To the Editor.—We would like to express a word of caution regarding the use of the XANAR vitreous fluorophotometer1 in the evaluation of retinal capillary permeability. Although our initial data recovered from this experimental model were found to be statistically significant,1,2 further investigations at our institution did not reveal such definitive results.
The fluorophotometer may be so sensitive in the measurement of retinal capillary fluorescein leakage (to 10−9 g/mL) that there may be variation in measurements due to positioning of the slit lamp. One must also compare post—septic-challenge fluorescein concentrations to initial preseptic values and not absolute values between different dogs.
The vitreous fluorophotometer has great potential as a diagnostic tool in the evaluation of capillary permeability changes. We hope that other physicians with better laboratory research funding will test this model further.