Comparison of Horizontal White-to-white Diameter Measured Using Four Devices

Purpose@#To compare the horizontal white-to-white (WTW) diameter measured using four devices. @*Methods@#We measured the horizontal WTW diameter of 52 eyes of 52 patients using the IOL Master 500, ANTERION, OA-2000, and Pentacam HR devices. Repeated-measures analysis of variance was used to compare the measurements. Correlations between the measurements were evaluated using the Pearson correlation test. Agreement between measurements obtained using different instruments was confirmed using a Bland-Altman plot. @*Results@#The mean horizontal WTW diameters obtained using IOL Master 500, ANTERION, OA-2000, and Pentacam HR were 11.65 ± 0.39, 11.52 ± 0.44, 11.51 ± 0.52, and 11.28 ± 0.41 mm, respectively. The horizontal WTW diameters obtained using IOL Master 500 and Pentacam HR were the largest and smallest, respectively. There was a statistically significant difference in mean diameter between IOL Master 500 and ANTERION (p = 0.03), as well as between Pentacam HR and the remaining three devices (all p 0.6, p < 0.001). The 95% limits of agreement between the measurements were 0.808-1.619 mm. @*Conclusions@#There were statistically significant differences in horizontal WTW diameter between IOL Master 500 and ANTERION, and between IOL Master 500 and Pentacam HR, but not between IOL Master 500 and OA-2000. Measurements obtained using IOL Master 500 and the remaining three devices are not interchangeable because of their low level of agreement.

Repeatability and Agreement of Chord Mu between Scheimpflug Tomography and Swept-Source Optical Coherence Tomography

Purpose@#To evaluate repeatability and agreement of chord mu between Scheimpflug tomography (Pentacam HR) and sweptsource optical coherence tomography–based optical biometer (IOLMaster 700). @*Methods@#In this retrospective study, 63 eyes from 33 patients were included. Chord mu, X and Y Cartesian distances between the corneal vertex and the pupil center (Px and Py), and the pupil diameter were compared using two instruments. Repeatability was evaluated using intraclass correlation coefficient (ICC), coefficient of variation (CoV), and within-subject standard deviation (Sw). Interdevice agreement was evaluated using paired t-tests and Bland-Altman plots. @*Results@#Although Sw values for all parameters were similar between the two devices, CoV values of chord mu and pupil diameter were lower, and ICC values of those parameters were higher, in the IOLMaster 700 than in the Pentacam HR. Chord mu and pupil diameter values were higher in IOLMaster 700 than Pentacam HR (p < 0.01). The width of the 95% limit of agreement was wide for all parameters. @*Conclusions@#IOLMaster 700 showed better repeatability than Pentacam HR in chord mu, Px, Py, and pupil diameter values. Because there were statistically significant differences and a low level of agreement in chord mu and pupil diameter values between the two devices, they cannot be used interchangeably.

Agreement between Two Swept-Source Optical Coherence Tomography Biometers and a Partial Coherence Interferometer

Purpose@#To evaluate the level of agreement between ANTERION (Heidelberg Engineering, Heidelberg, Germany), OA-2000 (Tomey, Nagoya, Japan), and IOLMaster 500 (Carl Zeiss AG, Jena, Germany). @*Methods@#Fifty-one eyes of 51 patients were included in the study. Flat keratometry (K) and steep K, vector component of astigmatism (Jackson cross-cylinder at 0° and 90° [J0] and Jackson cross-cylinder at 45° and 135° [J45]), anterior chamber depth, and axial length were compared using the three devices. Repeated measures analysis of variance was conducted to compare the mean values of the biometrics. Pearson correlation test was conducted to analyze the correlations of the measured values, and a Bland-Altman plot was used to assess the agreement between the three devices. The predicted intraocular lens power of each device was compared to the others using the SRK/T, Haigis, Barrett Universal II, and Kane formulas. @*Results@#All K values measured using ANTERION were flatter than those of other instruments. However, good agreement was observed for flat K (ANTERION - OA-2000; 95% limits of agreement [LoA], 0.86 diopters [D]) and steep K (ANTERION - OA2000; 95% LoA, 0.93 D) and OA-2000 - IOLMaster 500 (95% LoA, 0.93 D). J0 and J45 vector components of astigmatism were not statistically different; however, the agreements were poor between the devices (95% LoA ≥1.97 D). Anterior chamber depth values of ANTERION and OA-2000 were interchangeable (95% LoA, 0.15 mm). The axial length showed a high agreement (95% LoA ≤0.17 mm) among the three devices. The predicted intraocular lens powers of the three devices were not interchangeable regardless of formulas (95% LoA ≥1.04 D). @*Conclusions@#Significant differences in ocular biometrics were observed between ANTERION and the other two devices. This study demonstrated that only axial length showed good agreement among devices.

Morphologic Characteristics of the Outer Retina in Cone Dystrophy on Spectral-domain Optical Coherence Tomography

PURPOSE: To investigate the morphologic changes in the outer retina of patients with cone dystrophy, using spectral-domain optical coherence tomography (SD-OCT). METHODS: The medical records of 15 cone dystrophy patients examined from January 2007 to January 2012 were reviewed retrospectively. All patients underwent ophthalmic evaluation including best-corrected visual acuity (BCVA), color vision testing, fundus examination, full-field standard electroretinography (ERG), multifocal (mf) ERG, and SD-OCT. Qualitative and quantitative SD-OCT data and ERG responses were analyzed and compared among the patient categories and the normal control group. RESULTS: There were 4 major categories of SD-OCT findings, based on the status of the ellipsoid portion of the photoreceptor inner segment (ISe), outer segment (OS) contact cylinder, and retinal pigment epithelium (RPE) layer. Category 0 showed no structural abnormalities. Category 1 showed foveal ISe loss and obscurity of the border between the ISe band and the external limiting membrane (ELM). Category 2 showed foveal thinning and focal foveal ISe disruption with an intact ELM. Category 3 showed foveal thickening and perifoveal disruption of the ISe layer. Category 1 to 3 showed OS contact cylinder layer absence and RPE thickening. The patients in category 0 tended to be younger (mean, 10.0 years) than those in categories 1 to 3 (mean, 17.6 years), although this difference was not statistically significant. Category 1 to 3 patients exhibited statistically significant thinning of the central retina and outer nuclear layer and thickening of the RPE layer relative to the category 0 and normal control group. There was a significant correlation between the central foveal thickness and BCVA in the patients with cone dystrophy. ERG and mfERG responses did not differ significantly among the different cone dystrophy categories. CONCLUSIONS: The morphologic features of cone dystrophy as revealed by SD-OCT, could be categorized as either normal or 1 of 3 different types of outer retinal changes. The presence of normal retinal structures in young cone dystrophy patients with functional impairment (category 0) indicates that electrophysiologic studies are superior to current imaging modalities for the early diagnosis of cone dystrophy. The characteristic SD-OCT findings in cone dystrophy patients may aid in differential diagnosis and be useful for future research on the pathology of cone dystrophy.

Three-Year Surgical Outcome of Exotropia

PURPOSE: To investigate surgical results (> or =3 years) for exotropia and factors associated with the outcome. METHODS: Clinical records of 259 patients who underwent surgery for exotropia and had 3 or more years of follow-up were retrospectively reviewed. Surgical success was defined as esodeviation less than 5 prism diopters (Delta), orthophoria, or exodeviation less than 10Delta on the third year after operation. Overcorrection was defined as esodeviation greater than 5Delta and recurrence as exodeviation greater than 10Delta. Both overcorrection and recurrence were considered as surgical failure. Factors including age at surgery, gender, preoperative refractive errors, preoperative stereopsis, preoperative maximum deviation, type of surgery, and alignment at postoperative week 1 were investigated. RESULTS: Out of 259 patients, 155 patients (59.8%) achieved surgical success, 19 patients (7.3%) showed overcorrection and 85 patients (32.8%) had recurrence. Out of 44 patients (17.0%) who underwent reoperation, 2 patients showed overcorrection and 42 patients had recurrence. Alignment at postoperative week 1 was the only significant factor affecting the surgical results. The type of surgery was the only significant factor associated with reoperation after failure of the initial surgery. CONCLUSIONS: Alignment at postoperative week 1 was the only significant factor affecting surgical results. The type of surgery was the only significant factor associated with reoperation.