Clinical trial NCT04380077: Gas Tamponade for Prevention of Postoperative Vitreous Hemorrhage in Diabetics
Official title: Gas Tamponade for Prevention of Postoperative Vitreous Hemorrhage in Proliferative Diabetic Retinopathy Patients Undergoing Vitrectomy: a Randomized Clinical Trial
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Proliferative Diabetic Retinopathy
Lead sponsor: Rush Eye Associates
Sponsor class: OTHER
First posted: 2020-05-08
Enrollment: 150
Sex: ALL
Minimum age (years): 18
Maximum age (years): 85
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Hypothesis: Patients undergoing pars plana vitrectomy for the indication of diabetic vitreous hemorrhage will have a lower incidence of postoperative vitreous hemorrhaging during the 6-month trial period when vitreous substitution with 20-30% sulfur hexafluoride gas is utilized compared to vitreous substitution with balanced salt solution.

Detailed description: Subjects enrolled into the study are randomized into one of the ensuing treatment cohorts: Group A patients undergo vitreous substitution with 20-30% sulfur hexafluoride (SF6) gas during PPV, whereas Group B patients undergo vitreous substitution with balanced salt solution (BSS) during PPV. Simple randomization allocates patients into treatment groups during PPV. Once all relevant maneuvers are completed by the surgeon prior to vitreous substitution, a simulated coin toss program decides the vitreous substitute, and therefore which group the patient enters. Randomization intraoperatively mitigates against selection bias of utilized surgical maneuvers such as endodiathermy on the part of the surgeon and allows for subjects to not undergo randomization in cases where intraoperative retinal breaks occur that would preclude the subject from receiving vitreous substitution with BSS.

Subjects undergo data collection at 3 postoperative visits: 1) 15 +/- 5 days following PPV, 2) 40 +/- 10 days following PPV, and 3) 185 +/- 15 days following PPV. Study subjects are evaluated at non-study times at the judgment of the examiner.

Eligibility criteria: Inclusion:

1. The patient has medically-managed type I or II diabetes mellitus.
2. The age of the patient is \> 18 years old,
3. Snellen best-corrected visual acuity is from 20/40 to hand motions at one foot in the subject's study eye
4. Proliferative diabetic retinopathy with a clinically evident vitreous hemorrhage of duration of at least one month by subjective history is present in the subject's study eye.
5. The vitreous hemorrhage is symptomatic and primarily responsible for the patient's reduced vision in the judgement of the examiner.
6. Grade 0 or I vitreoretinal adhesion according to the classification system described by Ahn et al \[@\] in the study eye is clinically present.

   * Ahn J, Woo SJ, Chung H, et al. The effect of adjunctive intravitreal bevacizumab for preventing postvitrectomy hemorrhage in proliferative diabetic retinopathy. Ophthalmology. 2011; 118: 2218-2226.

Exclusion:

1. The subject's study eye previously underwent anterior or posterior vitrectomy.
2. A lens or cornea opacity is thought to be responsible for two or more lines of reduced visual acuity in the subject's study eye (cataract, corneal scar, ectasia, etc.).
3. Optic nerve or retina disease otherwise not related to diabetes mellitus is thought to be responsible for two or more lines of reduced visual acuity in the subject's study eye (optic neuritis, macular degeneration, glaucoma, epiretinal membrane, etc.).
4. A non-ocular cause (i.e. cerebrovascular accident) or amblyopia is thought to be responsible for two or more lines of reduced visual acuity in the subject's study eye
5. Neovascular glaucoma with a high intraocular pressure ( \> 30 mm Hg) is discovered in the subject's study eye.
6. Medically uncontrolled systemic hypertension (systolic \> 200 mmHg or diastolic \> 120 mmHg) is present.

Primary outcomes:
measure: postoperative vitreous hemorrhage rate
timeFrame: 6 months
Secondary outcomes:
measure: unplanned vitrectomy rate
timeFrame: 6 months
measure: visual acuity
timeFrame: 6 months
Other outcomes:
Locations:
city: Montemorelos
country: Mexico
facility: La Carlota Hospital
state: Nuevo Leon
Study officials:
affiliation: panhandle eye group
name: Ryan Rush, MD
role: PRINCIPAL_INVESTIGATOR
References: