Pentacam Measurements Research Articles

Relationship between hyperglycemia and intraocular pressure, corneal biomechanics, and corneal topography during the oral glucose tolerance test in nondiabetic patients.

Altered corneal biomechanics in patients with diabetes may affect intraocular pressure (IOP) measurements. Although a relationship between IOP and glucose levels has been reported in diabetic and nondiabetic patients, the mechanism by which hyperglycemia influences IOP is unclear. The aim of this study was to determine the effects of hyperglycemia on IOP, corneal biomechanics, and anterior segment parameters during the oral glucose tolerance test (OGTT) in nondiabetic patients. Twenty-one patients without DM who underwent OGTT were included in this study. A complete ophthalmologic examination was performed before the test. Blood glucose, insulin level, IOP (iCare rebound tonometer), Ocular Response Analyzer, and corneal topography (Pentacam) measurements were obtained at 0, 1, and 2h during the OGTT. Data from the patients' right eyes were included in the analysis. The mean age of the patients was 46.9 ± 11.0years. There was a statistically significant difference in IOP between 1 and 2h (p = 0.03) and a clinically significant difference between 0 and 1h (p = 0.06). Corneal resistance factor was lower at 2h than 1h (p = 0.03), while central cornea thickness was increased at 1h (p = 0.01) and 2h (p = 0.05) compared to 0h. There was positive partial correlation between hyperglycemia and IOP at 1h (p = 0.049, r = 0.67). The positive partial correlation between IOP and glucose level suggests that acute hyperglycemia may lead to increased IOP. However, further research is needed to explain the mechanism of IOP elevation in the hyperglycemic phase during OGTT.

Intrasession repeatability and agreement of the anterior corneal assessment provided by a multidiagnostic device

ABSTRACT Clinical relevance Multidiagnostic systems have recently appeared on the market. Knowledge of the repeatability and validity of any instrument is mandatory before its introduction in clinical practice. Background The aim of this work is to examine the intrasession repeatability of anterior pole measurements provided by the multidiagnostic device Wave Analyzer Medica 700 (WAM700) and agreement with Pentacam measurements in normal eyes. Methods In the right eyes of 113 participants, three repeat measurements of central keratometry, central corneal thickness, anterior chamber depth and corneal eccentricity were made with the WAM700 and Pentacam in random order. Intrasession repeatability and agreement were determined. Results Employing WAM700, intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth was good (ICCs ≥ 0.992; CV 0.48–0.98%), yet worse than the values obtained for the Pentacam (ICCs ≥ 0.998; CV 0–0.33%). WAM700 showed excellent intrasession repeatability when used to measure the anterior chamber depth (Sw 0.03 mm). However, the repeatability of this device was inferior for central corneal thickness (Sw 4.24 μm) and keratometry measurements (Sw < 0.21 D) and was poor for corneal eccentricity (Sw 0.07; ICC 0.908; CV 14.58%). Agreement between WAM700 and Pentacam showed a high ICC for the keratometry measurements, central corneal thickness and anterior chamber depth (>0.972) but lower for corneal eccentricity (ICC 0.762). Conclusions In healthy eyes, the WAM700 multidiagnostic device showed good intrasession repeatability for keratometry, central corneal thickness and anterior chamber depth measurements. Agreement between WAM700 and Pentacam was good for the anterior chamber depth measurement. However, these instruments cannot be considered interchangeable for keratometry, central corneal thickness and eccentricity readings.

Exploring the Location of Corneal Pigmented Arc and Myopia Control Efficacy in Orthokeratology-Treated Children Using Pentacam Measurements.

To determine the location and intensity of the corneal pigmented arc in orthokeratology (ortho-k)-treated children and its relationship with annual axial length (AL) change using Pentacam. This retrospective cohort study enrolled children aged 9 to 15 years who had been followed up for at least one year after ortho-k treatment for myopia control. A Pentacam was used to determine the location and intensity of pigmented arc after lens wear. Annual AL changes were further used as the outcome measurement to determine their relationships with the location and intensity of pigmented arc using generalized estimating equations (GEE). In total, 62 eyes from 33 patients (mean age 10.9 years) were included in our final analysis. The mean follow-up time was 30.6 months. The mean annual AL changes were 0.10 mm. Age statistically correlated with annual AL change (GEE, P= 0.033). In addition, the annual AL change was negatively associated with the relative vertical distance of the lowest density of pigmented arc point based on the visual center, pupil center, and corneal thinnest point after adjustment with age ( P =0.005, P =0.004, and P< 0.001, respectively). Pentacam could be a useful tool for evaluating the location and intensity of the corneal pigmented arc. In addition, there was a negative correlation between the vertical distance of the pigmented arc and annual AL change. These findings may provide important information regarding myopia control, next-generation ortho-k design, and prescription.

Comparisons of biometric parameters measurements by OPD-SCAN Ⅲ and Pentacam in cataract

BackgroundComparison of OPD-Scan III and Pentacam measurements of relevant parameters guiding the selection of multifocal intraocular lenses in cataract patients. MethodsA retrospective study included 120 patients (120 eyes) with cataract. Their chord kappa, chord alpha, corneal spherical aberration, and pupil size were measured by OPD-Scan Ⅲ and Pentacam. Pairwise t-tests, Pearson tests, and Bland-Altman analyses were used, respectively, to assess the difference, correlation, and agreement between the devices. ResultsThere was no significant difference in photopic chord kappa and corneal spherical aberration between the two instruments (P = 0.054, P = 0.065). Chord alpha and pupil size varied significantly between the two instruments (P < 0.001). OPD-Scan III results revealed a significant association between photopic chord kappa and mesopic chord kappa (r = 0.823, P < 0.001). There was a significant positive correlation between photopic and mesopic chord kappa measured by OPD-Scan Ⅲ and chord kappa measured by Pentacam (r = 0.840, r = 0.757, P < 0.001). The chord alpha evaluated by the two tools had a moderate correlation (r = 0.442, P < 0.001) between them. Bland-Altman analysis showed that there was excellent agreement between the two instruments in measuring chord kappa and corneal spherical aberration, while the chord alpha and pupil size were not consistent. ConclusionsThe chord kappa and corneal spherical aberration measured by OPD-Scan III and Pentacam were consistent in the preoperative decision making of multifocal intraocular lens implantation in cataract patients, both of which have clinical guiding significance. In addition, OPD-Scan III provides more comprehensive day and night chord kappa and pupil diameters, which improves clinical advice for patients with complicated ocular diseases and high demands for nocturnal vision.

Comparing Repeatability and Agreement between Commonly Used Corneal Imaging Devices in Keratoconus.

Keratometry and pachymetry are important for diagnosis and monitoring of keratoconus. Many corneal imaging units exist but comparison to determine repeatability and agreement are paramount for adequate keratoconus management in primary and secondary care. To evaluate the repeatability and agreement of a Placido disc-based videokeratoscope (Medmont-E300 topographer) used in primary care with spectral-domain optical coherence tomography (Revo-NX) and Scheimpflug corneal tomography (Pentacam-AXL) in secondary-care. This was a prospective, single-center study where one eye was randomized to have central and thinnest corneal thickness (CCT, TCT) and maximum, mean, steep and flat keratometry (Kmax, Kmean, Ksteep and Kflat), measured with all three devices. Three measurements were completed per device to assess intra-observer repeatability. 110 eyes from 110 patients with keratoconus were analyzed. Repeatability was best with the Pentacam for CCT, Kmax, Kmean, Ksteep and Kflat parameters (precision = 9.21,0.8,0.38,0.52,0.58). The Medmont had better repeatability than the Revo with Kmax, Kmean, Ksteep and Kflat (precision = 1.41,1.35,1.43,1.59). Revo had the best repeatability with TCT (precision = 3.81). The intraclass correlation coefficient was ˃0.94 for all parameters in all devices. Agreement was generally poor between devices. However, there was good agreement between Pentacam and Medmont Kflat measurements (P˃.05). Repeatability of keratometry parameters with the Pentacam and Medmont were greater than the Revo, suggesting a lower threshold for change for anterior corneal changes. The Revo had the greatest repeatability for TCT, suggesting a lower threshold for assessing thinning in disease progression and corneal-crosslinking safety. There was poor agreement between devices so devices cannot be used interchangeably.

Repeatability of pupil diameter measurements using three different topography devices.

To evaluate the intra- and inter-device repeatability of pupil diameter measurements using three different devices in patients prior to corneal refractive surgery. We examined preoperative measurements from a total of 204 eyes (102 patients) scheduled for corneal refractive surgery at two private centers between July and December 2021. Three consecutive scans were performed with three different devices (Sirius anterior segment analyzer, Pentacam HR, IOLMaster 500) in the same session by the same examiner under standardized conditions. To assess the intra- and inter-device repeatability, we calculated the Intraclass Correlation Coefficient (ICC) and demonstrated results using Bland-Altman plots. The measurement accuracy (intra-device repeatability) of Sirius and IOLMaster was comparable (ICC = 0.64 and 0.61, respectively), with almost no statistically significant differences. Sirius showed the highest measurement accuracy among the three devices. Pentacam measurements resulted in lower precision, with an ICC of 0.09. The agreement between the pairs of devices (inter-device repeatability) was low (wide LoA ranges, Table 5). In this study, the intra-device repeatability of Sirius and IOLMaster was higher than that of the Pentacam, although it did not achieve an optimal level across all three devices. The three devices examined cannot be used interchangeably.

New simulation software to predict postoperative corneal stiffness before laser vision correction.

To develop a new virtual surgery simulation platform to predict postoperative corneal stiffness (Kc mean ) after laser vision correction (LVC) surgery. Narayana Nethralaya Eye Hospital and Sankara Nethralaya, India; Humanitas Clinical and Research Center, Italy. Retrospective observational case series. 529 eyes from 529 patients from 3 eye centers and 10 post-small-incision lenticule extraction (SMILE) ectasia eyes were included. The software (called AcuSimX) derived the anisotropic, fibril, and extracellular matrix biomechanical properties (using finite element calculation) of the cornea using the preoperative Corvis-ST, Pentacam measurement, and inverse finite element method assuming published healthy collagen fibril orientations. Then, the software-computed postoperative Kc mean was adjusted with an artificial intelligence (AI) model (Orange AI) for measurement uncertainties. A decision tree was developed to classify ectasia from normal eyes using the software-computed and preoperative parameters. In the training cohort (n = 371 eyes from 371 patients), the mean absolute error and intraclass correlation coefficient were 6.24 N/m and 0.84 (95% CI, 0.80-0.87), respectively. Similarly, in the test cohort (n = 158 eyes from 158 patients), these were 6.47 N/m and 0.84 (0.78-0.89), respectively. In the 10 ectasia eyes, the measured in vivo (74.01 [70.01-78.01]) and software-computed (74.1 [69.03-79.17]) Kc mean were not statistically different ( P = .96). Although no statistically significant differences in these values were observed between the stable and ectasia groups ( P ≥ .14), the decision tree classification had an area under the receiver operating characteristic curve of 1.0. The new software provided an easy-to-use virtual surgery simulation platform for post-LVC corneal stiffness prediction by clinicians and was assessed in post-SMILE ectasia eyes. Further assessments with ectasia after surgeries are required.

Efficacy and safety of laser peripheral iridoplasty with different energy levels and locations in the treatment of primary angle closure disease assessed by swept-source anterior segment optical coherence tomography

BackgroundTo explore the efficacy and safety of laser peripheral iridoplasty (LPIp) with different energy levels and locations in the treatment of primary angle closure disease (PACD) assessed by swept-source anterior segment optical coherence tomography (AS-OCT).MethodsWe enrolled patients with PACD following best-corrected visual acuity (BCVA), intraocular pressure (IOP), anterior chamber gonioscopy, ultrasound biomicroscopy(UBM), optic disc OCT, and visual field examinations. After Pentacam and AS-OCT measurements, the patients were randomly divided into four treatment groups for LPIp with two different energy levels (high vs. low energy) and two locations (far from the periphery vs. near the periphery) and combined with laser peripheral iridotomy. BCVA, IOP, pupil diameter, central anterior chamber depth, anterior chamber volume, anterior opening distance (AOD)500, AOD750, trabecular iris angle (TIA)500, and TIA750 in four quadrants before and after laser treatment were compared.ResultsWe followed up 32 patients (64 eyes; average age, 61.80 ± 9.79 years; 8 patients/16 eyes per group) for up to 2 years. The IOP of all enrolled patients was decreased after surgery compared to that before (t = 3.297, P = 0.002), the volume of the anterior chamber was increased (t=-2.047, P = 0.047), and AOD500, AOD750, TIA500, and TIA750 were increased (all P < 0.05). Within-group comparisons showed that BCVA in the low-energy/far-periphery group was improved after surgery (P < 0.05). After surgery, the IOP was decreased in the two high-energy groups, whereas the volume of the anterior chamber, AOD500, AOD750, TIA500, and TIA750 were increased in all groups (all P < 0.05). However, when comparing every two groups, the high-energy/far-periphery group showed a stronger effect on pupil dilation than the low-energy/near-periphery group (P = 0.045). The anterior chamber volume in the high-energy/near-periphery group was larger than that in the high-energy/far-periphery group (P = 0.038). The change in TIA500 was for 6 points smaller in the low-energy/near-periphery group than in the low-energy/far-periphery group (P = 0.038). Other parameters showed no significant group differences.ConclusionLPIp combined with iridotomy can effectively reduce IOP, increase anterior chamber volume, increase chamber angle opening distance, and widen the trabecular iris angle. Intraoperatively, high-energy laser spots positioned one spot diameter from the scleral spur can obtain the best effect and safety. Swept-source AS-OCT can safely and effectively quantify the anterior chamber angle.

Determination of the repeatability of corneal densitometry as measured with a Scheimpflug camera device in refractive surgery candidates.

Corneal densitometry analysis provides an objective measurement of corneal transparency in patients undergoing photorefractive keratectomy (PRK). To date, no study that focuses on determining the reliability and smallest real difference (SRD), specifically in PRK candidates, has been published. The study was conducted at Clínica de Oftalmología Sandiego, Medellín, Colombia. This was a prospective and analytical study. Refractive surgery candidates underwent Pentacam measurements twice with five minutes of difference. Repeatability of measurements was evaluated for every area using Wilcoxon signed-rank test, Spearman's rank-order correlation, and the intraclass correlation coefficient, followed by a within-subjects factor (Sw) finishing with a determination of the SRD for all areas. Bland-Altman plots were created and analyzed. A total of 110 eyes were included. The mean total densitometry was 18.67 ± 1.56 grayscale units (GSU) and 18.65 ± 1.49 GSU for the first and second measurements, respectively. Wilcoxon was non-significant (P > 0.05) while the intraclass correlation coefficient demonstrated an excellent agreement. SRD ranged from 0.21 GSU (posterior × 6-10 mm) to 1.79 GSU (total × 10-12 mm). Anterior depths and 10-12 mm annulus had consistently more variability and greater (worse) SRD. The 10-12 mm annulus showed great dispersion on the Bland-Altman plots. Corneal densitometry has an excellent repeatability in refractive surgery candidates for areas below 10 mm. Any densitometry change ≥1.0 GSU in areas under 10 mm should be considered as well above measurement noise and corresponding to a real change in measured parameters. The 10-12 mm area does not seem to be reliable enough in refractive surgery candidates to warrant surveillance after corneal-based surgery.

Comparison of Central Corneal Thickness Measurements with Four Different New Devices and Ultrasound Pachymetry

To assess the central corneal thickness (CCT) with 5 different devices, evaluate the repeatability of the devices, and determine the possible relationship between thickness values and sex. The study included 308 eyes of 154 patients (76 women, 78 men) between the ages of 18-30 who presented to the Ophthalmology Clinic of Muğla Sıtkı Koçman University Training and Research Hospital. Autorefractor (Topcon, Japan), ultrasound pachymetry (UP) (Ceniscan, USA), high-resolution Pentacam (Oculus, USA), anterior segment-optical coherence tomography (AS-OCT) (Optovue, USA), and Spectralis AS-OCT (Heidelberg, Germany) measurements were assessed. The mean age of the study participants was 23.2±0.2 years and the mean CCT was 540±14.1 μm, with no statistically significant difference in CCT between sexes (p&gt;0.05). Mean CCT values were 557.0±26.7 μm with the autorefractor, 543.6±32.9 μm with UP, 533.8±30.2 μm with the Oculus Pentacam, 519.8±30.1 μm with Optovue AS-OCT, and 547.5±31.6 μm with Heidelberg AS-OCT. Pairwise comparisons between devices showed that the Optovue AS-OCT gave significantly lower CCT measurements than the autorefractor and Heidelberg AS-OCT device (p=0.027 and p=0.033, respectively). The coefficient of repeatability for autorefractor, UP, high-resolution Pentacam, Optovue AS-OCT, and Heidelberg AS-OCT CCT measurements were 1.51%, 2.46%, 3.72%, 2.57%, and 3.34%, respectively. Measurements made with five different devices showed that CCT was comparable and clinically usable. However, it was determined that the Optovue AS-OCT showed lower CCT values compare to other devices. When compared in terms of repeatability, it was found to be lower in the Pentacam than other devices.

Performances of Corneal Topography and Tomography in the Diagnosis of Subclinical and Clinical Keratoconus.

AimThe purpose of the study was to assess the efficacy of topographical and tomographical indices given by the Pentacam (pachymetric, tomopetric, and aberometric) in clinical and subclinical keratoconus (KCN) diagnosis.Material and MethodsIn this observational analytic retrospective study, patients with abnormal findings in topography and tomography maps but with no signs on clinical examination (subclinical KCN group, sKCN), patients with clinical keratoconus (KCN group), and healthy subjects (Control group) were evaluated.ResultsThe KCN group proved significantly different (p < 0.001) values of the investigated parameters than the Control group. Eleven out of 28 investigated parameters proved significantly different in the sKCN group compared to controls (p < 0.001). Two topographic measurements, namely I-S (cut-off = 1.435, a large value indicates the presence of KCN) and CCT (cut-off = 537, a small value indicates the presence of KCN), showed AUCs equal to 1 [0.999 to 1]. Six other Pentacam measurements, including Back maximum keratometry (Back Kmax) proved to be excellent parameters for case-finding and screening. In distinguishing sKCN from normal eyes, Pentacam index of vertical asymmetry (IVA), inferior-superior difference (I-S) value, thinnest point (TP), Belin Ambrosio Enhanced Ectasia Display (BAD_D) and root mean square total (RMS total) performed best.ConclusionsIn distinguishing sKCN from normal eyes, Back Kmax, IVA, I-S, and RMS total values demonstrated higher accuracy and utility. Six indices, namely ISV, IVA, KISA, PRC, RMS-HOA, and Back Kmax demonstrate excellent utility in case-finding and screening for clinical KCN.

Proposing an ensemble learning model based on neural network and fuzzy system for keratoconus diagnosis based on Pentacam measurements

The present study was done to evaluate efficiency of an ensemble learning structure for automatic keratoconus diagnosis and to categorize eyes into four different groups based on a combination of 19 parameters obtained from Pentacam measurements. Pentacam data from 450 eyes were enrolled in the study. Eyes were separated into training, validation, and testing sets. An ensemble system was used to analyze corneal measurements and categorize the eyes into four groups. The ensemble system was trained to consider indices from both anterior and posterior corneal surfaces. Efficiency of the ensemble system was evaluated and compared in each group. The best accuracy was achieved by the ensemble system with both multilayer perceptron and neuro-fuzzy system classifiers alongside the Naïve Bayes combination method. The accuracy achieved in KC versus N distinction task was equal to 98.2% with 99.1% of sensitivity and 96.2% of specificity for KC detection. The global accuracy was equal to 98.2% for classification of 4 groups, with an average sensitivity of 98.5% and specificity of 99.4%. In this study, authority of an ensemble learning system to work out intricate problems was presented. Despite using fewer parameters, herein, comparable or, in some cases, better results were obtained than methods reported in the literature. The proposed method demonstrated very good accuracy in discriminating between normal eyes and different stages of keratoconus eyes. In some cases, it was not possible to directly compare our results with the literature, due to differences in definitions of KC group as well as differences in selection of items and parameters.

Predicted and Measured Changes in Posterior Corneal Astigmatism after Uncomplicated Femtosecond Assisted LASIK (FsLASIK) and Microkeratome LASIK Correction for Myopia and Low Astigmatism

ABSTRACT Purpose: To compare predicted and measured changes in astigmatism at the posterior corneal surface (PCS) after FsLASIK or LASIK. Methods: Astigmatism was measured at both corneal surfaces (PentacamTM) before and 3 months after unremarkable FFsLASIK (roup 1,n = 100) or LLASIK (roup 2,n = 100) for myopia (−7.25DS to −0.75DS) and low astigmatism (≤1.00DC). Photoablation was achieved using Schwind Amaris750STM laser (Aberration Free profile, centered on corneal vertex). Pre-and postop astigmatic data, according to subjective refraction and estimates for the corneal surfaces (over the central 3.2 mm zone), were subjected to vector analysis to calculate surgically induced astigmatism (SIA) by refraction (SIAR), at the anterior (SIAFact) and posterior corneal surfaces (SIABact). The difference vector between SIAR and SIAFact was regarded as the predicted SIA at the PCS (SIABest). Results: Reporting key findings. Mean(±sd,95%CI) SIABest and SIABact powers in group 1 were −0.52DC(±0.35,-0.56 to −0.45) and −0.11DC(±0.08,-0.13 to −0.10) in group 1, −0.35DC(0.20,-0.39 to −0.32) and −0.08DC(0.07,-0.09 to −0.06) in group 2. Differences between SIABest and SIABact were significant for powers but not axes. Significant correlations(p < .01) were revealed between (I) SIAR and SIAFact powers [Group 1, SIAR = 0.370.SIAFact-0.292,r = 0.299. Group 2, SIAR = 0.484.SIAFact-0.394,r = 0.519] but not the axes and (II) ΔC (difference between pre-[x1] and postop measured PCS astigmatic powers) and x1 [Group 1, ΔC = 0.384x1 + 0.119,r = 0.423. Group 2, ΔC = 0.135x1 + 0.047,r = 0.229,p = .022]. There was no correlation between SIABest and SIABact powers or axes. Conclusion: The changes in posterior corneal astigmatic powers according to Pentacam measurements are small and do not account for the deficit between SIAR and SIAFact after FsLASIK or LASIK.

Comparison of refractive outcomes using Scheimpflug Holladay equivalent keratometry or IOLMaster 700 keratometry for IOL power calculation.

This study aims to compare postoperative refractive error results using Pentacam (Oculus Optikgeräte GmbH) Holladay equivalent keratometry readings (EKR) or IOLMaster 700 (Carl Zeiss Meditec AG) keratometry (K) values in IOL power calculation. This retrospective study included 54 eyes of 31 patients who underwent cataract surgery. Preoperative biometric measurements of all patients were obtained using IOLMaster 700 followed by Pentacam measurements. IOLMaster 700K measurements on horizontal (K1) and vertical (K2) axes and EKR measurements on 2mm (EKR2mm), 3mm (EKR3mm) and 4.5mm (EKR4.5mm) corneal zones were recorded. EKR4.5mm value and IOLMaster 700K values were used in Holladay-II, SRK/T, Haigis, and Hoffer-Q formulas to calculate predictive refractive error (PRE). Absolute refractive error (ARE) was calculated as the absolute difference between actual postoperative refractive error (APRE) and PRE values. Mean age was 72.2 ± 8.3 (51-87) years and mean IOL power was 21.5 ± 2.9 D (18-23 D). There was no significant difference between PRE values when IOLMaster 700K measurements and EKR4.5mmK measurements were used in Holladay-II, SRK/T, Haigis, and Hoffer-Q formulas (p = 0.571, p = 0.833, p = 0.165, p = 0.347, respectively). There was no significant difference between APRE and ARE values (p = 0.124). According to mean ARE results, the closest estimate was achieved when the IOLMaster 700K values were used in the Holladay-II formula (p = 0.271). IOLMaster 700K measurement and Pentacam EKR4.5mm measurements can be used interchangeably. IOLMaster 700K values yielded the most predictive measurement of the refractive result using the Holladay-II formula.

Evaluation of intraocular pressure change and anterior segment parameters after intravitreal bevacizumab injection - Cannula size matters.

PURPOSE:To determine the changes in intraocular pressure (IOP) and anterior chamber parameters following intravitreal bevacizumab injection with different sizes of cannulas.METHODS:This clinical trial was conducted with 70 eyes of 70 patients who received an intravitreal injection of bevacizumab with 26 G (Group 1) or 30 G (Group 2) needle. Preinjection and postinjection 30th-min IOP and pentacam measurements were obtained. Anterior chamber depth (ACD), anterior chamber volume (ACV), central corneal thickness (CCT), corneal volume (CV), and iridocorneal angle (ICA) measurements were evaluated in pentacam.RESULTS:Preinjection mean IOP values in Group 1 and 2 were 14.7 ± 3.29 mm Hg and 15.1 ± 2.87 mm Hg, respectively. Postinjection mean IOP in Group 1 was 16.8 ± 6.24 mm Hg and in Group 2 was 20.3 ± 3.66 mm Hg. Postinjection mean IOP values were significantly higher than preinjection values in both groups (Group 1 P < 0.005 and Group 2 P < 0.001). IOP change was significantly higher in Group 2 after injection (P < 0.05). In both groups, the change in IOP found to be more significant in phakic eyes than pseudophakic eyes (Group 1 P < 0.001, Group 2 P < 0.001). CCT and CV were significantly higher in both groups 30 min after the injection than preinjection (Group 1 and Group 2; P < 0.01). In Group 2 ACD, ACV and ICA values were significantly lower than preinjection values (P < 0.05).CONCLUSION:Needle bore size is an important parameter that influences anterior segment parameters and IOP change in the intravitreal injection. IOP rise and anterior segment changes are more prominent with a thinner cannula.

Asymmetric Thickness Intracorneal Ring Segments for Keratoconus.

PurposeTo describe the anatomical and functional results of the implantation of asymmetric thickness intracorneal ring segments (AS-ICRS) in eyes with keratoconus and asymmetric/irregular astigmatism (type 2 – Duck – and type 3 – Snowman – phenotypes, Fernandez-Vega/Alfonso morphologic Keratoconus classification).Materials and MethodsRetrospective observational study including 19 consecutive patients (21 eyes) with keratoconus who underwent manual implantation of the Keraring® Asymmetric ICRS (AS). Analysis included demographic and clinical data and Pentacam (Oculus®) measurements: topographic astigmatism; topographic flat meridian (K1), steepest meridian (K2) and the maximum keratometric point (Kmax); total root mean square (RMS) and high order RMS (HOA) aberrations and comatic Zernike coefficients (Z31;Z3−1) at 0º and 90º meridians.ResultsOverall mean age was 35.3±11.7 years and median follow-up was 7.1 months (range 6–12). At the end of follow-up, a significant improvement from baseline was achieved in both UDVA (0.24±0.22; p=0.017) and CDVA (0.21±0.17; p<0.001). Regarding topographic measurements, the greatest decrease was observed in K2 (2.76±1.9D; p<0.001) and astigmatism (1.97±1.5; p<0.001). Aberrometry analysis showed a reduction of 1.27±3.2µm in the total RMS (p=0.085), 0.24±0.9µm in HOA (p=0.227) and 0.78±0.5 (p<0.001) in the 90º component of comatic aberration. The procedure effects in the CDVA, topographic and aberrometric parameters were higher in type 2 cones without statistical significance (p>0.05 in all).ConclusionImplantation of the Keraring® Asymmetric ICRS in keratoconus with asymmetric/irregular astigmatism allowed an improvement of several clinical, topographic and aberrometric parameters, with clinical efficacy and safety, with a tendency to a greater effect in the type 2 cones.

Correlation between Corneal Endothelial Cell Density and Central Ocular Surface Temperature in Normal and Keratoconus Eyes

ABSTRACT Purpose In keratoconus (KC), an increase of the corneal back surface area may result in endothelial cell density (ECD) decrease and an increase of the corneal front surface area in ocular surface temperature (OST) decrease due to increased heat dissipation. Along with these hypotheses, we aimed to analyse the correlation between ECD and central corneal OST in patients with KC and healthy controls. Patients and methods A total of 154 eyes with KC (mean age 36.1 ± 12.5 years) and 92 healthy eyes (mean age 36.4 ± 12.8 years) were examined. Corneal front and back surface area at the central 5 mm corneal diameter (FSA and BSA) were calculated based on Pentacam measurement data: FSA or BSA = 2×3.14×R(R-√R2-D/2)2, where R referred to corneal front or back surface radius of curvature and D to the corneal front or back surface diameter (5 mm for the present study), respectively. ECD was determined by specular microscopy (EM-3000) and central corneal OST by thermography (TG-1000). Results ECD was significantly lower in KC (2498 ± 356/mm2) patients than in controls (2638 ± 294/mm2; p < .001). FSA (20.35 ± 0.26 mm2 vs. 20.17 ± 0.03 mm2) and BSA (20.84 ± 0.58 mm2 vs. 20.45 ± 0.08 mm2) were significantly higher in KC patients than in controls (p = .001; p < .001), but the average central corneal OST did not differ significantly between both groups (34.2 ± 0.6°C vs.34.3 ± 0.7°C; p = .62). OST at the corneal centre correlated weakly, positively with ECD (r = 0.2; p < .05), but OST did not correlate with FSA (r = 0.045) or BSA (r = 0.064). Conclusions Endothelial cell density seems to have a mild impact on central ocular surface temperature in keratoconus and normal subjects. This effect is not correlated to the corneal front or back surface area.

Ocular findings in children with attention deficit hyperactivity disorder: A Case–Control study

BackgroundTo evaluate the differences of ocular abnormalities between children with attention deficit hyperactivity disorder and non-attention deficit hyperactivity disorder children using siblings of cases in Jordan. MethodsA case–control study of 55 children with attention deficit hyperactivity disorder, and 55 children without the disorder as a control group using siblings of cases. Examination included visual acuity, motility, anterior and posterior segments, convergence, optical coherence tomography and corneal topography. ResultsThirty-eight patients from the attention deficit hyperactivity disorder group had visual acuity better than 0.8 in both eyes; 36.4% had normal cyclorefraction, while 54.5% had mild hyperopia. Most of them did not need glasses. Tomography showed normal values with no statistically significant differences between the two groups. The near point of convergence showed significantly abnormal values in 41.9% of children with attention deficit hyperactivity disorder. Pentacam measurements showed normal values with no statistically significant differences between the two groups. ConclusionsChildren with attention deficit hyperactivity disorder show significant low near point convergence compared with the study control group.

Crystalline Lens Power and Associated Factors in Highly Myopic Children and Adolescents Aged 4 to 19 Years

To investigate the distribution characteristics of lens power in highly myopic Chinese children and adolescents and its association with age, axial length (AL), and spherical equivalent (SE). Cross-sectional study. A total of 459 highly myopic (SE ≤-5 diopter [D]) children and adolescents aged 4-19 years were included in the study. Participants underwent a series of ophthalmic examinations, which included AL, cycloplegic refraction, and Pentacam measurements. Lens power was calculated using Bennett's formula with its distribution described by age, AL, and SE. Multiple regression was conducted to analyze the associated factors of lens power. Greater lens power was independently associated with younger age, girls, shorter AL, and thicker lens thickness (standardized β=-0.203, 0.214,-0.379 and 0.492, respectively; all P < .001). However, a significant difference in lens power with age was only found in participants younger than 9 years, after which it reached a plateau (mean difference of 1.23 and 0.084 D per age group, respectively). Lens power was negatively associated with AL only in participants with AL <27mm. No correlation was observed between lens power and SE. Among highly myopic children and adolescents, differences in lens power with age declined significantly after 9 years of age, which was 1 year earlier than non-high myopic patients in previous studies, which implied differences in pathophysiological process between non-high myopia and high myopia. The decoupling of lens power and AL in eyes >27mm might represent the limited influence of AL on lens power.

Pentacam changes in primary angle-closure glaucoma after different lines of treatment.

To assess the changes in the anterior chamber parameters using Pentacam following four different lines of treatment of primary angle-closure glaucoma (PACG). A retrospective comparative study included 126 patients (126 eye) presented within 24-48h after acute angle-closure glaucoma (AACG). Patients were divided into 2 groups: group A (68 eyes) with controlled intraocular pressure (IOP) ≤21 mm Hg, which included subgroup A1 (34 eyes) with clear lens underwent Nd:YAG laser peripheral iridotomy (LPI) and subgroup A2 (34 eyes) with cataract underwent standard phacoemulsification; and group B (58 eyes) with uncontrolled IOP, which included subgroup B1 (30 eyes) with clear lens underwent trabeculectomy and subgroup B2 (28 eyes) with cataract underwent combined phacoemulsification and trabeculectomy. Patients were followed up for at least 3mo. Primary outcomes were Pentacam anterior segment measurements [anterior chamber angle (ACA) and depth (ACD)]. Secondary outcomes were changes in IOP, visual acuity (VA) and recorded complications. At the 3rd month, there was significant increase in the ACA values in all studied groups compared to preoperative values (P<0.001). The highest percent of increase in ACA was recorded in phacotrabeculectomy group B2 (128.40%). There was significant increase in ACD values at 3rd month compared with baseline values (P<0.001) for groups A1, A2, and B2; without change in B1 trabeculectomy group. The maximum deepening of ACD was noticed in group B2 with 94.27% increase. Significant decrease in postoperative IOP in groups A2, B1 and B2 (P<0.001, P=0.014, and P<0.001 respectively). In group A1 there was significant increase in 3rd month postoperative IOP from baseline values (P<0.001). The maximum decrease in IOP was noticed in group B2 with 59.54% decrease. VA improvement in 3rd month postoperative was recorded in all studied groups, maximum VA improvement was observed in group B2 up to 0.2 logMAR. Pentacam can be a helpful tool in studying and comparing the effect of the different lines of management of PACG on the anterior chamber measures. Phacotrabeculectomy was proved to be an effective line for managing PACG with resultant significant increase in the anterior chamber parameters, IOP reduction as well as maximum VA improvement. LPI has only temporary effect on IOP with significant changes in ACA and ACD. Phacoemuslification alone can be an option in treating PACG. Trabeculectomy resulted in temporary increase in the anterior chamber parameter which subsequently returned to baseline values.