The effect of two different anesthesia methods used for cataract surgery on the vascular structure of the optic nerve head
| ISRCTN | ISRCTN13084070 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN13084070 |
| Sponsor | Sağlık Bilimleri Üniversitesi |
| Funder | Investigator initiated and funded |
- Submission date
- 25/06/2026
- Registration date
- 26/06/2026
- Last edited
- 26/06/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Eye Diseases
Plain English summary of protocol
Background and study aims
Retrobulbar anesthesia and topical anesthesia are both commonly used during cataract surgery. Although retrobulbar anesthesia provides excellent pain control and prevents eye movement during surgery, concerns have been raised about its possible effects on the blood supply of the optic nerve. Optical coherence tomography angiography (OCTA) is a non-invasive imaging technique that can measure the tiny blood vessels around the optic nerve. The aim of this study is to compare changes in optic nerve head blood vessel density after cataract surgery in patients receiving retrobulbar anesthesia or topical anesthesia.
Who can participate?
Adults aged 50 years or older with age-related cataract who are scheduled to undergo routine phacoemulsification cataract surgery and are able to provide written informed consent.
What does the study involve?
Participants are randomly allocated to receive either topical anesthesia or retrobulbar anesthesia before cataract surgery. All participants undergo standard phacoemulsification with implantation of a monofocal intraocular lens. Eye examinations, including best-corrected visual acuity, intraocular pressure measurements, slit-lamp examination, and OCTA imaging, are performed one week before surgery and repeated at one week and one month after surgery.
What are the possible benefits and risks of participating?
Participants may not receive any direct medical benefit from taking part in the study. However, the information gained may improve understanding of the effects of different anesthesia techniques on the optic nerve and help guide future cataract surgery practice. The risks associated with participation are the same as those associated with routine cataract surgery and the anesthesia technique used. OCTA is a non-invasive imaging test and does not expose participants to radiation.
Where is the study run from?
Department of Ophthalmology, Gulhane Training and Research Hospital, University of Health Sciences, Ankara, Türkiye.
When is the study starting and how long is it expected to run for?
December 2025 to March 2026.
Who is funding the study?
Investigator initiated and funded. The study receives no external funding.
Who is the main contact?
Dr. Alper Can Yılmaz, dralpercnylmz@icloud.com
Contact information
Public, Scientific, Principal investigator
General Tevfik Saglam caddesi, no:1 Etlik/Ankara
Ankara
06010
Türkiye
 ORCID ID |
0000-0001-7554-0843 |
|---|---|
| Phone | +90 554 695 53 73 |
| dralpercnylmz@icloud.com |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Active |
| Assignment | Parallel |
| Purpose | Treatment |
| Scientific title | Quantitative assessment of radial peripapillary capillary plexus vessel density after retrobulbar block in cataract surgery |
| Study objectives | 1. To compare changes in radial peripapillary capillary (RPC) plexus vessel density measured by optical coherence tomography angiography (OCTA) between patients receiving retrobulbar anesthesia and those receiving topical anesthesia for phacoemulsification cataract surgery. 2. To evaluate longitudinal changes in RPC plexus vessel density from baseline to postoperative week 1 and month 1 within each anesthesia group. 3. To compare postoperative clinical outcomes, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), surgical duration, cumulative dissipated energy (CDE), and intraoperative and postoperative complications between the two anesthesia groups. |
| Ethics approval(s) |
Approved 23/12/2025, University of Health Sciences Scientific Research Ethics Committee (University of Health Sciences, General Tevfik Saglam Caddesi, No. 1, Ankara, 06010, Türkiye; +90 312 304 61 35; gulhane.baek@sbu.edu.tr), ref: 2025-578 |
| Health condition(s) or problem(s) studied | Assessment of the effects of retrobulbar versus topical anesthesia on optic nerve head microvasculature in patients undergoing phacoemulsification cataract surgery. |
| Intervention | Eligible participants are randomly allocated in a 1:1 ratio to receive either topical anesthesia (active comparator) or retrobulbar anesthesia (experimental intervention) before routine phacoemulsification cataract surgery. Randomization is performed using computer-generated random numbers (Microsoft Excel RAND function) by an independent investigator who is not involved in patient examination, image analysis, or statistical evaluation. Participants allocated to the topical anesthesia group receive topical 0.5% proparacaine hydrochloride ophthalmic drops immediately before surgery. Participants allocated to the retrobulbar anesthesia group receive an ultrasound-guided retrobulbar injection consisting of 4 mL of a local anesthetic mixture containing 40 mg/2 mL lidocaine and 0.025 mg/2 mL epinephrine after negative aspiration to avoid intravascular administration. All participants undergo standard phacoemulsification cataract surgery with implantation of a single-piece monofocal intraocular lens in the capsular bag. Optical coherence tomography angiography (OCTA) examinations are performed one week before surgery (baseline) and repeated at postoperative week 1 and month 1. Best-corrected visual acuity, intraocular pressure, and slit-lamp examinations are also performed at each scheduled visit. OCTA images are independently reviewed by two masked graders for image quality and segmentation accuracy before quantitative analysis. |
| Intervention type | Procedure/Surgery |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) | |
| Completion date | 07/03/2026 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 50 Years |
| Upper age limit | 90 Years |
| Sex | All |
| Target sample size at registration | 72 |
| Total final enrolment | 72 |
| Key inclusion criteria | 1. Adults aged 50 years or older with age-related cataract scheduled for phacoemulsification surgery 2. Presence of visually significant cataract requiring elective cataract surgery 3. Ability to undergo optical coherence tomography angiography (OCTA) with adequate image quality 4. Ability to provide written informed consent |
| Key exclusion criteria | 1. Previous intraocular surgery or ocular trauma 2. Corneal disorders affecting OCTA image quality, including corneal ectatic diseases or significant media opacity 3. Retinal vascular disease, age-related macular degeneration, high or degenerative myopia, or any other retinal pathology that could affect OCTA measurements 4. Glaucomatous or non-glaucomatous optic neuropathy 5. Systemic vascular diseases that could influence ocular microvascular measurements 6. Inability to obtain high-quality OCTA images or to complete the scheduled follow-up examinations |
| Date of first enrolment | 26/12/2025 |
| Date of final enrolment | 07/02/2026 |
Locations
Countries of recruitment
- Türkiye
Study participating centres
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | De-identified individual participant data underlying the results reported in this study will be made available upon reasonable request to the corresponding author, dralpercnylmz@icloud.com (Alper Can Yılmaz), subject to institutional policies and ethical approval. |
Editorial Notes
26/06/2026: Study’s existence confirmed by the University of Health Sciences Scientific Research Ethics Committee, Turkey.
