## 3 Results
### Results of Synthesis
#### 3.4.1 Cornea Preservation Quantitative Parameters  
The most assessed quantitative parameter was the viable endothelial cell density (ECD) (Table 7) employed in nine of the studies [13; 22; 24; 26; 27; 29; 30; 31; 32]. Cornea (769) were evaluated by specular microscopy [13; 22; 26; 32; 34]. By assessing this parameter, Basak reported a significant difference for Cornisol at ten days (\(p\) = 0.049) [22]. Cornea Cold showed statistically significant results from 1 up to 4 weeks, with lower mortality and better preservation of endothelial cells in Cornea Cold when compared with Optisol-GS (\(p\) < 0.05) [13]. No significant difference was observed for Sinasol versus Optisol-GS for 14 days [28]. Regarding the relationship between time, temperature, and medium composition in Kerasave containing 2.5 mg/mL amphotericin B no statistically significant difference was observed from Optisol-GS up to 14 days at 2-8 \({}^{\circ}\)C at all tested time points [30; 32]. The ECD in Chen medium was not different between paired corneas at baseline [31]. Despite the Eusol-C medium having a significant difference in composition from Optisol-GS, no statistical difference was found between these solutions up to 7 days [34]. When amphotericin B was tested in Optisol-GS as an antifungal additive in three different concentrations, the decrease in ECD was more significant in the groups supplemented with 0.12-\(\upmu\)g/mL amphotericin B for corneas stored between 0-14 days [24]. On the other hand, the decrease in the donor corneal endothelial cell counts after a 7-day storage period in Optisol-GS with the antibiotic daptomycin did not differ significantly from that observed in paired controls stored in unsupplemented Optisol-GS [29]. A total of 266 corneas were evaluated in six studies employing central corneal thickness (CCT) as a measured parameter [13; 29; 30; 31; 32] (Table 8). There was no statistically significant difference in the CCT values between the Kerasave and Optisol-GS storage groups [30; 32]. The use of Cornea Cold resulted in an increase in corneal thickness compared with Optisol-GS at all exposure times (7, 14, 21, and 28 days) [13]. CTT increased in Chen medium (CM) stored corneas after three weeks of storage [31]. As observed with ECD, the inclusion of daptomycin as an additive of the Optisol-GS storage medium resulted in no statistical difference from unsupplemented Optisol-GS (control) during ten days [29]. \begin{table}
\begin{tabular}{c c c c} \hline
**Constituent** & **Optisol with Supplements** & **MEM with Supplements [18]** & **Coconut Water Solution [27]** \\ \hline \multirow{3}{*}{Base medium} & Tissue culture medium 199 & \multirow{3}{*}{MEM} & \multirow{3}{*}{ACP-412 powdered coconut water} \\  & Eagle’s balance salt solution and & & \\  & MEM & & \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Buffer} & HEPES & & Yes \\ \cline{1-1} \cline{2-4}  & Gentamicin, streptomicin, & No & Gentamicin 200 \(\upmu\)g/mL \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Chondroitin sulfate} & 2.5\% & 2.5\% & 2.5\% \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Dextran} & T-40 & No & 1\% \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{ATP precursors} & Yes & No & Not reported \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Sodium bicarbonate} & Yes & Yes & Not reported \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Asorbic acid} & Yes & No & Not reported \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Sodium pyruvate} & Yes & No & Not reported \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Antifungal additives} & \multirow{2}{*}{Voriconazole or amphotericin B} & No & Not reported \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Additional supplements} & \multirow{2}{*}{or vancomycin} & \multirow{2}{*}{No} & Not reported \\ \cline{1-1} \cline{2-4} \multirow{2}{*}{Additional supplements} & \(\alpha\)-tocopherol & & Not reported \\ \hline \end{tabular}
\end{table} 
Table 6: List of other modified media and alternative solution compositions.