Comparative analysis of pupillometry in two scheimpflug-based measurement systems

Area of Science:

• Ophthalmology
• Optometry
• Medical Device Technology

Background:

• Accurate pupillometry and keratometry are crucial for ophthalmic assessments and refractive surgery planning.
• Comparing measurement devices under various conditions ensures reliable clinical data.
• The Sirius™ and AL-Scan™ are modern devices used for ocular measurements.

Purpose of the Study:

• To compare pupillometry measurements (photopic and mesopic) between the Sirius™ and AL-Scan™ devices.
• To evaluate and compare the topographic (keratometric) measurements from both devices.
• To assess device agreement under different lighting conditions.

Main Methods:

• A prospective study included 45 non-smoking patients aged 18-45 years with spherical equivalents between +3.00 D and -5.00 D.
• Pupillometry was measured after 1 minute of dark adaptation.
• Keratometry (K1, K2, KAvg) and pupillometry (photopic and mesopic) were compared between the Sirius™ and AL-Scan™ devices.

Main Results:

• Mesopic pupillometry (MP) showed good correlation between Sirius™ and AL-Scan™ (p=0.65).
• Keratometric values (K1, K2, KAvg) and photopic pupillometry (PP) showed no significant agreement between the devices (p<0.05).
• AL-Scan™ average K1, K2, Kavg: 42.99±1.50 D, 44.04±1.74 D, 43.58±1.62 D.
• Sirius™ average K1, K2, Kavg: 42.94±1.51 D, 43.90±1.75 D, 43.41±1.61 D.
• Average PP: AL-Scan™ 3.97±1.08 mm, Sirius™ 5.05±1.04 mm.
• Average MP: AL-Scan™ 6.04±1.08 mm, Sirius™ 6.01±1.08 mm.

Conclusions:

• The Sirius™ and Nidek AL-Scan™ devices provide comparable mesopic pupillometry data.
• Photopic pupillometry measurements are inconsistent between the two devices.
• Further investigation is required for optimal device selection when repeated pupillometry data is needed.