The authors have no financial interestThe authors have no financial interest

Blanco Torcal B; Sánchez-Pina, JMª; Lorente Hevia P; Villar Arrondo E; Carrillo Ramos V; García-Pérez J;

Álvarez-Rementería Capelo L.

INTRODUCTION Ultrasound pachymetry (US) is the gold standard to

measure central corneal thickness (CCT) limitations : 1-3

Reproducibility , Contact instrument , Mild patient discomfort, …

Studies comparing CCT between US and noncontact devices : 4-10

low-coherence reflectometry optical coherence tomography (OCT) scanning-slit topography/ pachymetry noncontact specular microscope rotating Scheimpflug camera.(Pentacam, Galilei, Sirius)…

1.Gordon A, Boggess EA, Molinari JF (1990) Variability of ultrasonic pachometry. Optom Vis Sci; 67:162-165.2.Miglior S, Albe E, Guareschi M, et al. Intraobserver and interobserver reproducibility in the evaluation of ultrasonic pachymetry measurements of central corneal thickness. Br J Ophthalmol 2004; 88:174–1773.Marsich MM, Bullimore MA. The repeatability of corneal thickness measures. Cornea 2000; 19:792–7954.Barkana Y, Gerber Y, Elbaz U, Schwartz S, Ken-Dror G, Avni I, Zadok D (2006) Central corneal thickness measurement with the Pentacam Scheimpflug system, optical low-coherence reflectometry pachymeter, and ultrasound pachymetry. J Cataract Refract Surg; 31:1729-1735.5. Bechmann M, Thiel MJ, Neubauer AS, et al. Central corneal thickness measurement with a retinal optical coherence tomography device versus standard ultrasonic pachymetry. Cornea 2001; 20: 50–546. Chakrabarti HS, Craig JP, Brahma A, et al. Comparison of corneal thickness measurements using ultrasound and Orbscan slit-scanning topography in normal and post-LASIK eyes. J Cataract Refract Surg 2001; 27:1823–18287.Suzuki S, Oshika T, Oki K, Sakabe I, Iwase A, Amano S, Araie M (2003) Corneal thickness measurements: scanning-slit corneal topography and noncontact specular microscopy versus ultrasonic pachymetry. J Cataract Refract Surg; 29:1313-1318.8. Barkana Y, et al. Central corneal thickness measurement with the Pentacam Scheimpflug system, optical low-coherence reflectometry pachymeter, and ultrasound pachymetry J Cataract Refract Surg 2005; 31:1729–17359. Huang J et al; Precision of a new Scheimpflug and Placido-disk analyzer in measuring corneal thickness and agreement with ultrasound pachymetry; J Cataract Refract Surg 2013; 39:219–224.10. Faramarzi A et al; Central corneal thickness measurements after myopic photorefractive keratectomy using Scheimpflug imaging, scanning-slit topography, and ultrasonic pachymetry; J Cataract Refract Surg 2010; 36:1543–1549

But to our knowledge, this is the first study to compare OCULUS-Pentacam® CCT measurements with the NIDEK CEM-530 Specular microscope.

PURPOSETo compare central corneal thickness in cataratous

adult eyes measured with OCULUS-Pentacam® and with the NIDEK CEM-530 Specular microscope.

METHODS Prospective, observational and cross-sectional study.

CCT was measured in 84 right eyes of 84 consecutive patients .

All CCT measurements were performed by the same examiner, using a: Rotating Scheimpflug camera topographer (OCULUS-Pentacam®) before and after cataract

surgery NIDEK CEM-530 (specular microscope) previous to the surgery

All measurements were made between 4 and 7 p.m. to avoid diurnal variations of CCT.

The mean of 3 measurements was calculated for each case with the 3 devices.

Specular before Surgery

Pentacambefore Surgery

PentacamAfter Surgery

CCT (μm) 554.72 ± 29.82 546.09 ± 27.44 546.44 ± 29.33

RESULTS

• The Paired Student's t-test only show a statistically significant difference (p<0.05) comparing the pachymetry before cataract surgery with the two devices.

CONCLUSION NO difference in CCT measurements in adult eyes before and after cataract

extraction with Pentacam® can suggest that the lens opacity does not affect the pachymetry can also suggest that cataract surgery performed without problems does not change

the corneal thickness.

There was a statiscally significative difference in CCT between OCULUS-Pentacam® and NIDEK CEM-530 in eyes before cataract surgery, but is not clinically relevant.

The OCULUS-Pentacam® Rotating Scheimpflug camera topographer and NIDEK CEM-530 specular microscope seems to be 2 interchangeable non-contact devices to measure CCT.

CONCLUSION NO difference in CCT measurements in adult eyes before and after cataract

extraction with Pentacam® can suggest that the lens opacity does not affect the pachymetry can also suggest that cataract surgery performed without problems does not change

the corneal thickness.

There was a statiscally significative difference in CCT between OCULUS-Pentacam® and NIDEK CEM-530 in eyes before cataract surgery, but is not clinically relevant.

The OCULUS-Pentacam® Rotating Scheimpflug camera topographer and NIDEK CEM-530 specular microscope seems to be 2 interchangeable non-contact devices to measure CCT.