Corneal Diameter Measurements Research Articles

Precision of a new SS-OCT biometer to measure anterior segment parameters and agreement with 3 instruments with different measurement principles.

To evaluate the repeatability of a new swept source optical coherence tomography (SS-OCT)-based biometer to measure anterior segment parameters and to assess the agreement with 3 other imaging devices based on different measurement principles. Unit of Eye and Vision, Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden. Prospective, comparative case series. 3 consecutive measurements were obtained in unoperated eyes with the Eyestar900 (SS-OCT), Lenstar 900, MS-39, and Sirius. The following anterior segment parameters were evaluated: central corneal thickness (CCT), corneal diameter (CD), aqueous depth (AQD), and corneal power metrics. The repeatability limit (Rlim), coefficient of variation (CoV), and a repeated measures Bland-Altman analysis were performed. 74 eyes of 74 participants were measured. The Rlims for CCT, CD, and AQD were lower than 10 μm, 0.3 mm, and 0.10 mm for all devices, respectively. The corresponding CoVs for these parameters never exceeded 1.2%. The Rlim for the corneal power metrics never exceeded 0.60 diopter (D) for any of the instruments. Lenstar showed the best agreement with the MS-39 to measure CCT, CD, and AQD (limit of agreement interval, LoA: 15.54 μm, 0.55 mm, and 0.16 mm, respectively). The mean difference for keratometry parameters was lower than 0.3 D for all device comparisons, and the LoA interval ranged between 0.52 D and 1.21 D. The repeatability for measuring anterior segment parameters was good, and the agreement among all the instruments was good for CD and AQD measurements. However, for CCT and keratometer parameters, the instruments cannot be used interchangeably due to large LoA interval.

Comparing the Use of Smartphone and Vernier Calipers for Corneal Diameter Measurement in Nigerian Term Neonates.

Corneal diameter (CD) measurement in newborns is essential for the detection of blinding ocular pathologies. It requires specially trained personnel, contact techniques, and the use of anesthesia. Smartphone use may obviate these challenges. This study compares CD measurement among newborns using a Smartphone and manual calipers. This is a cross-sectional comparative study done at Alex Ekwueme Federal University Teaching Hospital, Abakaliki, Nigeria. Consecutively selected stable term neonates whose mothers consented to the study and met the inclusion criteria had their CDs measured with both calipers and smartphones and the values compared. Mean, range, and standard deviation were calculated using Statistical Package for the Social Sciences (SPSS) IBM (version 22), while paired t-test calculated the difference in mean CD measurements between both methods. Pearson's correlation and Bland-Altman's analysis determined the correlation and agreement between both methods, respectively. Inter and intraobserver repeatability were assessed. A P value less than 0.05 was taken as statistically significant. The mean CD measurement using calliper method was 10.01 ± 0.29mm and 10.03 ± 0.24 mm right eye (RE) and left eyes (LE), respectively) for investigator 1 and 10.16 ± 0.25 mm and 10.19 ± 0.21 mm (RE, LE) for investigator 2. Using smartphone measurement, mean CD measurements of 9.98 ± 0.21 mm and 10.00 ± 0.29 mm (RE, LE) were observed for investigator 1 and 10.07 ± 0.19 mm and 10.06 ± 0.21 mm (RE, LE) for investigator 2. The difference in mean CD for both instruments and by both investigators was not statistically significant (P value > 0.05). Corneal diameter measurement in neonates using smartphone technology does not deviate significantly from caliper measurement; it is safe, easy to use, and advocated.

Agreement of Corneal Diameter and Anterior Chamber Depth Measurements with the IOLMaster 500 and the IOLMaster 700 Optical Biometers in Myopic Eyes.

To assess the agreement in automated corneal diameter (CD) and anterior chamber depth (ACD, measured from corneal epithelium to lens) distances measurements between the IOLMaster 500 and 700 optical biometers in myopic eyes. One hundred and sixteen eyes of 116 myopic patients aged between 21 to 60 years were included in this study. Measurements of CD and ACD distances were taken with each biometer for all patients in the same session. A t-test and a p-value less than 0.05 was considered statistically significant when the measurements were compared. The agreement between biometers was studied by applying a Bland-Altman analysis. The mean CD values obtained using the IOLMaster 500 and 700 biometers were 12.26±0.35 mm and 12.13±0.34 mm, respectively. The mean ACD distance values were 3.61±0.29 mm and 3.62±0.31, for the IOLMaster 500 and 700 biometers, respectively. There were statistically significant differences between the two devices only for CD measurements (p<0.001), but not for ACD measurements (p=0.26). The limits of agreement obtained were wide in both types of measurements, being 0.422 mm for the CD distance and 0.389 mm for the ACD distance. There were statistically significant differences between the IOLMaster 500 and 700 biometers regarding CD but not in ACD measurements in healthy myopic eyes. These differences could be clinically significant in some cases. According to these results, medical judgement should be used to assess whether the two devices could be used interchangeably for CD and ACD measurements during the clinical practice.

Agreements' profile of Scheimpflug-based optical biometer with gold standard partial coherence interferometry.

To determine the agreement of ocular biometric indices including axial length, keratometric readings, anterior chamber depth, and horizontal corneal diameter between the Pentacam AXL and IOL Master 500. The study was a large cross-sectional population-based study (Tehran Geriatric Eye Study) conducted from Jan 2019 to Jan 2020. A total of 160 clusters were randomly selected proportional to size (each cluster contained 20 individuals) from 22 strata of Tehran city. All people aged 60y and above were invited to participate in the study. For all participants, preliminary ocular examinations were performed including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, anterior and posterior segment examinations. All participants underwent an ocular biometry using the Pentacam AXL and IOL Master 500. The 95% limits of agreement (LoA) between the two devices were -0.13 to 0.19, -0.15 to 0.17, and -0.13 to 0.19 in normal, pseudophakic, and cataractous eyes, respectively. With increasing the axial length, the difference between the two devices significantly increased in all three groups of normal, pseudophakic, and cataractous eyes (P<0.001). The 95% LoAs between the two devices regarding the mean keratometry shows that the best LoAs were seen in cataractous (-0.33 to 0.81) and followed by normal eyes (-0.36 to 0.86) and the pseudophakic eyes (-0.48 to 0.90) had the widest LoA. The 95% LoAs for horizontal corneal diameter measurements were -0.08 to 0.86, -0.03 to 0.83, and -0.07 to 0.87 in normal, pseudophakic, and cataractous eyes, respectively. The 95% LoAs of anterior chamber depth measurements between the two devices was -0.39 to 0.19 and -0.37 to 0.13 in normal eyes and cataractous, respectively. The Pentacam AXL has excellent agreement with the gold standard, IOL Master 500 in measuring axial length. In eyes with cataracts, the difference between the two devices is more scattered. With the increasing of axial length, the difference between the two devices increased, which should be considered when using Pentacam AXL.

Corneal diameter measurements by 3 optical biometers and their effect on phakic intraocular lens sizing.

To compare phakic intraocular lens size calculations based on corneal diameter (CD) measurements by 3 instruments. G.B. Bietti Foundation I.R.C.C.S., Rome, Italy. Retrospective interventional case series. Preoperatively, CD was measured with the Aladdin, IOLMaster 700, and Pentacam AXL Wave. The simulated ICL size was computed by entering CD measurements into the manufacturer's calculator. Postoperatively, vaulting was measured by anterior segment optical coherence tomography. The optimal ICL size (OIS) was calculated and compared with the commercially available OIS (CAOIS). 54 eyes (29 patients) with the implantable collamer lens (ICL) were enrolled. The mean CD was 12.02 ± 0.36 mm with the Aladdin, 12.35 ± 0.39 mm with the IOLMaster 700, and 12.22 ± 0.41 mm with the Pentacam AXL Wave ( P &amp;lt; .0001), with the closest agreement between the Pentacam AXL Wave and IOLMaster 700 (95% limits of agreement: -0.43 to +0.17 mm). Vaulting (mean: 558 ± 261 μm) was within 251 and 1000 μm in 49 eyes (83.3%). The mean difference between the simulated ICL size and OIS ranged between -0.11 ± 0.35 mm and 0.10 ± 0.30 mm ( P &amp;lt; .0001), with no statistically significant difference between the IOLMaster 700 and Pentacam AXL Wave. The simulated ICL size was equal to CAOIS in 38 eyes (70.37%) with the Aladdin, 37 eyes (68.52%) with the IOLMaster 700, and 39 eyes (72.22%) with the Pentacam AXL Wave, without any statistically significant difference. CD measurements by the 3 devices lead to similar percentages of eyes with an ICL size equal to the OIS. Agreement is closer between the IOLMaster 700 and Pentacam AXL Wave.

Comparison of two new integrated SS-OCT tomography and biometry devices.

To evaluate the agreement in biometry measurements and intraocular lens (IOL) power calculations between 2 integrated swept-source optical coherence tomography (SS-OCT) tomography/biometry devices: the Eyestar 900 and the Anterion. Tel Aviv Medical Center, Tel Aviv, Israel. Retrospective comparative study. 113 eyes of 66 consecutive patients who were evaluated prior to cataract surgery using both devices on the same visit were included. Measurements of axial length, anterior and posterior keratometry, anterior chamber depth, corneal diameter (CD), central corneal thickness, and lens thickness were recorded from both devices and analyzed for agreement and correlation. IOL power calculations using Barrett Universal II formula were compared between the devices in addition to prediction error (PE) and the mean absolute error (MAE). The mean age was 71.6 ± 9.8 years. Clinically, the mean differences in measured variables were small. Measurement correlation and agreement between the devices were excellent for all variables, except for CD (Spearman r = 0.763, P &amp;lt; .001, and Bland-Altman 95% limits of agreement -0.21 to +0.65 mm). Good agreement was found between the devices in IOL power calculations, PE, and MAE, and the agreement was better when using the Eyestar 900 reflective keratometry measurements than the Eyestar 900 SS-OCT keratometry measurements (IOL power agreement within ±0.5 diopter (D) in 90.5% [n = 95] and 81.0% [n = 85], respectively [ P = .076], and within ±0.25 D in 64.8% [n = 68] and 44.8% [n = 47], respectively [ P = .005]). The 2 integrated SS-OCT tomography/biometry devices had good agreement in biometry measurements and IOL power calculations. Agreement was better when the Eyestar 900 reflective anterior keratometry measurements were used rather than the Eyestar 900 SS-OCT anterior keratometry measurements. Measurements of CD had reduced agreement and were not interchangeable.

Prediction of anterior ocular surface sagittal heights using Placido‐based corneal topography in healthy eyes

To investigate the validity of Placido-based corneal topography parameters to predict corneoscleral sagittal heights measured by Fourier-based profilometry at various diameters. Minimal (Minsag ), maximal (Maxsag ) sagittal height, toricity (Maxsag - Minsag ) and axis of the flattest meridian (Minsag ) of 36 subjects (mean age 25.4 SD ± 3.2 years; 21 female) were measured using the Eye Surface Profiler and analysed for diameters (chord length) of 8 to 16 mm (in 2-mm intervals). Furthermore, corneal central radii, corneal astigmatism, eccentricity and diameter were measured using the Keratograph 5M. Using multiple linear regression analysis, the best equation for predicting the sagittal heights for 8 mm (r2 =0.95), and 10 mm (r2 =0.93) diameters included corneal central radii and eccentricity. The best equation for predicting sagittal heights for 12 mm (r2 =0.86), 14 mm (r2 =0.78) and 16 mm (r2 =0.65) diameters included corneal central radii, eccentricity and corneal diameter. Corneal astigmatism was significantly correlated with sagittal height toricity for 8 and 10 mm diameters (r2 =0.50 and 0.29; p < 0.01), while no correlation was observed for 12, 14 and 16 mm diameters (p=0.18 to p=0.76). The axis of the flattest corneal meridian measured by Placido-based topography was significantly correlated with the axis of the flattest meridian measured by Fourier-based profilometry for 8, 10 and 12 mm diameters (r2 =0.17 to 0.44; p < 0.05), while there was no correlation for 14 and 16 mm diameters (p=0.48 and p=0.75). For a typical soft contact lens diameter of 14 mm, 78% of the variance could be determined with a corneal topographer and 68% with keratometry and corneal diameter measurement. The combination of corneal central radii, eccentricity and corneal diameter measured by Placido-based topography is a valid predictor of the corneoscleral sagittal height in healthy eyes. Scleral toricity and axis of the flattest meridian seem to be independent from Placido-based corneal parameters and requires additional measuring tools.

Ocular biometry with swept-source optical coherence tomography-based optical biometer in Japanese patients with EYS-related retinitis pigmentosa: a retrospective study

BackgroundThis study aimed to identify the features of ocular biometry in patients with EYS-related retinitis pigmentosa using IOLMaster 700.MethodsWe retrospectively reviewed the medical records of patients with retinitis pigmentosa. Patients with records of the following were included: (1) ocular biometry measurements using the IOLMaster 700 and (2) genetic diagnostic tests. Axial length, keratometry, anterior chamber depth, aqueous depth, lens thickness, central corneal thickness (CCT), and corneal diameter (white to white) measurements were extracted. Based on keratometry measurements, (1) standard keratometric astigmatism, (2) posterior corneal astigmatism, and (3) total corneal astigmatism were obtained. Demographics and biometric parameters were compared between patients with EYS-related retinitis pigmentosa and other patients with retinitis pigmentosa.ResultsA total of 86 eyes of 44 patients (23 females and 21 males; mean age: 47.7 years) with retinitis pigmentosa were included. Of these, 18 were identified as having EYS variants. CCT was significantly thinner (P < 0.001) and the posterior corneal curvature at the steepest meridian was significantly smaller (P = 0.024) in patients with EYS-related retinitis pigmentosa than in other patients with retinitis pigmentosa. The magnitudes of all corneal astigmatism measurements was higher in patients with EYS-related RP, although these differences were not statistically significant.ConclusionPatients with EYS-related retinitis pigmentosa had unique features in ocular biometry, such as thinner central corneal thickness and smaller posterior corneal curvature radius at the steepest meridian compared with other patients with retinitis pigmentosa. The findings suggest that patients with retinitis pigmentosa have different ocular dimension features among the different causative genes.

Comparison of Anterior Segment Measurements between Scheimpflug-Placido Camera and New Swept-source Optical Coherence Tomography

Purpose: We compared anterior segment measurements obtained using a Scheimpflug-Placido topographer (SIRIUS®, Costruzione Strumenti Oftalmici, Florence, Italy) and a new anterior module for a swept-source optical coherence tomography system (ANTERION®, Heidelberg Engineering Inc., Heidelberg, Germany).Methods: Anterior segment measurements were evaluated in 74 eyes of 101 patients with the two devices. Central corneal thickness (CCT), anterior chamber depth (ACD), corneal refractive power (K), J0 (Jackson cross-cylinder with axes at 180° and 90°), J45 vector (Jackson cross-cylinder with axes at 45° and 135°), and white-to-white corneal diameter (WTW) measurements obtained using the SIRIUS® system and the new anterior segment module of ANTERION® were compared.Results: The mean CCTs measured by SIRIUS® and ANTERION® were 558.69 ± 44.65 and 540.26 ± 36.57 μm, respectively. The difference was statistically significant (p &lt; 0.005), and there were high correlations between the two methods (r = 0.915, p &lt; 0.001). The mean ACD measurements were 3.34 ± 0.53 and 3.34 ± 0.51 mm (p = 0.856), respectively, for SIRIUS® and ANTERION®. The measurements were strongly correlated (r = 0.966, p &lt; 0.001). The measurements of WTW, total mean K, and J0 obtained with the two systems differed significantly (p &lt; 0.005, p = 0.017, and p &lt; 0.005, respectively), with high correlations between the two systems (r = 0.875, r = 0.967, and r = 0.933, respectively; all p &lt; 0.001).Conclusions: There were significant differences in measurements of K, CCT, WTW, and J0 between the two devices. Agreement analysis suggests that SIRIUS® and ANTERION® should not be used interchangeably.

Comparative analysis of 2 biometers using swept-source OCT technology.

To report the repeatability, level of agreement, and correlation of 2 swept-source optical coherence tomography (SS-OCT) biometers, the IOLMaster 700 (biometer A) and the ANTERION (biometer B). Rothschild Foundation Hospital, Paris, France. Prospective comparative case series. Consecutive patients who attended for cataract assessment had SS-OCT biometry performed with the reference, biometer A, and biometer B. Axial length, mean keratometry, central corneal thickness, anterior chamber depth, lens thickness, and corneal diameter measurements (white-to-white [WTW] distance) were measured. The intraoperator repeatability was calculated using analysis of variance and repeatability limits. Correlations were assessed, and the level of agreement between the biometers was represented with the Bland-Altman method. The study comprised 63 patients (125 eyes). There was a statistically significant difference between the 2 biometers in all measurements (P < .05). All repeatability measurements were very high, as were the level of correlation and level of agreement between biometer A and biometer B for all parameters. Biometer B provided good agreement and repeatability compared with biometer A; however, all parameters were not interchangeable, particularly, the WTW measurement and the high keratometric values.

Agreement between the biometric measurements used to calculate the size of the implantable collamer lenses measured with four different technologies.

Purpose:To evaluate the agreement between the biometric measurements used to calculate the size of the implantable collamer lenses (ICL) with different technologies: swept-source optical coherence tomography, spectral domain optical coherence tomography, and Scheimpflug tomography.Methods:This retrospective observational study included subjects undergoing refractive surgery with posterior chamber phakic IOL implantation to correct their myopia. The anterior chamber depth (ACD) and the horizontal white to white (WTW) or the angle to angle (ATA) distance were measured with the following four devices: the IOLMaster 700 biometer (Carl Zeiss Meditec, Jena, Germany), based on swept-source optical coherence tomography; the Cirrus and Visante optical coherence tomographs (Carl Zeiss Meditec) based on low-coherence interferometry; and the Pentacam rotating Scheimpflug camera (Oculus, Wetzlar, Germany).Results:In the horizontal corneal diameter measurements, there were statistically significant differences between Pentacam–IOLMaster 700 pair (P < 0.001) and Pentacam–Visante pair (P < 0.001). WTW from CIRRUS showed the lowest correlation when paired with Pentacam and IOLMaster 700 (R2 = 0.452 and 0.385 for Visante and R2 = 0.494 and 0.426 for Cirrus). Regarding the linear correlation of the ACD measurements, all pairs of devices were statistically significant and all of them showed a very good correlation index.Conclusion:There is a good agreement between the different devices under evaluation for ACD measurements. As for WTW, the values measured with the different devices showed large discrepancies with low correlation levels, especially when comparing the tomographs with the other devices under evaluation.

Agreement between corneal diameter measurements obtained with an optical biometer and a Placido-based topographer.

The purpose of this study was to compare the white-to-white distance measurements of two devices (IOL Master 500 and Atlas corneal topographer) commonly used in clinical practice to determine if they were interchangeable. Providing information on instrument interchangeability could eliminate several unnecessary tests and consequently reduce the economic burden for the patient and society. In this prospective, comparative case series, the white-to-white distance was measured by independent examiners using the Atlas topographer (Carl Zeiss Meditec) and the IOL Master 500 (Carl Zeiss Meditec). One eye each of 184 patients was tested. Statistical analyses were performed using a paired t-test, Pearson correlation analysis, and Bland-Altman analysis to compare the measurement methods. The mean white-to-white distance measurements with the Atlas topographer and the IOL Master 500 were 12.20 ± 0.44 mm and 12.12 ± 0.41 mm, respectively (p<0.001). The mean white-to-white difference between the two devices was 0.07 mm (95% confidence interval of mean difference: 0.04-0.11 mm). The Pearson correlation coefficient between the two devices was 0.85 (p<0.0001). The 95% limits of agreement between the two devices were -0.38 mm to 0.53 mm. The Atlas topographer and IOL Master 500 can be used interchangeably with respect to white-to-white distance measurements, as the range of differences is unlikely to affect clinical practice and decision making.

A Study on the Relationship between Corneal-Related Value and Ocular Sagittal Height

Purpose : To investigate the effect of corneal related values on the ocular sagittal height and which factors have the greatest influence on the ocular sagittal height. Methods : For 240 healthy eyes in their 20, 30, 40, and 50s, the anterior chamber depth and axial length were measured with IOLMaster 700. The corneal curvature radius and corneal eccentricity were measured with Keratograph 4, and spherical equivalent power was measured using KR-800. The corneal sagittal height was calculated using the formula. Results : The most influential factor in the corneal sagittal height was the corneal diameter, followed by the corneal eccentricity. And the corneal curvature radius had the least effect. A change in corneal saggital height of about 0.10mm corresponds to a change in corneal diameter of 0.20mm, and corneal eccentricity of 0.05 to 0.10 Conclusion : If soft contact lens fitting is greatly affected by the relationship between the sagittal depth of the contact lens and the sagittal height of the cornea, measurements of corneal diameter and corneal eccentricity are considered appropriate methods for selecting parameters of contact lenses. In addition, the numerical relationship between corneal sagittal height, corneal diameter and corneal eccentricity could be used as additional information for soft contact lens fitting.

Megalocornea, anterior megalophthalmos, keratoglobus and associated anterior segment disorders: A review.

Megalocornea and anterior megalophthalmos (megalocornea spectrum) disorders are typically defined by corneal diameter > 12.5 mm in the absence of elevated intraocular pressure. Clinical features overlap with keratoglobus but are distinct from buphthalmos and severe (globus) keratoconus. Megalocornea spectrum disorders and keratoglobus are primarily congenital disorders, often with syndromic associations; both can present with large and thin corneas, creating difficulty in diagnosis, however, only keratoglobus is typically progressive. Molecular genetics provide significant insight into underlying aetiologies. Nonetheless, careful clinical assessment remains intrinsic to diagnosis. Surgical management can be challenging due to the enlarged ciliary ring and weakened zonules in megalocornea spectrum disorders and the extreme corneal thinning of keratoglobus. In this review, the established literature on measurement of corneal diameter, diagnosis of megalocornea, anterior megalophthalmos and keratoglobus, differentiation from severe keratoconus, recent molecular genetics research and key surgical modalities in the management of these rare disorders are outlined and discussed.

Comparison of horizontal corneal diameter measurements using the Aladdin biometer and Medmont E300 corneal topographer

Purpose: Superiority in corneal diameter, white-to-white (WTW) distance, measurements using objective imaging devices over subjective face-to-face measurements by eye care practitioners (ECP) have been reported previously. The primary aim of this study was to compare manual and automated corneal diameter measurements using two different objective imaging devices. A secondary aim was to compare results obtained by an experienced ECP and novice user.

Myopia Prevalence and Ocular Biometry Features in a General Japanese Population: The Nagahama Study

To describe the distribution of ocular biometry and refraction in Japanese adults. Cross-sectional analysis of a prospective cohort study. A total of 9850 individuals participated in the first follow-up of the Nagahama Prospective Cohort for Comprehensive Human Bioscience (the Nagahama Study) conducted between 2013 and 2016. Participants were between 34 and 80 years of age. All participants underwent axial length (AL; in millimeters), anterior chamber depth (ACD; in millimeters), corneal diameter (white to white; in millimeters), and central corneal thickness (CCT; in micrometers) measurement (IOL Master; Carl Zeiss Meditec, Dublin, CA) and refraction (spherical equivalent [SE]; in diopters [D]) and corneal curvature (CC; in millimeters) measurement (ARK-530A; Nidek, Aichi, Japan). Distribution of these ocular biometric parameters and prevalence of myopia, high myopia, and extreme myopia were summarized. Distribution of ocular biometry and refraction. After standardization to the national population of 2015, estimates of mean AL and SE were 24.21 mm and -1.44 D, respectively. Estimates of mean CC, corneal diameter, CCT, and ACD were 7.69 mm, 12.01 mm, 543.96 μm, and 3.21 mm, respectively. After standardization of age and gender, the prevalence of myopia (SE, ≤-0.5 D) and high myopia (SE, ≤-6.0 D) were 49.97% and 7.89%, respectively. Approximately 70% of the younger participants (34-59 years of age) showed myopia, whereas high myopia was observed in approximately 10%. Although the number of individuals with myopia or high myopia was higher in the younger age groups, the prevalence of more extreme phenotypes remained stable across all ages, especially in women. Axial length of more than 30 mm was observed only in older women (n= 5 [0.05%]). We showed detailed distributions of various ocular biometry and refraction parameters using a large general Japanese cohort. Prevalences of myopia and high myopia from 2013 through 2016 were higher thanthose in earlier studies, which reflects recent environmental change. However, constant prevalence of extreme myopia across all ages suggests high genetic predisposition of the extreme phenotype.

Evaluation of Intranasal Dexmedetomidine as a Procedural Sedative for Ophthalmic Examination of Children With Glaucoma.

This study evaluated 2 doses of intranasal dexmedetomidine (IND) (3.0 and 3.5 µg/kg) as a procedural sedative for postoperative examination of children with glaucoma. A dose of 3.5 µg/kg was more efficacious and obviated the need for repeated general anesthesia. This study was carried out to determine the safety and effective dose of IND as a procedural sedative for postoperative follow-up examinations after glaucoma surgery in children in place of repeated examination under anesthesia. In this prospective randomized double-blinded interventional study, consecutive children aged 6 months to 6 years were randomized to receive 3.0 and 3.5 µg/kg IND using a mucosal atomizer device in the preoperative area of the operating room, under continuous monitoring of vital signs. Intranasal midazolam 0.25 mg/kg was used as a rescue agent in case of inadequate sedation, and general anesthesia was administered in case of persistent failure. All infants underwent a complete anterior and posterior segment evaluation including intraocular pressure and corneal diameter measurements. A total of 30 and 31 children aged 23.9±15.0 and 19.2±10.1 months, respectively, received 3.0 and 3.5 µg/kg IND. Adequate sedation was possible in 18 of 30 (60%) children receiving 3.0 µg/kg and 24 of 31 (77.4%) receiving 3.5 µg/kg IND alone (P=0.17). In combination with midazolam, successful sedations were 86.6% versus 100%, respectively (P=0.052). One patient in the 3.5 µg/kg group had ventricular arrhythmia, reversed with dextrose-saline infusion and injection glycopyrrolate. IND appears to be a safe and effective procedural sedative for postoperative follow-up examinations of pediatric glaucoma patients at doses of 3 and 3.5 µg/kg. The dose of 3.5 µg/kg was successful in more children.

Effect of orthokeratology on precision and agreement assessment of a new swept-source optical coherence tomography biometer

BackgroundTo evaluate the effect of orthokeratology on precision of measurements in children using a new swept-source optical coherence tomography (SS-OCT) optical biometer (OA-2000), and agreement between its measurements and those provided by the commonly used IOLMaster based on partial coherence interferometry (PCI).MethodsThis study recruited fifty-one eyes of 51 normal children (8–16 years). An operator took measurements with the two biometers. Then, a second operator took measurements with the SS-OCT biometer. After orthokeratology was performed for one month, the same operators repeated the same procedures. Axial length (AL), mean keratometry (Km) at 2.5 mm and 3.0 mm diameters (Km2.5 and Km3.0), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and corneal diameter (CD) were analyzed.ResultsWith the SS-OCT optical biometer, the test-retest repeatability of AL measurements was < 0.06 mm. For all parameters, the coefficients of variation were < 1.23% and the intraclass correlation coefficients were > 0.95. The 95% limits of agreement of difference between the two devices for CD parameter were up to 1.53 mm. After orthokeratology, the fluctuation ranges of difference for Km3.0 measurement was 1.11 times higher than before orthokeratology, while the absolute values of difference for AL, Km2.5, ACD and CD measurements were comparable.ConclusionsBefore and after orthokeratology, the SS-OCT biometer showed high repeatability and reproducibility for all measurements. Wearing orthokeratology contact lenses affected the agreement between SS-OCT and PCI biometers for Km3.0 measurements. The CD measurement showed poor agreement between the two devices.

Normative ocular data for juvenile and adult Japanese quail (Coturnix japonica).

To obtain normative ocular data for Japanese quail as they mature from juveniles to adults. Twenty-six captive Japanese quail comprising thirteen males and thirteen females, free of ocular disease, were included in the study. Ophthalmic reference values were measured in both eyes at 1 and 5months of age. A complete ophthalmic examination was performed, including neuro-ophthalmic reflexes, slit lamp biomicroscopy, phenol red thread test (PRTT), rebound tonometry, fluorescein staining, horizontal corneal diameter measurement, indirect ophthalmoscopy, and ocular ultrasound biometry. Ultrasound biomicroscopy measurements of axial globe length, lens thickness, vitreal chamber length, and pecten length were recorded. The depth of the anterior chamber was calculated by subtracting the lens thickness and vitreous length from the axial globe length. Measures of association and descriptive statistics were analyzed using STATA-14 and STATA-15. Juvenile and adult females were heavier than age-matched males. Weight, intraocular pressure, horizontal corneal diameter, axial globe length, and lens thickness measurements increased with age. No statistically significant differences were found in the remainder of measurements among individuals in different sex or age-groups. This work provides reference values and clinical findings that can be used in future research on quail and ocular disease.

Ophthalmic findings in cinereous vultures (Aegypius monachus).

The aim of the present study was to provide ophthalmic reference values under normal physiological conditions for Aegypius monachus (cinereous vulture). Thirty-two eyes of sixteen adult captive cinereous vultures were used for this study. Tear tests and tonometry in conscious and anesthetized states, neuro-ophthalmic tests, measurement of corneal diameter, slit-lamp biomicroscopy, ophthalmoscopy, and funduscopy were performed. Schirmer tear test (STT) value was 11.4±2.6 and 11.5±2.8mm/min in the right (OD) and left eye (OS), respectively. Phenol red thread test (PRT) values were 22.3±2.1mm/15s OD and 22.8±3.0mm/15s OS. The results showed a strong correlation between STT and PRT in both eyes. Intraocular pressure (IOP) values were 32.8±6.9mmHg OD and 31.9±7.1mmHg OS with TonoVet and 20.7±4.5mmHg OD and 19.5±4.1mmHg OS with Tono-Pen. There were significant differences in IOPs between rebound and applanation tonometry in both OD and OS. Tear production and IOP values showed significant reductions with general anesthesia in both tear tests and both tonometry (P<.001). Horizontal corneal diameter (mm) was 15.56±0.96 OD and 15.56±0.96 OS. Vertical diameter (mm) was 14.13±0.96 OD and 14.06±1.06 OS. The horizontal diameter was significantly longer than vertical diameter (P<.001). Ocular morphologic information and normal reference range values for various ophthalmic measurements were obtained in clinically healthy cinereous vultures, which can facilitate accurate diagnosis and better management of ophthalmic diseases in cinereous vultures.