Measurement of central corneal thickness and precorneal tear film thickness of rabbits using the Scheimpflug system

AIM:To measure central corneal thickness(CCT) and pre-corneal tear film thickness using the Galilei dual Scheimpflug analyzer(GSA) in New Zealand White rabbits.METHODS:Ten normal New Zealand White rabbits(20 eyes) were included in this study.With the assistance of 0.1% fluorescein,the pre-corneal tear film can be well visualized.Both eyes of each rabbit were scanned once with the GSA pre- and post-instillation of 1μL 0.1% fluorescein.The difference between the two measurements of CCT(4-mm diameter) was recorded as the pachymetric values of the central tear film.RESULTS:The CCT of pre- and post-instillation was 388.8±9.5μm and 407.0±10.5μm,respectively.After a paired t-test analysis,the central pre-corneal tear film thickness of 4mm diameter was 18.2±5.31μm with a 95% confidence interval of(15.7,20.6)μm(P<0.001).CONCLUSION:GSA can be used to measure CCT and analyze central tear film thickness of rabbits with the help of fluorescein.