Impact of Anterior Clinoid Process Pneumatization on Optic Canal and Retinal Nerve Fiber Layer

February 27, 2026 updated by: Sinem Keser, Elazıg Fethi Sekin Sehir Hastanesi

Evaluation of the Effects of Anterior Clinoid Process Pneumatization on Optic Canal Morphometry and Retinal Nerve Fiber Layer Thickness Using Computed Tomography and Optical Coherence Tomography: A Retrospective Cohort Study

This retrospective cohort study aims to evaluate the potential effects of anterior clinoid process (ACP) pneumatization on optic canal morphometry and retinal nerve fiber layer (RNFL) thickness. ACP pneumatization is an anatomical variation that may alter the morphology of the optic canal and potentially influence the optic nerve.

Patients aged 18-65 years with available head and neck computed tomography (CT) imaging and optical coherence tomography (OCT) examinations between August 2018 and July 2025 will be retrospectively reviewed. Optic canal length and diameter will be measured using CT images, and RNFL thickness parameters will be obtained from OCT records. Measurements will be compared between patients with and without ACP pneumatization.

Study Overview

Status

Completed

Conditions

Study Type

Observational

Enrollment (Actual)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Turkey (Türkiye)
- - Elâzığ, Turkey (Türkiye)
    - Fethi Sekin City Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Adult
Older Adult

Accepts Healthy Volunteers

Sampling Method

Non-Probability Sample

Study Population

This study population consists of adult patients aged 18 to 65 years who underwent both head and neck computed tomography (CT) imaging and optical coherence tomography (OCT) examinations at Elazığ Fethi Sekin City Hospital between August 2018 and July 2025. Patients will be retrospectively identified through the hospital electronic medical record and PACS archive systems. Participants will be categorized based on the presence or absence of anterior clinoid process (ACP) pneumatization on CT imaging.

Description

Inclusion Criteria:

Adults aged 18 to 65 years.
Availability of head and neck computed tomography (CT) imaging in the hospital archive.
Availability of optical coherence tomography (OCT) examination records in the hospital archive.
CT and OCT examinations performed between August 2018 and July 2025.

Exclusion Criteria:

Age <18 years or >65 years. History or evidence of diabetes mellitus. History or evidence of hypertension. Glaucoma. Any condition or diagnosis that may cause optic nerve pathology (e.g., optic neuritis, compressive optic neuropathy, optic atrophy, demyelinating disease affecting the optic nerve).

Inadequate image quality or incomplete CT/OCT data preventing reliable measurements.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
ACP Pneumatization Present Participants with radiologically confirmed anterior clinoid process (ACP) pneumatization identified on computed tomography imaging.
ACP Pneumatization Absent Participants without radiological evidence of anterior clinoid process (ACP) pneumatization on computed tomography imaging.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Optic Canal Length Time Frame: Baseline (retrospective review of CT images obtained between August 2018 and July 2025)	Optic canal length measured on computed tomography (CT) images.	Baseline (retrospective review of CT images obtained between August 2018 and July 2025)
Optic Canal Mean Diameter Time Frame: Baseline (retrospective review of CT images obtained between August 2018 and July 2025)	Optic canal mean diameter measured on computed tomography (CT) images.	Baseline (retrospective review of CT images obtained between August 2018 and July 2025)
Retinal Nerve Fiber Layer (RNFL) Thickness Time Frame: Baseline (retrospective review of OCT images obtained between August 2018 and July 2025)	Peripapillary retinal nerve fiber layer thickness measured by optical coherence tomography (OCT).	Baseline (retrospective review of OCT images obtained between August 2018 and July 2025)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Elazıg Fethi Sekin Sehir Hastanesi

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 1, 2025

Primary Completion (Actual)

January 25, 2026

Study Completion (Actual)

February 1, 2026

Study Registration Dates

First Submitted

February 20, 2026

First Submitted That Met QC Criteria

February 27, 2026

First Posted (Actual)

March 5, 2026

Study Record Updates

Last Update Posted (Actual)