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Aim: To evaluate the efficacy and safety of glaucoma drainage device Ex-PRESS(®) P-50 for combined cataract surgery and glaucoma., Methods: Patients having cataract and open angle glaucoma or patients with open advanced glaucoma which needed two or more antiglaucoma medications were included. Combined cataract surgery and glaucoma with Ex-PRESS(®) P-50 model placed under scleral flap was performed., Results: Out of 40 eyes of 40 patients (55% male and 45% female) completed the study during one-year follow-up. The mean of age was 76.6±11.02y. The intraocular pressure (IOP) decreased significantly during the 12-month follow-up from 23.5 mm Hg to 16.8 mm Hg (Wilcoxon signed ranks test, P<0.001). A 59.5% of patients did not need any topical treatment, 10.8% of them needed one active principle, 27% needed two active principles, and 2.7% of them needed three active principles for successful IOP control (<21 mm Hg)., Conclusion: Combined surgery of phacoemulsification with ExPRESS(®) P-50 lowers IOP from the preoperative baseline and reduces significantly the number of antiglaucoma active principles for IOP control after the operation.

Purpose: To compare the anterior segment measurements obtained with optical low-coherence reflectometry (OLCR) (Lenstar LS 900, version 2.1.1) and rotating dual Scheimpflug analysis (Galilei G1, version 3)., Setting: Private practice, Policlinic Lleida, Lleida, Spain., Design: Prospective comparative observational study., Methods: The following measurements were performed in patients requiring a preoperative study for a refractive procedure or cataract surgery and healthy volunteers from the clinic's staff: central corneal thickness (CCT), anterior chamber depth (ACD), horizontal limbal distance (white-to-white distance [WTW]), pupil diameter, keratometry (K) readings at the steepest meridian (steep K) and the flattest meridian (flat K), corneal astigmatism power, and plus astigmatic cylinder. Measurements were taken using the OLCR device and rotating dual Scheimpflug analyzer. The main outcome measure was the degree of agreement between steep K, flat K, astigmatism power, cylinder axis, CCT, ACD, WTW, and pupil diameter measurements., Results: The study enrolled 100 eyes of 100 subjects. Steep K, flat K, corneal astigmatism power, cylinder axis, and WTW measurements with the OLCR device and Scheimpflug analyzer showed narrow 95% limits of agreement (LoA), which implies good agreement (P>.05, Bland-Altman plot analysis). In contrast, the range and 95% LoA for CCT, ACD, and pupil diameter values were statistically significantly different (P<.05, Bland-Altman plot analysis)., Conclusion: In clinical practice, the OLCR device and the rotating dual Scheimpflug analyzer system can be used interchangeably for WTW measurements and K readings but not for CCT, ACD, and pupil diameter values., Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned., (Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.)

Purpose. To examine biomechanical parameters of the cornea in myopic eyes and their relationship with the degree of myopia in a western healthy population. Methods. Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann correlated intraocular pressure (IOP), and corneal compensated IOP (IOPcc) were measured using the ocular response analyzer (ORA) in 312 eyes of 177 Spanish subjects aged between 20 and 56 years. Refraction was expressed as spherical equivalent (SE), which ranged from 0 to -16.50 diopters (D) (mean: -3.88 ± 2.90 D). Subjects were divided into four groups according to their refractive status: group 1 or control group: emmetropia (-0.50 ≤ SE < 0.50); group 2: low myopia (-0.75 ≤ SE < 3.00 D); group 3: moderate myopia (-3.00 ≤ SE ≤ -6.00 D); and group 3: high myopia (SE greater than -6.00 D). We analyzed the relationship between corneal biomechanics measured with ORA and SE. Results. CH in the emmetropia, low myopia, moderate myopia, and high myopia groups was 11.13 ± 0.98, 11.49 ± 1.25, 10.52 ± 1.54, and 10.35 ± 1.33 mmHg, respectively. CH in the highly myopic group was significantly lower than that in the emmetropic group (P = 0.07) and low myopic group (P = 0.035); however, there were no differences with the moderate myopic group (P = 0.872). There were no statistically significant differences regarding IOP among the four groups (P > 0.05); nevertheless, IOPcc was significantly higher in the moderately myopic (15.47 ± 2.47 mmHg) and highly myopic (16.14 ± 2.59 mmHg) groups than in the emmetropia (15.15 ± 2.06 mmHg) and low myopia groups (14.53 ± 2.37 mmHg). No correlation between age and the measured parameters was found. CH and IOPcc were weakly but significantly correlated with SE (r = 0.171, P = 0.002 and r = -0.131, P = 0.021, resp.). Conclusions. Present study showed only a very weak, but significant, correlation between CH and refractive error, with CH being lower in both moderately and highly myopic eyes than that in the emmetropic and low myopic eyes. These changes in biomechanical properties of the cornea may have an impact on IOP measurement, increasing the risk of glaucoma.

Purpose: To study the biomechanical effect of riboflavin-ultraviolet A irradiation (UVA)-induced collagen cross-linking (CXL) in porcine corneas using two different exposure times of 30 and 60 min., Methods: Seventeen enucleated porcine eyes were divided into three groups: group A, six eyes without any treatment, group B, six eyes treated by UVA CXL for 30 min, and group C, five eyes treated by UVA CXL for 60 min. Riboflavin (vitamin B2) was used as a photosensitizer in both groups of treatment. Then, the stress-strain behavior of all the specimens was measured to compare the corneal biomechanical properties among the three groups. The Young's modulus E of the mean curve of each group shows the stiffness of treated and untreated tissue. The stress data necessary for stretches of 6, 8, and 12% were used to perform the statistical analysis of the values., Results: Group B (riboflavin-UVA-CXL, 30 min, E = 46 MPa) showed a stiffer behavior than group A (control, E = 29 MPa) . Group C (60 min CXL, E = 28 MPa) showed lower stiffness than group B and a similar mechanical behavior than group A. The statistical analysis of the stress-strain curves showed significant differences in the corneal response between group B and the control at the three values of stretch considered, 6, 8, and 12% (p = 0.025, p = 0.025 and p = 0.037, respectively) and between group B and group C (p = 0.028, p = 0.028, and p = 0.028). No statistically significant difference was found between group C and control (p = 0.855, p = 0.715, and p = 0.584)., Conclusions: The application of 30-min UVA CXL treatment with riboflavin increased stiffness of the porcine corneal tissue. A 60-min UVA-radiated tissue presents lower stiffness than the 30-min treated tissue, showing a similar biomechanical behavior than the untreated corneas. A prolongation of the UVA irradiation time may cause structural weakening of the porcine corneas.

Purpose: To investigate the effects of Fuchs' corneal dystrophy (FCD) on corneal biomechanical properties and the results of IOP readings in relation to changes in corneal hysteresis (CH) and central corneal thickness (CCT)., Methods: Corneal biomechanical properties, including CH, corneal resistance factor (CRF), and CCT, were measured with the ocular response analyzer (ORA) in 11 eyes of 11 patients with clinically confirmed FCD and 12 eyes of 12 healthy subjects. The ORA was also used to determine the values of intraocular pressure (IOP(g)) and corneal compensated IOP (IOP(cc)). Goldmann applanation tonometry (GAT) was also measured., Results: CH measured 10.3 +/- 1.6 mm Hg (range, 8.7-13.8) in normal eyes and 6.9 +/- 1.8 mm Hg (range, 4.6-11.7) in FCD eyes (P = 0.001). CRF in the normal and FCD eyes was 10.5 +/- 1.5 mm Hg (range, 8.5-13.3) and 8.1 +/- 1.9 (range, 4.5-11.2), respectively (P = 0.005). CCT was higher in FCD eyes (606 +/- 20 microm; range, 578-635) than in normal eyes (538.4 +/- 24.9 microm; range, 495-575; P = 0.0001). IOP(g) was 16.2 +/- 2.2 mm Hg (range, 13.5-18.7) in control eyes compared with 17.6 +/- 2.7 mm Hg (range, 12.8-18.6) in FCD eyes (P = 0.201). However, IOP(cc) in the FCD group (21.8 +/- 4.6 mm Hg; range, 12.8-29.0) was higher than in the control group (16.5 +/- 3.4 mm Hg; range, 11.9-23.9; P = 0.006). GAT in the normal and FCD eyes was 16.7 +/- 2.1 mm Hg (range, 12.8-18.6) and 16.9 +/- 2.3 mm Hg (range, 13.1-19.0), respectively (P = 0.205)., Conclusions: FCD led to a change of corneal biomechanical properties. CH and CRF were significantly lower in FCD eyes than in normal eyes. IOP(cc) was significantly higher in FCD eyes than in control eyes. These values may be useful in addition to CCT when assessing corneal rigidity. Thus, FCD may cause an underestimation error in IOP measurement.