Endoscopic Assisted Anterior Hyaloid Peeling in Boston Type 1 Keratoprosthesis (KPro-HP-Endo)

Postoperative Complications Clinical Trial

— KPro-HP-Endo  

Official title:

Impact of Endoscopic Assisted Anterior Hyaloid Peeling in Boston Type 1 Keratoprosthesis in Reducing Postoperative Complications

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04337944
• Other study ID #: CE19.382
• Status: Recruiting
• Phase: N/A
• Start date: April 8, 2020
• Est. completion date: March 2025

Study information

• Verified date: July 2023
• Source: Centre hospitalier de l'Université de Montréal (CHUM)
• Contact: Marie-Catherine Tessier, M.Sc.
• Phone: 1-514-890-8000
• Email: marie-catherine.tessier.chum[@]ssss.gouv.qc.ca
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Common complications of the Boston keratoprosthesis type 1 (KPro) surgery include retroprosthetic membrane formation, glaucoma, and retinal detachment. Often pars plana vitrectomy (PPV) is performed at the same time as KPro surgery for different indications. It has been shown to reduce postoperative complications in comparison to when it is performed after the KPro surgery. Patients who receive a complete PPV with peeling of the anterior hyaloid membrane have a lower incidence of retroprosthetic membrane formation and less vision loss due to glaucoma when compared to patients with partial PPV or anterior vitrectomy. During a complete PPV, peeling of the anterior hyaloid membrane is a difficult step because visualisation is poor, but it can be improved using endoscopy. The investigators suggest that peeling of the anterior hyaloid membrane assisted by endoscopy during KPro surgery would decrease postoperative complications in comparison to a PPV done after KPro surgery and without endoscopy.

Description:

Boston keratoprosthesis type 1 (KPro) surgery is the most common corneal graft and is used to restore vision in patients with high risk of failure with traditional penetrating keratoplasty. Common complications of KPro surgery include retroprosthetic membrane formation behind the backplate of the KPro. Glaucoma is the most common threat to vision rehabilitation in patients with KPro. Glaucoma is often present before surgery and progresses after KPro, seven times faster than in patients with only glaucoma. Retinal detachment is a common posterior segment complication that arises post-KPro and can lead to a serious loss of vision. Pars plana vitrectomy (PPV) is the standard treatment for patients with vitreoretinal diseases and opacities. PPV can include peeling of the anterior hyaloid membrane to ensure total resection of the vitreous body. PPV allows for example for retroprosthetic membrane excision, installation or revision of a glaucoma drainage device, or repair of retinal detachment. Often PPV is performed at the same time as KPro surgery for different indications. It has been shown to reduce postoperative complications in comparison to when it is performed after the KPro surgery. Patients who receive a complete PPV with peeling of the anterior hyaloid membrane have a lower incidence of retroprosthetic membrane formation and less vision loss due to glaucoma when compared to patients with partial PPV or anterior vitrectomy. Combined surgeries of KPro and PPV offer a complete evaluation of the optic nerve and of the retina, which would not be possible otherwise. During a complete PPV, peeling of the anterior hyaloid membrane is a difficult step because visualisation is poor, especially with a KPro in place. Visualisation can be improved using endoscopy to visualize the inside of the eye over 360 degrees. The investigators suggest that peeling of the anterior hyaloid membrane assisted by endoscopy during KPro surgery would decrease postoperative complications in comparison to a PPV done after KPro surgery and without endoscopy.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: March 2025
• Est. primary completion date: October 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• Aged from 18 to 80 years old

• Informed consent

• Boston keratoprosthesis candidate

• Pars plana vitrectomy candidate

• Ability to be followed for the duration of the study

Exclusion Criteria:

• Aged less than 18 or more than 80 years old

• Inability to give informed consent

• Repeat Boston keratoprosthesis

• Repeat pars plana vitrectomy

Related Conditions & MeSH terms

• Corneal Transplantation
• Endoscopy
• Glaucoma and Ocular Hypertension
• Ocular Hypertension
• Postoperative Complications
• Vitrectomy

Intervention

Procedure:
• Boston keratoprosthesis type 1 and anterior hyaloid membrane peeling assisted by endoscopy
Patients will receive at the same time a Boston keratoprosthesis type 1 (KPro) with a pars plana vitrectomy (PPV) with anterior hyaloid membrane peeling assisted by endoscopy.

Locations

Country	Name	City	State
Canada	Centre Hospitalier de l'Université de Montréal (CHUM)	Montréal	Quebec

Sponsors (1)

Lead Sponsor	Collaborator
Centre hospitalier de l'Université de Montréal (CHUM)

Country where clinical trial is conducted

Canada, 

References & Publications (12)

Boscher C, Kuhn F. Endoscopic evaluation and dissection of the anterior vitreous base. Ophthalmic Res. 2015;53(2):90-9. doi: 10.1159/000370032. Epub 2015 Jan 27. — View Citation

Crnej A, Paschalis EI, Salvador-Culla B, Tauber A, Drnovsek-Olup B, Shen LQ, Dohlman CH. Glaucoma progression and role of glaucoma surgery in patients with Boston keratoprosthesis. Cornea. 2014 Apr;33(4):349-54. doi: 10.1097/ICO.0000000000000067. — View Citation

Dohlman CH, Zhou C, Lei F, Cade F, Regatieri CV, Crnej A, Dohlman JG, Shen LQ, Paschalis EI. Glaucoma After Corneal Trauma or Surgery-A Rapid, Inflammatory, IOP-Independent Pathway. Cornea. 2019 Dec;38(12):1589-1594. doi: 10.1097/ICO.0000000000002106. — View Citation

Harissi-Dagher M, Durr GM, Biernacki K, Sebag M, Rheaume MA. Pars plana vitrectomy through the Boston Keratoprosthesis type 1. Eye (Lond). 2013 Jun;27(6):767-9. doi: 10.1038/eye.2013.58. Epub 2013 Apr 12. — View Citation

Khan BF, Harissi-Dagher M, Khan DM, Dohlman CH. Advances in Boston keratoprosthesis: enhancing retention and prevention of infection and inflammation. Int Ophthalmol Clin. 2007 Spring;47(2):61-71. doi: 10.1097/IIO.0b013e318036bd8b. No abstract available. — View Citation

Modjtahedi BS, Eliott D. Vitreoretinal complications of the Boston Keratoprosthesis. Semin Ophthalmol. 2014 Sep-Nov;29(5-6):338-48. doi: 10.3109/08820538.2014.959204. — View Citation

Moussally K, Harissi-Dagher M. Long-term complications associated with glaucoma drainage devices and Boston keratoprosthesis. Am J Ophthalmol. 2011 Nov;152(5):883-4; author reply 884-5. doi: 10.1016/j.ajo.2011.07.014. No abstract available. — View Citation

Robert MC, Pomerleau V, Harissi-Dagher M. Complications associated with Boston keratoprosthesis type 1 and glaucoma drainage devices. Br J Ophthalmol. 2013 May;97(5):573-7. doi: 10.1136/bjophthalmol-2012-302770. Epub 2013 Feb 23. — View Citation

Szigiato AA, Bostan C, Nayman T, Harissi-Dagher M. Long-term visual outcomes of the Boston type I keratoprosthesis in Canada. Br J Ophthalmol. 2020 Nov;104(11):1601-1607. doi: 10.1136/bjophthalmol-2019-315345. Epub 2020 Feb 17. — View Citation

Talajic JC, Agoumi Y, Gagne S, Moussally K, Harissi-Dagher M. Prevalence, progression, and impact of glaucoma on vision after Boston type 1 keratoprosthesis surgery. Am J Ophthalmol. 2012 Feb;153(2):267-274.e1. doi: 10.1016/j.ajo.2011.07.022. Epub 2011 Oct 7. — View Citation

Wang Q, Harissi-Dagher M. Characteristics and management of patients with Boston type 1 keratoprosthesis explantation--the University of Montreal Hospital Center experience. Am J Ophthalmol. 2014 Dec;158(6):1297-1304.e1. doi: 10.1016/j.ajo.2014.08.037. Epub 2014 Aug 28. — View Citation

Yu YZ, Zou YP, Zou XL. Endoscopy-assisted vitrectomy in the anterior vitreous. Int J Ophthalmol. 2018 Mar 18;11(3):506-511. doi: 10.18240/ijo.2018.03.23. eCollection 2018. — View Citation

* Note: There are 12 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Rate of retroprosthetic membrane formation	Rate of postoperative retroprosthetic membrane formation behind the backplate of the Boston keratoprosthesis. Retroprosthetic membrane formation is diagnosed by the investigator using an examination of the anterior chamber performed at the slit-lamp.	12 months
Primary	Rate of retinal detachment	Rate of postoperative retinal detachment. Retinal detachment is diagnosed by the investigator using a dilated fundus (retinal) examination performed at the slit-lamp.	12 months
Primary	Rate of glaucoma development	Rate of development or progression of glaucoma, determined based on intraocular pressure increase of > 21 mmHg, increase of glaucoma medications, optic nerve excavation progression, or need to undergo glaucoma filtration surgery.	12 months
Secondary	Proportion of patients with visual acuity better than 20/200	Proportion of patients with visual acuity better than 20/200 after surgery. The visual acuity is measured using the Snellen chart.	12 months
Secondary	Change of visual acuity	Change of visual acuity compared between before and after surgery. The visual acuity is measured using the Snellen chart.	12 months
Secondary	Time to retroprosthetic membrane formation after surgery	Time to retroprosthetic membrane formation, calculated in months from the time of the surgery. Retroprosthetic membrane formation behind the backplate of the Boston keratoprosthesis is diagnosed by the investigator using an examination of the anterior chamber performed at the slit-lamp.	12 months
Secondary	Time to retinal detachment after surgery	Time to retinal detachment, calculated in months from the time of the surgery. Retinal detachment is diagnosed by the investigator using a dilated fundus (retinal) examination performed at the slit-lamp.	12 months
Secondary	Proportion of participants requiring glaucoma surgery	Proportion of participants requiring glaucoma surgery (including glaucoma drainage device, trabeculectomy or cyclophotocoagulation) after the Boston keratoprothesis surgery.	12 months
Secondary	Proportion of patients with visual field loss of 30% or more	Proportion of patients with visual field loss of 30% or more, measured using the automated Humphrey 24-2 visual field. The loss of 30% or more of visual field is calculated using the first two postoperative tests as a reference.	12 months
Secondary	Proportion of patients with thinning of the nerve fiber layer	Proportion of patients with thinning of the nerve fiber layer, determined by Spectral Domain Optical Coherence Tomography (SD-OCT) in average and for each of the four quadrants.	12 months
Secondary	Rate of Boston keratoprosthesis complications	Rate of Boston keratoprosthesis complications. Complications from the Boston keratoprosthesis include: corneal melt, retroprosthetic membrane formation, retinal detachment, cystic macular edema, extrusion, hypotony, choroidal hemorrhage.	12 months