Measurement of corneal thickness using Pentacam HR versus Nidek CEM-530 specular microscopy

Objective To compare corneal thickness (CT) measurements using the CEM-530 (Nidal, Gamagori, Japan) and Pentacam HR (Oculus, Wetzlar, Germany). Methods The CT of 209 healthy subjects (209 right eyes) aged 24 to 89 years (71.35 ± 10.72 years) was measured at the corneal apex (CA), pupil center (PC), and thinnest point (TP) with the Pentacam HR and at the corneal center with the CEM-530 in random order at the same time of day. Results A good correlation but statistically significant difference was found between the CEM-530 and Pentacam HR measurements at the CA (6.10 ± 8.12 µm, R2 = 0.8947), PC (7.46 ± 8.57 µm, R2 = 0.8826), and TP (12.44 ± 10.04 µm, R2 = 0.8392). Comparison of the two devices produced the following regression formulas: y = 0.8859x + 57.644 for the CA, y = 0.8852x +56.657 for the PC, and y = 0.8557x + 68.148 for the TP, where x is the CT obtained with the CEM-530 and y is that obtained with the Pentacam HR. Conclusions These findings indicate that the CEM-530 produces a thicker corneal measurement than the Pentacam HR. The herein-proposed correcting factors are needed to reliably compare these devices.

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Corneal thickness evaluation in healthy eyes: Comparison between two different Scheimpflug devices

PLoS ONE ◽

10.1371/journal.pone.0243370 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243370

Author(s):

Nicola Rosa ◽

Maddalena De Bernardo ◽

Angela Pepe ◽

Livio Vitiello ◽

Giuseppe Marotta ◽

...

Keyword(s):

Observational Study ◽

Corneal Thickness ◽

Pupil Center ◽

Regression Formula ◽

Ct Measurements ◽

Corneal Apex ◽

Thickness Evaluation ◽

Healthy Eyes

Purpose To evaluate the correlation between corneal thickness (CT) measurements obtained with two Scheimpflug devices, Pentacam HR and Precisio, and to elaborate, if necessary, a regression formula which could make these results comparable. Design Retrospective, Comparative, Observational study. Setting Department of Medicine, Surgery and Dentistry, “Scuola Medica Salernitana” University of Salerno, Italy Methods One hundred twenty four healthy eyes of 124 volunteers (65 males; range: 20–32 years; mean age of 24.8 ± 1.7) were included in this study. CT was measured using Pentacam HR and Precisio in three different points: the pupil center (PC), the corneal apex (CA) and the thinnest point (TP). Results CT obtained with both devices at the PC, at the CA and at the TP showed a good correlation (r = 0.97, r = 0.97, r = 0.97, respectively), but Pentacam HR measurements were significantly thicker than those provided by Precisio (p < 0.01). The differences between Pentacam HR and Precisio were 21.9 ± 8.8 μm at the PC, 21.9 ± 8.9 μm at the CA, 19.1 ± 9.0 μm at the TP. The calculated regression formulas were: y = 0.9558x + 2.3196 for the PC, y = 0.9519x + 4.5626 for the CA, y = 0.9364x + 15.436 for the TP, where x is the CT measured with Pentacam HR and y is the Precisio measurement. Conclusions The findings provided by this study highlight that Precisio measures thinner corneas compared to Pentacam HR. The identified regression formulas could be utilized to make interchangeable the results obtained with these two devices.

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Comparison between two devices in the detection of corneal thickness changes after cataract surgery

Scientific Reports ◽

10.1038/s41598-021-86158-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Maddalena De Bernardo ◽

Livio Vitiello ◽

Giulia Abbinante ◽

Ilaria De Pascale ◽

Luigi Capasso ◽

...

Keyword(s):

Cataract Surgery ◽

Corneal Thickness ◽

Specular Microscopy ◽

Slit Lamp ◽

Thickness Increase ◽

Pupil Center ◽

Scheimpflug Camera ◽

Corneal Apex

AbstractThis study compared corneal thickness (CT) changes obtained with specular microscopy (SM) and a rotating Scheimpflug camera (RSC) after conventional phacoemulsification surgery (PS). One hundred sixty six eyes of 83 patients were analyzed before and one month after PS. One eye underwent PS, while the fellow phakic one was used as control. CT was measured with SM at the center of the cornea and with RSC at the pupil center, at the corneal apex and at the thinnest point. In the operated eye, SM showed a larger CT mean increase than those one detected at the three different measurements’ points evaluated by RSC. Inversely, in the fellow phakic eye, SM showed a greater CT mean decrease than those one registered by RSC at its three measurement’s points. Thus, one month after surgery, even if cornea appears clear at the slit-lamp, a significant thickness increase is still present. This is even more evident if the slight decrease of the fellow phakic eye is considered. The differences between the two devices are probably related to the different measured areas.

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Comparison of Anterior Ocular Biometric Measurements Using Swept-Source and Time-Domain Optical Coherence Tomography

Journal of Ophthalmology ◽

10.1155/2020/9739878 ◽

2020 ◽

Vol 2020 ◽

pp. 1-6

Author(s):

Sisi Chen ◽

Rongrong Gao ◽

Colm McAlinden ◽

Junming Ye ◽

Yiran Wang ◽

...

Keyword(s):

Time Domain ◽

Corneal Thickness ◽

Intraclass Correlation ◽

Anterior Segment ◽

Anterior Chamber Depth ◽

Correlation Coefficients ◽

Random Order ◽

Optical Coherence ◽

Swept Source ◽

Significant Difference

Purpose. To compare central corneal thickness (CCT), aqueous depth (AQD), and anterior chamber depth (ACD) measurements using the swept-source (CASIA SS-1000, Tomey, Japan) and time-domain (Visante, Carl Zeiss Meditec, USA) anterior segment optical coherence tomographers (OCT) in normal eyes. Methods. Sixty-eight eyes of 68 subjects were included. Three consecutive scans of each subject were obtained using both devices in a random order by one experienced operator. Standard deviation (Sw), coefficient of repeatability (CoR), coefficients of variation (CoV), and intraclass correlation coefficients (ICC) were used to evaluate the intraoperator repeatability. Agreement was assessed using the Bland–Altman plots and 95% limits of agreement (LoA). Results. All measurements of the swept-source OCT (SS-OCT) and time-domain OCT (TD-OCT) showed high repeatability with low CoR (CCT: 2.34 μm and 6.16 μm; AQD: 0.05 mm and 0.09 mm; ACD: 0.06 mm and 0.09 mm), low CoV (CCT: 0.16% and 0.42%; AQD: 0.61% and 0.97%; ACD: 0.53% and 0.83%), and high ICC (>0.98). The mean CCT with SS-OCT was slightly thicker than the results with TD-OCT (difference = 4.55 ± 2.62 μm, P<0.001). There was no statistically significant difference in AQD or ACD measurements between the two devices (0.01 ± 0.05 mm, P=0.111; 0.02 ± 0.05 mm, P=0.022, respectively). The 95% LoA between the SS-OCT and TD-OCT were −0.59 to 9.69 μm for CCT, −0.10 to 0.12 mm for AQD, and −0.09 to 0.12 mm for ACD. Conclusions. High levels of repeatability and agreement were found between the two devices for all three parameters, suggesting interchangeability. SS-OCT demonstrated superior repeatability compared with TD-OCT.

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Study of central corneal thickness using non-contact techniques: Specular microscopy (Nidek CEM-530), corneal tomography (Pentacam HR), and optical coherence tomography (Cirrus HD-OCT 5000) in healthy adult patients

Ciencia y Tecnología para la Salud Visual y Ocular ◽

10.19052/sv.4365 ◽

2018 ◽

Vol 16 (1) ◽

pp. 25-31

Author(s):

Patricia González-Rodríguez ◽

Vanesa Blázquez-Sánchez ◽

Sara Fernández-Cuenca

Keyword(s):

Optical Coherence Tomography ◽

Central Corneal Thickness ◽

Healthy Adult ◽

Adult Population ◽

Corneal Thickness ◽

Adult Patients ◽

Specular Microscopy ◽

Optical Coherence ◽

Significant Difference ◽

Corneal Tomography

Objective: To study and compare the value of central corneal thickness in a healthy adult population, using different non-contact techniques from daily clinical practice. Method: This work examines and compares the pachymetric measurements of 71 eyes of 36 healthy adult patients. Corneal thickness was evaluated using three non-contact instruments: a CEM-530 specular microscope (Nidek), Pentacam HR corneal tomography (Oculus), and Cirrus HD-OCT 5000 optical coherence tomography (Carl Zeiss Meditec). Tests were performed consecutively by a single observer in the same session and under the same environmental conditions. Results: The results obtained using the three devices are interchangeable, given that no statistically signiﬁcant difference was observed among them. The study did not ﬁnd statistically signiﬁcant difference with respect to gender either. Conclusion: These three non-contact methods for the measurement of corneal central pachymetry are a reliable alternative to ultrasonic contact pachymetry.

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Influence of diabetes mellitus on corneal thickness

Srpski arhiv za celokupno lekarstvo ◽

10.2298/sarh1410529s ◽

2014 ◽

Vol 142 (9-10) ◽

pp. 529-534 ◽

Cited By ~ 2

Author(s):

Ivan Sencanic ◽

Miroslav Stamenkovic ◽

Vesna Jovanovic ◽

Sinisa Babovic ◽

Vesna Jaksic ◽

...

Keyword(s):

Diabetes Mellitus ◽

Diabetic Retinopathy ◽

Healthy Subjects ◽

Corneal Thickness ◽

Ultrastructural Changes ◽

Control Group ◽

Diabetic Patients ◽

Ophthalmological Examination ◽

Study Results ◽

Significant Difference

Introduction. Ultrastructural changes in corneas of patients with diabetes mellitus have been previously described. Objective. The aim of this study was to compare central corneal thickness (CDR) values in diabetic patients without retinopathy at the stage of diabetic nonproliferative and proliferative retinopathy and CDR in a control group of healthy subjects. Methods. The study included 121 diabetic patients and 125 healthy subjects matched according to gender and age. Each patient underwent ophthalmological examination involving a dilated fundus examination and CDR measurement using the ultrasound pachymeter. The eyes of diabetic patients were classified according to Early Treatment Diabetic Retinopathy Study into three groups: without diabetic retinopathy (NDR), with nonproliferative diabetic retinopathy (NPDR) and a group with proliferative diabetic retinopathy (PDR). Only one eye of each subject was chosen for the study. Results. The mean CDR value was significantly higher in the diabetic group (570.52?31.81 ?m) compared with the control group (541.42?27.82 ?m). The difference between the two groups was statistically significant (p<0.0001). The highest mean CDR value was recorded in the PDR group (585.97?28.58 ?m), followed by the NPDR group (570.84?30.27 ?m), whereas the lowest mean CDR value was recorded in the NDR group (559.80?31.55 ?m). There was a statistically significant difference in CDR between the NDR and PDR groups, as well as between the NPDR and PDR groups (p<0.001, p<0.05 respectively). No significant difference was recorded between the NDR and NPDR groups (p>0.05). Conclusion. CDR of diabetic patients was higher compared to healthy subjects. The highest mean value of CDR was registered in the PDR group, followed by the NPDR and the NDR groups.

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Evaluation of Optical Low Coherence Reflectometry Parameters in Patients with Exfoliation Syndrome

Journal of Ophthalmology ◽

10.1155/2015/658091 ◽

2015 ◽

Vol 2015 ◽

pp. 1-4

Author(s):

Emrullah Beyazyıldız ◽

Özlem Beyazyıldız ◽

Süleyman Günaydın ◽

Emrah Kan ◽

Mert Şimşek ◽

...

Keyword(s):

Healthy Subjects ◽

Corneal Thickness ◽

Anterior Chamber Depth ◽

Exfoliation Syndrome ◽

Low Coherence ◽

Significant Difference ◽

The Mean ◽

Group 2 ◽

Optical Low Coherence Reflectometry ◽

Group 1

Purpose. To evaluate optical low coherence reflectometry (OLCR) parameters in patients with exfoliation syndrome (EXS) undergoing cataract surgery.Methods. Forty-seven eyes of 47 patients with EXS (Group 1), and 55 eyes of 55 healthy subjects (Group 2) were included in the study. Anterior chamber depth (ACD), lens thickness (LT), axial length (AL), central corneal thickness (CCT), horizontal corneal length (HCL), and pupil diameter (PD) parameters were measured by OLCR (Lenstar LS 900, Haag-Streit) and compared between groups. Shapiro-Wilk test and Mann WhitneyUtests were used for statistical analyses.Results. The mean ACD, HCL, and PD values were significantly lower in EXS group than in healthy subjects (P= 0.01,P= 0.04, andP<0.001, resp.). The mean LT was significantly higher in EXS group than in healthy subjects (P= 0.007). There was no significant difference between groups in means of AXL and CCT.Conclusions. According to OLCR measures, eyes with EXS have shallower ACD, smaller PD, thicker LT, shorter HCL, and no significantly different CCT levels.

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The Effect of Body Posture Changes and Central Corneal Thickness on Intraocular Pressure among Healthy Malays

Walailak Journal of Science and Technology (WJST) ◽

10.48048/wjst.2021.9172 ◽

2021 ◽

Vol 18 (6) ◽

Author(s):

Nadiah RASHIDI ◽

Md Muziman Syah MD MUSTAFA ◽

Norsham AHMAD ◽

Megat Ahmad Fadhil MEGAT BASRI ◽

Nor Ariza MOHAMMAD ◽

...

Keyword(s):

Intraocular Pressure ◽

Prone Position ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Body Posture ◽

Significant Difference ◽

Group A ◽

Group B ◽

The Relationship ◽

Corneal Apex

Purpose: To study the relationship between intraocular pressure (IOP), posture, and central corneal thickness (CCT) among healthy Malays. Method: Thirty-four young adults had their IOPs measured using a handheld tonometer (Accutome, Pennsylvania, USA) after maintaining 5 min at four different postures; sitting upright, supine, supine & 45° inclination, and prone positions. The sequences of the postures were made random. CCT was measured using Oculus Pentacam (Oculus, Wetzlar, Germany), and the value at the corneal apex was taken. Participants were grouped into Group A with CCT of < 550 μm, and Group B of > 550 μm. Results: The highest IOP was recorded at the prone position 23.77±2.71 mmHg (p < 0.001), and the lowest was at sitting upright 15.43±2.67 mmHg (p < 0.001). IOP at the supine position was 17.31±3.07 mmHg, and at the supine & 45° inclination position was 16.00±2.80 mmHg. IOPs were significantly different between sitting upright and supine (p = 0.03), between sitting upright and prone (p < 0.001), between supine and prone (p < 0.001), and between supine & inclined 45° and prone (p < 0.001). There was no significant difference in IOPs between Group A and Group B at different postures (p > 0.05). Conclusions: Change in body posture significantly affects IOP, with the lowest IOP during the sitting upright position, and the highest at the prone position. IOP change upon posture shifts was not affected by CCT.

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Quantitative Sensory Testing in Cluster Headache: Increased Sensory Thresholds

Cephalalgia ◽

10.1111/j.1468-2982.2006.01134.x ◽

2006 ◽

Vol 26 (9) ◽

pp. 1043-1050 ◽

Cited By ~ 36

Author(s):

J Ladda ◽

A Straube ◽

S Förderreuther ◽

P Krause ◽

T Eggert

Keyword(s):

Cluster Headache ◽

Healthy Subjects ◽

Quantitative Sensory Testing ◽

Time Of Day ◽

Sensory Thresholds ◽

Sensory Testing ◽

Pain Thresholds ◽

Antinociceptive System ◽

Significant Difference ◽

The Right

To determine if recently reported changes in sensory thresholds during migraine attacks can also be seen in cluster headache (CH), we performed quantitative sensory testing (QST) in 10 healthy subjects and in 16 patients with CH. Eight of the patients had an episodic CH and the other eight a chronic CH. The tests were performed on the right and left cheeks and on the right and left side of the back of the hands to determine the subjects' perception and pain thresholds for thermal (use of a thermode) and mechanical (vibration, pressure pain thresholds, pin prick, von Frey hairs) stimuli. Six patients were examined in the attack-free period. Three were also willing to repeat the tests a second time during an acute headache attack, which was elicited with nitroglycerin. The healthy subjects performed the experiments in the morning and evening of the same day to determine if sensory thresholds are independent of the time of day. If they were, this would allow estimation of the influence of the endogenous cortisone concentration on these thresholds. The control group showed no influence of the time of day on the thresholds. There was a significant difference in pain sensitivity between the back of the hands and the cheeks ( P < 0.05): higher thresholds were found on the back of the hands. The thresholds generally exhibited little intersubject variability, indicating that QST is a reliable method. There was also a significant difference between the test areas in the patient group ( P < 0.001): the cheeks were also more sensitive than the back of the hands. In comparison with reference data of healthy volunteers, the detection thresholds were increased in the patients on both test areas. These were statistically significant for warmth, thermal sensory limen (TSL), heat and pressure on the back of the hands ( P < 0.04) and for the warmth and TSL thresholds on the cheeks ( P < 0.05). There were no differences in the thresholds regardless of whether the patients were examined in or outside of a cluster bout. Furthermore, we found no cutaneous allodynia in the three patients tested during an attack. The increased sensory thresholds on the cheeks as well as on the back of the hands are in agreement with an increased activation of the patients' antinociceptive system. The seasonal variation and the temporal regularity of single attacks as well as the findings in imaging studies indicate that the hypothalamus is involved in the pathophysiology of CH. In view of the strong connectivity between the hypothalamus and areas involved in the antinociceptive system in the brainstem, we hypothesize that this connection is the reason for the increased sensory thresholds in CH patients found in our study.

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Corneal status following modified Blumenthal technique of manual small incision cataract surgery (MSICS) compared to phacoemulsification in treatment of grade III or more nuclear sclerosis-cohort study

Nepalese Journal of Ophthalmology ◽

10.3126/nepjoph.v7i1.13166 ◽

2015 ◽

Vol 7 (1) ◽

pp. 47-51 ◽

Cited By ~ 3

Author(s):

K Jain ◽

K PS Malik ◽

S Gupta

Keyword(s):

Endothelial Cell ◽

Central Corneal Thickness ◽

Corneal Thickness ◽

Cell Loss ◽

Specular Microscopy ◽

Endothelial Cell Loss ◽

Significant Difference ◽

Group A ◽

Group B ◽

Grade Iii

Objective: To evaluate the endothelial cell loss and central corneal thickness in modified Blumenthal technique of MSICS and Phacoemulsification. Method: A prospective study in which 50 cases of nuclear sclerosis grade III (LOCS III) or more were randomized in two groups of 25 each. Group A underwent modified Blumenthal MSICS. Lens expression was facilitated by viscoelastic injection through ACM and scleral pressure by iris repositor. Group B underwent 2.8 mm phacoemulsi¿cation. Specular microscopy and pachymetry were done at 1st POD, 1st, 3rd and 6th week.Results: No significant difference in endothelial cell loss and central corneal thickness between group A and group B (p > 0.05) was found.Conclusion: This technique of MSICS is not inferior, an innovative, safe and highly effective in hard cataracts.

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A Rabbit Model Study to Determine the Efficacy of a Prototype Corneal Endothelium Protector during Cataract Surgery

Journal of Ophthalmology ◽

10.1155/2017/6906139 ◽

2017 ◽

Vol 2017 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Annabel C. Y. Chew ◽

Anita Chan ◽

Monisha E. Nongpiur ◽

Gary Peh ◽

Veluchamy A. Barathi ◽

...

Keyword(s):

Corneal Endothelium ◽

Corneal Thickness ◽

Anterior Segment ◽

Rabbit Model ◽

Cell Loss ◽

Specular Microscopy ◽

Endothelial Cell Loss ◽

Surgical Time ◽

Model Study ◽

Significant Difference

Purpose. We evaluated the efficacy and safety of a mechanical device, the P-chute, in corneal endothelium preservation during phacoemulsification in a rabbit model. Methods. Twenty-four rabbits were randomly assigned into 2 groups. One eye of each rabbit underwent phacoemulsification that simulated the removal of a dense nucleus, with or without the P-chute. Serial slit-lamp examinations, anterior segment optical coherence tomography (ASOCT) scans, and specular microscopy were performed. Three rabbits from each group were sacrificed on postoperative days (PODs) 1, 5, 7, and 14. Histological analysis of the corneas was performed. Results. There was a trend towards lesser endothelial cell loss for the P-chute group at POD1 (4.9% versus 12.5%, p=0.53), POD5 (10.4% versus 12.2%, p=0.77), and POD7 (10.5% versus 17.2%, p=0.52). There was no significant difference in the corneal thickness (p=>0.05) between the 2 groups. The insertion of the device was challenging. The use of the P-chute only added an extra 15% to the surgical time. Conclusions. There was a trend towards better endothelium preservation with the P-chute even though the results were not statistically significant. We believe that the device could be useful in certain surgical situations. Further work is needed to improve the device insertion.

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