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Purpose: To evaluate the correlation between automated achromatic perimetry (AAP) and the output of two retinal nerve fiber layer (RNFL) analysers: scanning laser polarimetry (GDx-VCC) and optical coherence tomography (OCT). Methods: Quantitative RNFL measurements with GDx-VCC and Stratus-OCT were obtained in one eye from 52 healthy subjects, 38 ocular hypertensive (OHT) patients and 94 glaucomatous patients. All patients underwent a complete examination, including AAP using the Swedish interactive threshold algorithm (SITA). The relationship between RNFL measurements and SITA visual field global indices were assessed by means of the following methods: analysis of variance, bivariate Pearson's correlation coefficient, multivariate linear regression techniques and nonlinear regression models, and the coefficient of determination (r2) was calculated. Results: RNFL thickness values were significantly lower in glaucomatous eyes than in healthy and ocular hypertensive eyes for both nerve fiber analysers (P≤0.001), except for the inferior 120° average thickness in GDx-VCC. Linear regression models constructed for GDx-VCC measurements and OCT-derived RNFL thickness with SITA visual field global indices demonstrated that, for the mean deviation, the only predictor in the model was the nerve fiber indicator for GDx-VCC (r2=0.255), and for the pattern standard deviation, the predictors in the model were the nerve fiber indicator for GDx-VCC (r2=0.246) and the maximum thickness in the superior quadrant for Stratus-OCT (r2=0.196). The best curvilinear fit was obtained with the cubic model. Conclusions: Quantitative measurements of RNFL thickness using either GDx-VCC or OCT correlate moderately with visual field global indices in moderate glaucoma patients. We did not find a correlation between visual field global indices and RNFL thickness in early glaucoma patients. Further study is needed to develop new analytical methods that will increase RNFL analyser's sensitivity in early glaucoma patients.

PURPOSE To analyze oxidative stress in primary open-angle glaucoma (POAG). MATERIAL AND METHODS A case-control study including 90 eyes of 90 patients who needed antiglaucomatous surgery in the course of POAG (glaucoma group, n=50) and from patients who were operated of nonpathologic cataracts (cataract group, n=40). Free radical formation via lipid peroxidation by malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) test and total antioxidant status in the aqueous humor samples of both groups were determined. Statistical analyses were carried out in relation to MDA-TBARS and total antioxidant status and their correlations with glaucoma risk factors. RESULTS Significantly higher MDA-TBARS were detected in the POAG with respect to the comparative group of cataract subjects (P

Purpose: To assess the changes of the visual field (VF) caused by transient intraocular pressure (IOP) peaks during laser in situ keratomileusis (LASIK) surgery for myopia using automated perimetry. Methods: This prospective study involved 94 eyes of 94 patients who underwent a conventional LASIK procedure. A complete eye examination was carried out in which the IOP measurement, and Humphrey 24-2 SITA standard VF were tested prior to LASIK and 6 and 12 months after LASIK. Patients were divided into two subgroups according to their refractive error. VF global indices, Glaucoma Hemifield Test and the number of depressed points deviating at p

PURPOSE To identify differences in applanation tonometry between retreated and nonretreated eyes (primary LASIK eyes) 6 months after hyperopic laser in situ keratomileusis. METHODS In a prospective study 100 eyes (100 patients) underwent conventional hyperopic laser in situ keratomileusis under a 160-microm flap. Central Goldmann applanation tonometry was determined before and 6 months after surgery in 78 (78%) primary LASIK eyes and before surgery and 6 months after the retreatment date in 22 (22%) retreated eyes. RESULTS Preoperative mean tonometry was 14.96 +/- 1.96 mm Hg and 15.30 +/- 1.95 mm Hg in primary LASIK and retreated eyes, respectively. Six months after surgery it was 12.99 +/- 2.03 mm Hg (P < 0.001) and 12.67 +/- 2.20 mm Hg (P < 0.001), respectively. No significant differences in mean tonometry were found between retreated and primary LASIK eyes 6 months after surgery (P = 0.537). Decreased tonometric values were found in 20 retreated eyes (90.91%) and in 62 primary LASIK eyes (79.48%). Increased tonometric values higher than 1 mm Hg were found in 3 primary LASIK eyes (3.84%), but no retreated eyes showed increased values 6 months after surgery. Two retreated eyes (9.09%) and 10 primary LASIK eyes (79.49%) presented the same tonometric values before surgery and at the end of the study. CONCLUSIONS After hyperopic laser in situ keratomileusis there was no significant difference in Goldmann applanation tonometry between retreated and primary LASIK eyes.

PURPOSE: To assess intraocular pressure measured with a Goldmann tonometer over a period of 1 year after implantation of a Worst-Fechner anterior chamber phakic intraocular lens to correct myopia of -7.00 D or more. METHODS: We performed a prospective, nonmasked study of 100 patients (100 myopic eyes) who had a Worst-Fechner phakic intraocular lens implanted to correct myopia of -7.00 D or greater. Central corneal Goldmann tonometry was performed before surgery and 1, 3, 6, and 12 months after surgery. The influence of different variables was assessed. RESULTS: IOP showed a significant increase of of a mean 2.1 mmHg at 3 months after surgery (P=. 001). There was not a statistically significant difference between IOP before surgery and 6 months after PIOL implantation (P=.244) or 1 year after surgery (P=.845). In one eye, the lens was explanted 11 months after surgery because of the presence of ocular hypertension. No variables studied showed a statistically significant difference from before to after surgery. CONCLUSIONS: Worst-Fechner anterior chamber phakic intraocular lens implantation led to a slight transitory increase of intraocular pressure during the first 3 months after surgery, but returned to preoperative levels by 6 months after implantation. [J Refract Surg 2003; 19:131-136]

Purpose. To determine the reliability and identify pitfalls in intraocular pressure measurement by Goldmann applanation tonometry after hyperopic laser in situ keratomileusis (LASIK). Methods. Prospective non-masked case series at University of Valencia, Faculty of Medicine and Rahhal Ophthalmology Clinic, Valencia, Spain. One hundred three patients (103 eyes) treated with hyperopic LASIK were evaluated. The main treatment was hyperopic LASIK using a microkeratome Chiron Hansatome (Chiron Vision Corp, Claremont, CA) and the excimer laser Chiron Technolas 217-C LASIK (Chiron Technolas GmbH, Dornack; Germany). Central Goldmann applanation tonometric readings before surgery and 1, 3, and 6 months after surgery were analyzed. Results. After hyperopic LASIK, a significant decrease in intraocular pressure was observed in the postoperative controls. In the low hyperopia patients (range: 1.00-3.00 D) a decrease of 2.43 mmHg was observed at the 6-month follow-up (p < 0.001). In the moderate hyperopia group (range: 3.25-6.00 D) a decrease of 2.05 mmHg was observed at the 6-month follow-up (p < 0.001). There were no significant differences between low and moderate hyperopia (p = 0.812). There was no statistically significant correlation between the magnitude of decrease in tonometry and gender, age, treated spherical equivalent, pachymetry, and anterior chamber depth (ACD). Conclusions. This clinical study displays that postoperative tonometry after hyperopic LASIK was significantly lower than the preoperative, hence modifying the reliability of Goldmann tonometry, and causing an intraocular pressure underestimation. A correcting factor should be applied when using applanation tonometry to measure postoperative intraocular pressure in patients who have undergone hyperopic LASIK.

Purpose:To report one year outcomes of focal Navigated Retina Laser Therapy (NAVILAS) for diabetic macular edema (DME).Methods:Retrospective cohort series of 7 diabetic patients treated with NAVILAS focal laser. Statistical analysis included descriptive and continuous variables (Best-corrected logMAR Visual Acuity and time-domain optical coherence tomography (OCT) parameters) which were compared using a non-parametric procedure, the Friedman tests for repeated measures. A p-value of less than 0.05 was considered to denote statistical significance.Results:diabetic patients (4 male; 3 female) with an average age of 60.8 years (range 48-85 years) were included. All treated eyes were phakic; patients had an average hemoglobin A1C of 9.1 (range 7.8-11.7) at baseline and 8.0 (range 7.4-8.4) at 12 months. Six of the 7 patients had intravitreal bevacizumab injections prior to focal laser treatment with 1 patient having had more than 1 prior injection (total 3). At 12 months, median logMAR improved from 0.695 (± interquartile range 0.574) to 0.477 (± 0.573, p Conclusions:Focal NAVILAS showed to be safe and effective in treating DME with improvement in visual acuity and macular edema on OCT over 12 months in this case series. In clinical practice, combined treatment with focal laser including NAVILAS and anti-vascular endothelial growth factor may provide long-term improvement in DME.

We read with interest the article by Bock et al ,1 in which the association between retinal nerve fibre layer (RNFL) and total macular volume (TMV) was analysed by optical coherence tomography (OCT) and contrast sensitivity was measured by functional acuity contrast testing in relapsing-remitting multiple sclerosis (MS) patients. The authors found that the functional contrast vision in MS is influenced by morphological changes in the anterior visual pathway. This work emphasised that contrast sensitivity is reduced in MS, and that RNFL and TMV, as morphological measures of retinal axon loss, are predictors of contrast sensitivity. Ophthalmological examinations were the basis of the Bock et al 1 study. There …

The purpose of this study was to compare the efficacy of intravitreal ranibizumab in the treatment of macular edema due to branch retinal vein occlusions (BRVO) with and without serous macular neuroretinal detachment (SMD). Forty-nine eyes of 49 patients with macular edema due to branch retinal vein occlusion (22 with SMD and 27 without SMD) were included in this prospective, parallel-group, comparative study. Intravitreal injection of ranibizumab was administered at baseline. Thereafter patients were followed monthly and further injections were performed in the presence of persistence or recurrence of macular thickening. Flattening of the macula was considered success. At the last visit, best-corrected visual acuity (BCVA), and spectral-domain optical coherence tomography (SD-OCT) quantitative parameters (central subfield thickness, cube volume, average cube thickness) were compared between groups. In patients with SMD, BCVA and all the SD-OCT quantitative parameters improved significantly after a mean number of 5.0 ranibizumab intravitreal injections through a median follow-up of 12.5 months (range, 7–34). In patients without SMD, all the variables analyzed improved significantly except for the cube volume, after a mean number of 4.3 ranibizumab intravitreal injections through a median follow-up of 10.4 months (range, 6.5–40.2). The numbers of injections were similar in both groups. The final BCVA was better in patients without SMD at baseline but without significant differences in the SD-OCT parameters between groups. The presence of SMD may be a baseline predictive factor for ranibizumab treatment outcomes in BRVO patients, with no influence in the number of treatments needed between patients with or without SMD at baseline. Further studies are needed in order to confirm the role of SMD as an independent predicitive factor in cases of BRVO.

PURPOSE Currently there is little information available about the corneal thickness values of healthy emmetropic subjects. Therefore, the authors decided to analyze the corneal thickness in healthy emmetropic subjects. METHODS The authors analyzed the difference in thickness values between the thinnest corneal site and the central and paracentral cornea in 124 eyes of 124 healthy emmetropic white subjects. RESULTS The mean difference between the thinnest site of the cornea and the thickness values obtained in the areas analyzed was as follows: 12+/-6 microm center; 140+/-19 microm superonasal; 133+/-23 microm nasal; 117+/-26 microm inferonasal; 122+/-19 microm superotemporal ; 89+/-22 microm temporal; and 99+/-29 microm inferotemporal (p

PURPOSE This study was designed to analyze the differences in central corneal thickness values determined with noncontact specular microscopy and scanning-slit corneal topography. The measurements were performed on the same eye. METHODS We analyzed the central corneal thickness values of 93 patients (n = 93) by means of noncontact specular microscopy (Topcon SP-2000P noncontact specular microscope, Topcon Corp., Tokyo, Japan) and scanning-slit corneal topography (Orbscan Topography System II, Orbscan Inc., Salt Lake City, UT). One experienced physician performed 3 consecutive central corneal thickness measurements with both devices. RESULTS The central corneal thickness values obtained by means of Orbscan pachymetry were 17 +/- 2.7 (range, 12-24) microm greater. A significant correlation was observed between scanning-slit corneal topography and noncontact specular microscopy (Pearson correlation coefficient, r = 0.976; P < 0.001). CONCLUSIONS Researchers should know of the existence of this difference between noncontact specular microscopy and Orbscan pachymetry when interpreting central corneal thickness values.

To study and compare the corneal thickness values of postmenopausal women with dry eye and postmenopausal women without dry eye.The corneal thickness value of 30 postmenopausal women with dry eye (dry eye group; aged 52 to 55 years) and 32 postmenopausal women without dry eye (normal group; aged 51 to 55 years) was analyzed with the Orbscan Topography System II. Each woman underwent a tear breakup test, the Schirmer test, fluorescein staining of the cornea, and an analysis of the meibomian gland by slit lamp before corneal thickness measurement. The statistical analysis was performed by means of the unpaired Student t test.The mean corneal thickness value was significantly decreased in postmenopausal women with dry eye (P0.001 at each corneal location). The central cornea had the thinnest mean values in dry eyes and normal eyes (533.10 +/- 4.74 microm and 547.63 +/- 15.11 microm, respectively), whereas superonasal cornea had thicker mean values in both groups (632.43 +/- 6.11 microm and 648.78 +/- 14.98 microm in dry eye and normal eyes, respectively).Postmenopausal women with dry eye have lower corneal thickness values than postmenopausal women without dry eye. Special care must be taken with these reduced corneal thickness values when selecting postmenopausal women for surgery involving corneal photoablation.

PURPOSE To study the corneal thickness of young emmetropic subjects. METHODS One thousand eyes of 1000 young healthy emmetropic subjects were analyzed with the Orbscan Topography System II (Orbscan, Inc, Salt Lake City, UT) from January 2001 to May 2003. The age of the subjects ranged from 20 to 30 years old (mean +/- SD = 27.12 +/- 2.86). The mean of 5 consecutive measurements of the corneal thickness in the center of the cornea and at temporal, superotemporal, inferotemporal, nasal, inferonasal, and superonasal cornea were recorded. RESULTS The corneal thickness at the following areas ranged as follows: 518 to 589 microm center; 603 to 678 microm nasal; 620 to 689 microm superonasal; 600 to 669 microm inferonasal; 571 to 639 microm temporal; 601 to 669 microm superotemporal; and 572 to 647 microm inferotemporal. In each individual the difference between the central thickness and the maximum paracentral thickness ranged from 85 to 107 microm (mean +/- SD, 99.21 +/- 3.80). The difference between the central thickness and the minimum paracentral thickness ranged from 36 to 59 microm (48.97 +/- 4.23 microm). The difference between the minimum paracentral corneal thickness and the maximum paracentral corneal thickness ranged from 37 to 58 microm (50.24 +/- 4.30). The tonometry was statistically correlated with the corneal thickness (P < 0.05 at each corneal location analyzed). CONCLUSIONS In emmetropic corneas the difference between the minimum paracentral thickness and the maximum paracentral thickness was similar to the difference between the central thickness and the minimum paracentral thickness.

BACKGROUND The aim of this study was to investigate the inter-observer variability of central corneal thickness measurements carried out with a non-contact specular microscope in patients who had undergone myopic laser in situ keratomileusis. METHODS Twenty-six eyes of 26 subjects who had undergone myopic laser in situ keratomileusis were studied with the Topcon SP-2000P non-contact specular microscope (Topcon Corp, Tokyo, Japan). The mean of three consecutive measurements of the central corneal thickness was recorded by two investigators prior to and one month after myopic laser in situ keratomileusis. Results obtained by each of the two physicians were compared. RESULTS Prior to surgery the mean central corneal thickness was 536.2 +/- 22.2 microm for physician 1 and 536.3 +/- 22.2 microm for physician 2 (p = 0.980). The pre-operative 95 per cent confidence interval was 522.7 to 544.2 microm (physician 1) and 523.1 to 544.1 microm (physician 2). The mean central corneal thickness was 485.8 +/- 29.3 microm for physician 1 and 485.6 +/- 28.0 micro m for physician 2 one month after laser in situ keratomileusis (p = 0.977). The post-operative 95 per cent confidence intervals were 470.1 to 496.2 microm and 470.3 to 495.4 microm for physicians 1 and 2, respectively. CONCLUSION Central corneal thickness measurements can be carried out by different clinicians after laser in situ keratomileusis with non-contact specular pachymetry, without there being any significant differences among them.