_Applied_  
_sciences_  
_Solid Storage Media versus Optisol-GS in the Preservation of_  
_Corneal Quality for Keratoplasty: A Systematic Review_  
**[PERSON] 1,2, [PERSON] 3, [PERSON] 2, [PERSON] 3, [PERSON] 4, [PERSON] 2,5, [PERSON] 3 and [PERSON] 6,7,8**  
Footnote 1: [[https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci)]([https://www.mdpi.com/journal/applsci](https://www.mdpi.com/journal/applsci))  
-anterior lamellar keratoplasty (DALK), and Descemet stripping automated endothelial keratoplasty (DSAEK) [2]. However, the lack of available donors and eye banks capable of providing corneas in adequate numbers and quality for transplants is still a reality despite many efforts. Furthermore, limitations of the different national corneal transplantation programs worldwide may contribute to lower rates of donor cornea usage and a considerable shortage of corneal graft tissue constantly identified by global surveys [3]. In this context, biomedical advances on tissue engineering and preservation have contributed with methods that are essential for enhancing the quality of donor corneas, mainly intending to preserve the integrity of corneal endothelium, a critical factor for the successful long-term outcome of corneal transplantation [4]. Furthermore, longer storage times allow for increased flexibility with a reduced waste of donor tissue. Nonetheless, the preservation of human donor corneas is still limited to a maximum of 10-14 days by hypotothermic storage, considered a simple and effective method that uses cold cornea storage media [5]. Different studies have identified corneal storage for periods superior to 7 days as a risk factor for primary graft failure and lower 3-year graft survival after keratoplasty [6]. However, improvements in surgical techniques and preservation of cornea have reduced intraoperative cell loss and graft dislocation after procedures such as Descemet stripping automated endothelial keratoplasty (DSAEK), with clinically insignificant differences for cornea grafts under 12 days of preservation [6]. An Indian report in 2019 indicates that the storage medium is a major factor among the various causes that affect the success rates of donated cornea utilization, which may reach 88% in developed countries with access to high-quality products [7]. Nowadays, different types of cold cornea storage media are used in corneal preservation for different purposes, such as corneal transplantation. Optisol (Bausch and Lomb Inc., Rochester, NY, USA), a hybrid of K-sol and Dexsol, was introduced in the early 1990s [5]. The addition of two different antibiotics, gentamicin sulfate and streptomycin sulfate, resulted in the development of Optisol-GS [5; 8; 9; 10]. This distinct pharmaceutical composition is used as a tissue culture medium, enriched with polypeptides, dextran (osmotic agent), chondro sulfate, and the aforementioned antibiotics. This commercial solution improved antimicrobial efficacy, even though there is still no hypothermic antifungal agent commercially available in the USA [5]. Optisol-GS is traditionally considered as the popular choice among storage media used in the United States and is the \"gold standard\" medium for preservation at 2-8 \({}^{\circ}\)C for up to 14 days before corneal transplantation [11]. However, regarding the cost perspective, Optisol-GS can be considered expensive and less affordable. [PERSON] et al. [12] pointed out that reasonably priced and effective storage media are an integral part of a successful cost-effective corneal transplantation program, especially in developing countries, leading to the need for a wider choice of available options for the international ophthalmological community. In this sense, advances in corneal preservation for keratoplasty are achieved by the development and proposal of novel formulations of cold storage media aimed at improving cost-effective corneal transplantation care [11].