Keratoprosthesis – A Long term review

Br J Ophthalmol, 1983 July ; 67 (7) 468 -474 JJ Barnham and MJ Roper Hall

AIM of the study

The aim of this study was to review the 35 patients with 55 KP insertions with regard to visual outcome, length of time vision maintained,retention time and complications

Patients and methods

Thirty five patients were reviewed with a total of 55 KP insertions of which 39 were 1 st timers, 8 were 2 nd, 4 were 3 rd, 3 were 4 th 1 was 5 th in a single eye.

Follow up time ranged from 1 month to 15 yrs with only 4 patients been followed up for less than 6 months.

A preoperative diagnosis of Bullous keratopathy was made in 20 patients of which 16 followed cataract extraction, 1 followed lens dislocation,3 had fuch’s dystrophy - surgery unrelated.

Of remaining 15 pts ,3 had corneal damage following perforating injury , 2 followed explosion, 1 followed lime burn, 1 had thermal burn sustained in road accident . 4 had herpetic keratitis , 1 interstitial keratitis, 2 had band keratopathy following iridocyclitis , 1 had SJ syndrome.

49 underwent penetrating KP and 6 underwent Intralamellar KP.

References1.DeVoe AG . A current evaluation of

Corneal prosthetic devices. Arch Ophthalmol 1967;78:269-71

2. Giles CL. Henderson JW . Keratoprosthesis : current status.Am J Med Sci 1967 ; 253:239-42

3.Girard IJ . Hawkin RS. Nieves R, et al. Keratoprosthesis : a 12 – year follow up.Trans Am Acad Ophthalmol Otolaryngol 1977;83:252-67

Keratoprosthesis is a surgical procedure where a severely damaged or diseased cornea is replaced with an artificial cornea to restore useful vision or to make the eye comfortable in painful keratopathy

It is a double plated PMMA device with a central rigid optic that perforates Cornea .

Type 1 is a collar button shaped device with front plate ,central optic stem, back plate .

Type 2 is a through – the – lid design with a 2 mm anterior nub designed to penetrate through a tarsorrhaphy

When use a Boston type 1 Keratoprosthesis ?

When corneal transplant carries a particular poor prognosis

1. Multiple corneal transplant rejection & failures

2. Tear deficiency syndromes

3.Eyelid contour irregularities

4.Aniridia

5.Chemical /thermal injury

When use a Boston type 2 Keratoprosthesis ?

Severe Cicatrical ocular surface diseases 1.Steven Johnson syndrome/ Toxic epidermal

necrolysis

2.Severe Alkali burn

3. Mucous membrane pemphigoid

4. Severe Aqueous tear deficiency

Indications of Type 2 Boston Keratoprothesis:

When not likely to successful type 1

keratoprosthesis

- Symblepharon and loss of conjunctival fornices

- Severe keratinizing dry eye

Threaded design Snap in design

MOOKP – Eye tooth

Originally described by Strampelli later it was Giancario Falcinelli who modified the technique.

This technique uses a composite bone-tooth lamina to help anchor a polymethyl methacrylate cylinder to the cornea.

Problems Need for atleast two lengthy surgeries Need for oral surgery [minimum tooth size & good dental health] Cosmetic result unacceptable [tooth loss, protuding eye, prosthetic shell

help]