Subclinical Optic Nerve Changes After Le Fort I Osteotomy
Evaluation of Subclinical Optic Nerve Head Changes After Le Fort I Osteotomy Using Retinal Nerve Fiber Layer Optical Coherence Tomography
Le Fort I osteotomy is a common jaw surgery that includes a step called pterygomaxillary dysjunction, during which force applied with a surgical instrument (osteotome) can be transmitted toward the eye socket (orbit) and the optic nerve canal. Serious eye complications after this surgery are rare, but it is not known whether smaller, subclinical changes occur in the optic nerve that go unnoticed without special testing. This study uses a non-invasive eye imaging test called optical coherence tomography (OCT) to measure the thickness of the nerve fiber layer around the optic nerve, before and after Le Fort I surgery, to find out whether such changes occur.
Study Overview
Status
Conditions
Detailed Description
Fifty patients aged 18-45 years scheduled for isolated Le Fort I osteotomy or Le Fort I osteotomy combined with bilateral sagittal split osteotomy (BSSO) will be enrolled in this single-center, prospective, observational cohort study. Each patient serves as their own control (within-subject comparison across time points). All participants will undergo ophthalmologic examination, RNFL-OCT imaging, optic disc morphology assessment (disc area, elongation ratio, presence of disc head hemorrhage), and Humphrey 30-2 visual field testing at three time points: preoperatively (T0, within 1 week before surgery), 1 week postoperatively (T1), and 3 months postoperatively (T2). All ophthalmologic measurements will be performed by a single examiner blinded to intraoperative surgical details, using the same device throughout. Maxillary advancement amount and pterygomaxillary junction depth/concavity angle will be measured preoperatively on CBCT (pterygomaxillary junction measured bilaterally, with Observer 1 measuring twice for intraobserver reliability and Observer 2 measuring once for interobserver reliability). No intervention, randomization, or treatment-group allocation occurs as part of this study; all participants receive their routine, already-planned orthognathic surgical care. A priori power analysis (G*Power, RM ANOVA within-between interaction, f=0.25, epsilon=1, alpha=0.05, power=0.90) indicated a minimum required sample size of N=36; n=50 was set to allow for attrition.
Study Type
Enrollment (Estimated)
Contacts and Locations
Study Contact
- Name: Yağmur M Okumuş, Assistant Professor, DDS, Phd
- Phone Number: +90 5304054615
- Email: yagmur.malkoc@medipol.edu.tr
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Sampling Method
Study Population
Adult patients aged 18-45 years scheduled for isolated Le Fort I osteotomy or Le Fort I combined with bilateral sagittal split osteotomy (BSSO) at Istanbul Medipol University, with no pre-existing ocular or orbital pathology that could independently affect retinal nerve fiber layer thickness or optic disc morphology.'
Description
Inclusion Criteria:
Aged 18-45 years, able to provide written informed consent. Isolated Le Fort I osteotomy or Le Fort I + BSSO (bilateral sagittal split osteotomy) planned.
ASA Physical Status Classification I-II. Standard osteotome technique used for pterygomaxillary dysjunction. Sufficient ocular media clarity to permit OCT imaging.
Exclusion Criteria:
Known glaucoma, optic neuropathy, retinal disease, or other ocular pathology affecting the retinal nerve fiber layer.
Prior ocular/orbital surgery or trauma. Craniofacial syndrome (e.g., cleft lip/palate). Segmental Le Fort osteotomy or revision orthognathic surgery. Unwilling or unable to provide informed consent.
Study Plan
How is the study designed?
Design Details
- Observational Models: COHORT
- Time Perspectives: OTHER
Cohorts and Interventions
Group / Cohort |
Intervention / Treatment |
|---|---|
|
Le Fort I osteotomy cohort
Patients undergoing isolated Le Fort I osteotomy or Le Fort I combined with bilateral sagittal split osteotomy (BSSO). No randomization or treatment allocation; all participants receive their routine, already-planned orthognathic surgical care. Diagnostic Test: RNFL-OCT and optic disc morphology assessment (disc area, elongation ratio, disc head hemorrhage), performed preoperatively (T0) and at 1 week (T1) and 3 months (T2) postoperatively. Diagnostic Test: Humphrey 30-2 visual field testing, performed at the same three time points. Diagnostic Test: Preoperative CBCT measurement of pterygomaxillary junction depth and concavity angle, and maxillary advancement amount from surgical planning data. |
Peripapillary retinal nerve fiber layer thickness and optic disc morphology (disc area, elongation ratio, presence of disc head hemorrhage) measured by optical coherence tomography, performed preoperatively (T0) and at 1 week (T1) and 3 months (T2) postoperatively. Humphrey 30-2 Visual Field Testing Açıklama: Standard automated perimetry (Humphrey 30-2 program) performed at the same three time points (T0, T1, T2) to assess mean deviation and pattern standard deviation. Cone-beam computed tomography measurement of pterygomaxillary junction depth and concavity angle, and maxillary advancement amount from virtual surgical planning data, obtained preoperatively. |
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Change in Peripapillary Retinal Nerve Fiber Layer (RNFL) Thickness
Time Frame: Baseline (T0, preoperative) to 3 months (T2) postoperatively
|
Change in peripapillary retinal nerve fiber layer (RNFL) thickness, measured by optical coherence tomography (OCT), from baseline (T0, preoperative) to 1 week (T1) and 3 months (T2) after Le Fort I osteotomy. |
Baseline (T0, preoperative) to 3 months (T2) postoperatively
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Change in Optic Disc Area and Elongation Ratio
Time Frame: Baseline (T0) to 3 months (T2) postoperatively
|
Change in optic disc area and elongation ratio (vertical/horizontal), measured by OCT, from baseline (T0) to 1 week (T1) and 3 months (T2) after Le Fort I osteotomy. |
Baseline (T0) to 3 months (T2) postoperatively
|
Collaborators and Investigators
Sponsor
Investigators
- Study Director: Sina Uçkan, prof., Medipol University
Study record dates
Study Major Dates
Study Start (Estimated)
Primary Completion (Estimated)
Study Completion (Estimated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- IstanbulMUH-DF-YM-03
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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