Pterygopalatine Ganglion Stimulation for the Treatment of Geographic Atrophy

N/ANot Yet RecruitingNCT07570355

Shanghai Institute of Acupuncture, Moxibustion and Meridian62 enrolled

Overview

The goal of this clinical trial is to evaluate the feasibility and safety of pterygopalatine ganglion (PPG) stimulation in adults with geographic atrophy (GA) secondary to age-related macular degeneration (AMD). The main questions it aims to answer are: Is PPG stimulation feasible to implement, as reflected by participant adherence to the intervention and completion of follow-up assessments? Is PPG stimulation safe, as assessed by the incidence of adverse events and clinical ophthalmic examinations? What are the preliminary effects of PPG stimulation on choroidal perfusion, retinal sensitivity, visual acuity, and the progression of GA lesion area? Researchers will compare active PPG stimulation with sham stimulation (a procedure that mimics the intervention without delivering real stimulation) to assess feasibility and safety, while exploring potential therapeutic effects. Participants will: Receive active or sham PPG stimulation according to randomization over a 12-month study period Attend scheduled clinic visits for safety monitoring and multimodal ophthalmic assessments Undergo examinations including optical coherence tomography (OCT), fundus autofluorescence imaging, microperimetry, and visual acuity testing

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

Conditions

Geographic Atrophy

Interventions

Pterygopalatine ganglion stimulationPROCEDURE

Electrical stimulation was delivered using a disposable sterile needle electrode (0.30 × 60 mm; Beijing Keyuan Medical Devices Co., Ltd., China). Under ultrasound guidance, the needle tip was advanced into the pterygopalatine fossa. Ipsilateral pterygopalatine ganglion stimulation was administered to the study eye using an intermittent waveform at a frequency of 5 Hz and a current intensity of 1-2 mA for 10 minutes. The stimulation intensity was adjusted to elicit a mild local electrical sensation as perceived by the participant.

Sham pterygopalatine ganglion stimulationPROCEDURE

During sham stimulation, a disposable stainless steel needle (0.25 × 25 mm) was inserted superficially at the same anatomical location as in the active stimulation group, to a depth of approximately 2 cm. Ultrasound guidance was applied in an identical manner to that used in the active intervention to mimic the procedural experience. However, the internal circuitry of the stimulation device was disconnected to prevent current delivery. The device interface continued to display real-time parameters, including current intensity, frequency, and stimulation duration, thereby maintaining the appearance of active operation.

Eligibility

Sex: ALLMin age: 50 YearsMax age: 80 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Best-corrected visual acuity (BCVA), as measured using the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, ranging from 25 to 80 letters (Snellen equivalent, 20/320 to 20/25). * A confirmed diagnosis of geographic atrophy (GA) secondary to age-related macular degeneration (AMD), with no involvement of the foveal center. Fundus autofluorescence (FAF) imaging must demonstrate a total GA area of 2.5 to 17.5 mm² located within a 30° field centered on the fovea, with the presence of any pattern of increased autofluorescence at the junctional zone of GA. In cases of multifocal GA, at least one lesion must be ≥1.25 mm² in size. * If both eyes meet the eligibility criteria, the eye with the worse BCVA will be selected as the study eye. If BCVA is equal in both eyes, the right eye will be designated as the study eye. Exclusion Criteria: * History or evidence of submacular surgery or other treatments for AMD in the study eye, with the exception of oral vitamin and mineral supplementation. * History of intraocular surgery within 3 months prior to screening, or the presence of ocular conditions requiring surgical intervention during the study period. * Receipt of any periocular or intravitreal injection therapy in the study eye within 3 months prior to screening. * History or evidence of choroidal neovascularization in either eye, or the presence of any other retinal disease that may confound the assessment of macular structure or function (e.g., diabetic retinopathy or pathologic myopia). * Presence of severe systemic disease or any other condition deemed unsuitable for study participation. * Inability to comply with scheduled visits or complete study procedures due to cognitive impairment or other factors, as judged by the investigator.

Outcomes

Primary Outcomes

Proportion of participants who completed the trial

Proportion of participants who were successfully randomized to either intervention group, fully adhered to the assigned intervention protocol, and completed all scheduled follow-up assessments.

Time frame: At 12 months

Secondary Outcomes

Incidence of adverse events

Time frame: From enrollment to 12 months

Choroidal structure

Time frame: -7 to 0 days, 1, 3, 6, 9, and 12 months

Retinal sensitivity

Time frame: Baseline (0), 6 months, and 12 months

Standard and low-luminance best corrected visual acuity

Time frame: -7 to 0 days, 1, 3, 6, 9, and 12 months

Geographic atrophy lesion area and square root-transformed geographic atrophy area

Time frame: -7 to 0 days, 6 months, and 12 months

Contrast sensitivity

Time frame: Baseline (0), 1, 3, 6, 9, and 12 months

25-item National Eye Institute Visual Function Questionnaire score

Vision-related quality of life was assessed using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25). This corresponds to a score between 0 and 100, with higher scores indicating better visual quality of life

Time frame: Baseline (0), 6 months, and 12 months

Treatment credibility scale score

Assessed by asking participants to rate their response to five questions on a 10-point treatment credibility scale developed by Borkovec and Nau. Higher scores represent higher expectations of efficacy.

Time frame: 1 week and 12 months