Optic Nerve Injury in Obstructive Sleep Apnea Patients

Optic Nerve Injury and the Effect of CPAP Treatment in Obstructive Sleep Apnea Patients

Ischemic optic neuropathy (ION) is damage to the optic nerve caused by ischemia and hypoxia of the optic nerve due to an impairment of the blood supply to the optic nerve from the arteries. Obstructive Sleep Apnea Hypoventilation Syndrome (OSAHS) is a sleep-breathing disorder characterized by recurrent upper airway obstruction and apnea during sleep, leading to recurrent intermittent hypoxemia with fragmented sleep and daytime sleepiness. Due to the lack of accurate methods to evaluate blood flow, the correlation between the two is unclear and uncertain. The study will enroll 80 patients from the First Affiliated Hospital of Nanjing Medical University and categorize them into mild, moderate, and severe OSA groups according to their apnea-hypopnea index (AHI). Participants will undergo a baseline evaluation, including polysomnography (PSG) and ophthalmologic examinations such as optic nerve and macular blood flow OCT, visual acuity, refraction, intraocular pressure, and visual fields. Eligible patients will be treated with CPAP for 3 months, after which their PSG and ophthalmologic examination-related results will be re-evaluated to assess treatment efficacy.

Study Overview

• Status: Recruiting
• Conditions: Obstructive Sleep Apnea (OSA); Ischemic Optic Neuropathy/Optic Nerve Stroke
• Intervention / Treatment: Device: CPAP Treatment

Detailed Description

Ischemic optic neuropathy (ION) is damage to the optic nerve caused by ischemia and hypoxia in the optic nerve due to impairment of the blood supply of the arteries supplying the optic nerve. ION is an important blinding eye disease. It has been found that patients with OSAHS are often misdiagnosed as having normotensive glaucoma due to chronic hypoxia resulting in optic nerve ischemia and hypoxia, leading to the development of ION. However, the correlation between the two has been poorly studied and is uncertain due to the lack of accurate methods to evaluate blood flow.

The study will enroll 80 patients from the First Affiliated Hospital of Nanjing Medical University between the ages of 18-80 years. Participants will be diagnosed with OSA according to established guidelines and must be first-time visitors with no prior history of OSA surgery or CPAP treatment. Patients with severe cerebrovascular disease, psychiatric disorders, diagnosed diabetes mellitus with severe vascular complications, severe COPD, pulmonary hypertension, heart failure, or pregnancy will be excluded.

All participants will undergo a polysomnography (PSG) to determine the Apnea Hypopnea Index (AHI) and will be categorized into mild, moderate, or severe OSA groups. Ophthalmologic-related examinations will be performed to measure ocular parameters such as optic nerve and macular blood flow OCT, visual acuity, refraction, intraocular pressure (IOP), visual fields, and IOLMaster measurements of the eye axis.

Eligible patients will receive CPAP treatment for 3 months. After 3 months of CPAP treatment, participants will undergo another PSG examination with ophthalmologic correlation to re-evaluate sleep parameters and ocular parameters.

The collected data will be analyzed using SPSS software. Correlation analysis will be performed to assess the relationship between AHI, minimum SPO2, hypoxic load, respiratory load, blood pressure variability, heart rate variability, pulse wave amplitude decline index, ESS drowsiness score, and the following ophthalmologic parameters: optic nerve and macular blood flow OCT, visual acuity, refraction, intraocular pressure, visual field, and eye axis as measured by IOLMaster. Paired t-tests will be performed to analyze the changes in the above indexes before and after CPAP treatment; ANOVA with repeated measurements will be performed to analyze the long-term changes in the above indexes.

The aim of this study is to analyze the relationship between sleep apnea severity hypoxia indexes and ION in OSAHS patients. To analyze the improvement of ischemic optic neuropathy (ION) after 3 months of CPAP treatment and to establish a long-term cohort to observe the occurrence of ION in patients with OSA of different severities, as well as the improvement of ION with long-term CPAP treatment.

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ning Ding,MD,PhD; Phone Number: 86-25-68136723; Email: dr.ningding@live.cn

Study Locations

• China
  • Jiangsu
    • Nanjing, Jiangsu, China, 210029
      • Recruiting
      • the First Affiliated Hospital of Nanjing Medical University
      • Contact: Ning Ding, doctor; Phone Number: 86-25-68136723; Email: dr.ningding@live.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Patients aged between 18 and 80 years.
2. Diagnosed with Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS)(apnea-hypopnea index≥5/h).
3. First-time diagnosis, with no previous surgical interventions or CPAP treatment for OSA.
4. Ability and willingness to provide informed consent for participation in the study.

Exclusion Criteria:

1. History of severe stroke or cerebral hemorrhage, or presence of neurological or psychiatric conditions that could affect study results.
2. Presence of active malignancies or other severe underlying diseases, such as severe liver or kidney dysfunction. Diagnosed with diabetes or other significant vascular diseases.
3. Presence of severe chronic obstructive pulmonary disease (COPD), severe asthma, severe pulmonary hypertension, or heart failure caused by any condition.
4. Pregnancy or having other conditions that make participation in this study unsuitable.
5. Extremely debilitated patients or those with severe underlying conditions.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: CPAP Treatment Group; Patients with Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) who are eligible for CPAP therapy.	Device: CPAP Treatment; CPAP therapy will be administered to patients for 3 months. The CPAP device will be set to deliver a continuous flow of air at a prescribed pressure to keep the patient's airway open during sleep.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Optic nerve and macular blood flow	Changes in optic nerve and macular blood flow in patients with OSA of varying severity were measured using blood flow optical coherence tomography (blood flow OCT).	Baseline and 3 months of CPAP therapy
Apnea Hypopnea Index (AHI)	Number of apneas and hypoventilations per hour of sleep	Baseline and 3 months of CPAP therapy
Hypoxic Burden（HB）	The sum of the area between the SpO2 trace and the desaturation baseline associated with all apnoea and hypopnoea events is divided by the total time of sleep.	Baseline and 3 months of CPAP therapy
Ventilatory burden	The average ventilatory burden per event was defined as the multiplication of the average ventilation during the respiratory event and average duration of respiratory events. The total ventilatory burden for each participant was defined as the multiplication of respiratory event rate and average ventilatory area per event.	Baseline and 3 months of CPAP therapy
Blood pressure variability	The main studies were on ultrashort-term variability (blood pressure variability between each heart beat) and short-term variability (blood pressure variability over a 24-hour period).	Baseline and 3 months of CPAP therapy
Heart rate variability	Heart rate variability (HRV) is the variation of differences between consecutive cardiac cycles. For example, the standard deviation of NN intervals in 24 h (SDNN), the standard deviation of the mean of NN intervals per 5 min (SDANN), and the SDNN during wakefulness and sleep.	Baseline and 3 months of CPAP therapy
Pulse Wave Amplitude Drops Index	The number of decreases (>30%) in pulse wave amplitude per hour detected by pulse oximetry based on photoplethysmographic volumetric tracing (PPG) signals during sleep.	Baseline and 3 months of CPAP therapy

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time below 90% Saturation	Percentage of total time with oxygen saturation below 90% of total monitoring time.	Baseline and 3 months of CPAP therapy
Lowest SpO2 at night	The lowest SpO2 value recorded during the nightly test.	Baseline and 3 months of CPAP therapy
Mean SpO2	Mean SpO2 values during nighttime monitoring.	Baseline and 3 months of CPAP therapy
Oxygen Desaturation Index	The number of oxygen desaturation events per hour of sleep.The desaturation thresholds of 3% (ODI3) or 4% (ODI4) are commonly chosen in the analysis of OSA.	Baseline and 3 months of CPAP therapy
Vision	The patient's naked eye visual acuity in the right and left eyes was checked using a visual acuity chart.	Baseline and 3 months of CPAP therapy
Diopter	Qualitative and quantitative analysis of the refractive status of the eye under test using computerized optometry.	Baseline and 3 months of CPAP therapy
Intraocular pressure	Measurement of intraocular pressure (IOP) in the eye under test using a non-contact tonometer.	Baseline and 3 months of CPAP therapy
Field of view	An automated visual field meter was used to detect the total loss of the visual field and the extent and depth of limiting defects in the tested eye.	Baseline and 3 months of CPAP therapy
Axon of the eye	The IOLMaster was utilized to measure the eye axis of the tested eye.	Baseline and 3 months of CPAP therapy

Collaborators and Investigators

• Sponsor: Nanjing Medical University

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2025
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): January 31, 2026

Study Registration Dates

• First Submitted: December 19, 2024
• First Submitted That Met QC Criteria: December 19, 2024
• First Posted (Actual): December 27, 2024

Study Record Updates

• Last Update Posted (Actual): June 27, 2025
• Last Update Submitted That Met QC Criteria: June 24, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Obstructive Sleep Apnea; CPAP treatment; Nonarteritic Ischemic Optic Neuropathy
• Additional Relevant MeSH Terms: Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Wounds and Injuries; Respiratory Tract Diseases; Respiration Disorders; Eye Diseases; Sleep Wake Disorders; Signs and Symptoms, Respiratory; Sleep Disorders, Intrinsic; Dyssomnias; Craniocerebral Trauma; Trauma, Nervous System; Cranial Nerve Diseases; Cranial Nerve Injuries; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Apnea; Optic Nerve Diseases; Optic Neuropathy, Ischemic; Optic Nerve Injuries
• Other Study ID Numbers: 2024-SR-204

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The individual participant data will not be shared. The informed consent will be ansigned before enrolled in the study and ensured to keep personal information confidential.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No