Assessing retinal sensitivity after removing silicone oil

ISRCTN	ISRCTN43187564
DOI	https://doi.org/10.1186/ISRCTN43187564
Secondary identifying numbers	N/A

Submission date: 19/10/2018
Registration date: 19/11/2018
Last edited: 28/05/2019

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Eye Diseases

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Background and study aims
The retina is the thin layer at the back of the eye that contains the light-sensing cells. Retinal detachment is when this layer separates from the layer behind that contains blood vessels and other cells that support the survival of the light-sensing cells. Retinal detachment must be treated quickly to prevent vision loss. It is commonly managed by a vitrectomy procedure (removing some of the liquid in the eyeball) with the injection of silicone oil to hold the retina in place while it reattaches to the underlaying layer, but the oil may affect retinal function. Therefore removing the oil after the retina has healed might result in improved vision. This study aims to investigate whether the sensitivity of the retina to light is affected by silicone oil by measuring sensitivity before and after silicone oil removal.

Who can participate?
Participants included any patient who underwent a vitrectomy (retinal surgery) for retinal detachment using a silicone oil tamponade (a heavy oil used to maintain the retina in its place). Participants eyes were examined before and after silicone oil removal.

What does the study involve?
The study involves a non-invasive investigation called microperimetry to assess retinal sensitivity. It also includes tests of vision and pressure in the eye.

What are the possible benefits and risks of participating?
Participants might benefit from more explanation of their surgery and more investigation if their sight has worsened. All the tests are non-invasive, so there was no additional risk from participating in the study.

Where is the study run from?
Cairo University Hospital

When is the study starting and how long is it expected to run for?
August 2016 to May 2017

Who is funding the study?
The investigators funded the study.

Who is the main contact?
Dr Hebatalla Makled, Lecturer of Ophthalmology, Kasr Al-Ainy teaching hospital.

Study website

Contact information

Dr Hebatalla Makled
Scientific

Ophthalmology department
Kasr Al-Ainy hospital
Faculty of Medicine- Cairo university
Cairo
11562
Egypt

ORCID ID	0000-0002-3834-2538

Dr Maha Youssef
Scientific

Ophthalmology department
Kasr Al-Ainy hospital
Faculty of Medicine- Cairo university
Cairo
11562
Egypt

ORCID ID	0000-0003-1637-056X

Study information

Study design	Observational prospective comparative study
Primary study design	Observational
Secondary study design	Prospective comparative
Study setting(s)	Hospital
Study type	Treatment
Participant information sheet	No participant information sheet available
Scientific title	Retinal sensitivity before and after silicone oil removal using microperimetry
Study objectives	To investigate the effect of silicone oil on the retina through assessment of retinal sensitivity, using microperimetry, before and after silicone removal.
Ethics approval(s)	Cairo University Ophthalmology department ethics board, 17/10/2016. No reference number.
Health condition(s) or problem(s) studied	Rhegmatogenous retinal detachment
Intervention	All participants received microperimetry examination one day prior to and one month after silicone oil removal. Silicone oil removal was performed using an infusion-extraction technique with two standard sclerotomies. During microperimetry, participants were examined in a dark room for 15 minutes with occlusion of the non-tested eye. They were asked to fixate on a central target. A customised pattern centered on the central 11º was used, after auto-correction of patient's refractive error by the machine, with the following features: Goldmann III stimulus size, 200 millisecond stimulus duration, a 1500 millisecond interval between stimuli and a 4 – 2 strategy on a 1.27 cd/m² background. Retinal sensitivity was tested at 28 points: 4 stimuli at 2.3º, 12 stimuli at 6.6º and 12 stimuli at 11º. The stimulus level ranged between 0 dB and 20 dB. The total retinal sensitivity and sensitivity of each layer (inner, middle and outer) were assessed.
Intervention type	Procedure/Surgery
Primary outcome measure	Retinal sensitivity, assessed using microperimetry one day before silicone oil removal and one month after silicone oil removal.
Secondary outcome measures	The following are assessed one day prior to silicone oil removal and 1 day, 1 week, 2 weeks and 1 month after surgery: 1. Best corrected visual acuity (BCVA), assessed using a Snellen chart and converted into logMAR using statistical analysis 2. Intraocular pressure, assessed using the Goldmann applanation tonometer
Overall study start date	01/08/2016
Completion date	31/05/2017

Eligibility

Participant type(s)	Patient
Age group	Adult
Lower age limit	18 Years
Sex	Both
Target number of participants	22 (10 patients in group A, 12 patients in group B)
Total final enrolment	22
Key inclusion criteria	1. Macula off rhegmatogenous retinal detachment with any grade of proliferative vitreoretinopathy (PVR) 2. Pars plana vitrectomy (PPV) with silicone oil 5000 as a tamponading agent 3. Aged 18 years or older
Key exclusion criteria	1. Undergoing vitrectomies for proliferative diabetic retinopathy 2. Recurrent retinal detachments, 3. Macular holes, 4. Chorioretinal degenerations involving the macula 5. Developed the following complications following oil removal: 5.1. Visually significant cataracts 5.2. Secondary glaucoma with intraocular pressure (IOP) exceeding 26 mmHg 5.3. Silicone oil emulsification 5.4. Recurrent detachment 5.5. Hypotony
Date of first enrolment	01/11/2016
Date of final enrolment	30/04/2017

Locations

Countries of recruitment

Egypt

Study participating centre

Kasr Al-Ainy teaching hospital

Faculty of Medicine- Cairo University
Cairo
11562
Egypt

Sponsor information

Ophthalmology department, Kasr Al-Ainy hospital, Cairo University
University/education

Faculty of medicine
Kasr Al-Ainy street
Cairo
11562
Egypt

Website	www.medicine.cu.edu.eg
"ROR"	https://ror.org/03q21mh05

Funders

Funder type

Other

Investigator initiated and funded

No information available

Results and Publications

Intention to publish date	19/11/2018
Individual participant data (IPD) Intention to share	Yes
IPD sharing plan summary	Available on request
Publication and dissemination plan	We intend to publish our results in November 2018
IPD sharing plan	All the data used and/or analysed during the current study are available and can be presented by the corresponding author upon a reasonable request from Hebatalla Makled, MD (Lecturer of Ophthalmology, Kasr Al-Ainy Teaching Hospital, Faculty of Medicine, Cairo University) (dr.h.makled@hotmail.com)

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	11/04/2019	28/05/2019	Yes	No

Editorial Notes

28/05/2019: Publication reference and total final enrolment added.
23/11/2018: Internal review.