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.

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.

Analysis of visual quality after LENTIS Comfort Toric intraocular lens implantation / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the visual quality of LENTIS Comfort Toric intraocular lens implantation in cataract surgery.METHODS: A retrospective controlled clinical study was conducted on 40 patients(40 eyes)who received phacoemulsification combined with intraocular lens implantation assisted by digital navigation, with LENTIS Comfort Toric(MF15T)implanted in group A(24 eyes)and monofocal Toric intraocular lens implanted in group B(16 eyes). The visual acuity at different distances, the postoperative astigmatism center of mass value, the lens loss rate, the change of defocus curve and the stability of intraocular lens were observed at 3mo after surgery.RESULTS: There were no serious complications in both groups, and there was no significant difference in distance vision between group A and group B at 3mo after surgery(P>0.05); the visual acuity and near vision in group A were significantly better than those in group B(P<0.01); the postoperative lens loss rate in group A was 99%, and it was 45% in group B(P<0.05); the value of astigmatism center of mass in 3mo after surgery was improved compared with that before surgery, and there was no significant difference between groups(P>0.05); the defocus curve of group A peaked at +0.50 and -1.75D at 3mo after surgery, forming plateau and gently declining, while group B showed a steep decline after peaks at +0.25 and -0.25D. One eye(4%)in group A had the axial rotation of intraocular lens greater than 10° at 1d after surgery; In group B, 6 eyes(38%)had axial rotation of intraocular lenses greater than 10°, 2 eyes(33%)rotated clockwise, and 4 eyes(67%)rotated counterclockwise. No intraocular lens displacement occurred in either group.CONCLUSION: Both kinds of intraocular lenses can correct astigmatism, among which LENTIS Comfort Toric intraocular lens can provide personalized choices for people with cataract and astigmatism, solve astigmatism and obtain full visual acuity at the same time, with low incidence of postoperative optical interference, better stability, high visual quality and satisfaction.

Differences in refractive astigmatism, anterior corneal surface astigmatism and ocular residual astigmatism between dominant and non-dominant eyes in myopia / 中华实验眼科杂志

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.

Comparing IOLM700 TK, Berdahl and Hardten astigmatism fix calculator and Barrett Rx formula in managing residual astigmatism due to toric intraocular lens misalignment

Purpose: To compare the accuracy in astigmatism reduction by using IOLM 700 steep total keratometry (TK) axis, Berdahl and Hardten astigmatism fix, and Barrett Rx formula following misaligned toric intraocular lens (IOL). Methods: Ten patients with residual refractive astigmatism due to misalignment following toric IOL implantation were included in this retrospective study. They were analyzed at days 4, 7/8, and 10/11 following primary cataract surgery on the platform of Berdahl and Hardten astigmatism fix, Barrett Rx formula, and IOLM 700 to determine the optimum axis of repositioning, and underwent IOL realignment on the steep TK axis of IOLM 700 assisted by the Callisto eye. The final outcome parameters were subjective refraction and orientation of toric IOL assessed 22 ± 1 days following repositioning surgery. These parameters were fed in the Barrett Rx formula and its vector analysis graph was utilized to determine the predicted ideal axis with the least residual astigmatism and the estimated residual astigmatism if the toric IOL was realigned according to the axis suggested by Berdahl and Hardten astigmatism fix and Barrett Rx formula. Results: Realigning the toric IOL on IOLM 700 steep TK axis along with the Callisto eye reduces the residual refractive astigmatism significantly (P = 0.003) from 2.00 ± 0.78 D to 0.18 ± 0.12 D (90.5 ± 7.6%) in comparison to the estimated 0.57 ± 0.31 D (68.4 ± 21.9%) by Berdahl and Hardten astigmatism fix and 0.61 ± 0.33 D (66.4 ± 23.5%) by Barrett Rx formula. Conclusion: Realigning the misaligned toric IOL on the IOLM 700 steep TK axis gives a better reduction in the residual refractive astigmatism in comparison to Berdahl and Hardten astigmatism fix and Barrett Rx formula

Efficacy observation of Toric intraocular lens in correcting corneal astigmatism and vector analysis of residual astigmatism / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To observe the clinical effect of Toric intraocular lens(Toric IOL)implantation in the correction of corneal astigmatism, and vector analysis of residual astigmatism and corneal astigmatism.<p>METHODS: A retrospective case observation study. A total of 63 patients with 77 eyes who underwent phacoemulsification combined with Toric IOL implantation in our hospital from September 2018 to October 2019 were selected. LogMAR uncorrected distance visual acuity(UCDVA), best corrected distance visual acuity(BCDVA), residual astigmatism of subjective refraction were observed after operation in 1wk, 1mo, and 3mo. And after dilated pupil, the Toric IOL axis position was measured by OPD-scanⅢ, and compared with the target axis position(LAD).<p>RESULTS: The median(interquartile range)of UCDVA at 1wk, 1mo, and 3mo after operation were 0.22(0.15, 0.40), 0.30(0.15,0.40),and 0.30(0.15, 0.40), which were better than those of UCDVA \〖0.82(0.60, 1.22)\〗 and BCDVA \〖0.52(0.30, 0.70)\〗 before operation(<i>P</i><0.008). The residual astigmatism was 0.75(0.50, 1.00), 0.75(0.38, 1.00), 0.50(0.25, 1.00)D, respectively, which was significantly lower than that of preoperative corneal astigmatism \〖2.19(1.73, 2.69)D\〗(<i>P</i><0.008). At 3mo after surgery, the proportion of UCDVA(LogMAR)≤0.301 was 69%; the proportion of residual astigmatism ≤0.75D was 73%. The median LAD at 1wk, 1mo, and 3mo after surgery were 2.0°, 2.0°, and 3.0°; 81%, 82%, 77% were less than 5°. The maximum LAD value is 11°. Astigmatism vector analysis: preoperative corneal astigmatism was 2.31±0.80D, centroid value was 1.44D@177°±1.99D; Predicted postoperative residual astigmatism was 0.14±0.17D, centroid value was 0.02D@58°±0.22D; residual astigmatism at 3mo after operation was 0.69±0.53D, centroid value was 0.05D@142°±0.88D.<p>CONCLUSION: Toric IOL can effectively correct corneal astigmatism in patients with cataract and has good rotational stability. Astigmatism vector analysis can directly show the difference between predicting postoperative astigmatism and actual residual astigmatism, which is helpful to analyze and optimize the measurement of corneal astigmatism, calculation of IOL degree, surgical design, postoperative observation.

Applying vector analysis to evaluate influence of ocular residual astigmatism on astigmatism correction by FS-LASIK / 眼科新进展

Objective To investigate the influence of ocular residual astigmatism (ORA) on the correction of astigmatism by FS-LASIK with vector analysis.Methods The records of 182 patients who had accept FS-LASIK between January,2016 and April,2016 were retrosepectively reviewed.The patients whose ORA ≥ refractive cylinder were assigned to high ocular residual astigmatism group (HORA group),ORA ＜ refractive cylinder were assigned to low ocular residual astigmatism group (LORA group).All of the patients were followed 6 months or more.The visual acuity,error ratio and correction ratio were compared between HORA group and LORA group.Results The preoperative ORA of all patients was (0.61 ± 0.27) D,in which ＞ 0.75 D were 58 cases (31.9％),and the HORA group was more than the LORA group (P ＜ 0.05).At postoperative 6 months,there was no statistically significant difference in vision acuity between the HORA group (1.06 ± 0.15) and LORA group (1.08 ± 0.15) (t =0.97,P =0.35).There was statistically significant difference in the error ratio between the HORA group (58.11 ± 63.23) ％ and LORA group (26.12 ± 35.37) ％ (t =3.43,P ＜ 0.05).There was statistically significant difference in the correction ratio between the HORA group (146.45 ± 86.63) ％ and LORA group (122.56 ± 36.31) ％ (t =2.81,P ＜ 0.05).Conclusion The error ratio and correction ratio of astigmatic correction by FSLASIK is significantly higher in eyes with high ORA than in eyes with low ORA.Vector analysis should been carried out before the FS-LASIK.

Research progress in residual astigmatism after phacoemulsification cataract extraction and intraocular lens implantation / 中华实验眼科杂志

Phacoemulsification cataract extraction and intraocular lens (IOL) implantation has become the mainstream treatment of cataract.But the postoperative residual astigmatism still influences the postoperative uncorrected visual acuity.Reduce residual astigmatism is currently the ophthalmologists' pursuit.The formation of the residual astigmatism is affected by various factors,which mainly associated with preoperative corneal astigmatism and surgically induced astigmatism.Except for the above reasons,residual astigmatism after Toric IOL implantation has its special reasons.Understanding the reasons of formation of residual astigmatism can provide us the methods how to reduce it.This paper reviewed the causes of the residual astigmatism after phacoemulsification cataract extraction and IOL implantation.

Postoperative Astigmatic Outcomes Based on the Haptic Axis of Intraocular Lenses Inserted in Cataract Surgery

PURPOSE: This study was conducted to compare post-operative astigmatic outcomes of two groups, with-the-rule (WTR) and against-the-rule (ATR) astigmatism patients, according to the haptic axis of intraocular lenses (IOLs) inserted in cataract surgery. METHODS: Seventy-two eyes with WTR astigmatism and 79 eyes with ATR astigmatism had cataract surgery through a clear corneal temporal incision. These two groups of eyes were then each divided into 2 groups based on whether the haptic axis of the inserted IOL was at 180degrees or 90degrees. For ATR patients, the outcomes were analyzed according to the three types of IOLs. RESULTS: There was no difference in corneal astigmatism, but WTR patients with a 180degrees haptic axis of the inserted IOL and ATR patients with a 90degrees hepatic axis of the inserted IOL had a significant decrease in postoperative refractive astigmatism (p < 0.05). The changes in ATR astigmatism according to the IOL type were more effective in single-piece acrylic IOLs than in the three-piece polymethylmethacrylate haptic IOL group. CONCLUSIONS: Insertion of the IOL at the 180degrees haptic axis in WTR patients and at 90degrees in ATR patients during cataract surgery may have an effect in reducing pre-existing astigmatism. This observed effect was not consistent among the different types of IOLs.

Láser in situ keratomileusis en la corrección de miopía y astigmatismo residual posqueratotomía radial en casos seleccionados / Laser in situ keratomileusis to correct myopia and residual astigmatism after radial keratotomy in selected case

OBJETIVO: Evaluar la seguridad y la eficacia del tratamiento con láser in situ keratomileusis en pacientes con defectos residuales posqueratotomía radial. MÉTODOS: Se realizó un estudio descriptivo de tipo prospectivo longitudinal a 55 ojos de 31 pacientes con miopía y/o astigmatismo residuales posqueratotomía radial reoperados con láser in situ keratomileusis en el Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología Ramón Pando Ferrer desde enero a junio del 2007. En la selección de los pacientes, se utilizaron estrictos criterios de inclusión y exclusión utilizándose las variables: error refractivo residual en equivalente esférico medio, la agudeza visual sin corrección y la mejor agudeza visual corregida preLASIK y posLASIK, así como las complicaciones transoperatorias y postoperatorias. El seguimiento promedio de los pacientes fue de 12 ± 3 meses. RESULTADOS: El equivalente esférico posLASIK disminuyó notablemente en el primer día del posoperatorio y se mantuvo estable en la última consulta. La agudeza visual sin corrección posLASIK fue 1,0 (20/20) en 22 ojos (40 por ciento) y > 0,5 (20/40) en 44 ojos (80 por ciento). En 11 ojos (20 por ciento), la mejor agudeza visual corregida mejor 1 línea en la cartilla de Snellen. Se presentó como complicación intraoperatoria un ojo con perforación central del flap corneal y dentro de las complicaciones postoperatorias se reportaron detritus y restos hemáticos en la interfase en 2 ojos, pliegues finos del colgajo en un solo ojo y epitelización de la interfase fuera del eje visual igualmente, en un solo ojo. CONCLUSIONES: El Láser in situ keratomileusis puede ser usado exitosamente en la corrección de la miopía y el astigmatismo posqueratotomía radial en casos debidamente seleccionados

OBJECTIVE: To evaluate the safety and the efficacy of the Laser in Situ Keratomileusis treatment in patients with residual defects after radial keratotomy. METHODS: A prospective, longitudinal and descriptive study was performed in 55 eyes from 31 patients with residual myopia and/or astigmatism after radial keratotomy, who were re-operated on using Laser in situ keratomileusis at Refractive Surgery Service of Ramón Pando Ferrer Cuban Institute of Ophthalmology from January to June 2007. Strict inclusion and exclusion criteria were applied to select the patients, on the basis of following variables: residual refractive errors in average spheral equivalent, visual acuity without correction and best visual acuity with correction before and after LASIK as well as the transoperative and postoperative complications. The average follow-up period were 12 ± 3 months. RESULTS: The spheral equivalent after LASIK was substantially reduced in the first day of the postoperative phase and kept stable in the last appointment with the specialist. The visual acuity without correction after LASIK was 1,0 (20/20) in 22 eyes (40 percent) and > 0,5 (20/40) in 44 eyes (80 percent). In eleven eyes (20 percent), the best corrected visual acuity improved by one line in the Snellen´s chart. The transoperative complication was found in one eye with central corneal flap perforation whereas the reported postoperative complications were detritus and hematic remains in the interphase in 2 eyes, fine foldings of the flap in one eye and epithelization of the interphase out of the visual axis also in one eye. CONCLUSIONS: The Laser in situ keratomileusis can be used successfully to correct myopia and astigmatism after radial keratotomy in duly selected cases

Distribution and Change of Total Astigmatism, Corneal Astigmatism and Residual Astigmatism with Age in Patient with Emmetropia

PURPOSE: We evaluated the distribution and change of total, corneal and residual astigmatism with age in patients with emmetropia. METHODS: We examined the visual acuity, refraction, and corneal curvature in 263 persons aged from 3 to 83 years (mean, 38 years), with a spherical equivalent refraction of under +/-0.75 diopter (D). We analysed the distribution and change of the astigmatism. RESULTS: Total astigmatism was changed from with-the-rule (WTR) to against-the-rule (ATR) with aging based on WTR of 0.31 +/- 0.48 D in the 3-10 year-old group, ATR of 0.02 +/-0.52 D in the 31-40 year-old group and ATR of 0.65 +/- 0.66 D in the 71-83 year-old group. Corneal astigmatism showed a similar pattern to that of total astigmatism with WTR of 1.03 +/- 0.47 D, WTR of 0.37 +/- 0.78 D, ATR of 0.05 +/- 0.59 D and ATR of 0.31 +/- 0.64 D in the 3-10, 31-40, 61-70 and 71-83 year-old groups, respectively. Residual astigmatism showed ATR astigmatism in all age groups such as ATR of 0.71 +/- 0.48 D, ATR of 0.60 +/- 0.44 D and ATR of 0.35 +/- 0.71 D in the 3-10, 41-50 and 71-83 year-old groups, respectively. CONCLUSIONS: Total and corneal astigmatism showed the change from WTR to ATR, and residual astigmatism showed the pattern of decreasing ATR with aging in patients with emmetropia. The change of total astigmatism with aging seems to be influenced by that of corneal astigmatism rather than by that of residual astigmatism.

Pseudophakic Residual Astigmatism

We investigated pseudophakic residual astigmatism in order to minimize postoperative refractive astigmatism. We examined 110 eyes of 87 patients who had undergone phacoemulsification with small incision and posterior chamber intraocular lens (IOL) implantation. Corneal astigmatism was measured using an autokeratometer (RK-5, canon), refractive astigmatism by manifest refraction, and residual astigmatism by vector analysis. Mean pseudophakic residual astigmatism was +0.47 X 176degrees, predominantly against-the-rule. Variations of pseudophakic residual astigmatism according to sex, age and IOL type were not statistically significant. When performing cataract surgery as refractive surgery, we may consider that pseudophakic residual astigmatism is approximately 0.50D against-the-rule.