Abstract
Purpose :
SC injections have been performed over 1,000 times, emerging as an effective drug delivery route to the back of the eye. Retrospective correlations were performed between procedural and patient characteristics across 3 indications and 6 clinical trials. Specifically, SC injection completion rate with 900 µm needle, as opposed to switching to the 1100 µm needle, was evaluated.
Methods :
Post hoc analyses were conducted to evaluate the relationship between needle length for baseline SC injection and patient characteristics across 6 clinical trials (AZALEA, PEACHTREE, TYBEE, TANZANITE, SAPPHIRE and TOPAZ) and 3 diseases (non-infectious uveitis, diabetic macula edema and retinal vein occlusion). Pearson chi-square analysis and biserial correlations were performed for univariate analysis of categorial and continuous variables, respectively. Multivariate logistical regression was developed to confirm univariate findings.
Results :
Overall, 71% (412 of 581) of baseline injections were completed with the 900 µm needle while the rest were completed with the 1100 µm needle. No statistical relationships were found between needle length and indication, age, visual acuity, intraocular pressure, retinal central subfield thickness, lens status or race. Gender and administration quadrant were found to statistically (p<0.05) correlate with needle length both in the univariate and multivariate analyses: 76% (209 of 275) of injections were completed with 900 µm needles for female patients while 66% (202 of 306) were completed for male patients. Furthermore, 78% (214 of 275) of injections were completed with the 900 µm needle in the superotemporal quadrant while 65% (73 of 113) were completed in the inferotemporal quadrant. The variations in administration quadrant corroborates literature reports of thinner sclera in the superior hemisphere, compared to the inferior, at the pars plana. The variations by gender could be confounded by other factors, such as height or weight differences, which were not assessed.
Conclusions :
To date, this is the largest aggregate dataset of SC clinical injections with mounting evidence pointing to the reliability and consistency of the procedure. Despite the retrospective nature of the analyses, the results demonstrated the robustness of the SC injection regardless of indications. The two needle length options successfully accommodate for anatomical variations across patients.
This is a 2020 ARVO Annual Meeting abstract.