An observational study in Refractive Errors, sponsored by Assiut University. Not yet recruiting. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-21.
Sponsored by Assiut University · Observational
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.
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.
420 studies on the registry are indexed under Refractive Errors; 59 are open to participants now.
This study's planned enrollment of 266 is above the median of 150 across 108 observational studies indexed under Refractive Errors.
Browse Refractive Errors studies →Assiut University is the lead sponsor of 5,078 studies on the registry; 2,178 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 0 (0%) have results posted.
Counted across the registry records on this site, refreshed daily.
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
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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)
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)
Time frame: two years
No study locations are listed for this record.
Plan to share: Undecided
Start is estimated for Jan 2026; primary completion for Nov 2027, 22 months later.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.