Cooling Anesthesia for Intravitreal Injection: Results of the Prospective Open-Label, Dose-Ranging COOL-1 Trial

Figures & data

Figure 1 Numerical Rating Scale used in the COOL-1 study.

Figure 2 The components of the Cooling Anesthesia Device. (A) The hand-held device, which cools the single-use tips through a high performance thermoelectric cooling module powered by rechargeable batteries. (B) A single-use tip, which includes metal surface delivering the cooling treatment to the conjunctiva for instant anesthetic effect. (C) The battery charging dock, which is used to recharge the device.

Table 1 COOL-1 Subject Demographics

Demographics	Number
Men, n (%)	24 (55.8)
Women, n (%)	19 (44.2)
Age at screening, yrs, mean± SD, (range)	70.8±13.8 (33, 93)
# of previous injections, mean±SD, (range)	22.6±12.7 (3, 44)
AMD, n (%)	26 (60.4)
DME n, (%)	12 (27.9)
RVO n, (%)	4 (9.3)
DR n (%)	1 (2.4)

Table 2 Adverse Events. Parenthesis is Percentage Among All Cooling Applications (n = 43)

Adverse Event	−10°C for 20 Seconds (n = 20)	−15°C for 15 Seconds (n = 14)	−15°C for 20 Seconds (n = 9)
Ocular AE	0	0	0
Serious ocular AE	0	0	0
Syncope	1 (2.3)	0	0
Endophthalmitis	0	0	0
Corneal Abrasion	0	0	0

Table 3 Comparison of NRS Pain Scores Among Differing Groups

Group	−10° C for 20 Seconds	−15°C for 15 Seconds	−15°C for 20 Seconds	One-Way ANOVA Score P value
Pain during cooling application (mean±SD)	2.7±2.15	2.75±1.64	3.89±3.0
Pain score at time of injection (mean±SD)	3.7±2.5	2.5±1.7	4.3±1.8	0.13
Pain score 5 minutes post injection (mean±SD)	1.2±1.3	1.2±2.1	1.1±1.1	0.27
Pain score 24–48 hours post injection (mean±SD)	0.1±0.3	0.6±1.4	0.1±0.4	0.53

Figure 3 Numerical Rating Scale scores between different cooling treatments. (A) Numerical Rating Scale (NRS) scores at time of injection. Bars are illustrated as mean with 95% confidence intervals as error bars. (B) NRS scores 5 minutes after Injection. Bars are illustrated as mean with 95% confidence intervals as error bars. (C) NRS scores 24–49 hours after injections. Bars are illustrated as mean with 95% confidence intervals as error bars. *P < 0.05 n.s. not statistically significant, as measured by one way ANOVA.

Figure 4 Numerical Rating Scale (NRS) scores over time. NRS scores at time of injection, 5 minutes after injection, and 24–48 hours injection for each group. Bars are illustrated as mean with 95% confidence intervals as error bars. *P < 0.05, **P < 0.01, ***P < 0.001, as measured by paired t-test.