Keratoprosthesis for Underserved Communities
Editor:
Rachelle Srinivas
Dr. Rachelle Srinivas is a neuro-ophthalmology fellow at Michigan State University.
Corneal disease is one of the leading causes of blindness worldwide [1,2]. The causes of corneal blindness vary based on geographic area and include inflammatory diseases, infection, nutritional deficiency, and trauma [1,3,4].
PREVALENCE
Blindness due to corneal opacification is estimated to account for approximately 3.2% of all blindness worldwide, with the majority of individuals affected by corneal disease residing in low-income and developing countries [2,5,6]. Among those affected by corneal opacification, males have been found to have a higher prevalence compared to females [5]. Corneal blindness is also a common cause of preventable childhood blindness [1,7].
SOURCES OF DISPARITY
Developing countries experience a disproportionally high burden of corneal disease that is further exacerbated by a lack of available resources and limited access to eye care [3,8]. While prevention is of utmost importance, severe cases may necessitate the need for advanced treatment options such as corneal transplantation. However, transplantation can be accompanied by challenges such as inadequate supplies of donor corneal tissue, insufficient eye banks needed to facilitate the process, and financial barriers as well as associated complications [3,6].
Keratoprosthesis (Kpro) provides a viable option for cases not amenable to the standard keratoplasty or following multiple failed grafts [6,9]. The Boston Kpro is a commonly used model that has been shown to have promising results [6]. While it is considered a cost-effective treatment, it can still be relatively expensive, especially in developing countries. Additionally, the use of the Boston Pro may be accompanied by other barriers, such as the need for fresh corneal donor tissue and dependency on eye banks and infrastructure that may be lacking [3,6,8].
METHODS EMPLOYED TO ADDRESS THE ISSUE
In recent years, efforts to provide an accessible alternative to the Boston Kpro have led to the development of more cost-efficient Kpros such as LUCIA and AuroKPro [6,10,11,12]. These alternative models have been developed with the intent to be used in developing countries and require a fraction of the cost to produce [6,10,12]. Studies have shown promising results with comparable postoperative outcomes to the Boston Kpro [11,12].
Additionally, efforts are underway to address the limited supply of corneal donor tissue and challenges with storage. Studies evaluating the use of autologous corneal tissue in place of an allograft have had promising results and this could lead to a cost-efficient option that eliminates the need for tissue storage [13]. Investigations looking at methods to extend the time limits for the long-term storage of donor tissue are also being conducted with promising methods such as the use of gamma irradiation or dehydration with storage in glycerin [14,15, 16, 17]. Both methods may allow long-term tissue storage, and gamma irradiation may also allow storage at room temperature [16, 17, 18].
CONCLUSIONS
Blindness due to corneal disease is a public health issue that is disproportionately prevalent in low-income countries. While keratoprosthesis provides a promising option for severe cases, financial and organizational challenges exist. However, there is encouraging ongoing research for alternative models and methods that can alleviate some of these challenges and make Kpros more accessible.
References:
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