Clinical application of the Swiss Liquid Jet Aesthesiometer for corneal sensitivity measurement

Age-Related Changes in Corneal Sensitivity

“…Stimulus intensity is controlled with variable pressure levels, and its working principle and relevant physical properties, as well as its reliability for clinical application, were recently described elsewhere. 51,52 Corneal sensitivity measurements with means of SLACS were compared with those obtained with the only commercially available CB esthesiometer, which applies a mechanical stimulus in the form of a fine nylon filament to the cornea with varying pressures by adjusting its length to produce different stimulus intensities to the ocular surface. Although the SLACS stimulus differs in nature from the nylon filament, it was heated to match the OST to eliminate any thermal components and to generate a stimulus of mechanical nature.…”

“…The working principle and relevant physical properties of this new prototype as well as its reliability for clinical application have been recently described elsewhere. 51,52 The aim of this study was 1) to clinically explore whether corneal sensation thresholds differ between 2 different age groups, for each of the 2 stimulus types applied, and 2) to correlate corneal sensitivity thresholds and general pain perception.…”

Corneal Nerve Assessment by Aesthesiometry: History, Advancements, and Future Directions

“…Using a gas jet of carbon dioxide of adjustable flow and temperature, this device allowed for corneal stimulation by thermal, mechanical, and chemical means [ 17 , 34 ]. Later development of the CRCERT-Belmonte aesthesiometer allowed the clinician to control the temperature of the gas jet to minimize the thermal component of the stimulus [ 35 ]. The next innovation in esthesiometry came as a further modified noncontact aesthesiometer—the Swiss Liquid Jet Aesthesiometer—which employed small saline droplets at varying pressure levels to detect evidence of corneal hypo- or anesthesia [ 35 , 36 ].…”

“…Later development of the CRCERT-Belmonte aesthesiometer allowed the clinician to control the temperature of the gas jet to minimize the thermal component of the stimulus [ 35 ]. The next innovation in esthesiometry came as a further modified noncontact aesthesiometer—the Swiss Liquid Jet Aesthesiometer—which employed small saline droplets at varying pressure levels to detect evidence of corneal hypo- or anesthesia [ 35 , 36 ]. Most recently, the introduction of the Corneal Esthesiometer Brill, which employs a pulse of air to the corneal surface, offers a handheld alternative to traditional non-contact corneal aesthesiometers [ 37 ] ( Table 2 ).…”

“…Variations in the corneal location assessed, the subjective nature of what constitutes a bent filament, and the angle at which a clinician holds the aesthesiometer when approaching the eye can affect what is considered above or below threshold [ 42 ]. Additionally, the degree of apprehension the patient has regarding the invasive test and the visibility of the approaching instrument serve as other subjective factors with the potential to alter threshold values with the Cochet–Bonnet device [ 35 , 43 , 52 ]. This is especially true in the case of low-intensity stimuli, which the Cochet–Bonnet has been shown to be less effective at evaluating compared to other aesthesiometry devices [ 35 , 43 , 44 ].…”