Evaluation of corneal tomography in children and adolescents without ocular or systemic allergy / Avaliação da tomografia de córnea em crianças e adolescentes sem alergia ocular ou sistêmica

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.

Post-Bader procedure: a long-term follow-up case study / Procedimento pós-Bader: estudo de caso com acompanhamento de longo prazo

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.

Analysis of ocular biometric parameters in Tibetan patients with age-related cataract / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To compare the differences of ocular biometric parameters of age-related cataract between Tibetan and Han ethnic groups, and to analyze the distribution characteristics of ocular biometric parameters in Tibetan cataract patients.METHODS:Retrospective cohort study. A total of 661 patients(1 030 eyes)with age-related cataract confirmed in the hospital between January 2019 and December 2020 were enrolled. The parameters of axial length, anterior chamber depth, keratometry, corneal astigmatism and astigmatic axis were measured by IOL Master 500 in 483 cases(739 eyes)of Tibetan age-related cataract patients and 178 cases(291 eyes)of Han patients.RESULTS:The axial length, anterior chamber depth and corneal astigmatism of the Tibetan patients with age-related cataract were 23.33(22.81, 23.86)mm, 3.04(2.79, 3.30)mm and 0.73(0.47, 1.07)D. The mean keratometry was 43.89±1.35 D. The results indicated that Tibetan cataract patients had shorter axial lengths and smaller keratometry compared to Han patients(all P<0.05). Age in Tibetan patients was negatively correlated with axial length and anterior chamber depth, and positively correlated with keratometry(all P<0.05). Tibetan male patients had longer axial lengths, deeper anterior chambers, and flatter corneas compared to female patients(all P<0.05).CONCLUSION:There were differences in ocular biometric parameters between age-related cataract patients of Tibetan and Han ethnicities. The distribution of ocular biometric parameters in Tibetan cataract patients varied across different age groups and gender groups.

Efficacy of MyoRing implantation in the treatment of keratoconus / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To compare the anterior and posterior corneal astigmatism and total refractive astigmatism before and after MyoRing implantation in keratoconus(KCN)patients.METHODS: In this historical cohort study, the preoperative and postoperative total refractive, anterior and posterior corneal astigmatism of KCN patients implanted with a 360-degree full-ring implant(MyoRing)were compared before and after four consecutive follow-up sessions at 3, 6, 9, and 12 mo after surgery.RESULTS: The study encompassed 79 KCN patients(85 eyes), comprising 43 males and 36 females. The mean age of the patients was 29±7.41 years, ranging from 17 to 48 years. Throughout the follow-up sessions, a gradual decrease was observed in the trend of changes for total refractive astigmatism, anterior corneal astigmatism, and posterior corneal astigmatism. Postoperatively, total refractive astigmatism measurements exhibited a significant decrease of 2.09 D at 12 mo after MyoRing implantation(4.27±3.15 vs 2.18±1.63 D, P<0.001). Additionally, post-operative measurements revealed an enhancement of approximately 3.20 D and 0.59 D for anterior and posterior corneal astigmatism, respectively [6.40±1.90 vs 3.20±1.75 D for anterior corneal astigmatism(P<0.001)and 1.30±0.55 vs 0.71±0.35 D for posterior corneal astigmatism(P<0.001)].CONCLUSION: MyoRing implantation demonstrates significant improvements in astigmatism parameters, encompassing total refractive astigmatism as well as anterior and posterior corneal astigmatism.

Vector analysis of toric implantable collamer lens V4c implantation in correcting moderate to high myopia with high astigmatism / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the clinical effect of toric implantable collamer lens(TICL)V4c for correcting moderate to high myopia with high astigmatism using vector analysis and quality of life impact of refractive correction(QIRC).METHODS: Retrospective case series. A total of 55 patients(90 eyes)with moderate to high myopia and high astigmatism who received TICL V4c implantation in the refraction surgery center of ophthalmology department in our hospital from January 2019 to December 2022 were collected. Followed-up for 1 a, the uncorrected distance visual acuity(UDVA), best corrected visual acuity(BCVA)and diopters were observed. Alpins vector analysis was used to evaluate the effect of astigmatism correction, and QIRC scale was used to evaluate patients' quality of life.RESULTS: At 1 a postoperatively, the UDVA of 98% eyes was the same or better than pre-operative BCVA, the safety index was 1.11±0.14, and the efficacy index was 1.11±0.15. The angle of error of 97% of the astigmatic eyes was within ±15°. The results of vector analysis showed that correction index was 0.83±0.13, angle of error was 1.00±4.49°, and index of success was 0.21±0.15. The total higher order aberrations under a pupil diameter of 6 mm was significantly increased compared with preoperatively(P<0.05), the QIRC score was significantly better than that before surgery(P<0.001), and the increase of total QIRC scores was positively correlated with preoperative spherical equivalent(rs=0.215, P<0.05), indicating that the higher degree of myopia before surgery the patients, the better the quality of life after TICL implantation.CONCLUSION: TICL V4c implantation for the correction of moderate to high myopia with high astigmatism is safe and effective, and the patients' quality of life significantly improved after surgery.

Accuracy of a smartphone-assisted novel labeling method for marking target axial position in cataract surgery / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the convenience and accuracy of a novel smartphone-assisted “any-point two-step method” for finding the target axial position in cataract phacoemulsification combined with intraocular lens(IOL)implantation.METHODS: Prospective observational study. A total of 62 cases(62 eyes)of patients with age-related cataracts who underwent cataract phacoemulsification combined with IOL implantation in our hospital from October 2021 to April 2022 were selected. They were randomly divided into two groups: 31 cases(31 eyes)in the control group were applied with the “traditional two-step method” using slit lamp to mark the target axial position of the IOL, and 31 cases(31 eyes)in the experimental group were applied with the smartphone-assisted “two-step method” to mark the target axial position of the IOL. The Callisto eye navigation system was used as a standard reference, and the deviation of the reference marking point(deviation-1), the deviation of the target axial marking point(deviation-total), and the deviation of the angle from the reference marking point to the target axial marking point(deviation-2)were calculated and recorded as the preoperative axial marking time.RESULTS:Both deviation-1 and deviation-total values were lower in the experimental group than those in the control group(1.06°±1.39° vs 2.48°±2.23°, 1.77°±1.54° vs 2.81°±1.58°, all P<0.01), but there was no significant difference in the deviation-2 values between the two groups(1.35°±1.40° vs 1.48°±1.79°, P>0.05). The preoperative axial marking took shorter time in the experimental group than in the control group(1.77±1.70 min vs 2.88±3.20 min, P<0.01).CONCLUSION: The smartphone-assisted “any-point two-step method” for finding the target axial position in cataract phacoemulsification combined with IOL implantation is simple, time-saving, and accurate compared with the “traditional two-step method”.

Astigmatism inclusivity of regional refractive intraocular lens / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the effect of residual astigmatism on visual quality after phacoemulsification combined with regional refractive intraocular lens(IOL)implantation in patients with age-related cataract, and to evaluate the astigmatism inclusivity of regional refractive IOL.METHODS: Retrospective cohort study. The clinical data of 62 cases(73 eyes)of age-related cataract patients who underwent phacoemulsification combined with regional refractive IOL(Lentis Comfort LS-313 MF15)implantation from July 2020 to March 2022 at the ophthalmology department of our hospital were collected. They were grouped according to residual astigmatism at 6 mo postoperatively, taking 35 cases(40 eyes)with residual astigmatism of 0.75 D to 1.50 D as the experimental group, and 27 cases(33 eyes)with residual astigmatism ≤0.75 D as the control group. Visual acuity, defocus curves, objective visual acuity [wavefront aberrations, Strehl ratio(SR), modulation transfer functions(MTF)], subjective visual acuity(national eye institute visual function questionnaire-25), patients' satisfaction, and spectacle independence were compared between the two groups at 6 mo postoperatively.RESULTS:There was a difference in the preoperative astigmatism and the number of postoperative 6 mo residual astigmatism between the two groups(P<0.01). At 6 mo postoperatively, there was no difference in uncorrected distance, intermediate, and near visual acuity, objective visual quality, subjective visual quality, satisfaction, and spectacle independence between the two groups(P>0.05). The defocus curves showed that there was no difference in visual acuity between the two groups at all points in the +2.00 to -4.00 D defocus range of the additional spherical equivalent(P>0.05).CONCLUSION:Lentis Comfort LS-313 MF15 IOL was able to accommodate regular astigmatism of 1.50 D.

Clinical effect of cross positioning method for correcting low and moderate astigmatism during small incision lenticule extraction / 国际眼科杂志(Guoji Yanke Zazhi)

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.

Distribution characteristics of astigmatism in preschool children from Tongzhou District of Beijing and its effect on visual acuity / 国际眼科杂志(Guoji Yanke Zazhi)

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.

Bidirectional associations between hyperopia, myopia, astigmatism, and strabismus, and attention-deficit/hyperactivity disorder in children: a national population-based cohort study

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.

Phacoemulsification, pinhole pupilloplasty, and pre-Descemet抯 endothelial keratoplasty for keratoconus with Fuchs� endothelial dystrophy

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.

Comparison of clinical outcomes of Eyecryl toric and Alcon toric intra-ocular lenses – A real world study

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

Refractive outcomes of toric intra-ocular lens implantation in cases of high posterior corneal astigmatism

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.

Outcomes of preloaded toric intraocular lens implantation in eyes undergoing phacoemulsification

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

Comparative analysis of visual outcomes following small-incision lenticule extraction with or without cyclotorsion compensation in eyes with high astigmatism: Contralateral eye study

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.

Novel custom designed toric piggyback intraocular lens for the correction of residual postoperative astigmatism

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.

They see, they learn: Pre-COVID-19 prevalence of refractive errors in school children in suburban areas of North India

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

Estimation of surgically induced astigmatism after small-incision cataract surgery done by junior residents

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.

Patterns of Refractive Errors among Medical Students at the University of Zambia School of Medicine

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.

An evaluation of the accuracy of toric intraocular lens power calculation based on measured total corneal refractive power

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.