ RELITE organises treatments by mechanism: photothermal approaches that warm tissue to trigger a biologic response, photo-microdisruption techniques that selectively break down pigment granules, photochemical options such as photodynamic therapy, and photobiomodulation therapies aimed at cellular metabolism and signaling. This structured taxonomy can help researchers compare studies and guide clinicians in selecting and reporting laser parameters across different platforms.

From energy titration to precision delivery

Unlike anti-VEGF therapy—where dosing and retreatment intervals are clearly defined for conditions such as neovascular age-related macular degeneration (AMD), diabetic macular oedema, and retinal vein occlusion—subthreshold retinal laser treatment still lacks universally accepted parameters. Laser therapy aimed at stimulation below the threshold of tissue damage requires careful titration of energy, selection from among different laser modalities and ongoing refinement of delivery techniques to achieve consistent biological effects without collateral damage. This need for standardisation has fueled efforts to define dosimetry, compare laser types and develop image-guided navigated laser systems that can deliver and document subthreshold energy with reproducible precision. Building on that foundation, speakers emphasised the collective effort to reduce collateral retinal damage in subthreshold laser therapy.

As Yoko Miura, MD, PhD, outlined in her talk, carefully titrated energy delivery individually determined for each patient now allows subthreshold photothermal laser treatments that stimulate the retinal pigment epithelium (RPE) while sparing the neurosensory retina. Many mechanisms to do so are under investigation; currently, manual titration is the most widely accepted. In this approach, a subthreshold microsecond-pulse laser delivers energy in rapid bursts with a low-duty cycle, creating intermittent heat that downregulates VEGF, permeability factors, and inflammatory mediators without leaving visible burns. Lisa Toto, MD, PhD, described how international guidelines now recommend titration strategies—typically 30% to 50% of the manually titrated threshold power, spot sizes of 100 to 200 µm, and a 5% or 10% duty cycle—to standardise these subthreshold protocols; ongoing trials continue to refine parameters in search of a reproducible global standard.^2,3

Delivery technology is advancing just as rapidly. With navigated treatment-mapping systems, such as the Navilas Laser System (OD-OS GmbH), subthreshold laser therapy transforms from a vague idea into a reproducible, image-guided procedure. The system overlays multimodal imaging directly onto the treatment field, allowing plans to be drawn on fluorescein angiography, indocyanine green angiography, or optical coherence tomography (OCT) images and stored for future sessions so that each laser application is documented. Eye tracking and contact-free delivery improve precision and applicability. Because subthreshold burns are funduscopically invisible, spot mapping becomes part of the treatment, ensuring transparency and accurate retreatment over time. The EURETINA 2025 session carried that message forward, showing that the drive to standardise laser therapy is now backed by an expanding body of prospective data.

MacuTherm: Targeting intermediate AMD

The MacuTherm study (DRKS00031781) is one of the first prospective attempts to deliver a controlled, repeatable photothermal treatment for patients with intermediate AMD. I oversee one of the study sites, at University Eye Clinic at the Hannover Medical School in Hannover, Germany. The study uses navigated laser delivery (Navilas) and individualised titration to test whether carefully calibrated, maculawide subthreshold treatments can stimulate the choriocapillaris–Bruch membrane–retinal pigment epithelium (RPE) complex and slow disease progression. The protocol schedules 6 navigated treatments over 12 months, each guided by individualised energy titration and mapped across the entire macula. Primary goals include regeneration or stabilisation of the choriocapillaris–Bruch membrane–RPE–photoreceptor complex and prevention of disease progression, with endpoints spanning functional measures (best-corrected visual acuity, low-luminance and low-contrast visual acuity, mesopic perimetry, multifocal electroretinogram) and detailed structural metrics (OCT drusen volume, RPE integrity, OCT angiography perfusion). Consistency matters: by combining exact dosing with navigated, image-guided delivery and rigorous documentation, the MacuTherm researchers aim to make photothermal therapy reproducible across centres and provide the kind of controlled data that could move this technology toward routine clinical practice.

Photothermal trials for pseudodrusen and CSC

Giuseppe Querques, MD, PhD, presented “Treating Reticular Pseudodrusen by Photothermal Laser Therapy,” which focused on the interventional PASCAL trial (NCT02800356).⁴ PASCAL investigated subthreshold laser therapy for reticular pseudodrusen (RPD), a high-risk phenotype of AMD.
Early-phase work applied a subthreshold Pascal laser at approximately 30% of the titration threshold to small posterior pole areas and demonstrated no functional loss yet showed clear regression of RPD deposits and thickening of the outer nuclear layer. These structural changes are interpreted as signs of deposit resorption.⁴ Armed with safety and a biologic response, the researchers plan to escalate to a phase 2 multicentre programme: pan-macular navigated treatment using the Navilas system (ring annulus, 3.6-6.0 mm; ~192 spots of 200 µm) every 3 months for a year vs observation.

Chronic central serous chorioretinopathy (CSC) took centre stage in a presentation by Camiel J.F. Boon, MD, PhD, FEBO, who reviewed the latest evidence guiding therapy. The VICI trial (ISRCTN92746680), based in the United Kingdom, although not a laser study, showed that the mineralocorticoid antagonist eplerenone offered no significant benefit over placebo, highlighting the continued need for effective nonpharmacologic options.⁵

Against this backdrop, Boon highlighted the phase 4 PLACE trial (NCT01797861), the most rigorous head-to-head comparison to date, which demonstrated that half-dose photodynamic therapy (PDT) produced higher rates of complete subretinal fluid resolution and greater microperimetric sensitivity gains at 12 months than high-density subthreshold micropulse laser, although this study used an 800nm wavelength and a traditional manually controlled slit lamp laser system.⁶ Still, Boon noted that a 577-nm wavelength subthreshold micropulse laser remains a practical alternative—particularly when PDT is unavailable—and offers a nondestructive approach that can stabilise vision and reduce fluid in carefully selected chronic CSC cases.⁷

The EURETINA 2025 session made clear that the macular laser is entering a new era. With reproducible dosing and navigated delivery systems, clinicians can now test hypotheses and generate evidence with a rigor once reserved for pharmaceuticals. Although ongoing multicentre trials in intermediate AMD, RPD, and CSC have not yet determined whether these advances translate into long-term disease modification, the foundation for this evolution is now established.

Jan Tode, MD, FEBO

E: [email protected]

Tode is a senior ophthalmologist and translational vision science researcher. He is deputy head of the department at the Hannover Medical School in Germany and CEO of enVision Science UG. His research focus lies at the intersection of retinal disease, uveitis and novel therapeutic approaches (including selective retina laser therapy and photothermal stimulation). He has published over 50 peer-reviewed articles and is a guest editor for laser therapy special issues in ophthalmology.

Financial disclosure: Consultant for
AbbVie, Bayer, enVision Science, Novartis, OD-OS, Roche, Santen Pharmaceutical Co, Ltd.

References

1. von der Burchard C, Miura Y, Stanzel B, et al. Regenerative retinal laser and light therapies (RELITE): proposal of a new nomenclature, categorization, and trial reporting standard. Lasers Surg Med. 2024;56(8):693-708. doi:10.1002/lsm.23833

2. Chhablani J; SOLS (Subthreshold Laser Ophthalmic Society) writing committee. Subthreshold laser therapy guidelines for retinal diseases. Eye (Lond). 2022;36(12):2234-2235. doi:10.1038/s41433-022-02136-w

3. Keunen JEE, Battaglia-Parodi M, Vujosevic S, Luttrull JK. International Retinal Laser Society guidelines for subthreshold laser treatment. Transl Vis Sci Technol. 2020;9(9):15. doi:10.1167/tvst.9.9.15

4. Querques G, Sacconi R, Gelormin F, et al. Subthreshold laser treatment for reticular pseudodrusen secondary to age-related macular degeneration. Sci Rep. 2021;11(1):2193. doi:10.1038/s41598-021-81810-7

5. Lotery A, Sivaprasad S, O’Connell A, et al; VICI trial investigators. Eplerenone for chronic central serous chorioretinopathy in patients with active, previously untreated disease for more than 4 months (VICI): a randomised, double-blind, placebo-controlled trial. Lancet. 2020;395(10220):294-303. doi:10.1016/S0140-6736(19)32981-2

6. van Dijk EHC, Fauser S, Breukink MB, et al. Half-dose photodynamic therapy versus high-density subthreshold micropulse laser treatment in patients with chronic central serous chorioretinopathy. Ophthalmology. 2018;125(10):1547-1555. doi:10.1016/j.ophtha.2018.04.021

7. Toto L, D’Aloisio R, Quarta A, et al. Intravitreal dexamethasone implant (IDI) alone and combined with navigated 577 nm subthreshold micropulse laser (SML) for diabetic macular oedema. J Clin Med. 2022;11(17):5200. doi:10.3390/jcm11175200