Refractive ErrorsNCT07241806
Measurment of Optic Disc Parameters, RNFL Thickness and Ganglion Cell Complex in Myopic, Hypermetropic and Emmetropic Patients Using OCT and Axial Length Measurments
An observational study of Refractive Errors, run by Assiut University.
Trial summary
To evaluate the optic disc parameters, thickness of ganglion cell complex (GCC), and thickness of peripapillary retinal nerve fiber layer (RNFL) in myopic and hyperopic and emmetrop patients using optical coherence tomography (OCT), and to correlate these changes with axial length and degree of refractive error. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Refractive Errors
- What is being tested?
- OCT
- Type of treatment
- Medical device
- How many people
- 266 participants
- Where
- No sites listed yet
- Study dates
- Jan 2026to Dec 2027
- Phase
- Observational
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adults age starting from 18 years old Diagnosed with myopia (≤ -0.50 D) or hyperopia (≥ +0.50 D) Clear ocular media for high-quality OCT imaging No prior ocular surgeries Willing to provide informed consent IOP below 21 exculuding Presence of glaucoma or optic nerve pathologies Retinal diseases or degenerative changes Systemic diseases affecting the eye (e.g., diabetes, hypertension) History of trauma or intraocular surgery High astigmatism (> ±2.00 D) Poor OCT image quality
Who may be able to join
- Adults age starting from 18 years old Diagnosed with myopia (≤ -0.50 D) or hyperopia (≥ +0.50 D) Clear ocular media for high-quality OCT imaging No prior ocular surgeries Willing to provide informed consent IOP below 21
Who cannot join
- Presence of glaucoma or optic nerve pathologies Retinal diseases or degenerative changes Systemic diseases affecting the eye (e.g., diabetes, hypertension) History of trauma or intraocular surgery High astigmatism (> ±2.00 D) Poor OCT image quality
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Correlation Between Axial Length and Degree of Refractive Error With Optic Disc Parameters , Ganglion Cell Complex and Peripapillary RNFL Thickness
To evaluate the optic disc parameters, thickness of ganglion cell complex (GCC), and thickness of peripapillary retinal nerve fiber layer (RNFL) in myopic and hyperopic and emmetrop patients using optical coherence tomography (OCT), and to correlate these changes with axial length and degree of refractive error.
Read the detailed description
Refractive errors, particularly myopia and hyperopia, are among the most common ocular conditions globally, affecting both children and adults .
Myopia is frequently associated with axial elongation, which may induce structural changes in the posterior segment of the eye such as thinning of the peripapillary retinal nerve fiber layer (RNFL) and alteration of optic disc parameters . Hyperopia, conversely, is linked to shorter axial lengths and has been shown to affect retinal and optic nerve anatomy in distinct ways .
Optical coherence tomography (OCT), particularly spectral-domain OCT (SD-OCT), allows for high-resolution imaging of the RNFL and ganglion cell complex (GCC), which are crucial for visual processing. These layers are known to undergo subtle changes not only due to disease processes like glaucoma or optic neuropathies but also as a result of anatomical differences induced by refractive status .
While many studies have independently evaluated RNFL or GCC in myopic and hyperopic patients, few have directly compared these two refractive states while correlating structural findings with axial length and refractive error magnitude . Including an emmetropic control group provides a normative benchmark, enhancing the clinical relevance of the findings .
This study seeks to fill this gap by offering a comparative structural analysis using OCT, aiming to enhance diagnostic sensitivity and understanding of optic nerve and macular changes in various refractive profiles.
- Conditions
- Refractive Errors
- Being tested
- OCT
- Medical subject headings
- Refractive Errors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OCTDevice
Axial length measurement (using A-scan)
Spectral-domain OCT: All the patients will undergo OCT imaging using NIDEK RS-330 Retina scan duo 2 (SD-OCT)(CO-LTD made in Japan 2017) with scan speed 70.000 axial scans per second and wavelength of 880 nm for:
Peripapillary RNFL thickness in all quadrants GCC thickness (average, superior, inferior,nasal,temporal) Optic disc parameters (disc area, cup/disc ratio, rim area)
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the optic disc parameters, thickness of ganglion cell complex (GCC), and thickness of peripapillary retinal nerve fiber layer (RNFL) in myopic and hyperopic and emmetrop patients using optical coherence tomography (OCT)
To evaluate the optic disc parameters, thickness of ganglion cell complex (GCC), and thickness of peripapillary retinal nerve fiber layer (RNFL) in myopic and hyperopic and emmetrop patients using optical coherence tomography (OCT)
Measured: two years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Nov 2025
- Study startJan 2026 (estimated)
- Primary completionNov 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for Refractive ErrorsStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 266 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mariam Smeh Roshdy, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07241806
- Sponsor's protocol ID
- OCT in refractive error
- Status last verified
- Nov 2025
- First submitted
- 17 Nov 2025
- Last updated
- 21 Nov 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Holden BA, Fricke TR, Wilson DA, Jong M, Naidoo KS, Sankaridurg P, Wong TY, Naduvilath TJ, Resnikoff S. Global Prevalence of Myopia and High Myopia and Temporal Trends from 2000 through 2050. Ophthalmology. 2016 May;123(5):1036-42. doi: 10.1016/j.ophtha.2016.01.006. Epub 2016 Feb 11.
PubMed 26875007Chen Y, Li X, Wang J, et al. Recent large-sample findings reinforcing the relationship between myopia (axial elongation) and reduced RNFL thickness, with discussion of magnification correction. Sci Rep. 2024;14(1):12567.
Wu Z, Huang J, Wang Y, et al. Retinal structural changes associated with high refractive errors: A comparative OCT analysis. Eye (Lond). 2024;38(1):112-120.
Hougaard JL, Wang M, Fjeldstad JS. Quantitative OCT findings in high myopia and hyperopia. Acta Ophthalmol. 2023;101(4):e315-e322.
Liu S, Chen J, Xu Y, Li Y, Zhang X. Effects of refractive error on GCC and RNFL thickness: a meta-analysis. Eye Vis (Lond). 2023;10(1):14
Wang D, Zhang Y, Chen H, Li L, Zhou Y. Evaluation of RNFL thickness in hyperopic eyes: a comparative OCT-based study. Int J Ophthalmol. 2022;15(4):599-605.
. Leung CK, Yu M, Weinreb RN, Mak HK, Lai G, Ye C, et al. Impact of axial length on optic disc and retinal nerve fiber layer measurements. Invest Ophthalmol Vis Sci. 2011;52(1):291-9.
. Kim M, Choi EH, Lee HS, Park SW, Kim JH, Yu YS. Peripapillary and macular retinal thickness in high myopia measured with OCT. BMC Ophthalmol. 2020;20(1):285.