Comparison of outcomes of laser refractive surgery (LRS) alone and LRS with laser asymmetric keratectomy in patients with myopia: A retrospective study.

ABSTRACT: To compare and analyze the postoperative 1-year outcomes of laser refractive surgery (LRS) alone vs LRS with laser asymmetric keratectomy (LAK), in patients with myopia, for preventing and resolving LRS complications.This retrospective study compared the preoperative and 1-year postoperative outcomes between the control and comparison groups using a sum of deviations in corneal thickness in 4 directions >80 µm. The control group included 41 patients with myopia (41 eyes) who underwent LRS. The comparison group included 33 patients (33 eyes) who received LAK-linked LRS. Age, spherical equivalent (SE), sphere, cylinder, uncorrected distance visual acuity (UDVA), pupil size, kappa angle, central corneal thickness, corneal irregularity in the 3.0 mm zone on Orbscan maps (SUM), distance between the maximum posterior elevation (best-fit-sphere) and the visual axis (DISTANCE), postoperative blurring scores, frequency of postoperative myopic regression, and efficiency index were compared.Preoperative age (P = .198), SE (P = .686), sphere (P = .562), cylinder (P = .883), UDVA (P = .139), pupil size (P = .162), kappa angle (P = .807), central corneal thickness (P = .738), corneal irregularity (P = .826), SUM (P = .774), and DISTANCE (P = .716) were similar between the 2 groups. The 1-year postoperative SE (P = .024), sphere (P = .022), corneal irregularity (P = .033), SUM (P = .000), DISTANCE (P = .04), blurring scores (P = .000), and frequency of postoperative myopic regression (P = .004) were significantly decreased in the comparison group compared to the control group. UDVA (P = .014) and the efficiency index (P = .035) were higher in the comparison group.LAK with LRS improved corneal symmetry by reducing the SUM and DISTANCE. UDVA and efficiency index were also improved and blurring and myopic regression were reduced postoperatively.

Comparison of corneal thickness measurements using ultrasound pachymetry, noncontact tonopachy, Pentacam HR, and Fourier-domain OCT.

ABSTRACT: We retrospectively compared the central corneal thickness (CCT) obtained by ultrasound pachymetry (USP; SP-3000, Tomey Corp., Nagoya, Japan), non-contact tonopachy (TP) (NT-530P, Nidek Co., Ltd., Gamagori, Japan), Pentacam HR (OCULUS Inc., Wetzlar, Germany), and RTVue optical coherence tomography (OCT) (Optovue Inc., Fremont, CA, USA) in 78 eyes of 78 healthy subjects with myopia. Agreement between the measurement methods was evaluated using 95% confidence intervals for the limits of agreement (LoA). The mean CCT values were 546.9 ± 34.7, 548.1 ±â€Š33.5, 559.2 ±â€Š34.0, and 547.2 ±â€Š34.8 µm for USP, non-contact TP, Pentacam, and RTVue, respectively. The thickest and the thinnest mean CCT values corresponded to those obtained by Pentacam HR and USP, respectively. Plots of the differences against the means showed the best agreement between USP and RTVue (LoA, 10.14-10.70 µm), while the largest discrepancy was observed between RTVue and Pentacam systems (LoA, -25.47-1.44 µm). Our data showed that CCT measurements using these 4 instruments were well correlated. However, the results from Pentacam differed significantly from those of the other instruments.

Comparison of Central Corneal Thickness Measurements Using Optical and Ultrasound Pachymetry in Glaucoma Patients and Elderly and Young Controls.

PRéCIS:: Optical and ultrasound pachymetry cannot be used interchangeably in young, healthy adults. In elderly, healthy and glaucoma patients the speed of ultrasound in the cornea increases because of changing corneal biomechanical characteristics in age and disease and the different devices could be used interchangeably. PURPOSE: The purpose of this study was to compare central corneal thickness (CCT) using optical and ultrasound pachymetry in patients with open-angle glaucoma and young as well as elderly, healthy controls. Further to investigate whether the devices could be used interchangeably. METHODS: In total, 69 eyes of 41 glaucoma patients, 51 eyes of 32 elderly and 50 eyes of 25 young controls were consecutively included in this cross-sectional observational study. Optical CCT measurements were obtained using the noncontact Specular Microscope CEM-530 (NCSM). Ultrasound pachymetry (USP) was measured using the Pachy Meter SP 3000. RESULTS: In young subjects (27.2±4.8 y), the mean CCT taken with NCSM and USP was 562.1±33.6 µm and 565.8±35.8 µm, respectively. This was significantly different (USP>NCSM, P=0.019). In elderly subjects (70.6±10.7 y) CCT measured with NCSM (562.5±27.8 µm) compared to USP (564.9±27.1 µm) was not statistically significantly different (P= 0.121). In glaucoma patients (65.0±11.1 y), USP measured thinner CCT values compared to NCSM, without significant differences between the devices (NCSM 525.3±32.3 µm; USP 522.9±33.15 µm; P=0.067). CCT was significantly thinner in comparison to both healthy groups (P< 0.001). CONCLUSIONS: In young subjects, ultrasound pachymetry measurements are higher than they are with optical pachymetry. This difference is no longer observed in elderly subjects and is even reversed in glaucoma patients. A higher speed of ultrasound in the cornea due to changing corneal biomechanical properties in the elderly and glaucoma patients could explain this. The devices could be used interchangeably in older and glaucoma patients, but not in young individuals.

Comparison of central corneal thickness measurements obtained by community optometrists to those obtained in secondary care.

PURPOSE: Corneal central thickness (CCT) is an important risk factor for glaucoma, which also influences intraocular pressure (IOP) measurements. Recently, all community optometrists in Scotland were provided with pachymeters. This study examined the accuracy of CCT measured by community optometrists compared to measurements in the glaucoma clinic. METHODS: A retrospective analysis of consecutive patients referred to the glaucoma clinic at a university hospital between June and November 2016. 142 of 715 (19.9%) patients had CCT measurements included in the referral, all of whom had repeat measurements in the glaucoma clinic. CCT was measured using the PachPen (Accutome Inc) which generates a CCT reading by automatically taking the average of up to 9 measurements. Measurements were compared using Bland-Altman analysis. RESULTS: CCT measured by community optometrists was slightly thicker than CCT in the glaucoma clinic (558.3 ± 41.5 vs. 552.6 ± 58.8 µm, P < 0.001), however the mean difference was only 13.8 ± 18.0 µm. In 223 of 284 eyes (78.5%), CCT measurements taken by community optometrists were within 20 µm of those obtained in the glaucoma clinic. 61 of 284 (21.5%) differed by >20 µm, 40 (14.1%) by >30 µm and 17 (6.0%) by >50 µm. There was no significant relationship between difference in CCT and IOP (-0.02, 95% CI -0.05 to 0.002, P = 0.077), gender (0.00, 95%CI -0.01 to 0.01, P = 0.805), or age (-0.01, 95% CI -0.08 to 0.06, P = 0.791). CONCLUSIONS: There was good overall agreement between CCT measured by community optometrists and measurements obtained in the glaucoma clinic. The tendency for thicker CCT measurements by community optometrists may be due to more peripheral or non-perpendicular positioning of the pachymeter relative to the cornea.

Repeatability and Intersession Reproducibility of Pentacam Corneal Thickness Maps in Fuchs Dystrophy and Endothelial Keratoplasty.

PURPOSE: To assess intrasession repeatability and intersession reproducibility of Pentacam corneal thickness maps in patients with Fuchs endothelial corneal dystrophy (FECD) before and after endothelial transplantation. METHODS: In this observational diagnostic evaluation, 20 healthy subjects along with 81 consecutive patients were examined. Patients were classified into 4 groups: FECD without corneal edema, FECD with corneal edema, Descemet stripping automated endothelial keratoplasty, and Descemet membrane endothelial keratoplasty. Three consecutive scans of each eye were obtained at 2 different sessions. Raw pachymetry data were used to calculate average values of 4 concentric annular zones, which were also divided into 8 sectors. Repeatability and reproducibility coefficients (CR), coefficient of variation (CV), intraclass correlation coefficient, and 95% limits of agreement were calculated. RESULTS: The intrasession repeatability CV was ≤1% in the central 6 mm for all groups, with an intraclass correlation coefficient ≥0.97. It was better at the central zone than the periphery in all groups. Intersession reproducibility tended to be worse in the central area than the periphery in FECD without edema (CR ≤ 24.37; CV ≤ 1.48) and FECD with edema (CR ≤ 36.74; CV ≤ 2.03), whereas it was better in the central area in healthy eyes (CR ≤ 20.11; CV ≤ 1.32) and improved after Descemet stripping automated endothelial keratoplasty (CR ≤ 21.93; CV ≤ 1.31) and Descemet membrane endothelial keratoplasty (CR ≤ 30.83; CV ≤ 1.94). CONCLUSIONS: Pentacam corneal thickness maps showed good repeatability and intersession reproducibility in virgin and grafted corneas with FECD, which makes it a valid tool for monitoring these patients. Central areas showed the highest variability between sessions in diseased groups.

Morfología y morfometría del endotelio corneal en adultos sin alteraciones corneales según cantidad de células evaluadas / Morphology and morphometry of the corneal endothelium in adults without corneal alterations according to the number of evaluated cells

Objetivo: describir las características morfológicas y morfométricas del endotelio corneal en adultos sin alteraciones corneales según cantidad de células evaluadas atendidos en el Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología Ramón Pando Ferrer en el período comprendido de enero a febrero del año 2016. Métodos: se realizó una investigación descriptiva de corte transversal de serie de casos atendidos en el Servicio de Cirugía Refractiva. Después de aplicar los criterios de exclusión, la muestra quedó conformada por 90 ojos de 45 pacientes adultos sanos. Se realizó microscopia endotelial de no contacto SP-3000P, para identificar los valores morfológicos (hexagonalidad y coeficiente de variabilidad) y morfométricos (densidad celular y paquimetría), así como el promedio del tamaño celular corneal según cantidad de células evaluadas. Resultados: según la cantidad de células endoteliales evaluadas no hubo diferencias en cuanto a la paquimetría en ambos ojos (p> 0,05). En relación con la densidad no existieron diferencias significativas entre la cantidad de células evaluadas en ambos ojos (p> 0,05). Los valores de hexagonalidad, coeficiente de variabilidad y tamaño celular promedio no mostraron diferencias significativas (p> 0,05) en ambos ojos según la cantidad de células evaluadas. Conclusiones: el estudio del endotelio corneal mediante la utilización del microscopio especular constituye un método efectivo que permite conocer las características de las células endoteliales sin existir variaciones según la cantidad de células evaluadas(AU)

Objective: to describe the morphological and morphometric characteristics of the corneal endothelium in adults without corneal alterations according to the number of evaluated cells, who had been seen at the refractive survey service of Ramón Pando Ferrer Cuban Institute of Ophthalmology from January to February, 2016. Methods: descriptive, cross-sectional case-series research study of patients seen at the refractive surgery service. After applying the exclusion criteria, the sample was finally made up of 90 eyes from 45 healthy adult patients. SP-3000P non-contact endothelial microscopy was performed to determine the morphological (hexagonality and variability coefficient) and morphometric (cell density and pachymetry) values and the average of the average cellular corneal size according to the number of evaluated cells. Results: according to the number of evaluated endothelial cells, there were no differences as for the pachymetry in both eyes (p> 0.05). Regarding the cell density, there were no significant differences among the number of evaluated cells in both eyes (p> 0.05). The hexagonality, variability coefficient and average cell size did not show significant differences (p> 0.05) in both eyes according to the number of evaluated cells. Conclusions: the study of the corneal endothelium using the specular microscope is an effective method that allows to know the characteristics of the endothelial cells without no previous variations, according to the number of evaluated cells(AU)

A national survey of the use of pachymeters by optometrists in Scotland: experience, views and barriers to use.

PURPOSE: Thin central corneal thickness (CCT) is a risk factor for glaucoma. In 2016 all optometry practices in Scotland were provided with pachymeters aiming to improve risk assessment and accuracy of referrals to secondary care. We examined optometrists' experience and views of pachymetry, including perceived barriers to pachymetry in primary care. METHODS: A questionnaire was sent using the REDCap electronic data capture tool to all 1264 optometrists registered with NHS Education for Scotland (NES). The questionnaire evaluated year of qualification, previous pachymetry training, confidence performing and interpreting pachymetry, and perceived indications for and barriers to use. RESULTS: Respondents numbered 418 out of 1264 (33%) optometrists, of whom 56% had previous training in pachymetry. Those that had previous training were significantly more likely to report pachymetry to be useful, with median (inter-quartile range) usefulness score of 86 (71-98) where 0 indicated not at all useful, and 100 extremely useful, vs 76 (58-90), Wilcoxon-Mann-Whitney test, z = -4.67, p < 0.01. There are no valid scales for adjusting intraocular pressure (IOP) using CCT, however 45% of respondents reported using a scale. Optometrists planned to use pachymetry when assessing patients with ocular hypertension or suspected glaucoma. The greatest perceived barrier was the process of decontaminating or cleaning the pachymeter between patients, followed by lack of time and lack of training. CONCLUSIONS: Although the majority of optometrists were interested in performing pachymetry, many lacked confidence in performing and interpreting the results. Forty-one percent of those who reported training in pachymetry still used non-validated scales to convert IOP measurements illustrating the need for further training.

Repeatability and Agreement of Orbscan II, Pentacam HR, and Galilei Tomography Systems in Corneas With Keratoconus.

PURPOSE: To assess the repeatability and agreement of keratometry and pachymetry measurements obtained using 3 tomographers in eyes with keratoconus. DESIGN: Reliability analysis. METHODS: setting: Institutional. STUDY POPULATION: Fifty eyes of 50 participants with keratoconus. observational procedure: Steep keratometry, flat keratometry, central corneal thickness (CCT), and thinnest corneal thickness (TCT) measurements using Galilei, Orbscan II, and Pentacam HR. MAIN OUTCOME MEASURES: Repeatability was assessed using within-subject standard deviation (SW), coefficient of variation (CV), and intraclass correlation coefficient (ICC). Bland-Altman plots and 95% limits of agreement (LoA) were used to evaluate agreement between device pairs. RESULTS: For all studied parameters, ICC was >0.97 with the least repeatable measurements obtained using Orbscan II. Mean steep keratometry values were similar while mean flat keratometry values were significantly different between all devices. The Galilei and Pentacam HR had the lowest 95% LoA for both CCT and TCT. There were no significant differences in mean CCT between Galilei and Pentacam HR. Mean Orbscan II CCT measurements were not significantly different overall but had wide 95% LoA with Pentacam HR (-47.95 to 58.09 µm) and Galilei (-43.70 to 53.91 µm). Mean Orbscan II CCT measurements were significantly lower when an acoustic factor of 0.92 was applied (-33.6 µm vs Pentacam HR, P < .001; -33.6 µm vs Galilei; P < .001). CONCLUSIONS: Keratometric and pachymetric measurements of keratoconic eyes obtained by Galilei, Orbscan II, and Pentacam were disparate. Measurements were less repeatable with Orbscan II compared with Pentacam HR and Galilei, although overall repeatability was high for all instruments.

Corneal elevation in a large number of myopic Chinese patients.

PURPOSE: To establish a normative database for corneal elevation in Chinese myopic patients who underwent refractive surgery, and analyze the association of corneal elevation with sex, age, and ocular parameters. METHODS: A total of 3000 eyes in 1500 patients were evaluated with the Pentacam. Anterior and posterior elevations were measured at the apex and thinnest point. Normative thresholds were defined according to the Tukey method. Univariate and multivariate analyses were performed to assess the association of corneal elevation with sex, age, and ocular parameters. RESULTS: Normal upper limits for corneal elevation in adult Chinese were 4.95µm, 5.25µm, 6.2µm, and 11.0µm at the anterior apex, anterior thinnest point, posterior apex, and posterior thinnest point, respectively. Thinner corneal pachymetry at the apex and greater anterior corneal astigmatism tended to show greater anterior corneal elevation values. Younger age, greater anterior corneal astigmatism, lower anterior and posterior keratometry, and shallower anterior chamber depth resulted in greater posterior corneal elevation values. CONCLUSIONS: Locally derived thresholds may offer higher sensitivity and specificity when screening eyes for myopic refractive surgery, and keratoconic and post-orthokeratology eyes. Anterior and posterior corneal elevation at the apex and thinnest point were associated significantly with anterior corneal astigmatism, showing a positive correlation.

Evaluación del complejo ganglionar celular mediante tomografía de coherencia óptica en pacientes con hipertensión ocular / Ganglion cell complex evaluation with optical coherence tomography in patients with ocular hypertension

Objetivos: determinar el espesor del complejo ganglionar celular (CGC) mediante tomografía de coherencia óptica de dominio de Fourier (FD-OCT) en pacientes con diagnóstico de hipertensión ocular previa clasificación del riesgo de conversión a glaucoma utilizando la regla STAR (Scoring Tool For Assessing Risk). Materiales y Métodos: mediante la revisión de historias clínicas, se seleccionaron pacientes con diagnóstico previo de hipertensión ocular (HTO). A cada paciente se le realizó una valoración oftalmológica completa, medición del espesor del CGC mediante OCT y calculo del STAR. Los datos obtenidos se relacionaron con variables demográficas, presión intraocular, paquimetría central y perimetría computarizada. Resultados: se analizaron 106 ojos de 53 pacientes con HTO. La PIO promedio fue de 23.55 ± 0.69 mmHg. La regla STAR fue aplicada en 96 ojos. El 65.6% (63 ojos) se categorizó en alto riesgo de conversión a glaucoma en los próximos cinco años. Los pacientes de este grupo presentaron un espesor del CGC significativamente menor que el de los otros grupos. El valor promedio del espesor del complejo ganglionar superior e inferior fue de 83 ± 4.5 micras y 82.09 ± 4.98 micras respectivamente. Conclusión: los pacientes clasificados en el grupo de alto riesgo STAR tienen espesores del CGC significativamente menores. La disminución del espesor del CGC se correlacionó positivamente con las anormalidades registradas en la perimetría computarizada.

Objective: to determine the thickness of the ganglion cell complex (GCC) by Fourier domain optical coherence tomography (FDOCT) in patients diagnosed with ocular hypertension who were classified with the STAR rule (Scoring Tool for Assessing Risk) to determine the risk of conversion to glaucoma. Methods: patients with ocular hypertension previously diagnosed were selected from medical records. Each patient underwent a complete ophthalmic evaluation, measurement of the thickness of the CGC by FD-OCT (Nidek RS-3000) and calculation of the STAR. Data recorded was related to demographic variables, intraocular pressure, central corneal thickness and computerized perimetry. Results: 106 eyes of 53 patients with ocular hypertension were analyzed. The average intraocular presure was 23.55 ± 0.69 mmHg. The STAR rule was applied in 96 eyes. 65.6% (63 eyes) were categorized into high risk of conversion to glaucoma in the next five years. Patients in this group had a significantly lower thickness of the CGC than the other groups. The average value of the thickness of the upper and lower CGC was 83 ± 4.5 microns and 82.09 ± 4.98 microns respectively. Conclusion: patients classified in the STAR high risk group have a signifi cantly lower thickness of the CGC. The thinning of the CGC was positively correlated with abnormalities recorded in the computerized perimetry.

Características clínicas de la distrofia corneal endotelial de Fuchs / Clinical characteristics of Fuchs' endothelial corneal dystrophy in families under study

OBJETIVOS: caracterizar clínicamente la distrofia corneal endotelial de Fuchs en las familias estudiadas. MÉTODOS: se realizó un estudio observacional, descriptivo y transversal en familias con distrofia de Fuchs, en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer", del año 2008 al 2011. Se operacionalizaron variables como: estadio clínico de la enfermedad, amplitud de cámara anterior y ángulo iridocorneal, presión intraocular, longitud axial, paquimetría, densidad celular endotelial, pleomorfismo y polimegatismo. Se resumieron las variables utilizando frecuencias absolutas y relativas porcentuales. Para la relación entre densidad celular y paquimetría se hizo un análisis de correlación bivariado no paramétrico. RESULTADOS: los pacientes enfermos se encontraban en su mayoría en el estadio I y II, con 50 y 60 % para los recién diagnosticados y los ya conocidos respectivamente. La amplitud de la cámara anterior fue normal en el 51,9 %; el ángulo iridocorneal estrecho en el 55,6 %, la presión intraocular normal en el 66,7 % y una hipermetropía axial en el 55,6 % de los casos con distrofia corneal. No se encontró asociación significativa entre paquimetría y densidad celular, pero sí pleomorfismo y polimegatismo en el 100 % de los enfermos y en más del 50 % de los descendientes directos. CONCLUSIONES: las variables analizadas demuestran ser importantes a la hora de caracterizar la enfermedad, además de señalar daños endoteliales en descendientes no enfermos, aspecto a tener en cuenta para su seguimiento.

OBJECTIVE: to describe the clinical characteristics of Fuchs' endothelial corneal dystrophy in the families under study. METHODS: observational, descriptive and cross-sectional study of families with Fuchs' corneal dystrophy diagnosed at "Ramón Pando Ferrer" Cuban Institute of Ophthalmology from 2008 to 2011. The study variables were clinical stage of the disease, depth of anterior chamber and iridocorneal angle, intraocular pressure, axial length, corneal thickness, endothelial cell density, pleomorphism and polymegatism. The variables were summarized using percentage absolute and relative frequencies. For assessing the ratio of the cell density and pachymetry, a nonparametric bivariate correlation analysis was made. RESULTS: the patients with Fuchs' endothelial corneal dystrophy were mostly in the clinical stages I and II, accounting for 50 % of the newly diagnosed patients and 60 % of the previously known ones. The amplitude of the anterior chamber was normal in 51,9 %, the iridocorneal angle was narrow in 55,6 %. Intraocular pressure was normal in 66,7 % and axial hypermetropia was found in 55,6 % of cases with corneal dystrophy. No significant association was found between the corneal thickness and cell density, but it was between pleomorphism and polyimegathism in 100 % of patients and in more than 50 % of the direct descendants. CONCLUSIONS: the variables proved to be important in characterizing the disease as well as in pointing endothelial damages among non-sick descendants. This aspect should be considered on the follow-up period.

Queratoplastia lamelar predescemética para el tratamiento del queratocono / Predescemetic lamellar keratoplasty for treatment of keratoconus

OBJETIVO: describir los resultados de la queratoplastia lamelar profunda en el tratamiento quirúrgico del queratocono en el Servicio de Córnea del Instituto Cubano de Oftalmología "Ramón Pando Ferrer". MÉTODOS: se realizó un estudio descriptivo prospectivo en 7 ojos con queratocono operados de queratoplastia lamelar profunda. Se analizaron las variables edad, sexo, grado de queratocono, agudeza visual preoperatoria y posoperatoria, astigmatismo posquirúrgico, paquimetría y queratometría topográfica a la semana, al mes y a los tres meses de la intervención. La información se procesó a través de frecuencias absolutas, relativas, medias y desviación estándar. RESULTADOS: en el sexo masculino, el 42,9 % tenía entre 18 y 39 años de edad al igual que el grupo de 40-50 años en el sexo femenino. El 57,2 % de los casos presentó queratocono avanzado. En el posoperatorio se encontró que el 71,4 % de los casos poseía una agudeza visual corregida entre 0,1-0,3 y 5-10 dioptrías de astigmatismo posquirúrgico; la paquimetría fue superior a 560 µm en el 85,6 %; la queratometría promedio en el meridiano más fuerte fue de 47,77 y en el meridiano más débil, de 40,01. CONCLUSIONES: la queratoplastia lamelar predescemética es una técnica quirúrgica que ofrece ventajas superiores en relación con las queratoplastias penetrantes.

OBJECTIVE: to describe the results of deep lamellar keratoplasty in the surgical treatment of keratoconus in the Corneal Service of "Ramón Pando Ferrer" Cuban Institute of Ophthalmology. METHODS: a prospective descriptive study of 7 eyes with moderate keratoconus who underwent predescemetic lamellar keratoplasty. The universe consisted of 7 eyes fom patients who met the criteria for deep lamellar keratoplasty surgery. The variables age, sex, degree of keratoconus, pre-and postoperative visual acuity, postoperative astigmatism, topographic keratometry and pachymetry after a week, a month and three months of the surgery. Data were analyzed by using absolute, relative, mean frequencies and standard deviations. RESULTS: the 18-36 year age group in males represented 42,9 % as the 40-50 years-old group in females. In the studied group, 57,2 % of patients had advanced keratoconus. On the third postoperative month, 71,4 % of patients had visual acuity ranging 0,1 to 0,3 and 5-10 postsurgical astigmatism diopters. Pachymetry observed in 85,6 % of patients was higher than 560 um. The average keratometric value in the strongest meridian was 59,43 preoperatively and 47,77 postoperatively. In the weakest meridian, average keratometry was 50,28 and postoperative average amounted to 40,01. CONCLUSIONS: predescemetic lamellar keratoplasty is a surgical technique providing greater advantages if compared to penetrating keratoplasty.

Queratoplastia lamelar predescemética para el tratamiento del queratocono / Predescemetic lamellar keratoplasty for treatment of keratoconus

Objetivo: describir los resultados de la queratoplastia lamelar profunda en el tratamiento quirúrgico del queratocono en el Servicio de Córnea del Instituto Cubano de Oftalmología Ramón Pando Ferrer.Métodos: se realizó un estudio descriptivo prospectivo en 7 ojos con queratocono operados de queratoplastia lamelar profunda. Se analizaron las variables edad, sexo, grado de queratocono, agudeza visual preoperatoria y posoperatoria, astigmatismo posquirúrgico, paquimetría y queratometría topográfica a la semana, al mes y a los tres meses de la intervención. La información se procesó a través de frecuencias absolutas, relativas, medias y desviación estándar. Resultados: en el sexo masculino, el 42,9 por ciento tenía entre 18 y 39 años de edad al igual que el grupo de 40-50 años en el sexo femenino. El 57,2 por ciento de los casos presentó queratocono avanzado. En el posoperatorio se encontró que el 71,4 por ciento de los casos poseía una agudeza visual corregida entre 0,1-0,3 y 5-10 dioptrías de astigmatismo posquirúrgico; la paquimetría fue superior a 560 µm en el 85,6 por ciento; la queratometría promedio en el meridiano más fuerte fue de 47,77 y en el meridiano más débil, de 40,01. Conclusiones: la queratoplastia lamelar predescemética es una técnica quirúrgica que ofrece ventajas superiores en relación con las queratoplastias penetrantes(AU)

Objective: to describe the results of deep lamellar keratoplasty in the surgical treatment of keratoconus in the Corneal Service of Ramón Pando Ferrer Cuban Institute of Ophthalmology.Methods: a prospective descriptive study of 7 eyes with moderate keratoconus who underwent predescemetic lamellar keratoplasty. The universe consisted of 7 eyes fom patients who met the criteria for deep lamellar keratoplasty surgery. The variables age, sex, degree of keratoconus, pre-and postoperative visual acuity, postoperative astigmatism, topographic keratometry and pachymetry after a week, a month and three months of the surgery. Data were analyzed by using absolute, relative, mean frequencies and standard deviations. Results: the 18-36 year age group in males represented 42,9 percent as the 40-50 years-old group in females. In the studied group, 57,2 percent of patients had advanced keratoconus. On the third postoperative month, 71,4 percent of patients had visual acuity ranging 0,1 to 0,3 and 5-10 postsurgical astigmatism diopters. Pachymetry observed in 85,6 percent of patients was higher than 560 um. The average keratometric value in the strongest meridian was 59,43 preoperatively and 47,77 postoperatively. In the weakest meridian, average keratometry was 50,28 and postoperative average amounted to 40,01. Conclusions: predescemetic lamellar keratoplasty is a surgical technique providing greater advantages if compared to penetrating keratoplasty(AU)

[Difference and distance between the central and thinnest points of the cornea: impact of refractive state, age and ocular side]. / Differenz und Entfernung zwischen zentraler und dünnster Stelle der Hornhaut: Einfluss von Refraktion, Alter und Augenseite.

BACKGROUND: The aim of the study was to quantify the difference in corneal thickness between the central and thinnest points (∆PachyZ-PachyD), the distance between the center of the cornea and its thinnest point (vector length PachyD) and to explore the impact of refractive state, age and ocular side. PATIENTS AND METHODS: This was a multicenter, retrospective, cross-sectional study and medical records of 16,872 eyes were reviewed. The Orbscan® (Bausch and Lomb) procedure was used for pachymetry and keratometry. RESULTS: The results showed that ∆PachyZ-PachyD and vector length PachyD were higher in hyperopic eyes (∆PachyZ-PachyD: 11.99 ± 12.08 µm, vector length PachyD: 0.85 ± 0.44 mm) compared to myopic eyes (∆PachyZ-PachyD: 9.2 ± 7.86 µm, vector length PachyD: 0.7 ± 0.37 mm; p < 0.001). Refractive state, age and ocular side demonstrated an independent, statistically significant impact on ∆PachyZ-PachyD and vector length PachyD. CONCLUSIONS: As a result of the significant impact of refractive state, age and ocular side on ∆PachyZ-PachyD and vector length PachyD, these variables should be considered in a normative data collection.

Distribution of central corneal thickness and its association with ocular parameters in a large central European cohort: the Gutenberg health study.

MAIN OBJECTIVE: To evaluate the distribution of central corneal thickness (CCT) in a large German cohort and to analyse its relationship with intraocular pressure and further ocular factors. DESIGN: Population-based, prospective, cohort study. METHODS: The Gutenberg Health Study (GHS) cohort included 4,698 eligible enrollees of 5,000 subjects (age range 35-74 years) who participated in the survey from 2007 to 2008. All participants underwent an ophthalmological examination including slitlamp biomicroscopy, intraocular pressure measurement, central corneal thickness measurement, fundus examination, and were given a questionnaire regarding glaucoma history. Furthermore, all subjects underwent fundus photography and visual field testing using frequency doubling perimetry. RESULTS: Mean CCT was 557.3 ± 34.3 µm (male) and 551.6±35.2 µm in female subjects (Mean CCT from right and left eyes). Younger male participants (35-44 years) presented slightly thicker CCT than those older. We noted a significant CCT difference of 4 µm between right and left eyes, but a high correlation between eyes (Wilcoxon test for related samples: p<0.0001). Univariable linear regression stratified by gender showed that IOP was correlated with CCT (p<0.0001). A 10 µm increase in CCT led to an increase in IOP between 0.35-0.38 mm Hg, depending on the eye and gender. Multivariable linear regression analysis revealed correlations between gender, spherical equivalent (right eyes), and CCT (p<.0001 and p=0.03, respectively). CONCLUSIONS: We observed positive correlations between CCT and IOP and gender. CCT was not correlated with age, contact lens wear, positive family history for glaucoma, lens status, or iris colour.