Baseline Central Corneal Thickness Research Articles

Efficacy of Sutureless Scleral Fixation of One-Piece T-Shaped Haptic Intraocular Lens in Maintaining Anterior Chamber Stability During Descemet Membrane Endothelial Keratoplasty in Vitrectomized Eyes: Leak Test and Iris Diaphragm Reconstruction.

Objectives: This study aimed to describe the outcomes of a staged procedure combining Descemet membrane endothelial keratoplasty (DMEK) and sutureless scleral fixation (SSF) of a one-piece intraocular lens (IOL) in a case series. Co-performing endothelial keratoplasty (EK) and SSF is associated with intraoperative and postoperative complications such as graft deployment difficulties, air migration, graft detachment, and IOL opacification or tilt, all of which are evaluated in this study. Methods: This is a retrospective observational case series. Clinical data were collected from eight eyes of eight patients who underwent DMEK for endothelial failure and had previously received an SSF with one-piece IOL following complete vitrectomy. During DMEK surgery, an air leak test was conducted to check for air migration into the posterior chamber. If instability was detected, pupilloplasty was performed. Intraoperative and postoperative data, including DMEK graft unfolding time, were collected. Corrected Distance Visual Acuity (CDVA), refraction, endothelial cell density (ECD), central corneal thickness (CCT), intraocular pressure (IOP), and complications were recorded over a 12-month follow-up period. Results: We performed pupilloplasty in four patients (50%). The median CDVA improved from preoperative 0.85 logMAR (range: 0.60 to 1.00) at baseline to 0.18 logMAR (range: 0.10 to 0.70, p = 0.012) at 12 months. The median refraction value changed significantly from -1.00 to -0.50 at 12 months. The median percentage reduction in ECD after 12 months was 33.4% (range 30 to 40). The median baseline CCT was 689 μm (range: 651 to 701) at baseline visit and 541.5 μm (range: 525 to 591, p = 0.008) at 12 months. The median IOP was reduced significantly during follow-up. The median graft unfolding time was 6 min (5 to 9). One patient required rebubbling for partial detachment on postoperative day one. No complications occurred within 12 months. Conclusions: The effective compartmentalization of the anterior and posterior chambers in vitrectomized eyes with an SSF one-piece IOL and pupilloplasty can facilitate critical steps of DMEK surgery in complex eyes. Additionally, the air leak test could prove useful in identifying the need for iris-lens diaphragm reconstruction.

Transpalpebral intraocular pressure measurement by Diaton compared to Goldman applanation tonometer in myopic eyes before and after transepithelial photorefractive keratectomy in Saudi Arabia.

To compare intraocular pressure (IOP) measured via the trans palpebral IOP (tpIOP) method using a Diaton or with a Goldman applanation tonometer (GAT) and study the determinants of IOP difference in eyes undergoing transepithelial photorefractive keratectomy (TPRK) for myopia. This cross-sectional validation study was held in 2020 in an eye hospital in Saudi Arabia. IOP was measured by Diaton and GAT before treatment, after one week, and one month of TPRK. It is considered if IOP difference by Diaton and GAT was less than ±2 mm Hg acceptable. The IOP difference was tested if correlated to spherical equivalent (SE), central corneal thickness (CCT), age, gender, or tpIOP. Totolly 200 myopic eyes of 100 patients were included in the study. The mean difference of IOP measured by two methods before TPRK, 1wk, and 1mo after TPRK were 0.790, -0.790, and -0.920 mm Hg, respectively (P<0.001). Diaton could measure IOP effectively 89.5% eyes before TPRK and 82% and 84% at 1wk and 1mo after TPTK, respectively. At week 1, IOP differences were significantly correlated to baseline CCT (P=0.02) and tpIOP at week 1 (P<0.001). One month after TPRK, only tpIOP was significantly correlated to the difference in IOP (P<0.001). Diaton is a good screening tool for IOP before TPRK. It helps in monitoring IOP after surgery. Although more practical, it is less efficient than GAT. In eyes with high myopia and low tpIOP before surgery, IOP post-TPRK by Diaton and GAT could differ.

Cataract surgery in patients with Fuchs’ dystrophy and corneal decompensation indicated for Descemet's membrane endothelial keratoplasty

The availability of corneal donor tissue is limited in most developing countries. This study evaluated whether patients with coexisting cataract and Fuchs’ dystrophy with corneal decompensation awaiting Descemet’s membrane endothelial keratoplasty (DMEK) benefited from phacoemulsification. This is a retrospective case–control study which included patients with Fuchs’ dystrophy and evidence of corneal decompensation awaiting DMEK. Best-corrected visual acuity (BCVA) and central corneal thickness (CCT) were documented at baseline (pre-cataract surgery in the case group, or at the time of transplantation registry in the control group), 1-month and pre-DMEK. A total of 16 phakic patients with visually significant cataracts had cataract surgery during the study period, and 15 pseudophakic patients were included as controls. There was no significant difference with regard to BCVA at baseline, 1-month or pre-DMEK between the case and control groups. Similarly, no significant difference in CCT was found at baseline, 1-month or pre-DMEK. In the case group, 4 patients with improved visual acuity post-cataract surgery chose to defer DMEK. After stratification, statistical analysis showed significantly better BCVA in the deferred group (n = 4) at 1-month post-cataract surgery, compared to the DMEK group (n = 12) (0.21 ± 0.21 vs. 0.86 ± 0.29 LogMAR, P = 0.004). The other parameters, including baseline BCVA and CCT at any time point documented, were not statistically different. In conclusion, in patients with Fuchs’ dystrophy and decompensated corneas awaiting transplantation, phacoemulsification did not lead to significant increase of corneal thickness nor deterioration of visual acuity. A few patients achieved satisfactory vision after cataract surgery and deferred endothelial keratoplasty.

Intraocular pressure trend following myopic photorefractive keratectomy.

To evaluate the intraocular pressure (IOP) trend and risk factors for IOP rise after myopic photorefractive keratectomy (PRK). One eye of each patient undergone PRK for myopia was randomly assigned to this study. All eyes underwent tonometry by CorVis Scheimpflug Technology (CST) tonometer (Oculus Optikgeräte GmbH, Wetzlar, Germany) 1week, 2weeks, 1month, 2months, 3months and 4months after surgery. The eyes with IOP rise more than 5mmHg and the risk factors were evaluated by Kaplan-Meier graph and multiple Cox regression analysis. A total of 348 eyes of 348 patients were enrolled in this study. Forty-three eyes (12.35%) experienced a steroid-induced IOP rise of more than 5mmHg. Eyes with IOP rise had higher baseline IOP (Median 19mmHg (IQR 18-22) versus Median 15mmHg (IQR 14-16); p < 0.001). Baseline central corneal thickness (CCT) was higher in eyes without IOP rise (Median 520µm (IQR 509-541) versus Median 535µm (IQR 518-547); p = 0.009). In multivariate Cox regression analysis, higher baseline IOP was a risk factor for IOP rise (Hazard Ratio (HR) 1.59 (95% CI 1.43-1.77); p < 0.001) while higher baseline CCT was protective (HR 0.97 (95% CI 0.95-0.98); p < 0.001). Eyes with higher baseline IOP and lower baseline CCT are at increased risk of IOP rise after PRK and should be monitored more frequently.

Changes in Corneal Parameters after DMEK Surgery: A Swept-Source Imaging Analysis at 12-Month Follow-Up Time.

Purpose To assess the time course changes in corneal topographic parameters during the one-year follow-up after Descemet membrane endothelial keratoplasty (DMEK) surgery. Materials and Methods Twenty-one patients (24 eyes) who underwent DMEK surgery were evaluated. Best corrected visual acuity (BCVA), endothelial cell count (ECC), central corneal thickness (CCT), mean keratometry (MK), mean astigmatism (MA), astigmatism asymmetry (AA), and higher-order aberration (HOA) were assessed at baseline and 1, 3, 6 and 12 months after the surgery using CASIA2 anterior segment swept-source OCT (Tomey, Japan). Results In patients who underwent DMEK surgery, BCVA improved gradually at the subsequent visits during the 12-month follow-up. A significant reduction in ECC and CCT at the 1st month was noted, which remained stable until the 6th month postoperatively. Anterior and total MK values remained unchanged, whereas changes in posterior keratometry were noticeable until the 6th month after surgery. A significant reduction in the anterior, posterior, and total astigmatism magnitude as well as astigmatism asymmetry was observed during the first 6 months after surgery. A gradual anterior, posterior, and total HOA decrease was documented until the 12th month after surgery. Negative correlations between baseline values of CCT, MK, MA, AA, and HOA and postoperative variations in those parameters at consecutive follow-up time points were observed. Accordingly, negative correlations between baseline CCT and postoperative changes in corneal topographic parameters after surgery were found. Conclusion The stabilization of most corneal topographic parameters takes place within 6 months after the procedure, whereas HOA reduction and BCVA improvement gradually occur during the first year after surgery. Preoperative values of corneal topographic parameters strongly determine their changes detected after DMEK surgery, which may suggest that early therapeutic intervention results in better visual outcomes.

Myopia and glaucoma progression among patients with juvenile onset open angle glaucoma: A retrospective follow up study.

To identify the risk factors for glaucoma progression, especially the association with myopia, among treated juvenile open angle glaucoma (JOAG) patients. Glaucomatous progression was analysed in the eyes of JOAG patients with at least 5-years of follow up in this retrospective study. Baseline variables such as age, inheritance pattern, baseline intraocular pressure (IOP), baseline central corneal thickness, visual acuity, baseline refractive error, spherical equivalent (SE) and duration of follow-up were noted. Stereoparametric global trend analysis and Moorfields Regression Analysis on confocal scanning laser ophthalmoscopy were used to detect progression. Variables associated with glaucoma progression, with respect to progressors (PG) and non-progressors (NPG) were analysed. Since both eyes of a patient were taken for analysis, a generalised estimating equation method was used to correct the bias. Among 74 eyes (37 subjects), glaucoma progression was noted in 11 eyes (14.9%) of 8 patients, with a median time to progression of 7.4years (range 5-15.5years). For myopes (SE≤-1.00D), glaucoma progression was 18 times more likely than mild and no myopes (>-1DS) (p=0.03, 95% CI: 1.14, 217.44). The prevalence of myopia in the JOAG, PG and NPG cohorts was 70.3%, 87.5%, and 65.5%, respectively. Myopia progression was noted at follow up in 70% patients. One-unit increase in baseline vertical cup disc ratio, 1mmHg increase in IOP fluctuations and 1dB year-1 depression of visual field were associated with 0.44, 0.06 and 0.07D year-1 increases in the rate of myopia progression, respectively. JOAG progressors had a greater baseline myopic refraction and a faster myopia development over time. The development of myopia in JOAG eyes could be an indicator of glaucoma progression, and hence progressing myopic (≤-1D) JOAG patients should be followed up more rigorously.

Central corneal thickness and intraocular pressure in primary open angle glaucoma suspects in a south Indian population. Is it time for “corneal anthropology”?

To study correlation between central corneal thickness (CCT) and intraocular pressure (IOP) in the primary open angle glaucoma (POAG) suspects and to assess the importance of the local population reference CCT in pachymetry adjusted IOP.Prospective, cross sectional study.A total of 100 patients aged 40-70 years of age diagnosed as POAG suspects were included. CCT measurements using ultrasound pachymetry and IOP measurement with Goldmann applanation tonometer (GAT) was done. IOP was corrected to the local south-Indian baseline CCT and also to the International CCT and comparison was done.The study included 100 patients (58 male and 42 female) with mean age of 51.7 ± 6.1 years. The mean CCT was 518.91 ± 24.26 μm, 522.19 ± 21.56 μm among females, males respectively. The mean uncorrected IOP (GAT) was 19.50 mmHg, 20.14 mmHg (right, left sides). Significant, moderate positive correlation between CCT and IOP was observed. The two groups i.e mean IOP corrected for South-Indian CCT (Mean_CX_IOP) versus IOP corrected for CCT international (Mean_CX_INT_IOP) showed significant difference. The mean IOP in Indian CCT corrected group was 19.76 ± 2.81 mmHg and in international CCT group was 21.51 ± 2.83 mmHg. Levene's test indicated significant difference in mean IOP of 2 groups (p=0.000).CCT is an important parameter in glaucoma management and known to vary in different ethnic groups. Local ethnicity specific CCT should be used in IOP correction with the help of anthropologists.

Corneal Endothelial Cell Changes After Phacoemulsification Combined with Excisional Goniotomy with the Kahook Dual Blade or iStent: A Prospective Fellow-Eye Comparison.

PurposeTo characterize changes in endothelial cell density and morphology following phacoemulsification combined with either excisional goniotomy with the Kahook Dual Blade (KDB-phaco) or first-generation iStent trabecular microbypass implantation (iStent-phaco).SettingA single clinical practice.MethodsTwenty-one adult subjects from one center with visually significant cataract and mild-moderate open-angle glaucoma underwent KDB-phaco or iStent-phaco in one eye and the alternate procedure in the fellow eye as part of a prospective, multicenter, randomized trial. Specular microscopy and pachymetry were performed before and 6–29 months after surgery. Parameters analyzed included change from baseline of endothelial cell density (ECD), the coefficient of variation (CV), the percent of hexagonal cells (%HEX), and central corneal thickness (CCT).ResultsBaseline ECD, CV, %HEX, and CCT were similar between groups. A mean (standard deviation) of 18.2 (5.8) months postoperatively (range 12.5–28.7 months), the change from baseline in ECD was −90 ± 226 cells/mm2 (−3.4%) in KDB-phaco eyes (p=0.083) and −239 ± 247 cells/mm2 (−9.0%) in iStent-phaco eyes (p<0.001); the change in iStent-phaco eyes was significantly greater than in KDB-phaco eyes (p=0.013). The magnitude of Endothelial Cell Loss (ECL) was not correlated with length of postoperative follow-up time in either group. No significant differences in change from baseline in CV, %HEX, or CCT were noted with the exception of a decrease in %HEX in iStent-phaco eyes (p=0.017). No eyes manifested corneal edema, decompensation, or other cornea-related complications.ConclusionBoth KDB-phaco and iStent-phaco are associated with postoperative ECL, with iStent-phaco producing significantly greater ECL than KDB-phaco. The clinical significance of these findings is unclear, and future studies are warranted to more robustly characterize long-term effects of glaucoma surgical procedures—with and without permanent implants—on ECD and corneal health and to develop evidence-based guidelines for the pre- and post-operative evaluation of corneal health in eyes undergoing glaucoma surgery.

Comparison of endothelial cell loss by specular microscopy between phacoemulsification versus small incision cataract surgery

To compare endothelial cell density, central corneal thickness changes and evaluate best corrected visual acuity after small incision and phacoemulsification cataract surgery. In this prospective study, patient were presented with significant cataract. Cataract were graded using lens opacities classification system grading. Forty three patients underwent phacoemulsification and forty-one underwent SICS. Patient with any other ocular pathology were excluded. Phacoemulsifiaction was performed, the chop-stop technique and SICS by the viscoexpression technique. The endothelial cell count and central corneal thickness were measured by non-contact specular microscope and best corrected visual acuity evaluated by snellen chart preoperatively and postoperatively on day 1, 3 and 6 week respectively.The mean endothelial cell loss (cells/mm) in phacoemulsification was 194.28 (7.16%), 311.46 (11.48%) and 412.16 (15.20%) and in SICS was 155.41 (6.17%), 230.19 (9.14%) and 296.54 (11.89%) and was statistically significant (P&amp;#60;0.05). There is an increase in mean base line central corneal thickness from 530.44±12.34 micron increased by 62.62 micron (11.80%), 17.88 micron (3.37%)and 6.04 micron (1.13%) in phacoemulsification and 523.24±6.63 micron increase by 38.05 micron (7.26%), 21.24 micron (4.05%) and 2.63 micron (0.50%) in SICS at day i 3 week and 6 week respectively. There was statistically significant (P&amp;#60;0.001). BCVA of better than 6/18 was achieved in 95.34% of the eyes after phacoemulsification and 92.68% after SICS. There was statistically significant.No significant differences in endothelial less loss, central corneal thickness and best corrected visual acuity in between phacoemulsification and SICS.

The effect of inhaled steroids on the intraocular pressure.

Steroids are known to play a role in the pathogenesis of glaucoma, but little is known about the effect of inhaled corticosteroids (ICS). The purpose of this study was to investigate whether there is a clinically significant association between inhalational steroids and intraocular pressure (IOP). This was a cross-sectional, case-control study performed at St John's Medical College, Bengaluru, India, from October 2013 to July 2015 of 200 patients using 800 mcg of budesonide or its equivalent dose of ICS and 200 healthy controls not using any form of steroids. Patients using ICS for a period of at least 6 months with no usage of oral or topical steroids within the last 3 months were included as cases. Age- and sex-matched controls were recruited from among the general patient population of the ophthalmological department. IOP and central corneal thickness (CCT) were analyzed. Cases were divided into two subgroups. Group 1 had IOP of <21 mm Hg and cup-to-disc ratio of <0.5. Group 2 had IOP of ≥21 mm Hg or cup-to-disc ratio of ≥0.5 or cup-disc asymmetry ≥0.2. These two subgroups were analyzed to determine whether there was an increased risk of developing ocular hypertension or glaucoma with extended use of ICS. A total of 400 subjects participated, with 200 in each group. The mean IOP of cases was 15.31 ± 3.27 mm Hg, statistically significantly higher than the mean of 13.39 mm Hg ± 1.95 in controls (P < 0.001). The mean CCT in cases was 522.02 ± 30.47 μm, lower than the mean of 528.73 ± 29.09 μm of the control group (P > 0.001). Of the 200 cases, 11 (5.5%) had ocular hypertension and 2 (1%) had open-angle glaucoma. There was no statistically significant correlation between duration of inhaled steroids usage and increase in IOP (P = 0.62). There was no development of ocular hypertension or glaucoma among the controls. Our findings suggest a probable association between ICS and IOP and that it may be advisable to measure baseline IOPs and CCT and to follow patients on ICS at regular intervals.

Longitudinal Change in Central Corneal Thickness in the Tema Eye Survey

To determine the change and rate of change in central corneal thickness (CCT) and their determinants. Longitudinal observational population-based study. A total of 758 normal and 58 glaucomatous subjects underwent complete eye examination, with CCT measurements at 2 separate visits. Change and rate of change in CCT were determined. Univariate and multivariate linear regression analyses were performed to determine the factors associated with change and rate of change. The mean follow-up duration was 8.4 ± 0.7 years. The overall change was-8.9 ± 16.7μm in OD and-9.8 ± 16.2μm in OS, both P < .0001. Changes in glaucomatous and normal subjects were-14.1 ± 2.2μm vs-8.6 ± 0.6μm in OD (P= .02) and-14.5 ± 2.2μm vs-9.5 ± 0.6μm in OS (P= .03), respectively. The overall rate of thinning was-1.1μm/year (OD) and-1.2μm/year (OS). Rates in glaucomatous and normal eyes were-1.7 ± 0.3μm/year vs-1.0 ± 0.1μm/year in OD (P= .02) and-1.7 ± 0.3μm/year vs-1.1 ± 0.1μm/year in OS (P= .03), respectively. Change and rate of change were associated with baseline CCT (ß=-0.1 to-0.09 and-0.011, respectively, all P < .001) and glaucoma (ß=-6.8 to-5.6, P ≤ .009, and-0.75 to-0.69, P ≤ .007, respectively). CCT decreased significantly over time. The change and rate of change were greater in glaucomatous than normal eyes, and were greater than described in cross-sectional studies.

Clinical management outcomes of childhood glaucoma suspects.

PurposeTo investigate the outcomes of childhood glaucoma suspects.DesignRetrospective case series.MethodsRecords of childhood glaucoma suspects were identified using financial claims data; medical history, baseline biometric and exam findings were recorded. Conversion from suspect to glaucoma was determined based on the Childhood Glaucoma Research Network criteria. The study adheres to the tenets of the Declarations of Helsinki.Results214 subjects were enrolled, with median age at initial presentation of 6.37 years (interquartertile range: Q1 = 2.46, Q3 = 8.90). 22 (10.2%) subjects developed glaucoma, 64 (29.9%) had ocular hypertension but no glaucoma, 9 (4.2%) had high-risk condition or syndrome without either ocular hypertension or glaucoma after a mean follow up of 39 +/- 34 months. Neither a family history of glaucoma nor patient gender was significantly different between the groups. 40.2% of subjects (86 of 214) had two or more episodes of intraocular pressure (IOP) > 21 mmHg, among which 25.6% (22 of 86) developed glaucoma after a mean duration of 32.8 +/- 33.5 months.ConclusionsUp to 25% of children with 2 or more episodes of elevated IOP may develop glaucoma. In 50% of suspects who converted to glaucoma, elevated IOP was not present at the initial evaluation. There is no significant difference in gender, family history, or baseline central corneal thickness between suspects who developed glaucoma compared to the rest. While suspects who converted to glaucoma had higher average, maximum and minimum IOP measurements, there is no clear cutoff between the groups.

Effects of Mydrin eye‐drops on central corneal thickness values in adult patients with myopia

ObjectiveThis study aimed to evaluate the effect of Mydrin eye‐drops on central corneal thickness values and investigate the duration of the effect.MethodsIn this prospective randomised self‐controlled study, we enrolled 60 myopic patients (120 eyes) undergoing corneal laser refractive surgery. The central corneal thickness was measured before and one and four hours after administration of Mydrin eye‐drops (major components are tropicamide and phenylephrine hydrochloride) using the Orbscan II anterior segment analysis system and a SP-2000P non‐contact specular microscope, respectively.ResultsUsing the Orbscan II system, the baseline central corneal thickness (545 ± 27 µm) was significantly lower than that at one hour after Mydrin eye‐drop application (559 ± 31 µm; p < 0.001); it was comparable to that at four hours post‐Mydrin eye‐drop administration (544 ± 26 µm; p < 0.74). Measured by non‐contact specular microscopy, the baseline central corneal thickness (508 ± 26 µm) was significantly lower than that at one hour after Mydrin eye‐drop application (521 ± 29 µm; p < 0.001); it was comparable to that at four hours after Mydrin eye‐drop administration (506 ± 24 µm; p = 0.62). A significant difference was observed in the central corneal thickness at one and four hours after Mydrin eye‐drop application by both methods (p < 0.001). Bland–Altman plots showed agreement between the measurements by the two methods at different times.ConclusionCentral corneal thickness increases one hour after topical application of Mydrin eye‐drops and is normalised at four hours following the administration of the drops. For patients scheduled to undergo excimer laser corneal refractive surgery, the central corneal thickness should be measured before or four hours after administration of Mydrin eye‐drops.

Corneal aberration changes after rigid gas permeable contact lens wear in keratokonic patients

PurposeTo determine the short-term effect of rigid gas permeable (RGP) contact lenses on corneal aberrations in keratoconic patients. MethodSixteen keratoconic eyes with no history of RGP lens wear were included. They all had corneal aberrometry using Pentacam, and different aberration indices of the anterior and posterior surfaces of the cornea were measured before and 3 months after fitting RGP lenses. The effect of baseline parameters on these changes was tested in univariate and multiple models. ResultsTotal aberrations and individual Zernike coefficients did not show statistically significant changes after using RGP lenses. Although not statistically significant, vertical coma decreased in the anterior (p = 0.073) and posterior surface (p = 0.095). Relationships that remained statistically significant in the multiple model were between baseline central corneal thickness and changes in total higher order aberrations and anterior 4th order astigmatism 0°, and between baseline 2nd order astigmatism 45° and its changes. ConclusionIn this study, corneal aberrations remained unchanged 3 months after wearing RGP contact lens. Further studies with sufficient samples in different groups of keratoconus severity or baseline aberrations are needed to obtain more accurate results.

Central Corneal Thickness After Cross-linking Using High-Definition Optical Coherence Tomography, Ultrasound, and Dual Scheimpflug Tomography: A Comparative Study Over One Year

To assess central corneal thickness (CCT) and corneal haze in keratoconus eyes following corneal cross-linking (CXL). Prospective noncomparative case series. Forty patients (44 eyes) with keratoconus that had serial evaluation for CCT, following CXL, usinghigh-definition optical coherence tomography (HD-OCT), ultrasound pachymetry (USP), and dual Scheimpflug tomography. CCT was measured at baseline, then at 2weeks and 1, 3, 6, and 12months postoperatively. The mean baseline CCT measurements were 470.02μm, 469.79μm, and 466.66μm using the HD-OCT, the USP, and dual Scheimpflug tomography, respectively (P= .91). Following CXL, the mean CCT measurements by dual Scheimpflug, at all follow-up periods, were lower compared to mean baseline reading (P < .003). The mean CCT measurements by the HD-OCT and USP were similar to baseline readings except for the thicker readings at the 2-week follow-up visit. Overall, the mean CCT obtained by the USP was similar to that obtained by the HD-OCT throughout the 12-month period. However, the mean CCT measurements obtained by dual Scheimpflug tomography were statistically and clinically significantly lower than those obtained by both HD-OCT and USP at all follow-up visits. USP and HD-OCT showed better agreement in CCT readings at all visits, and may better estimate the true CCT following CXL as compared to dual Scheimpflug tomography. The lower mean CCTpost-CXL as measured by the latter seems to be correlated with the amount of haze that develops aftercross-linking.

Effect of 2% fluorescein on Scheimpflug central corneal thickness measurements.

To assess central corneal thickness (CCT) changes measured with Scheimpflug device following instillation of 2% fluorescein in normal subjects. This was a prospective randomized study of 60 hospital volunteers. After baseline CCT measurements of both eyes of 40 subjects were obtained using Scheimpflug system, a drop of preservative-free 2% fluorescein, was instilled in one eye and in other eye, one drop of normal saline (control). Measurements were repeated after 1, 2, 5, 10, 20, 30, 40, 50 and 60min (continuous assessment group). Twenty subjects had baseline CCT taken, then fluorescein was instilled in one eye and measurements were taken at 1min. Ten eyes had saline rinse after 1min and 10 other eyes did not, measurements were repeated at 2min (eye rinse group). The mean baseline CCT for continuous assessment group was 546.2 ±32.1 µm (range, 489.0-606.0), control eyes was 546.6±30.7 µm (range, 489.0-602.0). At 1min after fluorescein instillation, CCT significantly increased by 37.0±34.0 µm (P<0.001), then decreased gradually, reaching baseline at 60min. CCT variations were not significant in control group (P>0.05). For eye rinse group, CCT mean differences between baseline and 2min were 18.2 µm (95 % CI: -54.7 to 18.3) with rinse and 26.5 µm (95% CI: -62.9 to 9.9) without rinse; paired sample tests were not significant (P>0.05). The presence of fluorescein increased CCT value to a clinically relevant level of 6.8%. Eye rinse did not significantly reduce the effect at 2min post fluorescein timepoint.

Association between corneal hysteresis and the magnitude of intraocular pressure decrease after cataract surgery

To evaluate the relationship between baseline corneal hysteresis (CH) and the change in intraocular pressure (IOP) before and after cataract extraction in patients without glaucoma. Private practice, New York City, New York, USA. Retrospective cohort study. Charts of consecutive patients who had phacoemulsification cataract extraction with posterior chamber intraocular lens implantation were analyzed. All included patients had preoperative and postoperative measurements with the Ocular Response Analyzer 2 to 4 months and 10 to 12 months postoperatively. Data collected included age, baseline CH, baseline central corneal thickness (CCT), and IOP. Thirty nine (65 eyes) of the 230 patients met the inclusion criteria. The mean patient age was 70.8 years ± 8.6 (SD). The mean preoperative, 2- to 4-month and 10- to 12- month postoperative IOP values were 14.8 ± 3.5 mm Hg, 11.9 ± 3.4 mm Hg, and 12.6 ± 3.1 mm Hg, respectively (P < .05 for comparisons with preoperative IOP). The baseline CH was not predictive of the IOP reduction at 2 to 4 months (β = -0.3; 95% confidence interval [CI], -0.7 to 0.01; P = .06). However, the baseline CH (but not the baseline CCT) was statistically associated with the magnitude of IOP reduction at 10 to 12 months when controlling for patient age (β = -0.5; 95% CI, -0.8 to -0.1; P = .01). A low baseline CH was associated with a larger magnitude of IOP reduction after cataract extraction. Dr. Radcliffe is a consultant to Reichert Technologies and Glaukos Corp.; a consultant to and speaker for Allergan, Inc., Alcon Laboratories, Inc., Iridex Corp., Merge Healthcare, Carl Zeiss Meditec AG; and a speaker for Merck Pharmaceuticals. No other author has a financial or proprietary interest in any material or method mentioned.

Short-term effect of topical brinzolamide 1%-timolol 0.5% fixed combination on human central corneal thickness.

To evaluate the short-term effect of fixed combination of brinzolamide 1% and timolol 0.5% (FCBT) application on human central corneal thickness (CCT). This prospective clinical study included 97 patients having Nd:YAG laser posterior capsulotomy for posterior capsule opacification. Patients were randomized to receive apraclonidine hydrochloride 0.5% (APRA) (n=48) or FCBT (n=49) at 1 h before laser surgery. The baseline CCT was evaluated by ultrasonographic pachymetry from the central region ∼1 h before the laser procedure. CCT measurements were applied just before the laser application and then the first, second, and third hour, and the first, third, and seventh day after the Nd:YAG laser capsulotomy. There was no statistically significant difference between the baseline intraocular pressures, CCTs, and demographic and clinical data (age, sex, surgery laser interval, total laser energy) of the APRA and the FCBT groups. The mean CCT values of the APRA group at the first, second, and third hour, and the first, third, and seventh day were 553.8±28.0, 551.4±35.3, 556.8±28.7, 552.6±27.5, 548.2±26.2, and 546.2±25.5 μm, respectively. The mean CCT values of the FCBT group at the first, second, and third hour, and the first, third, and seventh day were 544.21±34.4, 549.4±27.6, 555.94±33.1, 550.8±33.4, 547.2±33.6, and 544.9±33.4 μm, respectively. No statistically significant difference was detected between the 2 groups. The difference in CCT increase between both groups was not statistically significant at any follow-up visits. FCBT application does not have a short-term effect on CCT.

Reduced central corneal thickness in patients with isotretinoin treatment

Context: It is well known that oral isotretinoin treatment causes numerous ocular side-effects.Objective: To investigate the effect of systemic isotretinoin treatment on central corneal thickness (CCT) values due to meibomian gland disease (MGD).Participants: In this prospective study, 47 patients (27 men, 20 women) with nodulocystic acne vulgaris treated with oral isotretinoin (0.8 mg/kg daily) were included.Methods: All patients were analyzed with the Pentacam Scheimpflug topography at baseline, on the 3rd and 6th month of treatment. Main outcome measures were MGD scores and CCT.Results: The mean age of patients was 25.1 ± 4.4 years. The mean MGD scores were significantly higher at 3rd month (1.3 ± 0.9) and 6th month (1.5 ± 1.0) of treatment compared with baseline (1.1 ± 0.9) (p < 0.001). The mean CCT value at baseline was 540.5 ± 22.1 µm; 536.9 ± 20.5 µm at 3rd month and 531.4 ± 22.2 µm at 6th month. The differences between baseline and 6th month CCT measurements were statistically significant (p < 0.001). There was negative correlation between mean MGD scores and CCT values at the 6th month of treatment which was statistically significant (p = 0.038, r = −0.221).Conclusion: Isotretinoin treatment causes higher MGD scores. A statistically significant decrease in CCT due to MGD was detected at 6th month of treatment.

Clinical Characteristics of First-Degree Relatives with Primary Open-Angle Glaucoma

Purpose: To investigate the clinical characteristics of first-degree relatives with primary open-angle glaucoma (POAG). Methods: Forty-four POAG patients (22 pairs of eyes from 2 first-degree relatives) were followed for an average of 3.3 years. Baseline characteristics and follow-up data were analyzed. Baseline data consisted of baseline intraocular pressure (IOP), central corneal thickness (CCT), spherical equivalent, visual field mean deviation (VF MD) and average retinal nerve fiber layer (RNFL) thickness measured using optical coherence tomography (OCT). Follow-up data consisted of mean follow-up IOP, mean IOP reduction from baseline (%) and progression rates determined by linear regression analysis of either VF MD value or OCT RNFL thickness. Mean data of both eyes and the worse eye were compared between first-degree relatives of the same family. Results: Among the 22 families, 16 pairs of eyes were from parent/offspring and 6 from siblings. No difference in mean baseline IOP and CCT were found between first-degree relatives. The older patients in parent-offspring families showed significantly more advanced glaucoma in terms of both VF and RNFL thickness, but were less myopic; however, no differences in variables were found between relatives in the 6 families composed of siblings. Among the 22 families, worse baseline VF MD was observed in younger patients compared with the older patients in 4 families. Mean follow-up IOP, mean IOP reduction from baseline, and progression rate did not differ between the older and the younger patient in each family. Conclusions: In our study, similar characteristics in terms of baseline IOP, IOP response to medication, and glaucoma progression rate were found in members of the same family. However, in some of the families, the younger patient had poorer baseline severity and more aggressive characteristics compared with the older patient, suggesting the clinical course of the disease may vary among first-degree relatives. J Korean Ophthalmol Soc 2015;56(3):396-403