By InvitationNot Applicable

Retinal OCT Changes and Biomarkers in Drug-Resistant Epilepsy

Turkey (Türkiye)250 participantsStarted 2026-07-01

Plain-language summary

This prospective, longitudinal observational study investigates whether epilepsy involves a progressive neurodegenerative process. Retinal structural and microvascular changes assessed by optical coherence tomography (OCT) and optical coherence (OCTA) will be analyzed alongside inflammatory biomarkers (sCD14, sCD163, CCL2, IL-1β). The study aims to explore their association with epilepsy pathophysiology, clinical phenotype, prognosis, and drug-resistant epilepsy (DRE). Among participants with epilepsy, seizure severity and antiseizure medication-related adverse-effect burden will also be assessed longitudinally using the National Hospital Seizure Severity Scale (NHS3) and the Turkish version of Liverpool Adverse Events Profile (LAEP-TR).

Who can participate

Age range

18 Years – 40 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Age between 18 and 40 years * Ability to provide written informed consent * For the epilepsy group: diagnosis of epilepsy for at least 1 year * For the epilepsy group: treatment with at least one antiseizure medication for at least 1 year * For the disease-control group: diagnosis of migraine, analgesic-overuse headache, or neuralgia * For the disease-control group: current treatment with at least one antiseizure medication for a non-epileptic indication * For the disease-control group: no history of epilepsy or unprovoked seizures * For the healthy-control group: no history of epilepsy, major neurological disease, ophthalmological disease, or regular antiseizure medication use Exclusion Criteria: * Age younger than 18 years or older than 40 years * Inability or unwillingness to provide written informed consent * History of ocular surgery, ocular trauma, glaucoma, retinal disease, optic neuropathy, or severe refractive error, defined as spherical equivalent greater than ±6.0 diopters * Media opacity or poor image quality preventing reliable OCT or OCTA assessment * Vigabatrin or Valproate use * Multiple sclerosis, Parkinson's disease, dementia, brain tumor, stroke, optic neuritis, or other major neurological disorders * Evidence of visual pathway lesions on MRI * Diabetes mellitus, uncontrolled hypertension, or other systemic vascular, metabolic diseases that may affect retinal or OCTA parameters * Chronic alcohol or psychoactive substance abuse * Ina…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Annualized percentage change in peripapillary retinal nerve fiber layer thickness measured by OCT

Timeframe: Baseline to 18 months after enrollment.

Annualized percentage change in ganglion cell-inner plexiform layer thickness measured by OCT

Timeframe: Baseline to 18 months after enrollment

Difference in annualized percentage change in peripapillary retinal nerve fiber layer thickness between drug-resistant and non-drug-resistant epilepsy groups

Timeframe: Baseline to 18 months after enrollment.

Difference in annualized percentage change in ganglion cell-inner plexiform layer thickness between drug-resistant and non-drug-resistant epilepsy groups

Timeframe: Baseline to 18 months after enrollment.

Trial details

NCT IDNCT07716930

SponsorKemal Tutkavul

Sponsor typeOTHER

Study typeOBSERVATIONAL

Primary completion2028-01

View on ClinicalTrials.gov More Epilepsy (Treatment Refractory) trials

Plain-language summary

Who can participate

Age range

18 Years – 40 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

What they're measuring

Annualized percentage change in peripapillary retinal nerve fiber layer thickness measured by OCT

Timeframe: Baseline to 18 months after enrollment.

Annualized percentage change in ganglion cell-inner plexiform layer thickness measured by OCT

Timeframe: Baseline to 18 months after enrollment

Difference in annualized percentage change in peripapillary retinal nerve fiber layer thickness between drug-resistant and non-drug-resistant epilepsy groups

Timeframe: Baseline to 18 months after enrollment.

Difference in annualized percentage change in ganglion cell-inner plexiform layer thickness between drug-resistant and non-drug-resistant epilepsy groups

Timeframe: Baseline to 18 months after enrollment.