This prospective cohort study aimed to assess the influence of tear film stability on corneal refractive power measurement and surgical planning in cataract patients. Participants were divided into tear film instability (tear film stability level 2) and control (level 0–1) groups based on Keratograph 5M results. Using IOL Master 700, two consecutive measurements were obtained with a 10-min interval. Parameters including standard keratometry (Kf, Ks and K), keratometric corneal astigmatism (KCA), total keratometry (TKf, TKs and TK) and total corneal astigmatism (TCA) were recorded. IOL power was calculated using SRK-T, SRK-T TK, Haigis, Haigis TK, Barrett Universal II, and Barrett Universal II TK formulas. The results showed significantly higher differences between two measurements in Kf, K, KCA, TKf, TK, and TCA, as well as the vector variability of corneal astigmatism in the tear film instability group (all P ​< ​0.05). Of all formulas, only the SRK-T formula displayed significantly higher variability in IOL power calculations in the tear film instability group compared to the control group (P ​< ​0.05). This study highlights that tear film instability can lead to deviations in corneal refractive power and astigmatism measurements, contributing to increased prediction errors in IOL power calculation, particularly with the SRK-T formula.

Purpose. To compare long-term clinical outcomes between patients with bilateral implantation of +3.0 diopter (D) multifocal intraocular lenses (IOLs) and mix and match implantation of +2.5 D and +3.0 D multifocal IOLs. Material and Methods. This retrospective observer-masked cohort study comprised 66 eyes of 33 patients with two different strategies of binocular multifocal IOLs implantation: bilateral +3.0 D (17 patients) (bilateral group) and mix and match +2.5 D and +3.0 D (16 patients) (blended group). Patients were recruited 1 year (±3 months) after second-eye surgery. The primary effectiveness endpoint was binocular uncorrected intermediate visual acuity (UCIVA) at 70 cm. The secondary assessments included binocular visual quality tests and quality-of-vision questionnaire. Results. The blended group showed clinically better UCIVA (0.10 ± 0.07 logMAR) at 70 cm than the bilateral group (0.26 ± 0.09 logMAR) with a difference of 0.16 ± 0.08 logMAR (P<0.001). Similar binocular visual acuities were achieved between the two groups at the near and far distance. The binocular defocus curves showed better performance in the blended group from 50 cm to 1 m. The mean binocular contrast sensitivities under the photopic conditions with or without glare and mesopic condition without glare were clinically better in the blended group. Both the groups reported low rate of visual phenomena, high rate of spectacle independence, and satisfaction. Conclusions. Comparing with bilateral implantation of +3.0 D multifocal IOLs during the cataract surgery, mix and match implantation of +2.5 D and +3.0 D multifocal IOLs provides a wider depth of binocular focus, especially for intermediate distances, and better binocular visual quality.

Purpose: To investigate the influence of posterior corneal astigmatism on the prediction accuracy of toric multifocal intraocular lens (IOL) calculation. Methods: The keratometric astigmatism measured by Lenstar LS 900 (KCA(L)), keratometric astigmatism (KCA(P)) and total corneal astigmatism (TCA) measured by Scheimpflug camera (Pentacam HR) were documented and analyzed accordingly. Three deduction models using different parameters were compared. Model 1: KCA(L) + keratometric corneal surgically induced astigmatism (KCSIA, 0.30 D @ 50 degrees); Model 2: KCA(P) + KCSIA); Model 3: TCA + total CSIA (TCSIA, 0.23 D @ 50 degrees). The prediction errors of each model as the difference vector between the actual and the intended residual astigmatism were compared. Results: Seventy-six eyes implanted with toric multifocal IOLs were included in this study. The vector differences of the actual KCSIA and TCSIA were statistically significant in the total sample and against-the-rule (ATR) subgroup (both P < 0.05). Model 1 deduced the smallest mean values of prediction error, while that of Model 3 were smaller than that of Model 2, both in the total sample and the ATR subgroups (all P < 0.05). Meanwhile, in the total sample and ATR subgroups, the centroid vector magnitudes of Model 3 were smaller than that of Model 1 (0.31 +/- 0.76 D and 0.39 +/- 0.76 D). Conclusions: The calculation of toric multifocal IOL should be individualized especially in the ATR eyes for the impact of PCA on the estimation of the preoperative corneal astigmatism and the CSIA.

A retrospective cohort study was conducted to observe the correction effect of Toric intraocular lens (IOL) implantation in cataract eyes with specific types of irregular corneal astigmatism. Thirty-four eyes with either the "asymmetric bow-tie" pattern (Type I) or the "angled bow-tie" pattern (Type II) were included. Corneal topography was assessed using Pentacam HR, and changes in preoperative corneal astigmatism, visual acuity, manifest refraction, and objective visual quality were measured and compared. The average uncorrected distance visual acuity improved significantly from 0.86 ± 0.40 logMAR to 0.22 ± 0.15 logMAR (P < 0.001). Preoperative corneal astigmatism of 2.05 ± 0.90 D was corrected to a postoperative residual astigmatism of 0.78 ± 0.57 D (P < 0.001), with 32% of eyes within 0.50 D. The residual astigmatism prediction errors in Type I and Type II cases were (0.97 ± 0.68 D) and (0.66 ± 0.37 D), respectively (P = 0.100). The mean spherical equivalent prediction error in Type II cases (0.07 ± 0.36 D) was significantly smaller than that in Type I cases (− 0.29 ± 0.52 D) (P = 0.030). This study concludes that Toric IOL implantation effectively corrects specific types of irregular corneal astigmatism in cataract surgery. Eyes with the "angled bow-tie" pattern show higher accuracy in refractive predictions compared to eyes with the "asymmetric bow-tie" pattern.

Purpose: Retinal microvasculature plays an important role in children's fundus lesions and even in their later life. However, little was known on the features of normal retina in early life. The purpose of this study was to explore the normal retinal features in the first 6 years of life and provide information for future research.Methods: Children, aged from birth to 6 years old and diagnosed with various unilateral ocular diseases were included. Venous phase fundus fluorescein angiography images with the optic disc at the center were collected. Based on the ResUNet convolutional neural network, optic disc and retinal vascular features in the posterior retina were computed automatically.Results: A total of 146 normal eyes of 146 children were included. Among different age groups, no changes were shown in the optic disc diameter (y = −0.00002x + 1.362, R² = 0.025, p = 0.058). Retinal vessel density and fractal dimension are linearly and strongly correlated (r = 0.979, p < 0.001). Older children had smaller value of fractal dimension (y = −0.000026x + 1.549, R²= 0.075, p = 0.001) and narrower vascular caliber if they were less than 3 years old (y = −0.008x + 84.861, R²= 0.205, p < 0.001). No differences were in the density (y = −0.000007x + 0.134, R²= 0.023, p = 0.067) and the curvature of retinal vessels (lnC = −0.00001x − 4.657, R²= 0.001, p = 0.667).Conclusions: Age and gender did not impact the optic disc diameter, vessel density, and vessel curvature significantly in this group of children. Trends of decreased vessel caliber in the first 3 years of life and decreased vessel complexity with age were observed. The structural characteristics provide information for future research to better understand the developmental origin of the healthy and diseased retina.

Purpose To compare the performance of Barrett toric calculator incorporated with measured posterior corneal astigmatism (PCA) derived from IOL Master 700 and Pentacam HR versus predicted PCA. Methods The predicted residual astigmatism using Barrett toric IOL calculator with predicted PCA, measured PCA from IOL Master 700 and measured PCA from Pentacam were calculated with the preoperative keratometry and intended IOL axis with modification. The vector analysis was performed to calculate the mean absolute prediction error (MAE), the centroid of the prediction error and the percentage of eyes with a prediction error within ±0.50 D, ±0.75 D, and ±1.00 D. Results In 57 eyes of 57 patients with mean age of 70.42 ± 10.75 years, the MAE among the three calculation methods were 0.59 ± 0.38 D (Predicted PCA), 0.60 ± 0.38 D (Measured PCA from IOL Master 700) and 0.60 ± 0.36 D (Measured PCA from Pentacam) with no significant difference, either in the whole sample, the WTR eyes and the ATR eyes (F = 0.078, 0.306 and 0.083, p = 0.925, 0.739 and 0.920, respectively). Measured PCA obtained from IOL Master 700 resulted in one level reduction (from Tn to Tn-1) in 49.12% eyes in cylindrical model selection, while measured PCA obtained from Pentacam resulted in one level reduction of toric model selection in 18.18% eyes. Conclusion The present study suggested that the incorporation of measured PCA values derived from IOL Master 700 and Pentacam produce comparable clinical outcome with the predicted PCA mode in Barrett toric calculator.