# An Alternative Approach to Cataract Surgery Using BSS Temperature of 2.7 \({}^{\circ}\)C
## 2 Materials and Methods  
All subjects gave their informed consent for inclusion before they participated in the study. The study was performed according to the ethical principles set in the Declaration of Helsinki [15], and the protocol was approved by the Ethics Committee of Messina, Italy (Project identification code 43/19). The study was conceived and developed in two steps: a preclinical one, simulated on experimental models, and a clinical one, conducted on 214 patients. In the first step, tests were conducted on an artificial eye model, made of PLA using a 1:1 scale 3D printer [16] and designed for the evaluation of the temperature variation (detected by an immersion probe) near the tip of the phacoemulsifier under different conditions. A thermometer with an immersion probe (WTW pH315i), an operating range between \(-\)5.0 \({}^{\circ}\)C and \(+\)105.0 \({}^{\circ}\)C, and a resolution of 0.1 \({}^{\circ}\)C, was employed for in this phase [17]. Tests were carried out in the operating room (its temperature and humidity were recorded). The temperature of the BSS employed during the simulation of the intervention (for a representative time of 15 min) was monitored in two specific conditions:  
1. Bottle kept in the operating room for at least three hours
2. Bottle kept in a thermal \"coat\" made of water and ice. In the second step, the effects of different temperatures during cataract phacoemulsification were investigated. Two hundred and fourteen patients of both sexes, in apparent good health, were enrolled from among patients that had to undergo cataract surgery from the central vitreous cavity, aged from 55 to 75 years (mean age 69 \(\pm\) 8.3 years, M:F = 130:84). Each patient was classified using an internal protocol, i.e., the degree of the cataract according to the Lens Opacities Classification System III (LOCSIII) [18]. Table 1 reports the degrees of the cataracts included in the study, for each feature proposed in [18] Patients with degree 3 or higher cataracts were included in the study. The exclusion criteria from the study were proliferative diabetic retinopathy, previous corneal diseases or any ocular surgical procedures, glaucoma, infections, autoimmune diseases, and malignant \begin{table}
\begin{tabular}{c c c} \hline \hline
**LOCS III Classification** & **Grade of Opacities** & **\% of Patients** \\ \hline Nuclear Opalescence (NO) and Nuclear Color (NC) & \(\geq\)3 & 75\% \\ \hline Cortical Cataract (C) & \(\geq\)3 & 20\% \\ \hline Posterior Subcapsular Cataract (P) & \(\geq\)3 & 5\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Cataract grade of patients, according to Lens Opacities Classification System (LOCSIII) classification, included in the study. All treated cataracts were cortical/nuclear, as it is difficult to provide a clear distinction between them. neoplasias. All patients were pretreated three days prior to the cataract surgery with 1% sodium hypochlorite 2X/day to deteriorate periorbital skin, 0.3% ofloxacin 1 gtt (abbreviation from the Latin \"_gutate_\") 3X/day, and bromfenac (0.9 mg/mL) 1 gtt 2X/day. Patients were treated using a stable mydriasis for successful cataract surgery and lens implantation (0.28 mg/5.4 mg) (Mydriasert(r), Thea Farma S.p.A., Milan, Italy). The 214 patients were randomly divided into two groups. Group A comprised 110 patients treated with BSS at room temperature in the operating room (i.e., about 20 \({}^{\circ}\)C). Group B comprised 104 patients treated with BSS at 2.7 \({}^{\circ}\)C.  
To standardize the two groups, clinical and demographic variables were chosen. In Table 2, the demographic data and the preoperative status lens of the two groups are reported. The use of the thermal \"coat\" of ice and water ensured that there was no temperature variation during the surgery.