Reliability of Noncontact Pachymetry after Laser In Situ Keratomileusis

Maldonado, Miguel J.; López-Miguel, Alberto; Nieto, Juan Carlos; Cano-Parra, J.; Calvo, Begoña; Alió, Jorge L.

doi:10.1167/iovs.09-3408

Cited by 17 publications

(10 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For CCT measurements, the 95% LoA using a single Scheimpflug imaging system, noncontact specular microscope (EM-3000, Tomey Corp.), and combined scanning-slit and Placido-disk topographer (Orbscan II, Bausch & Lomb) were reported to be À9.2 to 9.5 mm, À25.13 to 18.06 mm, and À32.1 to 26.4 mm, respectively. [19][20][21] In addition, Ali o and Piñero 22 found a significant corneal flap thickness variation after laser in situ keratomileusis of À9 mm to 37 mm, À12 mm to 31 mm, À9 mm to 23 mm using the M2 microkeratome (Moria), the Carriazo-Pendular microkeratome (Schwind Eye-Tech-Solutions GmbH & Co. KG), and the Intralase femtosecond laser (Abbott Medical Optics, Inc.), respectively. A meta-analysis showed the SD of the CCT in normal eyes is 31 mm.…”

Section: Discussionmentioning

confidence: 99%

Scheimpflug–Placido topographer and optical low-coherence reflectometry biometer: Repeatability and agreement

Chen

McAlinden

Pesudovs

et al. 2012

Journal of Cataract and Refractive Surgery

View full text Add to dashboard Cite

show abstract

Section: Discussionmentioning

confidence: 99%

Scheimpflug–Placido topographer and optical low-coherence reflectometry biometer: Repeatability and agreement

Chen

McAlinden

Pesudovs

et al. 2012

Journal of Cataract and Refractive Surgery

View full text Add to dashboard Cite

show abstract

“…A biometric parameter commonly reported in the literature is the central corneal thickness (CCT) which may be used to evaluate normal corneal development and to diagnose a variety of ocular/corneal pathologies (Ashwin et al, 2009; Doughty and Zaman, 2000; Fontes et al, 2010; Hager et al, 2009; Insull et al, 2010; Montiani-Ferreira et al, 2003) as well as pre- and post-surgical conditions (Maldonado et al, 2009). It is also a consideration in contact lens fitting and continuing care for contact lens wearers (Martin et al, 2007; Oh et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Assessment of postnatal corneal development in the C57BL/6 mouse using spectral domain optical coherence tomography and microwave-assisted histology

Hanlon¹,

Patel²,

Burns³

2011

Experimental Eye Research

View full text Add to dashboard Cite

The eyes of newborn mice are relatively underdeveloped and the lids remain closed for the first 2 weeks after birth. There after the eyes undergo a period of rapid growth for several weeks. Eventually the eyes reach an age at which many ocular structures stabilize for the remainder of the animal’s life, or for others, growth is significantly slowed. The central corneal thickness (CCT) is a parameter commonly reported in corneal studies. However there is a large discrepancy in values reported for adult mice as well as a lack of comprehensive values covering the time from birth through adulthood. In this study we report, for the first time, the use of spectral domain optical coherence tomography (SD-OCT) for in situ and in vivo determination of CCT from P0 to P250 for C57BL/6 mice. SD-OCT provided a reliable measure of CCT and we fit the data to an exponential rise to maximum growth curve resulting in a value of 49μm for P0 and a maximum adult value of 106μm. By comparison, corneas processed for conventional histology produced CCT values approximately 30–35% thicker and with greater variability. Ex vivo real-time imaging during fixation revealed swelling and gross distortion of the cornea beginning after only 10–15 minutes in fixative. The fixation artifacts were not observed when the cornea was processed using an optimized microwave fixation protocol. CCT values measured in corneas fixed with the microwave process compared favorably with values obtained with SD-OCT. We conclude that for corneal research, mice younger than 8 weeks of age should not be considered as adults since they are still in a rapid phase of growth up until that time. In addition we report the first use of microwave-processed histological specimens for visualizing the murine cornea. Tissue processed in this manner has minimal artifacts, a CCT equivalent to that measured in vivo by SD-OCT and ultrastructural detail comparable to conventional fixation methods.

show abstract

“…2 The main limitation of the current study is that the reason for the variability between measurements showed a wide distribution between methods was not completely addressed, although it can be explained by the measurement repeatability of Orbscan-II being generally lower than that of Topcon NCSM in postmyopic LASIK patients. 35 In addition, this study included only patients who had undergone LASIK to treat myopia, and, therefore, the conclusions cannot be applied to patients with hyperopia, in whom the postoperative corneal shape is more prolate. Finally, ultrasonic pachymetry was not performed in the study eyes, thus precluding direct comparison of both non-contact methods with the gold standard in order to find out which of the two is closer to the 'true' value.…”

Section: Discussionmentioning

confidence: 99%

Agreement of non-contact pachymetry after LASIK: comparison of combined scanning-slit/Placido disc topography and specular microscopy

López-Miguel

Nieto

Díez-Cuenca

et al. 2009

Eye

View full text Add to dashboard Cite

Purpose To assess the interchangeability of central corneal thickness (CCT) measurements between combined scanning-slit/Placido disc topography (Orbscan-II) and specular microscopy (Topcon SP-2000P) in patients who underwent laser in situ keratomileusis (LASIK) for myopia. Patients and methods We recruited 118 consecutive patients who underwent LASIK for myopia. The CCT was measured using Orbscan-II and Topcon SP-2000P randomly. Orbscan-II and Topcon SP-2000P CCT data were analysed using the paired-sample t-test and the limits of agreement (LoA) were calculated with the method described by Bland-Altman. Results The average CCT measurements by Orbscan-II and Topcon SP-2000P were 447.55 ± 49.78 lm and 461.38 ± 35.35 lm, respectively (Po0.0001; mean difference, 13.83±22.31 lm; 95% confidence interval, 9.77-17.09 lm). The Bland-Altman plot showed an inverse association between the average and the difference between the devices: TopconOrbscan-II ¼ 174.23 -0.353 Â Average (Po0.01). The widths of the crude and regression-based 95% limits of agreement were 87.45 and 63.72 lm, respectively. Conclusions Orbscan-II measurements of CCT after myopic LASIK were significantly lower than those obtained using Topcon SP-2000P. The limits of agreement between the two devices were too broad and, therefore, both pachymetric values cannot be used interchangeably. Further, the tendency towards comparably Orbscan-II readings in thinner corneas precludes that one technique can directly replace the other. This is important for the adequate medium-and longterm follow-up of the growing LASIK patient population.

show abstract

Reliability of Noncontact Pachymetry after Laser In Situ Keratomileusis

Cited by 17 publications

References 53 publications

Scheimpflug–Placido topographer and optical low-coherence reflectometry biometer: Repeatability and agreement

Scheimpflug–Placido topographer and optical low-coherence reflectometry biometer: Repeatability and agreement

Assessment of postnatal corneal development in the C57BL/6 mouse using spectral domain optical coherence tomography and microwave-assisted histology

Agreement of non-contact pachymetry after LASIK: comparison of combined scanning-slit/Placido disc topography and specular microscopy

Contact Info

Product

Resources

About