Rescue Photodynamic Therapy for Age-Related Macular Degeneration Refractory to Anti-Vascular Endothelial Growth Factor Monotherapy

Simulating PDT of port-wine stains in the in vivo chicken wattle model using Hemoporfin and radiation at 532 nm: Comparison of a LED and a laser source

Port-wine stain (PWS) birthmarks are congenital capillary malformations occurring in 0.3 %∼0.5 % of newborns. Hemoporfin-mediated vascular-acting photodynamic therapy (Hemoporfin PDT) is an emerging option for treating PWS. This in vivo study aimed to compare laser and light-emitting diodes (LED) as light source for Hemoporfin PDT. Chicken wattles were used as the animal model. Color and histopathological changes were evaluated after combining Hemoporfin with KTP laser or LED light source of 532 nm at the same doses. Both PDT approaches could induce significant vascular injury and color bleaching. Although the use of the laser resulted in a greater vascular clearance, the LED showed more uniform distribution both in the beam profiles and tissue reaction and exhibited better safety. This in vivo study suggests that the LED is a favorable choice for larger PWS lesion.

Evaluating photodynamic therapy versus brolucizumab as a second-line treatment for polypoidal choroidal vasculopathy

BACKGROUND

To compare the one-year outcomes between intravitreal brolucizumab (IVBr) monotherapy and photodynamic therapy (PDT) as a second-line treatment in patients with polypoidal choroidal vasculopathy (PCV) who did not respond to first-line therapy.

METHODS

This case-control study included eyes with PCV that do not respond to aflibercept or ranibizumab. The patients were retrospectively registered. We compared outcomes, including best-corrected visual acuity (BCVA), anatomical results, and the need for additional treatments, between IVBr and a combination therapy using PDT as second-line treatments for refractory PCV, after adjusting for potential confounders. We analyzed E-values to evaluate the robustness of the results against unmeasured confounders.

RESULTS

Twenty-two eyes received IVBr, and twenty-four underwent PDT. No apparent differences were observed in BCVA and central macular thickness (CMT) changes from baseline between the groups (IVBr vs. PDT: BCVA, 0.01 ± 0.47 logMAR vs. 0.04 ± 0.18 logMAR, P-value = 0.756; CMT: - 36.3 ± 99.4 μm vs. - 114.7 ± 181.4 μm, P-value = 0.146). Only in the PDT group, five eyes (20.8%) did not require additional treatment after the second-line treatment, the adjusted odds ratio indicating no further treatment needed was 11.98 (95% confidence interval: 1.42-2070.07, P-value = 0.019). The E-value for the adjusted odds ratio was 23.44.

CONCLUSIONS

Both second-line treatments for PCV exhibited similar visual and anatomical outcomes. Only in the PDT-treated eyes were there some patients who did not require further treatment after second-line therapy.

Age-Related Macular Degeneration - Therapies and Their Delivery

Age-related macular degeneration (ARMD) is a degenerative ocular disease that is the most important cause of irreversible vision loss in old-aged people in developed countries. Around fifty percent of vision impairments in developed countries are due to ARMD. It is a multifaceted disease that is associated with both genetic and environmental risk factors. The most important treatments option for ARMD includes laser photocoagulation, photodynamic therapy (PDT), Anti-VEGF Injections, and combination therapies. In this review, we also propose that topical ocular drug delivery with nanocarriers has more attention for the treatment of ARMD. The nanocarriers were specially designed for enhanced corneal residential time, prolonged drug release and action, and minimizing the frequency of administrations. Different types of nanocarriers were developed for the topical ocular delivery system, such as nanomicelles, nanoemulsions, nanosuspensions, liposomes, and polymeric nanoparticles. These topical ocular nanocarriers were administered topically, and they can fix the hydrophobic substances, increase solubility and improve the bioavailability of an administered drug. Hence the topical ocular delivery systems with nanocarriers provide a safe and effective therapeutic strategy and promising tool for the treatment of posterior segment ocular diseases ARMD.

Twenty-year outcome in neovascular age-related macular degeneration treated with photodynamic therapy and intravitreal bevacizumab/ranibizumab injections: a case report

A 64-year-old female presented with acute painless vision loss in the left eye was diagnosed with neovascular age-related macular degeneration. During the 20-year follow-up, the patient experienced subretinal fluid, subretinal hemorrhage, pigmentary epithelium detachment, intraretinal fluid, subretinal scar formation and macular atrophy. A total of 3 PDT treatments, 3 intravitreal bevacizumab and 16 ranibizumab injections were performed in the left eye. At the last visit, she remained best-corrected visual acuity of 20/200 with foveal macular atrophy and subfoveal fibrotic scar.

Increased PDT Efficacy When Associated with Nitroglycerin: A Study on Retinoblastoma Xenografted on Mice

Purposes: The aim of the study was to assess the efficacy of a treatment protocol that combines photodynamic therapy (PDT) and nitroglycerin (NG) on human retinoblastoma tumors xenografted on mice. We aimed to increase the PDT efficiency (in our least treatment-responsive retinoblastoma line) with better PS delivery to the tumor generated by NG, which is known to dilate vessels and enhance the permeability and retention of macromolecules in solid tumors. Methods: In vivo follow-up of the therapeutic effects was performed by sodium MRI, which directly monitors variations in sodium concentrations non-invasively and can be used to track the tumor response to therapy. NG ointment was applied one hour before PDT. The PDT protocol involves double-tumor targeting, i.e., cellular and vascular. The first PS dose was injected followed by a second one, separated by a 3 h interval. The timelapse allowed the PS molecules to penetrate tumor cells. Ten minutes after the second dose, the PS was red-light-activated. Results: In this study, we observed that the PDT effect was enhanced by applying nitroglycerin ointment to the tumor-bearing animal’s skin. PDT initiates the bystander effect on retinoblastomas, and NG increases this effect by increasing the intratumoral concentration of PS, which induces a higher production of ROS in the illuminated region and thus increases the propagation of the cell death signal deeper into the tumor (bystander effect).