High Corneal Astigmatism Research Articles

Assessment of the refractive outcomes of patients with regular corneal astigmatism implanted with high-power toric intraocular lenses.

To describe the refractive outcomes of eyes with high regular corneal astigmatism undergoing age-related cataract surgery. Astigmatic patients who underwent cataract surgery with implantation of high-power XY1AT HOYA® toric lenses (IOLs) (≥ T5) between March 2020 and June 2022 were included. Patients were divided into 2 groups based on the type of Total Corneal Astigmatism (TCA) used for the toric IOL calculation: group 1 = TCATK- 700 (TCA measured by the Iol Master 700®) and group 2 = TCAAK- 700 (TCA estimated from the anterior keratometry of the Iol Master 700® and using the Abulafia-Koch regression). The best-uncorrected (UDVA) and corrected (CDVA) distance visual acuity, subjective spherical equivalent (SSEq) and subjective residual cylinder (SRC) were assessed at 1 month. The predictability (centroid [CEPA] and mean absolute error in predicted astigmatism [MAEPA]) of the 2 TCA assessment methods was analyzed. 96 eyes of 74 patients were included. In the whole cohort, the UDVA was 0.14 ± 0.19 logMAR, the CDVA was 0.04 ± 0.07 logMAR. Postoperative SSEq was - 0.24 ± 0.53D. Postoperative SRC was - 0.48 ± 0.56D. The UDVA, SSEq and SRC did not significantly differ between groups. The MAEPA was significantly better with TCAAK-700 compared to TCATK-700: 0.58 ± 0.52D versus 0.65 ± 0.55D (p = 0.01). No significant difference was observed for the CEPA (p(x) = 0.09, p(y) = 0.19). XY1AT HOYA® toric IOLs are a very good alternative even in case of high toricity. Residual astigmatism predictability is high, it would be better with TCAAK- 700. This data should be confirmed with a larger sample of patients.

Posterior Eye Shape in Myopia

PurposeTo explore prevalence and associated factors of abnormalities of the posterior eye shape in dependence of axial length. DesignPopulation-based study. ParticipantsOut of the participants (n=3468) of the Beijing Eye Study, we included all eyes with an axial length of ≥25 mm, and a randomized sample of eyes with an axial length of <25 mm. MethodsUsing 30°-wide, serial horizontal, and fovea-centered radial, optical coherence tomographic (OCT) images, we examined location and depth of the most posterior point of the retinal pigment epithelium/Bruch´s membrane line (PP-RPE/BML). Main Outcome ParametersPrevalence and depth of an extrafoveal PP-RPE/BML. ResultsThe study included 366 eyes (314 individuals;age:63.7±9.7 years). On the radial OCT scans, the PP-RPE/BML was located in the foveola in 190 (51.9%;95%CI:46.9,56.9) eyes, in 121 (33.1%;95%CI:28.1,38.1) eyes in the 6 o´clock part of the vertical meridian at a mean distance of 1.73±0.70mm from the foveola, and in 54 (14.8%;95%CI:11.1,18.4) eyes in the 12 o´clock part of the vertical meridian at a distance of 2.01±0.66mm from the foveola. Deeper PP-RPE/BML depth increased with longer axial length (beta:0.28;B:12.3;95%CI:7.5,17.1;P<0.001), female sex (beta:0.17;B:30.2;95%CI:10.7,49.6;P=0.002), and higher corneal astigmatism (beta:0.12;B:13.9;95%CI:1.50,26.3;P=0.03). On the horizontal OCT scans, the PP-RPE/BML was located in the foveola in 304 (83.1%;95%CI:79.2,86.9) eyes, between the foveola and the optic disc in 36 (9.8%;95%CI:6.8,12.9) eyes (mean depth: 119±142μm; mean distance:1.59±0.76mm from the foveola), and temporal to the foveola in 26 (7.1%;95%CI:4.5,9.8) eyes (depth:71±46μm; distance:1.20±0.60mm). Higher prevalence of an extrafoveal PP-RPE/BML correlated with longer axial length (OR:1.55;95%CI:1.28,1.89;P<0.001), higher corneal astigmatism (OR:1.78;95%CI:1.14,2.79;P=0.01) and female sex (OR:2.74;95%CI:1.30,5.77;P=0.008). The curvature of the RPE/BM line at the posterior pole was similar to the RPE/BM line curvature outside of the posterior pole in 309 (84.4%;95%CI:80.7,88.2) eyes, and it was steeper (i.e., smaller curvature radius) in 57 (15.6%;95%CI:12.1,19.1) eyes. In these eyes, axial length was longer (24.41±1.78mm versus 27.74±1.88mm;P<0.001). ConclusionsWith longer axial length, the foveola is more often located outside of the geometrical posterior pole. It may be of importance for biometric axial length measurements. An extrafoveal location of the PP-RPE/BML may be due to an axial elongation-associated, meridionally asymmetric enlargement of Bruch´s membrane in the fundus midperiphery.

Refractive errors in patients with Bardet Biedl syndrome

ABSTRACT Purpose Bardet-Biedl Syndrome (BBS) is a rare autosomal recessive ciliopathy. Within corneal development, primary cilia serve a critical role. We sought to investigate the association of BBS with corneal astigmatism among a cohort of patients with BBS. Methods This was a cross-sectional, retrospective study performed at a pediatric ophthalmology department of a tertiary hospital. The study enrolled 45 patients with genetically confirmed Bardet-Biedl syndrome, encompassing a total of 90 eyes observed from February 2011 to August 2021. Spherical and cylindrical refractive errors and keratometry outcome measures, including diopter (D) values at the flattest and steepest axes, were recorded. Corneal astigmatism of greater than 3D is considered extreme corneal astigmatism based on previously published data. Results Among 45 patients (M:26; F:19), the mean age was 16.4 ± 8.2 years, and the mean best-corrected visual acuity was 20/60. The most common molecular diagnosis was BBS1, seen in 24 of 45 (53.3%). Among all the patients, the mean spherical refractive error was −2.9 ± 3.8D. The mean cylindrical refractive error was 2.6 ± 1.5D. The mean keratometry values at the flattest axis was 43.5 ± 5.3D (39.4–75.0) and at the steepest axis was 47.2 ± 7.3D(41.5–84.0). Among all the patients with BBS, the mean corneal astigmatism was 3.7 ± 1.0D(0.5–7.1), which is considered extreme. Conclusion A cohort of individuals with BBS demonstrated high corneal astigmatism. These results suggest an association between corneal astigmatism and primary ciliary dysfunction and may assist in clinical management and future therapeutic targets among BBS and other corneal disorders.

Ocular biometric characteristics of Han ethnicity in Tianjin and Uyghur ethnicity in Xinjiang undergoing cataract surgery.

To analyze and compare the differences among ocular biometric parameters in Han and Uyghur populations undergoing cataract surgery. In this hospital-based prospective study, 410 patients undergoing cataract surgery (226 Han patients in Tianjin and 184 Uyghur patients in Xinjiang) were enrolled. The differences in axial length (AL), anterior chamber depth (ACD), keratometry [steep K (Ks) and flat K (Kf)], and corneal astigmatism (CA) measured using IOL Master 700 were compared between Han and Uyghur patients. The average age of Han patients was higher than that of Uyghur patients (70.22±8.54 vs 63.04±9.56y, P<0.001). After adjusting for age factors, Han patients had longer AL (23.51±1.05 vs 22.86±0.92 mm, P<0.001), deeper ACD (3.06±0.44 vs 2.97±0.37 mm, P=0.001), greater Kf (43.95±1.40 vs 43.42±1.69 D, P=0.001), steeper Ks (45.00±1.47 vs 44.26±1.71 D, P=0.001), and higher CA (1.04±0.68 vs 0.79±0.65, P=0.025) than Uyghur patients. Intra-ethnic male patients had longer AL, deeper ACD, and lower keratometry than female patients; however, CA between the sexes was almost similar. In the correlation analysis, we observed a positive correlation between AL and ACD in patients of both ethnicities (rHan =0.48, rUyghur =0.44, P<0.001), while AL was negatively correlated with Kf (rHan =-0.42, rUyghur =-0.64, P<0.001) and Ks (rHan =-0.38, rUyghur =-0.66, P<0.001). Additionally, Kf was positively correlated with Ks (rHan =0.89, rUyghur =0.93, P<0.001). There are differences in ocular biometric parameters between individuals of Han ethnicity in Tianjin and those of Uyghur ethnicity in Xinjiang undergoing cataract surgery. These ethnic variances can enhance our understanding of ocular diseases related to these parameters and provide guidance for surgical procedures.

Spherical Aberration of Astigmatic Corneas in a Cataract Population.

To study the distribution of spherical aberration (SA) in astigmatic corneas in a cataract population and the relationship between magnitude of corneal astigmatism and fourth-order corneal SA. Data routinely collected using a Scheimpflug camera (Pentacam; Oculus Optikgeräte GmbH) were retrospectively analyzed. Patients with a minimum age of 60 years were included. Total corneal SA (from anterior and posterior corneal surface) was obtained for a 6-mm cor-neal area aligned with the pupil center. Exclusion criteria were insufficient measurement quality, total deviation index (Belin/Ambrósio Deviation) greater than 1.60, and corneal thickness at the thinnest point of less than 490 μm. One eye per patient was chosen randomly. Eyes were divided into low (≤ 1.00 diopters [D]), moderate (> 1.00 to ≤ 2.00 D), and high (> 2.00 D) astigmatism groups according to the Scheimpflug measurements. A total of 528 eyes were included in this analysis. Low astigmatism was found in 129 patients, moderate astigmatism in 265 patients, and high astigmatism in 134 patients. Mean astigmatism was 0.68 ± 0.24, 1.45 ± 0.28, and 2.91 ± 0.95 D in the low, moderate, and high astigmatism groups, respectively. Mean corneal SA in patients with moderate and high astigmatism was higher than in the low astigmatism group. The difference reached the significance level for the comparison of low and high astigmatism groups (P = .023). The fourth-order SA increased gradually with the magnitude of astigmatism with a slope of 0.015. SA was significantly larger in the cataract population with high corneal astigmatism. The increase of positive sign SA with the magnitude of astigmatism suggests that patients with moderate to high astigmatism may benefit more from intraocular lenses with negative sign SA correction. [J Refract Surg. 2023;39(8):532-538.].

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

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. 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. 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. 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.

Long-term variations and influential factors of the treatment zone of wearing orthokeratology lenses

PurposeTo investigate the variation trend of the treatment zone (TZ) during 12 months of Orthokeratology (Ortho-K) from the perspective of the treatment zone size (TZS), decentration (TZD) and the weighted Zernike defocus coefficient of the treatment zone (Cweighteddefocus). Methods94 patients were included in this retrospective study, who were fitted with a 5-curve vision shaping treatment (VST) lens (n = 44) or a 3-zone corneal refractive therapy (CRT) lens (n = 50). The TZS, TZD and Cweighteddefocus up to 12 months were analyzed. ResultsTZS (F(4,372) = 10.167, P＜0.001), TZD (F(4,372) = 8.083, P＜0.001) and Cweighteddefocus (F(4,372) = 7.100, P＜0.001) were significantly increased with time during overnight Ortho-K treatment. The TZS increased sharply from 1 week to 1 month of overnight Ortho-K (F = 25.479, P <.001) and stayed smooth then. It showed growing tendency from 6 to 12 months (F = 8.407, P =.005). The TZD (F = 16.637, P <.001) and Cweighteddefocus (F = 13.401, P <.001) increased significantly until 1 month and kept stable until 12 months (all P＞0.05). The univariant linear regression analysis showed that TZS of the last visit was correlated with baseline myopia (β = 0.219, P =.034). Also, the greater final Cweighteddefocus was correlated with higher baseline myopia (β = -0.589, P＜0.001) and higher corneal astigmatism (β = -0.228, P =.007) at the onset of lens wear with the multiple linear regression. ConclusionThe TZS, TZD and Cweighteddefocus kept stable after 1 month of Ortho-K while the TZS had an increasing trend after 6 months. Children with higher myopic eyes or higher corneal astigmatism at baseline tended to have smaller TZS and greater Cweighteddefocus at 12 months.

Visual and Refractive Outcomes of a Trifocal Toric Intraocular Lens Implanted in Eyes With High Corneal Astigmatism.

To analyze the refractive and visual outcomes following cataract surgery and implantation of a trifocal toric intraocular lens (IOL) in eyes with high degrees of corneal astigmatism. A total of 29 eyes from 21 patients who underwent implantation of a trifocal toric IOL (FineVision PODFT; PhysIOL) were evaluated in this study. Phacoemulsification with femto-second laser and intraoperative aberrometry were performed in all cases. All IOLs used exhibited a cylinder power of 3.75 diopters (D) or greater. The main outcome measures were refractive error and corrected distance visual acuity (CDVA) and uncorrected distance visual acuity (UDVA) values. Eyes were evaluated during a follow-up period of 5 years. A total of 96.30%, 100%, 95.83%, and 89.47% of eyes were within ±1.00 D at 1, 2, 3, and 5 years postoperatively, respectively. Furthermore, 92.31%, 86.36%, 82.61%, and 84.21% of eyes showed a refractive cylinder value of ±1.00 D at 1, 2, 3, and 5 years postoperatively, respectively. During the entire follow-up period, between 81.48% and 91.30% of eyes showed a CDVA of 20/25 or better. The mean monocular Snellen decimal CDVA values were 0.90 ± 0.12, 0.90 ± 0.11, 0.91 ± 0.11, and 0.90 ± 0.12 at 1, 2, 3, and 5 years postoperatively, respectively. No significant rotation was reported in any eye during follow-up. The current study suggests that use of this trifocal toric IOL in eyes with high amounts of corneal astigmatism provides accurate refractive outcomes with good distance visual acuity. [J Refract Surg. 2023;39(4):229-234.].

Acoustic density of the sclera of keratoconus eyes and its clinical significance

Purpose: to assess the biophysical properties of the sclera by measuring its acoustic density in keratoconus, highly myopic, and healthy eyes. Material and methods. We examined 34 patients (67 eyes) aged 15–45 with keratoconus of various stages, 15 patients (30 eyes) aged 17–28 with high myopia and 15 people (30 eyes) aged 28–37 without ophthalmic pathology. The acoustic density of the sclera (ADS) was measured on the Voluson Е8 ultrasound device (GE Healthcare, USA) in the posterior eye pole (ADS-1) and in the equatorial area (ADS-2). The axial length (AL) of the eye, corneal thickness (CT), anterior chamber depth (ACD), and lens thickness (LT) were determined using Galilei G6 (Ziemer Group, Switzerland). The vitreal chamber depth (VCD) was calculated according to the formula: VCD = AL – СT – ACD – LT. Results. In keratoconus patients, the average ADS-1 value was 242.5 ± 7.4 conventional units (CU), ADS-2 averaged 234.1 ± 12.1 CU, AL was 24.6±1.1 mm long, and VCD was 17.1 ± 0.4 mm. In high myopia group, the average value proved to be significantly lower: ADS-1 was 210.3 ± 15.7 CU, ADS-2 — 201.2 ± 11,2 CU, while AL and VCD were higher: resp. 27.0 ± 0.7 mm and 19.2 ± 0.5 mm (p &lt; 0,05). In the control group (healthy eyes), ADS-1 was 247.5 ± 2.8 and ADS-2 was 238.1 ± 0.6 CU, which practically showed no difference to the keratoconus group (p &gt; 0.05). AL was 23.7 ± 0.6 mm, and VCD was 16.0 ± 0.6 mm. An insignificant tendency toward ADS drop in keratoconus eyes with AL over 25.0 mm was observed. Probably, we are dealing here with a combination of keratoconus with axial myopia. Conclusion. The acoustic density of the sclera of keratoconus patients approaches the respective parameter of healthy eyes and is significantly higher than that of highly myopic eyes. The analysis of acoustic density of the sclera and vitreal chamber depth may be considered as a method of additional differential diagnostics of keratoconus and congenital myopia with high corneal refraction and astigmatism.

Case report: simultaneous femtosecond laser astigmatic keratotomy and toric intraocular lens implantation in femtosecond laser-assisted cataract surgery in a patient with surgically induced high corneal astigmatism

Case report: simultaneous femtosecond laser astigmatic keratotomy and toric intraocular lens implantation in femtosecond laser-assisted cataract surgery in a patient with surgically induced high corneal astigmatism

Refractive status, biometric components, and functional outcomes of patients with threshold retinopathy of prematurity: systemic review and a 17-year longitudinal study.

To assess the long-term refractive status, visual outcome, astigmatism, and the change in biometric optic components in older adolescents up to age 17years with threshold retinopathy of prematurity (ROP) treated with diode laser. A retrospective, longitudinal study in which cycloplegic refraction, keratometry, and the biometric measurement of optic components were performed on 28 consecutive preterm eyes with laser-treated threshold ROP at age 17years. The study results were statistically analysed and compared with age-matched full-term control. All patients with ROP had myopia (average spherical equivalent of - 6.35 D, ranges from - 1.25 to - 12.38 D), and 12 eyes (43%) were highly myopic (spherical equivalent < - 6.0 D). Threshold ROP eyes exhibited a significantly poorer visual acuity (P < 0.001), greater cylinder refractive error (P < 0.001), higher corneal astigmatism (P < 0.001), and flatter horizontal corneal curvature (P = 0.01) compared with age-matched controls. Biometric optic components analysis revealed a significant shallower anterior chamber depth (P < 0.001), thicker lens (P < 0.001), and shorter axial length (P = 0.021) in laser-treated ROP eyes compared with age-matched controls. In this 17-year longitudinal study, a higher prevalence of myopia and astigmatism was observed in laser-treated threshold ROP eyes compared with age-matched control eyes. Myopia and astigmatism in laser-treated ROP eyes typically progress through adolescence after school age. Therefore, we recommend that preterm patients with laser-treated threshold ROP should attend regular follow-up not only for refractive status but also for structural change of anterior segment until their adolescence.

Preoperative Characteristics of Ocular Biometry in Children with Unilateral Congenital Cataracts.

The ocular biometry characteristics are clinically significant for children with unilateral congenital cataracts, but there is a lack of data analysis concerning the preoperative measurements. The axial length (AL), mean keratometry (Km), corneal astigmatism (CA), and the anterior chamber depth (ACD) from both eyes before cataract surgery were obtained from 205 patients (410 eyes, 3-15years of age) with unilateral congenital cataracts. In the congenital cataract eyes, shorter AL (22.44 ± 1.52mm vs. 22.57 ± 1.04mm, p = 0.036) and higher CA (- 1.89 ± 0.91 D vs. - 1.24 ± 0.67 D, p < 0.001) were found, and no significant difference was found in the Km and the ACD measurements compared to the contralateralnormal eyes. Females had shorter AL and shallower ACD compared to males. However, the Km and CA in the females were significantly larger than that in males. Shorter AL, larger Km, higher CA, and shallower ACD were also found in females who had a binocular axial difference (the value obtained by subtraction of the contralateral normal eye from the congenital cataract eye) that less than zero. The preoperative ocular biometry of shorter AL, larger Km, higher CA, and shallower ACD should be considered in females with unilateral congenital cataracts. The age and the binocular axial differences had a statistically significant correlation (r = -0.192, p = 0.006). Therefore, changes in the binocular axial differences associated with aging may enhance the guidelines for intraocular lens selection and the management of congenital cataracts.

Interocular Difference of Axial Length, Anterior Chamber Depth, Keratometry, Corneal Astigmatism According to Axial Length

Purpose: To investigate the interocular difference of axial length (AL), mean keratometry (K), corneal astigmatism and anterior chamber depth (ACD) according to AL without history of ocular surgery.Methods: This study was performed on 16,411 patients (32,825 eyes) who were measured AL, K, corneal astigmatism and ACD by IOL Master® from April 2007 to September 2016, excluding patients with missing values and extreme values in AL. After, patients were divided into four groups based on AL; AL &lt; 24 mm, 24 mm ≤ AL &lt; 26 mm, 26 mm ≤ AL &lt; 28 mm, AL ≥ 28 mm, we investigated which variables were associated according to AL. To compensate for age and sex, 1:1:1:1 random matching was performed for age and sex.Results: The longer the average AL of both eyes, the greater the difference between the AL, ACD and mean corneal K of both eyes. The longer AL group had the deeper ACD, the flatter mean corneal K, the higher corneal astigmatism. The older age group had the more shallow ACD, the steeper mean corneal K, lower corneal astigmatism.Conclusions: Ophthalmologists have to be careful in setting fellow eye as control in treating or studying patients with long AL or axial myopia. Because, the longer the average AL of both eyes, the greater the difference between the AL, the ACD and the mean corneal K of both eyes.

Clinical Characteristics and Early Visual Outcomes of Highly Myopic Cataract Eyes: The Shanghai High Myopia Study.

Purpose: To report ocular characteristics and early visual outcomes of highly myopic cataract eyes, and to analyze the risk factors of low vision.Methods: A total of 2,027 eyes of 1,400 cataract patients with axial length (AL) ≥ 26 mm undergoing cataract surgery in Eye & ENT Hospital of Fudan University, who were registered in the Shanghai High Myopia Study, were analyzed. Routine pre-operative ophthalmic examinations were performed and macular scan of optical coherence tomography (OCT) were obtained. Macular complications, central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) were evaluated from OCT images. Ocular and surgical history and perioperative complications were also recorded. Uncorrected and best-corrected visual acuity (UCVA/BCVA) 1 month post-operatively and its influencing factors were evaluated.Results: The average AL of all involved eyes was 29.52 ± 2.26 mm, and 39.7% of which were with an AL > 30 mm and 26.4% of which were with a corneal astigmatism more than 1.5 D. Nuclear cataract accounted for the largest proportion (70.6%). The rate of overall macular complications was 27.6%. Postoperative UCVA and BCVA were 0.70 ± 0.46 and 0.25 ± 0.32 logMAR, respectively. BCVA improved significantly after surgery (vs. P < 0.001) and affected by the elongation of AL (P < 0.001) and thinning of CFT and SFCT (both P < 0.001). The risk factors of post-operative low vision (BCVA < 20/66) were macular atrophy, lamellar macular hole, high corneal astigmatism, long AL, thin SFCT and junior surgeons, odds ratios ranging from 1.54 to 54.87 (all P < 0.05).Conclusion: Cataract surgery could improve the VA of highly myopic eyes. Eye with macular complications, higher corneal astigmatism, longer AL, thinner SFCT, and who was treated by a junior surgeon, may have a high risk of low vision after surgery.

Comparison of trifocal toric and bifocal toric intraocular lens implantation in patients with cataract and high corneal astigmatism.

To investigate and compare the quality of life, satisfaction, contrast sensitivity, glare, depth perception, and intraocular lens (IOL) rotation in patients who underwent trifocal toric and bifocal toric IOLs. A total of 80 eyes of 40 patients were included in this prospective study. Twenty patients in each group were implanted with trifocal toric and bifocal toric IOL, respectively. Preoperative and postoperative 6-month measurements were recorded for both patient groups. Comprehensive anterior and posterior segment examinations, distance-intermediate-near visual acuity values and the visual function scale questionnaire results were evaluated at these examinations. Patient satisfaction, contrast sensitivity, glare, intermediate-near and distance stereopsis and IOL rotation were also evaluated. No significant difference was found between the groups in terms of distance and near visual acuities (P=0.269, P=0.451). Intermediate visual acuity was significantly increased in the trifocal toric group (P<0.001). The visual function scale results were increased after surgery in both groups (P=0.001 and P<0.001), with no difference determined between them (P=0.158 and P=0.691). The number of patients wearing glasses was low in both groups and there was no significant difference between the groups (P>0.05). The overall satisfaction in the trifocal toric group was significantly higher than in the bifocal toric group (P=0.03). The highest sensitivity was observed at 6 cpd spatial frequency in all patients under photopic conditions (1.80±0.24 logU, 1.74±0.20 logU). Distance-intermediate-near binocular depth perception results in both groups were higher in the trifocal toric group (P=0.02, 0.048, 0.003, respectively). Although there was no significant difference for 3 meters stereopsis, the trifocal toric group had higher depth perception (P=0.577). Mean rotation was 5.76°±3.93° in the trifocal toric group and 12°±7.1° in the bifocal toric group. Better results in the middle distance are obtained in the trifocal toric group and less IOL rotation due to digital system-coordinated surgery. Moreover, the overall satisfaction in the trifocal toric group is significantly higher than in the bifocal toric group.

High power custom toric intraocular lens for correcting high corneal astigmatism in post-keratoplasty and keratoconus patients with cataract.

Purpose:To analyze the outcomes of phacoemulsification with high power customized toric intraocular lens implantation (IOL) in patients with high corneal astigmatism (6-10 D Cyl) post keratoplasty and keratoconus eyes with cataract.Methods:Five eyes post keratoplasty with clear graft, four eyes with stable keratoconus, one eye with pterygium excision scar with visually significant cataract were included in this retrospective study. Phacoemulsification was done followed by implantation of custom made high power toric IOL in all patients. Outcomes included uncorrected and best-corrected distance visual acuity (UDVA, BCVA), pre-operative astigmatism at the corneal plane and IOL plane, post-operative residual astigmatism, mean torus of all IOLs used were calculated.Results:The minimum follow-up time was 12 months. At the last follow-up visit, there was a significant improvement (pre-operative vs post-operative) of UDVA (1.5 ± 0.47 vs 0.28 ± 0.14 logMAR; P < 0.05), cylindrical refraction (-9.0 ± 1.80 D vs - 1.1 ± 0.45 vs ; P < 0.05). Range of IOL powers used was 1.0-26.50 DSph and 9.0-15.5 DCyl. Post-operative mean residual spherical equivalent was 0.75 ± 0.5.Conclusion:This novel study describes the effectiveness of custom toric IOLs in high astigmatism in the range of 9.0-15.5 DCyl. Phacoemulsification with implantation of a customized high power toric IOL was effective in correcting high astigmatism in complex cases in our study.

Mini-Scleral Contact Lens for Asian Eyes Post-Penetrating Keratoplasty with Smaller Palpebral Aperture: Case Reports

PurposeTo report the use of miniscleral contact lenses (MSCLs) with diameter of 14.7 mm for Asian eyes to improve vision in patients after penetrating keratoplasty (PKP) surgery.MethodsTwo patients with high corneal astigmatism post-PKP were evaluated for a contact lens fitting. Visual acuity, slit lamp, and anterior segment OCT findings before and after fitted the lens of 14.7 mm diameter were recorded.ResultsA Kmax of case 1 and 2 were 52.8 D and 76.9 D, respectively at the first visit. Both patients were successfully fit with MSCLs, showing adequate corneal clearance of over 250 μm with no corneal touch on OCT and sufficient limbal clearance and edge alignment. MSCLs use resulted in improved comfort and visual acuity of 20/30 or better.ConclusionMSCLs with diameter of 14.7 mm can be considered a safe and effective option for patients with highly steep corneas post-PKP surgery in Asian eyes.

Mutation spectrum and genotype-phenotype correlations in Chinese congenital ectopia lentis patients

PurposeTo identify the spectrum and frequency of mutations in congenital ectopia lentis (CEL) and to investigate the correlations between genotype and clinical phenotype in Chinese CEL patients. MethodsNinety-three participants with CEL were enrolled from March 2017 to April 2020. Ocular and systemic examinations were performed for each included patient. Genomic DNA from the included patients was analysed by whole-exome sequencing to detect mutations. Clinical manifestations were compared for different mutation subgroups. ResultsGene mutations were detected in 79 patients. Sixty-five were FBN1-associated, and most were related to Marfan syndrome (MFS). The FBN1 mutations mainly consisted of missense mutations (49/65) and were concentrated in the 5′ region. Probands with missense mutations tend to show high corneal astigmatism (χ2 = 3.98, P = 0.046) and severe lens dislocation (t = 2.90, P = 0.006) compared to premature termination codon (PTC) mutations. ConclusionsMost Chinese CEL patients were identified as having FBN1 mutations. Those with missense mutations commonly showed severe ocular phenotypes; therefore, reinforced follow-up and long-term observation are required. These correlations implicated the crucial role of missense and cysteine-involving mutations in ocular phenotypes, which might be explained by dominant-negative and nonsense-mediated mRNA decay (NMD).

Central and mid-peripheral corneal astigmatism in an elderly population: a retrospective analysis of Scheimpflug topography results

Implantation of toric intraocular lenses (IOLs) has become standard in the correction of corneal astigmatism. The IOL selection is based on keratometric measurements of the central cornea. However, mid-peripheral corneal changes may yield suboptimal correction in patients with larger pupils. This study retrospectively analyzed corneal topography data collected using a Scheimpflug device during routine clinical examinations. Of 11,953 patients, 641 met the inclusion criteria. Total corneal astigmatism was compared between five concentric zones (2–6 mm) using vector analysis. The absolute difference between astigmatism at 2 mm and 6 mm was 0.30 D (− 0.36 to 0.64), which decreased to 0.10 D (0 to 0.20) between the 5- and 6-mm zone. With-the-rule astigmatism was the most prevalent (53%), 34% had against-the-rule (ATR), and 13% had oblique. The decrease of the cylinder power with the diameter differed significantly between the three types, with ATR and oblique astigmatism being associated with the steepest change. Patients with high corneal astigmatism tend to demonstrate larger differences between the center and mid-periphery than those with low and moderate astigmatism. In conclusion, we demonstrated that central corneal astigmatism differs from that measured at the mid-periphery and that a larger difference was found in patients with ATR, oblique and high astigmatism.

Evaluation of preoperative corneal astigmatism using swept-source optical biometry in Chinese cataract surgery candidates with high myopia: a prospective, comparative observational study.

BackgroundHigh myopia and cataracts are major causes of blindness in East and Southeast Asia. Corneal astigmatism is a major contributor to uncorrected poor vision after cataract surgery in patients with high myopia. The purpose of the present study was to evaluate the demographic characteristics and distribution of preoperative corneal astigmatism in Chinese cataract surgery candidates with high myopia.MethodsSwept-source optical coherence tomography-based optical biometry was performed preoperatively in consecutive cataract surgery candidates who were classified by axial length (AL) into a high myopia group (defined as AL ≥26.0 mm) and a control group (normal ALs). The demographics, ALs, and keratometry values were recorded.ResultsAmong 15,063 cataract surgery candidates (15,063 eyes), 1,921 patients (12.8%, 1,921 eyes) in the high myopia group and 11,880 patients (11,880 eyes) in the control group were enrolled. In the high myopia group, the mean age was 59.8±12.6 (standard deviation) years, which was younger than that in the control group (69.1±11.0 years, P<0.001). In the high myopia group, the mean corneal astigmatism was 1.20±0.83 dioptre (D), which was greater than that in the control group (0.93±0.69 D, P<0.001). In the high myopia group, 82.2% had corneal astigmatism ≥0.50 D, 51.4% ≥1.00 D, 27.4% ≥1.50 D and 14.4% ≥2.00 D, all of which were higher than the respective proportions in the control group (P<0.001 for all). In the high myopia group, 66.8% had moderate to high corneal astigmatism, and 42.8% had “with-the-rule” astigmatism, and both of these proportions were higher than the respective proportions in the control group (P<0.001 for both). In the high myopia group, corneal astigmatism tended to increase with increasing age (r =0.134, P<0.001) after the age of 50, which was consistent with the tendency in the control group.ConclusionsA significant burden of preoperative corneal astigmatism was observed in Chinese cataract surgery candidates with high myopia. Moderate to high corneal astigmatism was more common in highly myopic eyes than in normal AL eyes.