Development of a Newly Designed Double-Fixed Seoul-Type Keratoprosthesis

Abstract

Objective: To develop a newly designed double-fixed keratoprosthesis (Seoul-type keratoprosthesis [S-KPro]) and to assess its mechanical stability and biocompatibility.Methods: Twenty-five rabbits were divided into 4 groups by fixation technique, amniotic membrane (AM) implantation, and skirt material. The eyes were studied with the use of slitlamp, light, and electron microscopy. Stress testing was performed. In addition, 2 human subjects underwent S-KPro implantation. Best-corrected visual acuity was checked, and ophthalmic examination was performed. Results:The average retention period of the group receiving double-fixated polyurethane-S-KPro with AM was longer (Ͼ24 weeks) than that of the others. Fibroblast invasions were found in polyurethane pores but not in polytetrafluoroethylene (Gore-Tex) pores on light microscopy. The minimal pressure that induced aqueous leakage was greater than 250 mm Hg in all of the tested eyes. Two human subjects have maintained a good postoperative condition for 18 and 8 months. Conclusions:The double-fixation technique of applied S-KPro and AM appears to be helpful in improving the stability of the keratoprosthesis. Polyurethane with relatively large pore size (40 µm) may be used successfully as a material for the keratoprosthesis skirt.Clinical Relevance: Our results may be important for improving the clinical outcome of keratoprosthesis.

Comparative experiments for in vivo fibroplasia and biological stability of four porous polymers intended for use in the Seoul-type keratoprosthesis

“…6 However, degradation of the polyurethane was found in keratoprosthetic human eyes after a long term follow up (data not shown). We tried to find a different nondegradable polymer.…”

Comparative experiments for in vivo fibroplasia and biological stability of four porous polymers intended for use in the Seoul-type keratoprosthesis

“…6 However, degradation of the polyurethane was found in keratoprosthetic human eyes after a long term follow up (data not shown). We tried to find a different nondegradable polymer.…”

Artificial Cornea: Past, Current, and Future Directions

“…Soft skirt materials have been adopted in recent years to increase biointegration based on a variety of synthetic polymers with or without biofunctionalisation with macromolecules ( Table 3 ). Several skirt and optic type KPros have been brought to clinical trials over the decades, including the Keraklear ( 94 ), the MIRO ® Cornea ( 95 ), the Legeais BioKpro III ( 96 ) and the Korea Seoul-type KPro ( 99 , 100 ). However, for the purpose of this review, we will focus on the AlphaCor™ keratoprosthesis, the first soft KPro to obtain FDA approval almost 20 years ago, while mentioning the two newest soft synthetic KPros that have begun clinical trials in the last year (CorNeat, and EndoArt).…”

Seoul-Type Keratoprosthesis

“…The e-PTFE S-KPro was replaced with one made with a polyurethane skirt (pore size Ն 30 µm) because e-PTFE with a pore diameter of 20 µm or more is not commercially available and the pore size of polyurethane is easily fabricated. 10 However, after long-term follow-up in humans, polyurethane with a large pore size was found to dissolve easily (cases 1 and 3). Additionally, with in vivo experiments, nonwoven polypropylene was found to have an excellent property that encourages fibroblast ingrowth compared with polyurethane (Mee Kum Kim, MD, unpublished data, 2001).…”

Comparative experiments for in vivo fibroplasia and biological stability of four porous polymers intended for use in the Seoul-type keratoprosthesis

“…6 However, degradation of the polyurethane was found in keratoprosthetic human eyes after a long term follow up (data not shown). We tried to find a different nondegradable polymer.…”

Artificial Cornea: Past, Current, and Future Directions

“…Soft skirt materials have been adopted in recent years to increase biointegration based on a variety of synthetic polymers with or without biofunctionalisation with macromolecules ( Table 3 ). Several skirt and optic type KPros have been brought to clinical trials over the decades, including the Keraklear ( 94 ), the MIRO ® Cornea ( 95 ), the Legeais BioKpro III ( 96 ) and the Korea Seoul-type KPro ( 99 , 100 ). However, for the purpose of this review, we will focus on the AlphaCor™ keratoprosthesis, the first soft KPro to obtain FDA approval almost 20 years ago, while mentioning the two newest soft synthetic KPros that have begun clinical trials in the last year (CorNeat, and EndoArt).…”

Seoul-Type Keratoprosthesis

“…The e-PTFE S-KPro was replaced with one made with a polyurethane skirt (pore size Ն 30 µm) because e-PTFE with a pore diameter of 20 µm or more is not commercially available and the pore size of polyurethane is easily fabricated. 10 However, after long-term follow-up in humans, polyurethane with a large pore size was found to dissolve easily (cases 1 and 3). Additionally, with in vivo experiments, nonwoven polypropylene was found to have an excellent property that encourages fibroblast ingrowth compared with polyurethane (Mee Kum Kim, MD, unpublished data, 2001).…”

Comparative experiments for in vivo fibroplasia and biological stability of four porous polymers intended for use in the Seoul-type keratoprosthesis

“…6 However, degradation of the polyurethane was found in keratoprosthetic human eyes after a long term follow up (data not shown). We tried to find a different nondegradable polymer.…”

Artificial Cornea: Past, Current, and Future Directions

“…Soft skirt materials have been adopted in recent years to increase biointegration based on a variety of synthetic polymers with or without biofunctionalisation with macromolecules ( Table 3 ). Several skirt and optic type KPros have been brought to clinical trials over the decades, including the Keraklear ( 94 ), the MIRO ® Cornea ( 95 ), the Legeais BioKpro III ( 96 ) and the Korea Seoul-type KPro ( 99 , 100 ). However, for the purpose of this review, we will focus on the AlphaCor™ keratoprosthesis, the first soft KPro to obtain FDA approval almost 20 years ago, while mentioning the two newest soft synthetic KPros that have begun clinical trials in the last year (CorNeat, and EndoArt).…”

Seoul-Type Keratoprosthesis

“…The e-PTFE S-KPro was replaced with one made with a polyurethane skirt (pore size Ն 30 µm) because e-PTFE with a pore diameter of 20 µm or more is not commercially available and the pore size of polyurethane is easily fabricated. 10 However, after long-term follow-up in humans, polyurethane with a large pore size was found to dissolve easily (cases 1 and 3). Additionally, with in vivo experiments, nonwoven polypropylene was found to have an excellent property that encourages fibroblast ingrowth compared with polyurethane (Mee Kum Kim, MD, unpublished data, 2001).…”