Effect of Type of Head Positioning on Retinal Displacement in Vitrectomy for Retinal Detachment (DIAMOND)

Difference In Anatomic Integrity in Vitrectomy for Macula Off Rhegmatogenous RetiNal Detachments With Face Down Compared to Supine Positioning (the DIAMOND Study)

Patients may experience metamorphopsia, or image distortion, after having vitrectomy to repair their rhegmatogenous retinal detachments especially those with a detached macula. Retinal displacement, as measured on autofluorescence photography, likely contributes to this distortion. It is thought that the retina slips inferiorly due to the residual subretinal fluid shifting as the patient transitions from the supine position intraoperatively to the sitting up position in the immediate postoperative period. By having the patient immediate position facedown or according to the retinal break, the risk of slippage is theoretically decreased.

Study Overview

• Status: Recruiting
• Conditions: Retinal Detachment; Metamorphopsia
• Intervention / Treatment: Behavioral: Face down positioning; Behavioral: Supine positioning

Detailed Description

Rhegmatogenous retinal detachments (RRD) are a sight-threatening condition with an incidence of approximately 10 per 100 000 people. RRDs can be broadly classified into those with the macula still attached, and those with the macula detached. Visual prognosis for RRDs with attached macula tend to be much better than those with detached macula. Pars plana vitrectomy (PPV) is one of the procedures used to treat RRD. PPV is carried out in the operating room under regional anesthestic, and often times sedation. The retina is reattached by either draining the subretinal fluid through a peripheral retinal break, by draining the subretinal fluid through a posterior retinotomy, or by using a heavier-than-water liquid such as perfluorocarbon to push out the subretinal fluid. At the end of the surgery, the vitreous cavity is filled with a substance that will tamponade the retina to the wall of the eye. Tamponade agents can be temporary, such as sulfur hexafluoride (SF6) and octafluoropropane (C3F8), or long term, such as silicone oil. After the surgery, patients are usually told to put their facedown allowing the tamponade agent to keep the macula attached while the remaining subretinal fluid is reabsorbed by the retinal pigment epithelium. Alternatively, some surgeons ask that their patients position according to the location of their retinal breaks with the aim for the buoyant gas bubble to cover the break or breaks. Patients may experience metamorphopsia, or image distortion, after having their RRD repaired especially those with a detached macula. Retinal displacement, as measured on autofluorescence photography, likely contributes to this distortion. Supine positioning in theory covers all break locations as usually breaks occur in the anterior part of the retina near the vitreous base. This position has the advantage of being more ergonomic than face down. Depending on the results, this study might provide evidence for the current standard of care, which is face down positioning for the first day after vitrectomy for retinal detachment. Or, if supine positioning demonstrates superiority in reducing the risk of retinal displacement, patients would be able to maintain a more comfortable position after surgery.

• Study Type: Interventional
• Enrollment (Anticipated): 324
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5C 2T2
      • Recruiting
      • Department of Ophthalmology, St. Michael's Hospital
      • Contact: Rajeev Muni, MD Msc FRCSC; Phone Number: 4168677411; Email: Rajeev.Muni@unityhealth.to
      • Contact: Phillip To; Phone Number: 4168677411; Email: Philip.To@unityhealth.to

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age ≥ 18
• Diagnosis of primary rhegmatogenous retinal detachment needing pars plana vitrectomy with the detachment involving at least one of the temporal vascular arcades, which would allow retinal displacement to be detected on fundus autofluorescence photography

Exclusion Criteria:

• Rhegmatogenous retinal detachment with an attached macula
• Proliferative retinopathy grade C or worst
• Prior vitrectomy for retinal detachment. Patients having had pneumatic retinopexy that failed to completely reattach the retina and therefore now needing vitrectomy are allowed into the study
• History of preoperative binocular diplopia
• Tamponade with silicone oil instead of gas
• Inability to maintain post operation head positioning
• Mental incapacity

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Conventional face down positioning; Patients in third arm will be treated with the current standard of care, that is, they will be kept supine in the ophthalmic surgery chair after the completion of their surgery. They will then be taken to the recovery area where, once transferred to the care of the postoperative care unit staff, they will transition to face down positioning. They will maintain this positioning until their first day postoperative visit after which they will position according to the retinal breaks found during surgery.	Behavioral: Face down positioning; See description of the face down positioning group
Experimental: Supine positioning; Patients in the second arm will be kept supine after the completion of their surgery. They will then be taken to the recovery area where, once transferred to the care of the postoperative care unit staff, they will maintain supine positioning. They will maintain this positioning until their first day postoperative visit after which they will position according to the retinal breaks found during surgery.	Behavioral: Supine positioning; See description of the supine positioning group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Retinal displacement	The presence of retinal vessels printing on fundus autofluorescence imaging.	3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Distortion	measured with M chart.	3 months
Aniseikonia	Measured with aniseikonia testing. The aniseikonia test measures the ratio of image size difference between the 2 eyes	3 months
Optical coherence tomography (OCT) changes	Changes seen on OCT	3 months
Optical coherence tomography angiography (OCTA) changes	Changes seen on OCTA	3 months
Metamorphopsia	Metamorphopsia is the image distortion experienced by the patient. It will be recorded in a data collection sheet as "yes" or "no" according to the patient subjective complain on metamorphopsia.	3 months
Best corrected Visual Acuity measured in "Early Treatment of Diabetic Retinopathy Study" letters	Best corrected Visual Acuity measured in "Early Treatment of Diabetic Retinopathy Study" letters	3 months

Collaborators and Investigators

• Sponsor: Unity Health Toronto

Study record dates

Study Major Dates

• Study Start (Actual): August 26, 2019
• Primary Completion (Anticipated): October 1, 2024
• Study Completion (Anticipated): October 1, 2024

Study Registration Dates

• First Submitted: February 11, 2019
• First Submitted That Met QC Criteria: July 24, 2019
• First Posted (Actual): July 29, 2019

Study Record Updates

• Last Update Posted (Actual): April 28, 2021
• Last Update Submitted That Met QC Criteria: April 27, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Nervous System Diseases; Eye Diseases; Neurologic Manifestations; Retinal Diseases; Sensation Disorders; Retinal Detachment; Dissociative Disorders; Vision Disorders
• Other Study ID Numbers: 18-374

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No