Comparación entre las fórmulas SRK/T, Hoffer Q, Barrett Universal y HRBF para el cálculo del lente intraocular / Comparison of the formulas SRK/T, Hoffer Q, Barrett Universal and HRBF for intraocular lens calculation

Objetivo: Comparar la exactitud de las fórmulas SRK/T, Hoffer Q, Barrett Universal y HRBF en el cálculo del lente intraocular. Métodos: Se realizó un estudio descriptivo longitudinal prospectivo de 70 ojos de 70 pacientes operados de cirugía de catarata con implante de lente intraocular, de junio del año 2018 a junio del 2019, utilizando el IOL Master 700, en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer". Se determinó la exactitud de cada fórmula respecto al error de predicción del equivalente esférico y se compararon entre sí. Resultados: Los pacientes entre 60 y 80 años constituyeron el 70,00 por ciento de los casos y el sexo femenino representó el 61,43 por ciento. Los ojos de tamaño medio representaron el 91,43 por ciento del total. No hubo diferencias en el error de predicción absoluto medio entre de las fórmulas analizadas para el rango total de longitudes axiales. La fórmula de Barrett tuvo el 65,71 por ciento de ojos con un error de predicción dentro de ± 0,50 D. El mayor porcentaje de ojos con un error mayor a 1 dioptría recayó sobre la Hoffer Q (10,00 por ciento). Conclusiones: El grupo etario más representado está entre 60 y 80 años y el sexo femenino es mayoritario. Predominan los ojos de tamaño medio y las mensuraciones biométricas dentro de los valores promedio estándar. Las fórmulas HRBF, SRK/T, Hoffer Q y Barrett predicen el resultado refractivo posoperatorio con una exactitud similar para el rango total de longitudes axiales. La fórmula de Barrett logra el mayor porcentaje de ojos con errores de predicción posoperatorios dentro del rango de la emetropía(AU)

Objective: Compare the accuracy of the formulas SRK/T, Hoffer Q, Barrett Universal and HRBF for intraocular lens calculation. Methods: A prospective longitudinal descriptive study was conducted of 70 eyes of 70 patients undergoing cataract surgery with intraocular lens implantation from June 2018 to June 2019 at Ramón Pando Ferrer Cuban Institute of Ophthalmology. In all cases IOL Master 700 was used for lens calculation. Determination of the accuracy of each formula in error prediction of the spherical equivalent was followed by a comparison of the formulas. Results: Patients aged 60-80 years were 70.00 percent of the cases; female sex represented 61.43 percent. Medium sized eyes were 91.43 percent of the total eyes examined. Mean absolute prediction error did not show any difference between the formulas analyzed for the total range of axial lengths. The Barrett formula spotted 65.71 percent of the eyes with a prediction error within ± 0.50 D. The highest percentage of eyes with an error greater than 1 diopter corresponded to the Hoffer Q formula (10.00 percent ). Conclusions: The best represented age group was 60-80 years; female sex prevailed. A predominance was found of medium size and biometric measurements within standard mean values. The formulas HRBF, SRK/T, Hoffer Q and Barrett predict the postoperative refractive result with similar accuracy throughout the total range of axial lengths. The Barrett formula achieves the highest percentage of eyes with postoperative prediction errors within the range of emmetropia(AU)

Resultados del cálculo de la lente intraocular con la fórmula Holladay 2 en pacientes con catarata / Results of intraocular lens calculation with the Holladay 2 formula in cataract patients

RESUMEN Objetivo: Determinar los resultados refractivos en pacientes operados de catarata, según el cálculo del poder dióptrico de la lente intraocular con la fórmula Holladay 2. Métodos: Se realizó un estudio descriptivo prospectivo y longitudinal en 222 ojos de 173 pacientes operados de catarata mediante la técnica de facoemulsificación. Se empleó para el cálculo de la lente el IOL Master 700 y la fórmula Holladay 2. Resultados: Predominó el sexo femenino y el grupo etario mayor de 60 años. En el posoperatorio se observó una mejoría en la agudeza visual sin corrección y corregida de más de 4 líneas en la cartilla de Snellen, independiente de la longitud axial, sin cambios significativos en el cilindro queratométrico. En 69,0 por ciento de los casos el resultado refractivo final estuvo en el rango de la emetropía. Los ojos mayores de 26 mm presentaron una disminución del equivalente esférico superior a 6 dioptrías en el posoperatorio; los menores de 22 mm mostraron la mayor diferencia entre el poder dióptrico de la lente intraocular que se implantó y el que sugiere la fórmula convencional. Conclusiones: La fórmula Holladay 2 resulta útil para el cálculo de la lente intraocular en todos los rangos de longitud axial(AU)

ABSTRACT Objective: Determine refractive results in patients undergoing cataract surgery based on intraocular lens dioptric power calculation with the Holladay 2 formula. Methods: A prospective longitudinal descriptive study was conducted of 222 eyes of 173 patients undergoing cataract surgery by phacoemulsification technique. IOL Master 700 and the Holladay 2 formula were used for lens calculation. Results: There was a predominance of the female sex and the over-60 years age group. The postoperative period was characterized by improvement in visual acuity without correction and corrected of more than 4 lines on the Snellen chart, regardless of axial length, with no significant changes in the keratometric cylinder. In 69.0 percent of the cases, the final refractive result was within the range of emmetropia. Eyes larger than 26 mm displayed a spherical equivalent reduction above 6 diopters postoperative, whereas eyes smaller than 22 mm showed the greatest difference between the dioptric power of the intraocular lens implanted and the one suggested by the conventional formula. Conclusion: The Holladay 2 formula is useful for intraocular lens calculation in all axial length ranges(AU)

Effect of High Myopia on Optic Nerve Head by Confocal Scanning Laser Ophthalmoscopy in Nepalese Eyes

PURPOSE: To compare parameters of confocal scanning laser ophthalmoscopy (Heidelberg Retinal Tomograph [HRT] II) in high myopia with age- and sex-matched emmetropes. METHODS: A hospital-based cross-sectional study was conducted among Nepalese subjects aged 18 to 35 years at BP Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Maharajgunj, Kathmandu from November 2015 to October 2016. Fifty consecutive subjects with high myopia (spherical equivalent ranging from −6.00 to −12.00 diopters) and age- and sex-matched emmetropic subjects were enrolled for comparison. Correlations between disc area and other HRT parameters, asymmetry between the right and left eyes, and comparisons between male and female subjects in both high myopic and emmetropic groups were evaluated. RESULTS: Disc area was not significantly (p = 0.11) larger in high myopic eyes than in emmetropic eyes. HRT parameters in highly myopic eyes involved smaller cup parameters and greater rim parameters compared with emmetropic eyes. Disc area was found to be significantly positively correlated with inter disc parameters and significantly negatively correlated with rim to disc area ratio in the high myopia group. Disc area and other intra-disc parameters showed significant correlations between right and left eyes in both high myopia and emmetropia, and no significant differences between males and females from a Nepalese population. CONCLUSIONS: Characteristics of HRT parameters in high myopic eyes involved smaller cup parameters and greater rim parameters compared with emmetropic eyes in a Nepalese population. The effect of disc area on HRT parameters differed significantly only in height variation contour by emmetropic eyes.

Clinical Features of Children with +4.00 Diopters or More Hyperopia Weaning with Age

PURPOSE: To evaluate the clinical features of children with high hyperopia weaning with age. METHODS: The medical records of 203 children wearing spectacles due to hyperopia of +4.00 diopters (D) or greater in at least one eye based on the cycloplegic refraction and with follow-up for 3 years or more were reviewed. The patients were divided into those who showed a decrease in the spherical equivalent (SE) of 1.50 D or greater and those who maintained. The age of wearing spectacles, the magnitude of hyperopia, the angle of deviation, the ratio of accommodative-convergence to accommodation (AC/A), and the frequency of amblyopia and anisometropia were compared. RESULTS: Forty seven patients with decreased hyperopia and 156 patients with sustained hyperopia were included. The decreased-group started to wear spectacles later than the sustained-group (5.0 ± 2.3 years vs. 4.1 ± 2.4 years). The mean SE of the hyperopic eye in the decreased-group was significantly greater at the initial visit than in the sustained-group (6.29 ± 2.18 D vs. 5.47 ± 1.38 D); was identical at the 1 year follow-up (4.83 ± 1.72 D vs. 4.89 ± 1.55 D); and significantly lower at the last follow-up (3.15 ± 1.72 D vs. 4.65 ± 1.56 D). In the decreased-group, the mean hyperopia of 3.14 ± 2.02 D decreased during a mean period of 3.9 years, especially during the first year after spectacle correction. At baseline, the frequency and angle of esotropia at both distant and near with/without hyperopic correction was significantly larger in the sustained-group. The frequency of amblyopia and anisometropia and the AC/A were identical between the two groups, while the frequency of amblyopia at the last follow-up was significantly lower in the decreased-group. CONCLUSIONS: Some patients with hyperopia of +4.00 D or greater who had none or a small angle of esotropia and improved amblyopia showed a decrease in hyperopia with age.

Clinical Characteristics and Outcomes of Smartphone Overusers with Acute Acquired Comitant Esotropia

PURPOSE: To evaluate the clinical features and treatment outcomes of smartphone overusers with acute acquired comitant esotropia. METHODS: We retrospectively reviewed the medical records of patients ≥ 15 years of age who used a smartphone for > 4 hours a day for > 1 year, and who were diagnosed with acute acquired comitant esotropia from May 2011 to January 2016. We analyzed sex, age at the time of manifestation and duration of esotropia, refractive error, deviated angle at the first and final visits, and the results of refraining from smartphone use, use of the Fresnel prism, and surgery for esotropia. RESULTS: A total of 13 patients were studied, including 8 males and 5 females. The mean age at development of esotropia was 22.7 ± 9.7 years. The mean duration of esotropia before the first visit was 28.0 ± 33.0 months, and the mean follow-up period was 16.4 ± 16.4 months. The mean angle of esotropia was 21.8 ± 7.0 prism diopters (PD) at distance and 22.2 ± 7.9 PD at near. There were eight myopic patients; the other patients were emmetropia. The esotropia of all patients did not improve after refraining from smartphone use. There was no improvement in five patients who were wearing the Fresnel prism for ≥ 4 months. A total of six patients were treated with bilateral medial rectus recession; only one patient remained orthotropic at postoperative 6 months, three patients were undercorrected, and two had a recurrence. CONCLUSIONS: Esotropia persisted after refraining from smartphone use or wearing a Fresnel prism in acute acquired comitant esotropia patients who were smartphone overusers, and the surgical prognosis of these patients was relatively poor.

Anterior Segment Changes during Accommodation in Accommodative Esotropia

PURPOSE: To evaluate the anterior segment biometric parameters of non-accommodative and accommodative refractive accommodative esotropia (RAE). METHODS: Eighty-one eyes of 81 patients were included in this prospective, case-control study. The patients were divided into three groups as follows: the RAE group (n = 31), the hypermetropia group (n = 25), and the emmetropia group (n = 25). Measurements were obtained in the non-accommodative (0.0 diopters) and accommodative status (-5.0 diopters) using a Pentacam HR. The anterior chamber depth (ACD), anterior chamber volume (ACV), pupil diameter (PD), and anterior chamber angle (ACA) were evaluated at all four quadrants. RESULTS: The ACD, ACV and PD values in the RAE group were lower than those of the other groups in both states (p < 0.05). The ACD values were lower in the hypermetropia group than in the emmetropia group for the non-accommodative status (p = 0.024) but were similar for the accommodative status (p = 0.225). PD and ACV values were lower in the hypermetropia group than in the emmetropia group in both states (non-accommodative status, p = 0.011 and p = 0.022; accommodative status, p = 0.026 and p = 0.034, respectively). Changes in ACD, ACV and PD during accommodation (Δ) were not significant in the RAE group but were significant for the other groups (hypermetropia: ΔACD, p = 0.001; ΔACV, p = 0.001; ΔPD, p = 0.002; emmetropia: ΔACD, p < 0.001; ΔACV, p = 0.001; ΔPD, p < 0.001). These changes were significantly lower in the hypermetropia group than in the emmetropia group (ΔACD, p = 0.012; ΔACV, p = 0.031; ΔPD, p = 0.034). CONCLUSIONS: The anterior chamber in RAE patients was shallower and the increase in convexity of the anterior surface or forward movement of the crystalline lens was more limited during accommodation in RAE.

Choroidal Thickness Variation According to Refractive Error Measured by Spectral Domain-optical Coherence Tomography in Korean Children

PURPOSE: To assess choroidal thickness (CT) variation according to refractive errors using enhanced-depth imaging optical coherence tomography. METHODS: Eighty-nine eyes (in 89 children) <±6 diopter were categorized into three groups: hyperopia, emmetropia, and myopia, according to refractive error, and underwent choroidal scans using enhanced-depth imaging-optical coherence tomography. CT was measured at the fovea and at 1 mm and 3 mm nasal (N1 and N3), temporal (T1 and T3), superior (S1 and S3), and inferior (I1 and I3) from the fovea. RESULTS: Mean foveal CTs were 346.86 µm, 301.97 µm, and 267.46 µm in the hyperopia, emmetropia, and myopia groups, respectively (p < 0.05). CTs at N3 and T3 were 214.59 µm and 318.68 µm, 163.92 µm and 320.79 µm, and 153.93 µm and 295.61 µm in the hyperopia, emmetropia, and myopia groups, respectively (p < 0.05). All CTs in the hyperopia group were thicker than those of other groups (p < 0.05). Fovea was thickest and was significantly thicker than at N3 and I3 in hyperopia (p < 0.05). T3 thickness in the emmetropia and myopia groups was greater than thickness at other areas, particularly the nasal and inferior choroids (p < 0.05). CT was positively correlated with spherical equivalent (p = 0.029). CONCLUSIONS: In Korean children, CTs were greater in the hyperopia group than in the emmetropia and myopia groups. The temporal choroid was thicker than the nasal choroid, regardless of the refractive error. The thickest location in the hyperopia group was the fovea; however, the temporal choroid was thickest in the emmetropia and myopia groups.

Clinical Results of Pseudophakic Monovision 1 Year after Cataract Surgery

PURPOSE: In this study, the visual performance and patient satisfaction one year after monovision cataract surgery and the results after 2 months. METHODS: Thirty patients who had bilateral cataract surgery between February 2010 and January 2014 treated with monovision therapy and received postoperative examinations for at least one year after surgery were enrolled in the present study. The eye with the more severe cataract had the surgery first and was corrected for distance vision targeted at emmetropia. The fellow eye was operated for near vision targeted to -1.50~-2.50 diopter (D) range considering the patient's need for near task and preoperative refractive errors 2-4 weeks after the first operation. Binocular uncorrected distance visual acuity (UCDVA), uncorrected near visual acuity (UCNVA), spherical equivalent, anisometropia, stereopsis, patient satisfaction for far and near distance, and spectacle dependence were evaluated preoperatively and two months and one year postoperatively. RESULTS: The mean age of patients was 71.9 years. Two months and one year after the surgery, the binocular UCDVA (log MAR) were 0.03 ± 0.10 and 0.08 ± 0.14, UCNVA were 0.21 ± 0.15 and 0.25 ± 0.14, anisometropia were 1.28 ± 0.68 and 1.29 ± 0.76 D, and stereopsis were 301.67 ± 251.28 and 251.67 ± 269.28 arcsec, respectively. One year after the surgery, the number of patients answering ‘Better’ or ‘Much better’ for distant vision was 27 (90%) and for near vision 22 (73.3%); 11 patients (36.7%) answered ‘Not dependent on spectacles at all’. CONCLUSIONS: Monovision is an effective method to correct presbyopia after bilateral cataract surgery. Visual performances and patient satisfaction at one year after cataract surgery were not different compared with those at two months.

Analysis of Myopic Progression in Childhood Using the Korea National Health and Nutrition Examination Survey

PURPOSE: To investigate the degree, distribution, and change in refractive error in the pediatric population 5 to 20 years of age. METHODS: We collected data from 7,695 subjects aged 5 to 20 years who participated in the Korean National Health and Nutrition Examination Survey from 2008 to 2012. Non-cycloplegic refractive error was measured using an autorefractor. Mean spherical equivalent calculated from the measured refractive error data in both eyes was used. The subjects were categorized into mild, moderate, or high refractive abnormality or emmetropia according to the degree of refractive error. The degree and distribution of refractive error in all subjects and age-matched subjects were analyzed. The change in refractive error was analyzed according to age. RESULTS: Mean refractive error of the study subjects was -1.82 diopters. As subject age increased, myopia increased from +0.04 diopters at 5 years of age to -2.88 diopters at 20 years of age. Myopia was observed in 66.2% of subjects and accounted for only 18.5% of the 5-year-old subjects, but increased to 84.3% in the 20-year-old subjects. The rate among all study subjects was -0.19 diopters per year. The greatest myopic progression rate (-0.46 diopters per year) among all age groups was in subjects 7 to 9 years of age. Myopic progression continued until 16 years of age. CONCLUSIONS: The ratio of pediatric myopia subjects between 5 and 20 years of age was high in Korea. The rate of myopic progression was the fastest in subjects 7 to 9 years of age. After 16 years of age, myopic change paused.

Queratomileusis in situ asistida por láser de excímeros en la corrección del astigmatismo miópico / Excimer laser-assisted in situ keratomileusis for correction of myopic astigmatism

INTRODUCCIÓN: la queratomielusis es un procedimiento quirúrgico de valor en el tratamiento de las ametropías. OBJETIVO: determinar los resultados de la queratomileusis "in situ" asistida por láser de excímeros (LASIK) en la corrección del astigmatismo miópico. MÉTODOS: se realizó un estudio retrospectivo de 73 pacientes con astigmatismo miópico, operados con la técnica LASIK durante el año 2013 en el Hospital Militar "Dr. Carlos J. Finlay". Las variables fueron: edad, sexo, agudeza visual con corrección pre y postoperatorias, equivalente esférico, complicaciones trans-operatorias, postoperatorias inmediatas y tardías. Para el procesamiento de la información se utilizó programa SPSS. RESULTADOS: se mantuvo la agudeza visual previa corregida y no se detectaron complicaciones graves o irreversibles. Se observaron cambios significativos en las variables estudiadas con tendencia a la emetropía para un 92,3 %. CONCLUSIÓN: LASIK es una técnica segura y útil para la corrección del astigmatismo miópico, que permite mejorar la agudeza visual.

OBJETIVE: to determinate the results of Excímer laser assisted "in situ" keratomileusis (LASIK)in the correction of myopic astigmatism. METHODS: a descriptive, retrospective study of the results was performed after surgery LASIK in 73 patients with myopic astigmatism. The variables were: age, sex, pre and postoperative visual acuity without correction, spherical equivalent, intraoperative complications, postoperative immediate and late complications. Significant changes were observed in all the variables studied tending to emmetropia and 92.3 %. RESULTS: with the use of this surgical technique the corrected previous visual acuity remained and not serious or irreversible complications were detected. CONCLUSIONS: Lasik is a safe and useful technique for the correction of myopic astigmatism that improves visual acuity.

Calázio e características demográficas dos portadores em uma amostra populacional / Chalazion and demographic characteristics of patients in a population sample

Objetivo: Apresentar a frequência de ocorrência do calázio em uma amostra populacional, assim como as características de seus portadores. Métodos: Estudo transversal utilizando amostra populacional aleatorizada, realizado nos anos 2004/2005, na região centro-oeste do estado de São Paulo. Os participantes foram avaliados segundo variáveis demográficas e exame oftalmológico. Resultados: A frequência de ocorrência do calázio foi de 1,56%, sendo mais frequente em mulheres, portadores de astigmatismo ou hipermetropia de pequenos graus, com grande variação de idade de acometimento. Foi necessária prescrição de correção óptica e cirurgia em número expressivo de casos. Conclusão: O calázio tem baixa frequência de ocorrência na população geral. Ocorre predominantemente em mulheres e há associação importante com ametropia.

Purpose: To show the frequency of occurrence of chalazion in a population sample, as well as the characteristics of patients. Methods: A cross-sectional study using randomized population sample was carried out during 2004/2005, in the Midwest region of the state of São Paulo. Participants were evaluated according to demographic variables and ocular examination. Results: The frequency of occurrence of chalazion was 1.56‰, more common in women, people with astigmatism or low hyperopia, with wide variation in age of onset. It was necessary to prescribe optical correction and surgery in a significant number of cases. Conclusion: The chalazion has low frequency of occurrence in the general population. It occurs predominantly in women and there is a significant association with refractive error.

A Survey of Contact Lens-Related Complications in Korea: The Korean Contact Lens Study Society

PURPOSE: To investigate the epidemiology of contact lens (CL)-related complications in Korea. METHODS: A questionnaire regarding CL-related complications including patient's gender, age, causative factors, and signs and symptoms was distributed to members of the Korean Ophthalmological Society by The Korean Contact Lens Study Society and the results of the questionnaire analyzed. RESULTS: Responses to the questionnaire written by ophthalmologists from 22 institutes and clinics were collected from 499 subjects over a 20-month period starting in October 2008 and analyzed. The mean age of respondents was 22.9 years and the male-to-female ratio was 1:8.1. The soft CL and cosmetic colored lens comprised the majority (46.6% and 42.1%, respectively) of the reported cases, followed by the rigid gas permeable lens (RGP lens; 10.6%) and orthokeratology lens (0.8%). In subjects using a cosmetic colored lens, 62.2% showed emmetropia and 89.1% of the lenses were prescribed by opticians. The main complications included corneal erosion, sterile corneal infiltrate, allergic disease, conjunctival injection, corneal ulcer, and dry eye syndrome. The most common causative factor of complications was excessive lens wear. Comparing main causative factors according to the RGP lens prescriber, the most common factor was poor lens fit. CONCLUSIONS: The number of cosmetic colored lens-related complications in the emmetropic eyes of young patients is increasing rapidly. Considering opticians are the main CL prescribers in CL-related complications, Korean ophthalmologists need to pay more attention to CL fitting and constant education of patients regarding proper CL wear and care.

Clinical Results and Optical Quality of Diffractive Multifocal IOL Implantation after Myopic Refractive Surgery

PURPOSE: To evaluate the visual outcome and optical quality in eyes with diffractive multifocal intraocular lens (DMIOL) implantation after myopic refractive surgery. METHODS: Nineteen eyes (15 patients) were implanted with AcriSof ReSTOR(R) SN6AD1, the aspheric DMIOL after myopic refractive surgery (laser-assisted in situ keratomileusis [LASIK] 14 eyes, photorefractive keratectomy [PRK] 4 eyes, laser-assisted subepithelial keratomileusis [LASEK] 1 eye). Preoperative and postoperative visual acuities and manifest refraction were measured. Preoperative corneal higher-order aberrations (HOAs) were measured using Hartmann-Shack (H-S) aberrometer in dilated pupils, and optical qualities were measured 1 month postoperatively using H-S aberrometer and a double-pass system under mesopic conditions. Patient satisfaction was investigated using a questionnaire at 2 months postoperatively. RESULTS: Uncorrected distant and near visual acuities at postoperative 2 months were 0.11 +/- 0.19, and 0.19 +/- 0.12 (log MAR), respectively. Postoperative spherical equivalent (SE) of 16 eyes (84.2%) was within +/-0.50 diopters (D) and all eyes were within +/-1.00 D from emmetropia. Preoperative corneal and postoperative ocular spherical aberrations in a 4.0 mm pupil diameter were 0.08 +/- 0.08 and 0.07 +/- 0.07 (microm), respectively. Objective scatter index was 3.42 +/- 1.71 and modulation transfer function (MTF) cut-off value was 21.03 +/- 12.37 cpd. General satisfaction score was 3.52 +/- 0.96 points out of 5, and 8 patients (11 eyes) were not satisfied with DMIOL implantation. CONCLUSIONS: After DMIOL implantation in the eyes with previous myopic refractive surgery, postoperative SE was close to the target D, but optical qualities and patient satisfaction were poor.

Clinical Results and Optical Quality of Diffractive Multifocal IOL Implantation after Myopic Refractive Surgery

PURPOSE: To evaluate the visual outcome and optical quality in eyes with diffractive multifocal intraocular lens (DMIOL) implantation after myopic refractive surgery. METHODS: Nineteen eyes (15 patients) were implanted with AcriSof ReSTOR(R) SN6AD1, the aspheric DMIOL after myopic refractive surgery (laser-assisted in situ keratomileusis [LASIK] 14 eyes, photorefractive keratectomy [PRK] 4 eyes, laser-assisted subepithelial keratomileusis [LASEK] 1 eye). Preoperative and postoperative visual acuities and manifest refraction were measured. Preoperative corneal higher-order aberrations (HOAs) were measured using Hartmann-Shack (H-S) aberrometer in dilated pupils, and optical qualities were measured 1 month postoperatively using H-S aberrometer and a double-pass system under mesopic conditions. Patient satisfaction was investigated using a questionnaire at 2 months postoperatively. RESULTS: Uncorrected distant and near visual acuities at postoperative 2 months were 0.11 +/- 0.19, and 0.19 +/- 0.12 (log MAR), respectively. Postoperative spherical equivalent (SE) of 16 eyes (84.2%) was within +/-0.50 diopters (D) and all eyes were within +/-1.00 D from emmetropia. Preoperative corneal and postoperative ocular spherical aberrations in a 4.0 mm pupil diameter were 0.08 +/- 0.08 and 0.07 +/- 0.07 (microm), respectively. Objective scatter index was 3.42 +/- 1.71 and modulation transfer function (MTF) cut-off value was 21.03 +/- 12.37 cpd. General satisfaction score was 3.52 +/- 0.96 points out of 5, and 8 patients (11 eyes) were not satisfied with DMIOL implantation. CONCLUSIONS: After DMIOL implantation in the eyes with previous myopic refractive surgery, postoperative SE was close to the target D, but optical qualities and patient satisfaction were poor.

A Study of Foveal Shape in Emmetropia and Myopia Using Spectral Domain Optical Coherence Tomography

PURPOSE: To investigate the shape of normal fovea in Korean subjects in their 20's using spectral domain optical coherence tomography (SD-OCT). METHODS: One hundred-twelve emmetropic eyes of 60 subjects and 100 myopic eyes of 58 subjects between 20 and 29 years of age were included in this study. Central foveal thickness (CFT), regional maximal retinal thickness (MRT), pit diameter, pit depth, and slope were obtained using Spectralis OCT and analyzed according to spherical equivalent and gender. RESULTS: In emmetropic and myopic eyes, MRT was significantly thinner temporally (p < 0.001) than in other regions and pit diameter was wider horizontally than vertically (p < 0.001). The CFT was significantly thicker and all regional MRT was thinner in myopic eyes than in emmetropic eyes (p < 0.001). Foveal pits were narrower and shallower in myopic eyes (p < 0.001). In both groups, CFT and all regional MRT in males were significantly thicker than in females (p < 0.05); however, no difference between the genders in horizontal pit diameter, pit depth, and slope were found. CONCLUSIONS: In normal subjects, statistically significant differences were found in foveal shapes between subjects with different spherical equivalent and gender. These differences should be considered when interpreting a foveal shape. Knowledge of the normal foveal morphology is important when conducting further macular studies.

Multifocal electroretinogram in normal emmetropic subjects: Correlation with optical coherence tomography.

Aim of the Study: To establish the normative database for multifocal electroretinogram (mfERG) parameters in a normal emmetropic population. To correlate the data so obtained with the central macular thickness obtained using the optical coherence tomography (OCT) scan. Materials and Methods: mfERG data were obtained from 222 eyes of 111 emmetropic subjects. The amplitude (nv/deg2) and implicit times (ms) of the first-order kernel mfERG responses (N1, P1, and N2 waves) were obtained and grouped into five rings (Ring 1: Central 2°, Ring 2: 2–5°, Ring 3: 5–10°, Ring 4: 10–15°, Ring 5: >15°). The central macular thickness (CMT) was obtained using the macular thickness scan protocol of the OCT. Results: The mfERG data obtained were used to create a normative database. The amplitudes of the mfERG waves were maximum in the fovea and progressively decreased with increasing eccentricity (P = 0.0001). The latencies of the P1 and N2 waves were longest in the central ring and progressively shortened with eccentricity (P = 0.0001). No statistically significant correlations were observed between central ring 1 parameters and the CMT. Conclusion: This study establishes normative database for mfERG parameters in an emmetropic population. No statistically significant correlation was noted between CMT and mfERG parameters.

[Variation of accommodative and vergence responses with viewing at near addition lenses in three near viewing distances]

It is well accepted that accommodation system is characterized by steady state error in focus. Usually near addition lenses are prescribed to prepresbyopic individual for treatment of binocular motor problems such as convergence excess and accommodative disorder. The purpose of this study was to evaluate the near addition lenses in accommodative and vergence responses at three viewing distances. This semi-experimental study was done on 42 students of 17-25 years old in Zahedan, South-Eastern Iran during 2009. After correction of refractive error, phoria states with APCT and binocular and monocular lag of accommodation by MEM method with and without +2.00 lenses in three difference distances [30, 40, 50 cm] was measured. Data analyzed by ANOVA, t-student and paired t-tests. There was significant difference between average of lag of accommodation and phoria at various distances, with and without lens [P<0.05]. Also, there was significant difference between mean of lag in 3 fixation distance [P<0.017]. There was no significant difference between average of lag of accommodation and phoria at various distances in three group of refractive error. Our results showed that, near addition lens reduce the lag of accommodation. It is proposed, therefore, according to near emmetropization theory addition lenses may be effective in reducing of the myopia progression

Clinical Outcomes of Monovision Induced by Presbyopic Correcting Conductive Keratoplasty

PURPOSE: To evaluate the efficacy, safety, and satisfaction of patients who underwent conductive keratoplasty (CK). METHODS: CK was performed in 20 patients between April and December 2009. Surgeries were performed on the dominant eye with emmetropia as the postoperative goal and on the non-dominant eye with mild myopia as the postoperative goal. Patients' satisfaction, refractive change, and visual acuity were evaluated for at least 3 months after the surgery. RESULTS: Preoperatively, the mean manifest refraction spherical equivalent (MRSE) of the non-dominant and dominant patient eyes was 0.56 +/- 0.48 D and 0.88 +/- 0.25 D, respectively. Postoperatively, the mean MRSE of the non-dominant and dominant patient eyes was -1.65 +/- 0.56 D and -0.06 +/- 0.36D at 1 month, -1.33 +/- 0.40 D and 0.17 +/- 0.37 D at 3 months, and -1.10 +/- 0.44 D and 0.31 +/- 0.33 D at 6 months, respectively, indicating significant effect regression. Eleven out of 20 patients (55%) were disappointed with the results of CK. CONCLUSIONS: Conductive keratoplasty led to significant regression of refractive effects during follow-up. Monovision with CK is suggested to be a temporary refractive procedure in patients with presbyopia.

Eight-Year Follow-up of Laser Epithelial Keratomileusis for Correcting Moderate and High Myopia

PURPOSE: To evaluate the long-term prognosis and complications of laser epithelial keratomileusis (LASEK). METHODS: A retrospective study including 92 eyes of 46 myopic patients treated with LASEK from November 1999 to February 2003 was performed. Follow-up visits were at 3 months, 6 months, 1 year, and 8 years. Treated eyes were divided into 2 groups according to preoperative spherical equivalent (SE) : low and medium myopia (-6.0 D). The main outcome measures were UCVA, BCVA, postoperative SE, efficacy index, safety index, predictability, and postoperative complications. RESULTS: Preoperative visual acuity was 1.24 +/- 0.42 log MAR, and the average of SE was -5.28 +/- 1.63 D. Postoperative visual acuity log MAR was significantly improved compared to preoperative visual acuity, and the average of visual acuity was 0.12 +/- 0.13 log MAR. The percentage of eyes within +/- 1.0 D of emmetropia 8 years after having LASEK was 69.5% in the mild and moderate myopia group, and 63.6% in the high myopia group. There was no significant difference of safety index, efficacy index or complications between the 2 groups at 1 month, 3 months, 1 year, and 8 years. Safety index was maintained over 0.9 and efficacy index was larger than 0.8. There were no other complications during the observation period. CONCLUSIONS: An 8-year follow-up showed LASEK for mild to moderate and high myopia to be a safe and effective procedure.

New concepts in accommodation and presbyopia / Novos conceitos em acomodação e presbiopia

The authors conducted a review of classical and conflicting theories of accommodation and presbyopia. They make a critical comparison with the findings of magnetic resonance imaging (MRI) that have been developed in recent decades. Based on these studies, formulates a new approach on the subject, shifting the focus of the discussion of the lens to the posterior pole of the eye.

Os autores revisaram as teorias clássicas e conflitantes sobre acomodação e presbiopia. E as compararam criticamente com os achados de imagem por ressonância magnética (MRI) que têm se desenvolvido nas últimas décadas. Baseado nestes estudos, formulam uma nova abordagem sobre o tema, mudando o foco da discussão do cristalino para o polo posterior do olho.