ABSTRACT
ABSTRACT Purpose: To determine normal corneal tomographic parameters in children and adolescents without corneal disease or atopy diagnosis. Methods: This descriptive cross-sectional study evaluated patients aged 8-16 years who underwent a complete slit-lamp biomicroscopic examination and tomographic corneal evaluation by a dual Scheimpflug analyzer, excluding those with ocular disease (including allergic conjunctivitis) or a positive prick test for systemic atopies. Results: A total of 170 patients were evaluated, and 34 patients (68 eyes) were analyzed once the exclusion criteria were applied. The sample's mean age was 10.76 ± 2.31 years; with 19 (55.9%) men and 15 (44.1%) women. The mean keratometry in the flat meridian (Kflat), steep meridian (Ksteep), and maximum (Kmax) were 42.37 ± 1.63D, 43.53 ± 1.65D, and 43.90 ± 1.73D, respectively. The mean values for corneal asphericity (ε2) and thinnest point were 0.28 ± 0.11 and 550.20 ± 37.90 μm, respectively. The inferior-superior asymmetry ratio (I-S) and coma were 0.74 ±0.59D and 0.28 ± 0.12D, respectively. Conclusion: The knowledge of normal corneal tomographic parameters and their variation in children and adolescents without corneal disease or atopy may be useful for diagnosing keratoconus and initiating early disease treatment.
RESUMO Objetivo: Identificar parâmetros tomográficos de normalidade em córneas de crianças e adolescentes sem a presença de atopias sistêmicas e alergias oculares. Métodos: Este estudo descritivo transversal avaliou pacientes com idade entre 8 e 16 anos que foram submetidos a exame biomicroscópico completo por lâmpada de fenda e avaliação tomográfica da córnea por tomógrafo dual Scheimpflug, excluindo pacientes com doença ocular (incluindo conjuntivite alérgica) ou prick test positivo para atopias sistêmicas. Resultados: Cento e setenta pacientes foram avaliados e após cumpridos os critérios de exclusão, 34 (68 olhos) foram analisados. A média etária da amostra foi 10,76 ± 2,31 anos; 19 (55,9%) eram meninos e 15 (44,1%) meninas. A média da ceratometria em dioptrias (D) no meridiano mais plano (Kflat), mais curvo (Ksteep) e máxima (Kmax) foram 42,37 ± 1,63D, 43,53 ± 1,65D e 43,90 ± 1,73D, respectivamente. Os valores médios da asfericidade corneana (ε2) e do ponto mais fino da córnea foram 0,28 ± 0,11 e 550,20 ± 37,90 micras (μm). A assimetria corneana inferior-superior (I-S) e coma foi em média 0,74 ± 0,59D e 0,28 ± 0,12D, respectivamente. Conclusão: O conhecimento dos valores médios e sua variação de parâmetros tomográficos da córnea em crianças e adolescentes sem atopias sistêmicas ou alergias oculares pode ser útil para o diagnóstico precoce do ceratocone e o seu tratamento em estágio inicial.
ABSTRACT
ABSTRACT Keratoconus is a progressive disorder that manifests as a cone-like steepening of the central or paracentral inferior cornea and irregular stromal thinning. There is a gradual decrease in visual acuity due to corneal asymmetry, irregular astigmatism, and increased optical aberrations, consequently impacting the quality of life. Several procedures have been developed in an attempt to slow or reverse the progression. The Bader procedure, which includes a pattern of incisions around the circumference of the cornea and at the base of the protruding cone, is one such surgery. These incisions penetrate 70-90% of the cornea's depth. Its goal is to flatten the topography and reduce corneal asymmetry and irregular astigmatism. Though prior research found these to be highly promising, we report a patient who was given contact lenses to restore and maintain his vision while his corneal ectasia and thinning progressed over the following decade.
RESUMO O ceratocone é uma doença progressiva que se manifesta como uma elevação semelhante a um cone da córnea central ou paracentral inferior e é associada a uma redução irregular da espessura do estroma. Há uma diminuição gradual da acuidade visual devido à assimetria da córnea, ao astigmatismo irregular e a um aumento das aberrações ópticas, o que prejudica a qualidade de vida. Foram desenvolvidos vários procedimentos para tentar interromper ou mesmo reverter a evolução da doença. Um deles é o chamado procedimento de Bader, que inclui um padrão de incisões em volta da circunferência da córnea e na base do cone protuberante. Essas incisões penetram até 70%-90% da profundidade da córnea e têm o objetivo de achatar a topografia e diminuir a assimetria da córnea e o astigmatismo irregular. Embora essa técnica seja muito promissora, segundo um estudo anterior, aqui se apresenta o caso de um paciente no qual esses objetivos não foram atingidos. Esse paciente recebeu lentes de contato para restaurar e manter sua visão, enquanto sua ectasia corneana e a redução da espessura progrediram ao longo da década seguinte.
ABSTRACT
AIM: To evaluate the clinical outcomes of using the cross-positioning method for correcting low and moderate astigmatism during small incision lenticule extraction(SMILE)surgery with Alpins vector analysis.METHODS: A total of 50 patients(81 eyes)with low and moderate astigmatism with the rule ≤1.50 D who underwent SMILE surgery at the laser myopia treatment center of Xi'an No.1 Hospital from May 2022 to November 2022 were included in the prospective randomized controlled study, and they were divided into two groups according to the random table, with 25 case(41 eyes)in cross-positioning group and 25 cases(40 eyes)in control group. In the cross-positioning group, the patients' head position was adjusted based on the cross intersection lines before the standard SMILE procedure, aligning the lateral canthi with the horizontal line and the midpoint of the eyebrows and the nose bridge with the vertical line. Postoperative visual acuity and refractive results at 3 mo were observed in both groups, and astigmatic changes were analyzed and evaluated using the Alpins vector analysis method.RESULTS: During the follow-up period, 6 cases(11 eyes)in the cross-positioning group were lost to follow-up, while in the control group, 8 cases(14 eyes)were lost to follow-up, with 19 cases(30 eyes)and 17 cases(26 eyes)finally included in the cross-positioning group and the control group, respectively. At 3 mo postoperatively, the uncorrected visual acuity(UCVA)of both groups' operated eyes was ≥1.0, and no serious complications occurred, with no significant differences in UCVA, best corrected visual acuity(BCVA), spherical power, and spherical equivalent between the cross-positioning group and the control group(all P>0.05). The cylindrical power in the cross-positioning group was 0.00(0.00, 0.00)D, which was lower than -0.13(-0.50, 0.00)D in the control group(P=0.01). The vector analysis results showed that the difference vector(DV)in the cross-positioning group was lower than that in the control group [0.00(0.00, 0.00)vs 0.13(0.00, 0.50), P=0.01], and the index of success(IOS)was better than that of the control group [0.00(0.00, 0.00)vs 0.18(0.00, 0.77), P<0.01]. At 3 mo postoperatively, 26(87%)and 15(58%)eyes in the cross-positioning group and control groups achieved an angle of error(AE)within ±5°, respectively.CONCLUSION: The cross positioning method was used to calibrate the patients' head position during SMILE surgery, which reduced the axial position error and improved the accuracy of SMILE in correcting low and moderate astigmatism.
ABSTRACT
AIM: To explore the characteristics of astigmatism distribution among preschool children from Tongzhou District, Beijing, discuss its categorizations, severity, and the effect on preschoolers' vision, and clarify the influence of cycloplegic refraction on the detection of astigmatism.METHODS:In this cross-sectional study conducted from December 2021 to January 2022, a cluster random sampling method was utilized to assess 1 498 preschool children(2 996 eyes)from Tongzhou District, Beijing. The sample comprised 791 males and 707 females, with 222 children aged 3 to <4 years, 521 children aged 4 to <5 years, 647 children aged 5 to <6 years, and 108 children aged 6 to <7 years. Evaluations included visual acuity, anterior segment, computerized optometry, and cycloplegic refraction.RESULTS:Prior to cycloplegic refraction, the prevalence of astigmatism was found to be 61.88%(927/1498). For post-cycloplegic refraction, this percentage slightly increased to 64.02%(959/1498, P=0.095). Following cycloplegic refraction, the distribution of astigmatism severity was as follows: 51.87%(777/1498)had mild astigmatism, 9.41%(141/1498)had moderate astigmatism, and 2.74%(41/1498)had severe astigmatism. Astigmatism was predominantly with-the-rule across all age groups, with compound hyperopic astigmatism being the most frequent type. In cases of subnormal vision caused by astigmatism: low degree accounted for 9.38%, moderate degree accounted for 25.4%,and high degree accounted for 52.6%.CONCLUSION:The findings reveal a high incidence of astigmatism in preschool children, predominantly in a mild nature. Cycloplegic refraction was observed to have a negligible effect on the rate of astigmatism detection. Moreover, its impact on vision becomes more significant as the degree of astigmatism increases.
ABSTRACT
Objectives: The present study analyzed the reciprocal relationships between four common pediatric ophthalmic diseases (i.e., hyperopia, myopia, astigmatism, and strabismus) and attention‐deficit/hyperactivity disorder (ADHD) in children. Methods: This study enrolled 86,028 children with ADHD and 1,798,673 children without ADHD in the Taiwan Maternal and Child Health Database who were born at any time from 2004 to 2017. Cox proportional hazards regression models were used to estimate the bidirectional relationships of the four ophthalmic diseases with ADHD in children after adjusting for age, sex, and gestational age at birth. Survival curves for time-to-event variables were estimated using the Kaplan-Meier method, and the log-rank test was used to compare the curves. Results: The results indicated that ADHD significantly predicted the occurrence of hyperopia, myopia, astigmatism, and strabismus. Furthermore, hyperopia, myopia, astigmatism, and strabismus significantly predicted the occurrence of ADHD. The time between enrollment and ADHD diagnosis was shorter for patients with ophthalmic diseases than for the control group, and the time between enrollment and ophthalmic disease diagnosis was also shorter for ADHD patients than for the control group. Sex differences were found in the associations between ADHD and ophthalmic diseases. Conclusion: Clinicians should monitor children with ADHD for hyperopia, myopia, astigmatism, and strabismus to ensure appropriate treatment, and vice versa.
ABSTRACT
The comorbidity of keratoconus with Fuchs� endothelial dystrophy with cataract is a rare clinical combination. We present an amalgamation of surgical techniques to manage the above clinical conditions and its complications in single setting. The modified triple procedure, namely, the phacoemulsification, pinhole pupilloplasty, and pre-Descemet抯 endothelial keratoplasty (PDEK) in the order of description is followed in single sitting. Lens removal by phacoemulsification, correction of irregular astigmatism by pinhole pupilloplasty (pinhole optics), and exchanging the endothelial layer for PDEK forms the main segments of the triple procedure. This combination of techniques may decrease the risk of multiple surgeries and its related complications. Moreover, it will allow the patient for faster visual rehabilitation by improving the uncorrected visual acuity and visual quality.
ABSTRACT
Purpose: To compare the visual outcomes and residual astigmatism following implantation of Eyecryl toric versus Alcon AcrySof IQ toric intra?ocular lenses (IOLs). Methods: This retrospective, observational study included 143 eyes of 141 patients who underwent phaco?emulsification, followed by implantation of Eyecryl toric IOL (n = 83 eyes) or Alcon toric IOL (n = 60 eyes) in an eye hospital in South India from 2018 to 2021. At 1 month post?op, the uncorrected distance visual acuity (UCVA), best corrected distance visual acuity (BCVA), and residual astigmatism of the toric IOL were compared and analyzed. Results: The mean pre?op corneal astigmatism was 2.02 ± 0.81 D and 1.70 ± 0.68 D in the Alcon and Eyecryl groups, respectively (P = 0.005). The mean post?op corneal astigmatism at 1 month was 0.50 ± 0.51 D and 0.36 ± 0.42 D in the Alcon and Eyecryl groups, respectively, with no statistically significant difference between them (P = 0.87). The mean post?op UCVA in logarithm of minimum angle of resolution (logMAR) at 1 month was similar between the groups at 0.17 ± 0.18 and 0.17 ± 0.16 in the Alcon and Eyecryl groups, respectively (P = 0.98). The mean post?op BCVA in logMAR at 1 month was 0.06 ± 0.09 and 0.03 ± 0.10 in the Alcon and Eyecryl groups, respectively (P = 0.02). Conclusion: Both Eyecryl toric and Alcon AcrySof IQ toric IOLs showed comparable post?operative outcomes in terms of UCVA and residual astigmatism. The post?op BCVA was clinically similar between groups but statistically better in the Eyecryl toric group
ABSTRACT
Purpose: To evaluate whether the toric intra?ocular lens (IOL) power calculation based on total corneal astigmatism (TCA) in eyes with high posterior corneal astigmatism (PCA) could result in a systematic over?correction or under?correction after operation. Methods: The present study included a mono?centric retrospective study design. The data were collected from 62 consecutive eyes during uncomplicated cataract surgery by a single surgeon with a measured PCA of 0.50 diopters (D) or higher. Toric IOL calculations were made using TCA measurements. The eyes were grouped as either “with?the?rule” (WTR) or “against?the?rule” (ATR) on the basis of the steep anterior corneal meridian. The post?operative refractive astigmatic prediction error was analyzed 1 month post?operatively using the vector analysis by the Alpins method and double?angle plots method. Results: The correction indexes were 1.14 ± 0.29 in the ATR eyes and 1.25 ± 0.18 for the WTR eyes, indicating a tendency toward over?correction. The mean over?correction was 0.22 ± 0.52D in the ATR group and 0.65 ± 0.60D in the WTR group. The magnitude of error (ME) values were significantly different from the ideal value of zero in both groups (ATR: P = 0.03; WTR: P = 0.00). No significant difference in mean absolute error (MAE) in predicted residual astigmatism was found between ATR and WTR groups (0.61 ± 0.42 D versus 0.64 ± 0.39 D; P = 0.54). The ATR group yielded better results, with 48% <0.50D prediction error in the main analysis. Conclusions: The results suggested that in cases of high PCA, the toric IOL calculation, which was performed using TCA, may cause a potential over?correction in the ATR and WTR eyes. For ATR eyes, over?correction led to slight disruption of post?operative visual quality because of the “with?the?rule” residual astigmatism after operation. Therefore, we suggested using TCA for toric IOL calculation in ATR eyes.
ABSTRACT
Purpose: To evaluate the clinical outcomes of preloaded toric intraocular lens (IOLs) implantation in eyes undergoing phacoemulsification. Methods: This prospective study included 51 eyes of 51 patients with visually significant cataracts and corneal astigmatism ranging between 0.75 and 5.50 D. All patients underwent phacoemulsification with SupraPhob toric intraocular lens implantation under topical anesthesia. The main outcome measures were uncorrected distance visual acuity (UDVA), residual refractive cylinder, spherical equivalent, and IOL stability at 3 months follow?up. Results: At 3 months, 49% (25/51) of patients had UDVA equal to or better than 20/25 with 100% of eyes achieving better than 20/40. Mean logMAR UDVA improved from 1.02 ± 0.39, preoperatively to 0.11 ± 0.10 at 3 months follow?up (P < 0.001, Wilcoxon signed?rank test). The mean refractive cylinder improved from ? 1.56 ± 1.25 D preoperatively to ? 0.12 ± 0.31 D at 3 months follow?up (P < 0.001) while the mean spherical equivalent value changed from ? 1.93 ± 3.71D preoperatively to ? 0.16 ± 0.27D (P = 0.0013). The mean root mean square value for higher order aberrations was 0.30 ± 0.18 ?m while the average contrast sensitivity value (Pelli?Robson chart) was 1.56 ± 0.10 log unit, at the final follow?up. The mean IOL rotation at 3 weeks was 1.7 ± 1.61 degrees, which did not change significantly at 3 months (P = 0.988) follow?up. There were no intraoperative or postoperative complications. Conclusion: SupraPhob toric IOL implantation is an effective method for addressing preexisting corneal astigmatism in eyes undergoing phacoemulsification with good rotational stability
ABSTRACT
Purpose: To compare the visual outcomes in patients undergoing small?incision lenticule extraction (SMILE) for correction of myopic astigmatism (??1.50 D) with or without manual cyclotorsion compensation. Methods: A prospective, double?blinded, randomized, contralateral study was conducted in the refractive services of a tertiary eye care center. Eligible patients with bilateral high myopic astigmatism (?1.5 D) and intraoperative cyclotorsion (?5°) undergoing SMILE between June 2018 and May 2019 were included. Cyclotorsion compensation was performed using triple centration method before femtosecond laser delivery. Uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) measurement, manifest refraction, slit?lamp biomicroscopy, and corneal tomography were performed preoperatively and at 1 and 3 months’ postoperative visit. Astigmatic outcomes were analyzed using Alpins criteria. Results: A total of 30 patients (60 eyes) were included in this study. The patients underwent bilateral SMILE surgery, with manual cyclotorsion compensation in one eye (CC group, n = 30 eyes) and no cyclotorsion compensation in the other eye (NCC group, n = 30 eyes). Preoperative astigmatism and intraoperative cyclotorsion were ?2.0 D and 7.03° ± 1.06° (CC) and ?1.75 D and 7.24° ± 0.98° (NCC) (P = 0.472 and 0.240, respectively). No significant differences were noted in mean refractive spherical equivalent (MRSE), UDVA, CDVA, and refractive error between the two groups at 3 months’ postoperative visit. Astigmatic outcomes measured using Alpins criteria demonstrated no significant difference between the two cohorts. Conclusion: The cyclotorsion compensation technique provided no additional advantage in terms of astigmatic outcomes or postoperative visual quality, in eyes with high preoperative astigmatism and intraoperative cyclotorsion.
ABSTRACT
We report the outcomes of a custom-designed toric piggyback intraocular lens in a patient with high postoperative residual astigmatism. A 60-year-old male patient underwent customized toric piggyback IOL for postoperative residual astigmatism of 13 D, with follow-up examinations for IOL stability and refractive outcomes. The refractive error stabilized at two months and remained stable at one year, with a correction of nearly 9 D of astigmatism. The IOP remained within normal limits, and there were no postoperative complications. The IOL remained stable in the horizontal position. To our knowledge, this is the first case report of correction of unusually high astigmatism by a novel smart toric design of piggyback IOL.
ABSTRACT
Purpose: India has the largest population of youth in the world, thereby making them important contributors to the “India of Tomorrow”. Over 80% of knowledge gained is by the visual sense, thereby making school screening programs a necessity in our country. Data from the pre?COVID era, that is, 2017–18 was collected from close to 19,000 children in Gurugram, Haryana, a tier two city in National Capital Region, India. A similar prospective observational study is planned post COVID?19 (2022–23) for further analysis to depict the impact of COVID?19 in these areas. Methods: The program They See, They Learn was set at government schools in the area of operations (district of Gurgaon, Haryana), where the children and their families were unable to afford eye care services. All children who were screened underwent a comprehensive eye examination at the school premises itself. Results: A total of 18,939 students were screened over a period of 18 months, covering a total of 39 schools in the Gurugram belt, in the first phase of the program. Eleven point eight percent (n = 2254) of all school students had some form of refractive error. Girl students were found to have a higher refractive error rate (13.3%) compared to boy students (10.1%) across the schools screened. Myopia was the most common type of refractive error. Conclusion: School students require perfect vision or else they can be discouraged and may become a major burden to the economy of any developing nation. A school screening program aiming at populations that cannot afford such basic needs like spectacles is a must in all zones of the country
ABSTRACT
Purpose: To estimate the postoperative astigmatism after small?incision cataract surgery (SICS) done by junior residents at the end of 1 and 3 months. Methods: This observational longitudinal study was conducted at the Department of Ophthalmology of a tertiary eye care hospital and research center. 50 patients enrolled in the study underwent manual small incision cataract surgery by junior residents. Preoperative detailed ocular examination was done, which included keratometric estimation using autokeratometer (GR?3300K). Incision length, distance of incision from the limbus, and type of suturing technique were noted. Postoperatively, keratometric readings were noted at 1 and 3 months. Astigmatism (surgically induced astigmatism [SIA]) was estimated using Hill’s SIA calculator version 2.0. All the analyses were performed using Statistical Package for the Social Sciences (SPSS) ver. 26.0 (IBM Corp., USA) software, and the statistical significance was tested at a 5% level. Results: Out of 50 patients, 54% had SIA between 1.5 and 2.5 D and 32% had SIA of more than 2.5 D. Only 14% had SIA less than 1.5 D at the end of 1 month. While 52% had SIA between 1.5 and 2.5 D, 22% had SIA between 1.5 and 2.5 D and 26% had SIA less than 1.5 D at the end of 3 months. Conclusion: The SIA in most of the SICS done by junior residents was above 1.5 D. It depended mainly on the incision length, its distance from the limbus, and the suturing technique.
ABSTRACT
Background: Uncorrected refractive error is one of the leading causes of visual impairment and blindness world-over. The distribution and pattern of presentation is variable depending on various factors. Regardless of the type, refractive errors are easily correctable with spectacles if diagnosed early.Objective: The objective of this study was to evaluate the pattern of refractive errors among medical students at University of Zambia - School of Medicine.Methodology: This was a cross-sectional study conducted at the University Teaching Hospitals-Eye Hospital involving Master of Medicine, Master of Surgery (MBChB) students from third to seventh year of study at University of Zambia - School of Medicine, Ridgeway campus between October 2021 and March 2022. A total of 210 participants were recruited in the study. Subjects had non-cycloplegic autorefraction combined with a researcher administered questionnaire. Spherical equivalents (SE) ? - 0.50D were determined as myopia; SE of ? + 0.50D hyperopia and ? -0.50D cylinder as astigmatism. Statistical analysis was carried out using Stata version 13.0.Results: One hundred and forty-one (67.1%) subjects had a form of refractive error; 56.0%, 31.2% and 12.8% of them were astigmats, myopes or hyperopes, respectively. The prevalence of ametropia was 65.0 % in females and 69.0 % in males. Minus spherical errors ranged from -0.25 to -5.00D and plus spherical errors ranged from +0.25 to +3.00D. The mean spherical equivalent for the group was -0.45D. Parental history of refractive error was significantly associated with diagnosis of refractive error (p=0.001) while age and gender were not (p = 0.428 and 0.530, respectively). The majority (68.6%) of participants were not aware of their refractive error.Conclusion: The prevalence of refractive errors among medical students was high, with astigmatism being the most common type. The majority of those found with refractive error were not aware of the diagnosis.
ABSTRACT
Purpose: To evaluate a method using measured values of total corneal refractive power (TCRP) for a manufacturer’s online calculator by comparing it with the Barrett toric calculator (BTC) and Kane toric calculator (KTC) combined with simulated keratometry values (SimK). Methods: This was a retrospective case series. Patient records were reviewed to identify the patients who had biometry with the IOL Master 700 and Pentacam recorded before toric IOL implantation and refractive follow?up data after implantation. The predicted error in residual astigmatism was calculated by vector analysis according to the calculation methods and the measurements used. Results: A total of 70 eyes of 56 patients were included. The mean absolute astigmatism prediction errors were 0.6 ± 0.32, 0.59 ± 0.35, and 0.61 ± 0.35 D for the ATCTCRP, BTCSimK, and KTCSimK calculators, respectively (P = 0.934), and the centroid of the prediction errors were 0.3 D @ 178°, 0.11 D @ 102°, and 0.09 D @ 147°, respectively (P = 0.23). In the with?the?rule subgroup, the centroid of the prediction error was 0.34 D @ 176° for ATCTCRP and was the highest among the three calculation methods (P = 0.046). Conclusion: The ATCTCRP, BTCSimK, and KTCSimK calculators had similar performance with regards to their astigmatism prediction accuracy. The ATCTCRP calculator combined with 4.0?mm apex/ ring readings of TCRP was slightly intended to result in against?the?rule residual astigmatism.
ABSTRACT
Purpose: To develop a nomogram in cases with mismatch between subjective and Topolyzer cylinder, and based on the magnitude of the mismatch, customize a treatment plan to attain good visual outcomes post?laser?assisted in situ keratomileusis (LASIK) surgery. Methods: The patients were evaluated preoperatively using corneal tomography with Pentacam. Five optimal corneal topography scans were obtained from the Topolyzer Vario were used for planning the LASIK treatment. For the nomogram purpose, the patients were divided into three categories based on the difference between the subjective cylinder and Topolyzer (corneal) cylinder. The first group (group 1) consisted of eyes of patients, where the difference was less than or equal to 0.4 D. The second group (group 2) consisted of eyes, where the difference was more than 0.4 D and the subjective cylinder was lesser than the Topolyzer cylinder. The third group (group 3) included eyes where the difference was more than 0.4 D but the subjective cylinder was greater than the Topolyzer cylinder. LASIK was performed with the WaveLight FS 200 femtosecond laser and WaveLight EX500 excimer laser. Assessment of astigmatism correction for the three groups was done using Aplins vector analysis. For comparison of proportions, Chi?square test was used. A P value less than 0.05 was considered statistically significant. Results: The UDVA was statistically significantly different when compared between groups 1 and 2 (P = 0.02). However, the corrected distance visual acuity (CDVA) was similar among all the three groups (P = 0.1). Group 3 showed an increase of residual cylinder by ?0.25 D, which was significant at intermediate and near reading distances (P < 0.05). Group 3 showed significantly higher target?induced astigmatism (TIA) compared to groups 1 and 2 (P = 0.01). The mean surgically induced astigmatism (SIA) was the least in group 2, which was statistically significant (P < 0.01). Conclusion: The outcomes for distance vision using our nomogram postoperatively were excellent, but further refinement for improving the near vision outcomes is required
ABSTRACT
Objective:To investigate the differences in refractive astigmatism, the anterior corneal surface astigmatism and ocular residual astigmatism between dominant and non-dominant eyes in myopia.Methods:A corss-sectional study was conducted.Two hundred and seventy-six eyes from 138 patients with myopia who were to receive corneal refractive surgery in the Refractive Surgery Center of Tianjin Eye Hospital from January to March 2018 were included.Ocular dominance was assessed with the hole-in-the-card test.The manifest refraction and corneal topography were performed in order to measure the sphericity, spherical equivalent, the astigmatism of anterior corneal surface and total cornea.Vector analysis was used to calculate the value of the ocular residual astigmatism and the components of astigmatism, including J0 and J45 of both the refractive astigmatism and the astigmatism of anterior corneal surface.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Tianjin Eye Hospital (No.201909).Results:It was found that 61.6%(85/138) of the subjects was right-eye dominant.There was no significant difference in sphericity and spherical equivalent, J0 and J45 of the refractive astigmatism and the astigmatism of anterior corneal surface between dominant and non-dominant eyes (all at P>0.05). The magnitude of the ocular residual astigmatism of the dominant eye was 0.607(0.451, 0.808)D, which was lower than 0.701(0.497, 0.901)D of the non-dominant eye, showing a statistically significant difference ( Z=-2.52, P=0.01). Conclusions:In the myopic population with no significant difference in the sphericity and spherical equivalent between the dominant and non-dominant eyes, the magnitude of the ocular residual astigmatism of the dominant eye is significantly lower than that of the non-dominant eye, which may play an important role in the ocular dominance formation.
ABSTRACT
AIM: To investigate the effects of small incision extracapsular excision and phacoemulsification on the number of corneal endothelial cells, macular thickness and surgically induced corneal astigmatism in cataract patients.METHODS: Retrospective research. A total of 296 age-related cataract patients(296 eyes)admitted to our hospital from May 2019 to February 2023 were selected. They were divided into a small incision extracapsular excision group(144 eyes)and a phacoemulsification group(152 eyes)according to surgical method. The uncorrected visual acuity, best corrected visual acuity, numbers of corneal endothelial cells, macular thickness, surgically induced corneal astigmatism and postoperative complications between the two groups of patients at 7d, 1 and 3mo after surgery were compared.RESULTS: The uncorrected visual acuity and best corrected visual acuity of patients in the small incision extracapsular excision group after 7d of surgery were better than those of the phacoemulsification group, the number of corneal endothelial cells after 7d and 1, 3mo of surgery were higher than that of the phacoemulsification group, the macular thickness after 7d and 1mo of surgery was lower than that of the phacoemulsification group, and the incidence rate of postoperative corneal edema and incidence rate of total complications were lower than those of the phacoemulsification group(all P<0.05). Furthermore, there was no statistical significance in the values of surgically induced corneal astigmatism after 1, 7d and 1, 3mo of surgery compared with phacoemulsification group(P>0.05).CONCLUSION: Compared with phacoemulsification, the changes in the number of corneal endothelial cells and thickness of the macular area after small incision extracapsular excision are relatively small, visual recovery is faster, and the complications reduced.
ABSTRACT
AIM: To compare the differences and correlations between different types of anisometropia, binocular visual acuity and biological parameters in school-age children.METHODS: A total of 128 school-age children(6-12 years)with mild-to-moderate anisometropia were retrospectively analyzed. Subjects were divided into five groups according to anisometropia type. All participants underwent cycloplegic refraction, A-scan ultrasound biometry, and corneal topography. Refractive status, best-corrected visual acuity(BCVA), anterior chamber depth(ACD), lens thickness(LT), vitreous chamber depth(VCD), axial length(AL), corneal radius(CR), and ratio of AL and CR(AL/CR)were recorded. Kruskal-Wallis and Spearman rank correlation tests were then used for statistical analysis.RESULTS: Hyperopic anisometropia had the greatest binocular vision difference(0.14±0.20). Myopic anisometropia had the greatest asymmetry in AL and VCD(0.56±0.41 and 0.56±0.39 mm, respectively). Anisometropia was positively correlated with BCVA, VCD, AL, and AL/CR(r=0.266, 0.379, 0.350, 0.263, respectively; P&#x003C;0.05), and it was not significantly correlated with LT and CR(r=-0.019,-0.069, respectively; P&#x003E;0.05), while no parameters had a statistically significant correlation with anisometropia in each group.CONCLUSION: School-age children with hyperopic anisometropia showed the greatest difference of binocular acuity in the four types of anisometropia. The inter-ocular differences of biometric parameters in simple hyperopic or myopic anisometropia were mainly attributed to the asymmetry of VCD and AL, while the differences in ocular parameters were not statistically significant in school-age children with astigmatic anisometropia.
ABSTRACT
AIM: To evaluate the refractive outcomes after intrascleral fixation of posterior intraocular lens(IOL).METHODS: Retrospective clinical study. A total of 55 patients(55 eyes)who had undergone intrascleral fixation of posterior IOL in Peking University International Hospital from March 2017 to December 2021 were enrolled. Patients were assigned to conventional group(35 eyes)and modified group(20 eyes)according to different surgical procedures. IOL Master combined with SRK/T formula were applied to calculate the diopter of IOL and the residual refractive power, as well as acquiring preoperative values of corneal astigmatism. Optometry, IOL Master and Pentacam were performed 1 and 3mo postoperatively to obtain the postoperative corneal astigmatism, total ocular astigmatism and spherical equivalent which was calculated as the actual diopter. The Image-pro plus analyzer was used to measure the values of IOL tilt and decentration.RESULTS: The 55 eyes that underwent intrascleral fixation of posterior IOL presented hyperopic shift in refraction after operation and the refractive error was 0.75±0.63D at 3mo postoperatively. There was significant difference between the actual diopter and the residual diopter at 3mo after operation(t=2.553, P=0.011). Both conventional group and modified group showed hyperopic shift postoperatively. The refractive error at 1 and 3mo after operation were 0.80±0.43 and 0.84±0.46D in the conventional group and 0.43±0.39 and 0.47±0.26D in the modified group respectively, with significant differences between two groups(1mo: t=3.500, P=0.001; 3mo: t=3.311, P=0.002). There was no significant difference in corneal astigmatism between two groups both at 1 and 3mo postoperatively(all P<0.05). Total ocular astigmatism in the modified group was significantly lower than that in the conventional group(1mo: t=3.884, P<0.001; 3mo: t=3.314, P=0.002). In addition, IOL tilt and decentration in the modified group were significantly less than that in the conventional group at 1 and 3mo postoperatively(all P<0.05). No significant difference was found in IOL tilt and decentration for intra-group comparison at 1 and 3mo postoperatively(P<0.05). Complications of 55 eyes included 2 eyes of transient intraocular pressure elevation, 2 eyes of transient hypotony which recovered after topical medication and 1 eye of vitreous hemorrhage which resolved spontaneously.CONCLUSION: Intrascleral fixation of posterior IOL is proved to be a safe and effective surgical technique, with hyperopic shift easily present after operation. Increasing the refractive power of IOL and targeting mild myopia during IOL power calculation can prevent postoperative hyperopia, but long-term outcomes still need further observation.