Improving glaucoma management for the Boston keratoprosthesis type 1: tubes versus lasers

ABSTRACT

Introduction

The Boston Keratoprosthesis (KPro) is the most used artificial cornea. It restores vision in patients with a poor prognosis with penetrating keratoplasty. Significant improvements have occurred recently in terms of implant design and postoperative care. Nonetheless, glaucoma remains the primary reason for vision loss after KPro implantation. Management of inflammation and intraocular pressure (IOP) is challenging in KPro eyes. Progressive optic nerve damage often persists in spite of medical and surgical interventions. Significant efforts are being invested to determine the best management, even when IOP is controlled. Glaucoma drainage devices (GDD) implanted during KPro surgery could offer beneficial visual outcomes. Cyclophotocoagulation (CPC) may be reserved for end-staged glaucoma.

Areas covered

This review highlights glaucoma mechanisms in KPro eyes, the need to better monitor and treat glaucoma in KPro patients, and the latest innovation strategies. Recent data on current options and timing for GDD and CPC are discussed.

Expert opinion

Implantation of GDD before or during KPro surgery reduces the risk of glaucoma progression compared to CPC. Future developments could offer KPro implants integrated with drainage devices and IOP sensors. Targeted control of inflammation will be the next novel strategy to reduce optic nerve damage occurring despite appropriate IOP control.

KEYWORDS:

• Boston keratoprosthesis type 1
• glaucoma
• intraocular pressure
• glaucoma drainage device
• Ahmed glaucoma valve
• Baerveldt glaucoma implant
• cyclophotocoagulation
• trabeculectomy

Article highlights

• Glaucoma is a common complication in KPro patients and remains the primary reason for vision loss after KPro implantation.

• Assessment of glaucomatous changes and IOP monitoring are challenging in KPro eyes because of limited visualization and approximate measurements by digital palpation.

• Recent studies have demonstrated that glaucoma drainage devices implanted at the time of KPro surgery reduce the risk of glaucoma progression in comparison to CPC. Clear guidelines ought to be better established in the future.

• Special care should be taken when performing CPC in end-staged glaucomatous eyes because of a high risk of complications such as phthisis bulbi and endophthalmitis.

• In spite of all available medical and surgical interventions, a majority of KPro eyes will likely suffer from definite glaucoma progression, whether glaucoma is arising before or after KPro surgery.

• Promising innovations of the near future are needed to address the unmet need to better monitor and treat glaucoma progression, such options being KPro integrated with drainage devices and IOP sensors.

• Targeted control of inflammation will be the next novel strategy to reduce retinal and optic nerve damage that occurs despite appropriate IOP control.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

No funding supported this paper.