The ADVISE Study: Advanced Visualization In Corneal Surgery Evaluation

UMC Utrecht

Status: Completed

Conditions: Bullous Keratopathy; Fuchs Dystrophy; Vision Disorders; Endothelial Corneal Dystrophy

Treatments: Device: intraoperative optical coherence tomography (iOCT)

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT03763721

NL64392.041.17

Details and patient eligibility

About

Rationale: Intra-operative optical coherence tomography (iOCT) is a new technology that incorporates advanced imaging techniques in the ophthalmic operating theatre. This allows surgeons to visualize tissues in a way previously impossible We conceptualized an iOCT-guided surgical protocol for the treatment of endothelial cell dysfunction, that refrains from the current practice of over-pressurizing the eye at the end of surgery.

Objective: The aim of this study is to assess the clinical value of intraoperative OCT (iOCT) for Descemet Membrane Endothelial Keratoplasty (DMEK) by comparing an iOCT-optimized surgical protocol with current practice, where the eye is over-pressurized for a set period of time, in terms of surgical efficiency, clinical outcomes, and adverse events.

Study design: International multicentre non-inferiority randomized clinical trial Study population: Patients scheduled for posterior lamellar corneal surgery for endothelial cell dysfunction above the age of 18 years.

Intervention: Both groups will undergo Descemet Membrane Endothelial Keratoplasty. Patients will be randomized for either the iOCT optimized surgical protocol or current standard surgical protocol using 8 minutes of overpressure to facilitate graft adherence. Both groups will be evaluated with iOCT at the end of surgery.

Main study parameters/endpoints:

The main study parameter is the rate of adverse events (particularly graft dislocations). Secondary parameters/endpoints are surgical time, the recovery of visual acuity and endothelial graft quality at 3 and 6 months follow-up, and a detailed evaluation of the extent/duration of surgical tissue manipulations.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The use of iOCT during surgery does not entail additional risk to the patient. Participants to this study will adhere to the standard of care after corneal transplant surgery. In addition, they will receive study specific measurements and questionnaires. The additional measurements and questionnaires will be combined with regular follow up moments.

Enrollment: 65 patients

Sex: All

Ages: 18 to 100 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age ≥ 18 years
• Irreversible corneal decompensation caused by Fuchs corneal endothelial dystrophy or pseudophakic bullous keratopathy
• Eligible for posterior lamellar keratoplasty, specifically Descemet Membrane Endothelial Keratoplasty (DMEK)

Exclusion criteria

• Any ocular co-morbidity other than cataract, mild dry eye disease, ocular hypertension, simple primary open angle glaucoma, and mild age-related macular degeneration
• Prior corneal transplant surgery
• Human leukocyte antigen (HLA) matched keratoplasty
• Any disability that will interfere with performing or understanding the procedures and questionnaire fulfilment except if it is temporary of nature.
• Combined phaco-emulsification-DMEK surgery (triple procedure)

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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65 participants in 2 patient groups

iOCT optimized protocol (iOCT-p)

Experimental group

Description:

In the iOCT optimized protocol (iOCT-p) group, graft apposition will be assessed with special detail for graft orientation, interface fluid, and any peripheral folds as described by Xu et al. Potential tissue manipulations will be therefore based on the iOCT image. Apposition of the graft will be obtained using a complete filling of the anterior chamber with 20% sulphur hexafluoride (SF6) endotamponade for 1-2 minutes, whilst the OCT image is assessed and any graft manipulation can be performed if deemed necessary. After this period, the gas is partly exchanged for BSS (Balanced Salt Solution, Alcon) to achieve a bubble with a diameter of approximately the same size of the graft (i.e. 8.5mm)

Treatment:

Device: intraoperative optical coherence tomography (iOCT)

current practice protocol (CP-p)

Active Comparator group

Description:

In the current practice protocol (CP-p), graft apposition will be obtained using a complete and pressurized (approx. 65mmHg) filling of the anterior chamber with 20% SF6, for 8 minutes. Tissue manipulations, such as corneal swiping, will be performed as deemed necessary by the surgeon, based on the en face view from the conventional microscope image. The intraocular pressure is normalized by exchanging the SF6 gas for BSS, to achieve a gas bubble approximately the size of the graft (i.e 8.5mm). Now, the graft apposition is assessed using iOCT, to ensure all trial patients eventually undergo advanced iOCT imaging. Should this iOCT image reveal improper graft adherence or any other irregularity, the surgeon will perform additional manipulations or interventions as deemed necessary

Treatment:

Device: intraoperative optical coherence tomography (iOCT)