AlphaCor Artificial Cornea: Clinical Outcome

Abstract and Introduction

Abstract

Purpose The purpose of this study was to describe the long-term results of AlphaCor implantations, and to evaluate the main complications and risk factors.
Methods Retrospective analysis of preoperative and follow-up data from 15 AlphaCor implantations. Analysis of outcomes, trends, and associations was performed and compared with data from published clinical trials and a literature review.
Results The survival rate of the device at 1, 2, and 3 years was 87%, 58%, and 42%, respectively. Postoperative visual acuity ranged from hand movement to 0.8. The most significant complications were stromal melt (nine cases), optic deposition (three eyes), and retroprosthetic membrane formation (three eyes). The most common device-unrelated complication was trauma (three patients). All complications were managed without loss of the eye.
Conclusion AlphaCor provides a treatment option for patients with corneal blindness in which a donor tissue graft would not succeed.

Introduction

AlphaCor is a synthetic cornea made from poly(2-hydroxyethyl methacrylate) that has a peripheral region with interconnecting pores allowing biointegration with surrounding corneal tissue.^[1,2] The two concentric regions are joined by means of an interpenetration of polymers across a junctional zone known as the interpenetrating polymer network (IPN).^[3] The entire device has a diameter of 7.0 mm, a thickness of 0.6 mm, and surface curvatures that result in appropriate refractive power when implanted. The device is presently available in two powers: AlphaCor-A (for aphakic patients) and AlphaCor-P (for phakic or pseudophakic patients). It is placed within a lamellar corneal pocket with tissue posterior to the optic being removed at the time of implantation (stage I surgery) and the tissue anterior to the optic being removed secondarily (stage II surgery).^[1,2,4] The porous skirt remains enclosed within the corneal stromal tissue with which it biointegrates because of cellular colonization and collagen deposition.

AlphaCor is the result of many years of laboratory and clinical research.^[5–20] Several complications, associations, and risk factors have been identified.^[21–25] The indications and surgical techniques have been evolving with experience.^[26,27]

This study aims to evaluate the long-term results, the main complications, and risk factors of AlphaCor implantations.

Table 1. Patient data
Patient number	Age (in years)	Gender	Eye with AlphaCor	Previous grafts	Follow-up (months)	Survival (months)	Preoperative diagnoses	KPro type	Postoperative complications	Postoperative procedures	Reason for explantation
OD	OS
1	53	M	OS	3	7	67	47	Failed graft, chemical burn	AlphaCor-P	Optic deposition, stromal melting	Device explantation, PK	Stromal melting, partial extrusion
2	33	M	OD	1	0	54	20	Failed graft, penetrating injury	AlphaCor-P	Secondary glaucoma, optic deposition, stromal melting	Cyclocryocoagulation, device explantation, PK	Stromal melting
3	53	M	OD	3	0	54	54	Failed graft, penetrating injury	AlphaCor-A	None	None	0
4	46	M	OD	1	0	53	34	Failed graft, chemical burn	AlphaCor-A	Optic deposition, stromal melting	Phototherapeutic keratectomy × 4, device explantation, PK	Stromal melting, partial extrusion
5	51	M	OS	0	3	43	12	Failed graft, chemical burn	AlphaCor-P	Retroprosthetic membrane formation, stromal melting	Amniotic membrane, scleral patch, device explantation, PK	Stromal melting, partial extrusion
6	60	M	OS	5	0	43	15	Chemical burn, leucoma corneae	AlphaCor-P	Trauma	Damaged device explantation, PK	Postoperative trauma
7	39	M	OS	5	3	42	42	Failed graft, chemical burn	AlphaCor-A	Retroprosthetic membrane formation, stromal melting	Conjunctival flap	0
8	75	M	OS	4	0	41	41	Ocular cicatricial pemphigoid	AlphaCor-P	None	Cataract surgery	0
9	72	M	OS	1	0	37	5	Chemical burn, leucoma corneae	AlphaCor-P	Trauma	Damaged device and IOL explantation, PK	Postoperative trauma
10	73	M	OS	0	1	31	19	Failed graft, postoperative keratopathy	AlphaCor-A	Stromal melting	Scleral patch, device explantation, PK	Stromal melting, partial extrusion
11	81	F	OD	1	0	31	31	Failed graft, postoperative keratopathy	AlphaCor-A	None	None	0
12	42	M	OD	3	0	24	24	Failed graft, chemical burn	AlphaCor-A	Stromal melting	Conjunctival flap	0
13	72	M	OS	0	2	19	19	Failed graft, corneal dystrophy	AlphaCor-P	Stromal melting	Amniotic membrane, conjunctival flap	0
14	34	M	OD	3	0	19	0.24	Failed graft, HZV keratitis	AlphaCor-P	Trauma and AlphaCor loss	Suture of the wound (anterior lamela)	Postoperative trauma
15	68	M	OS	2	1	12	12	Failed graft, corneal dystrophy	AlphaCor-P	Retroprosthetic membrane formation, stromal melting	Conjunctival flap, surgical discision of RM	0

Table 1. Patient data

Patient number

Age (in years)

Gender

Eye with AlphaCor

Previous grafts

Follow-up (months)

Survival (months)

Preoperative diagnoses

KPro type

Postoperative complications

Postoperative procedures

Reason for explantation

Failed graft, chemical burn

AlphaCor-P

Optic deposition, stromal melting

Device explantation, PK

Stromal melting, partial extrusion

Failed graft, penetrating injury

AlphaCor-P

Secondary glaucoma, optic deposition, stromal melting

Cyclocryocoagulation, device explantation, PK

Stromal melting

Failed graft, penetrating injury

AlphaCor-A

None

Failed graft, chemical burn

AlphaCor-A

Optic deposition, stromal melting

Phototherapeutic keratectomy × 4, device explantation, PK

Stromal melting, partial extrusion

Failed graft, chemical burn

AlphaCor-P

Retroprosthetic membrane formation, stromal melting

Amniotic membrane, scleral patch, device explantation, PK

Stromal melting, partial extrusion

Chemical burn, leucoma corneae

AlphaCor-P

Trauma

Damaged device explantation, PK

Postoperative trauma

Failed graft, chemical burn

AlphaCor-A

Retroprosthetic membrane formation, stromal melting

Conjunctival flap

Ocular cicatricial pemphigoid

AlphaCor-P

None

Cataract surgery

Chemical burn, leucoma corneae

AlphaCor-P

Trauma

Damaged device and IOL explantation, PK

Postoperative trauma

Failed graft, postoperative keratopathy

AlphaCor-A

Stromal melting

Scleral patch, device explantation, PK

Stromal melting, partial extrusion

Failed graft, postoperative keratopathy

AlphaCor-A

None

Failed graft, chemical burn

AlphaCor-A

Stromal melting

Conjunctival flap

Failed graft, corneal dystrophy

AlphaCor-P

Stromal melting

Amniotic membrane, conjunctival flap

0.24

Failed graft, HZV keratitis

AlphaCor-P

Trauma and AlphaCor loss

Suture of the wound (anterior lamela)

Postoperative trauma

Failed graft, corneal dystrophy

AlphaCor-P

Retroprosthetic membrane formation, stromal melting

Conjunctival flap, surgical discision of RM

Table 2. Patient data

Patient number

Preoperative BCVA

Postoperative BCVA/comments

6 months after I. st.

12 months after I. st.

18 months after I. st.

24 months after I. st.

30 months after I. st.

36 months after I. st.

42 months after I. st.

48 months after I. st.

54 months after I. st.

0.4; near J.1

0.4

0.15

0.3

0.15

OpD

OpD, SM, exp

0.01

0.03

RM, SM, exp.

0.8; near J.1

0.125

0.02

OpD

OpD, SM, exp

RM, SM, exp

0.15; near J.1

0.1

Glaucoma

Trauma, exp

RM, SM

0.2; near J.3

0.1

0.3; near J.3

0.2; near J.3

0.3

0.1

Cataract

Phaco+PC IOL

OpD

0.25; near J.4

Exp 5 months after I.stage—trauma

Retinal pathology

SM, exp

0.01

Glaucoma

0.5; near J.2

Glaucoma

0.01

1 week after I.stage—trauma

0.01

0.005

AlphaCor Artificial Cornea

Clinical Outcome

Abstract and Introduction

Abstract

Introduction

Tables

Tables

References

Authors and Disclosures

Authors and Disclosures

Sidebar

Sidebar

Summary

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