Background: To evaluate the global burden of cataracts by year, age, region, gender, and socioeconomic status using disability-adjusted life years (DALYs) and prevalence from the Global Burden of Disease (GBD) study 2019. Methods: Global, regional, or national DALY numbers, crude DALY rates, and age-standardized DALY rates caused by cataracts, by year, age, and gender, were obtained from the Global Burden of Disease Study 2019. Socio-demographic Index (SDI) as a comprehensive indicator of the national or regional development status of GBD countries in 2019 was obtained from the GBD official website. Kruskal-Wallis test, linear regression, and Pearson correlation analysis were performed to explore the associations between the health burden with socioeconomic levels, Wilcoxon Signed-Rank Test was used to investigate the gender disparity. Results: From 1990 to 2019, global DALY numbers caused by cataracts rose by 91.2%, crude rates increased by 32.2%, while age-standardized rates fell by 11.0%. Globally, age-standardized prevalence and DALYs rates of cataracts peaked in 2017 and 2000, with the prevalence rate of 1283.53 [95% uncertainty interval (UI) 1134.46–1442.93] and DALYs rate of 94.52 (95% UI 67.09–127.24) per 100,000 population, respectively. The burden was expected to decrease to 1232.33 (95% UI 942.33–1522.33) and 91.52 (95% UI 87.11–95.94) by 2050. Southeast Asia had the highest blindness rate caused by cataracts in terms of age-standardized DALY rates (99.87, 95% UI: 67.18–144.25) in 2019. Gender disparity has existed since 1990, with the female being more heavily impacted. This pattern remained with aging among different stages of vision impairments and varied through GBD super regions. Gender difference (females minus males) of age-standardized DALYs (equation: Y = -53.2*X + 50.0, P < 0.001) and prevalence rates (equation: Y = − 492.8*X + 521.6, P < 0.001) was negatively correlated with SDI in linear regression. Conclusion: The global health of cataracts is improving but the steady growth in crude DALY rates suggested that health progress does not mean fewer demands for cataracts. Globally, older age, females, and lower socioeconomic status are associated with higher cataract burden. The findings of this study highlight the importance to make gender-sensitive health policies to manage global vision loss caused by cataracts, especially in low SDI regions.

Purpose: To compare the visual outcomes of digital and slit-beam manual marking for toric intraocular lenses (IOL) in cataract surgery. Setting: Single-center, Beijing Tongren Hospital, China. Design: Retrospective study. Methods: All patients with cataracts and regular corneal astigmatism greater than 0.75 diopters (D) underwent cataract surgery and astigmatism correction between June 2019 and June 2020. To mark the target axis of the toric IOL and the location of the incision, intraoperative digital marking was used by Callisto eye image-guided system in one group, while preoperative manual slit-beam marking was used in the other group. Uncorrected and best-corrected spectacle visual acuity, refraction, toric IOL axis, total higher order aberrations, coma, spherical aberration, and trefoil were evaluated at 1, 4, and 12 weeks postoperatively. Results: Seventy-two eyes of 58 patients were included. At 3 months after surgery, the mean residual refractive cylinder was 0.42 ± 0.45D in the digital group and 0.39 ± 0.40D in the manual group (P = 0.844). There were no significant differences between groups in spherical equivalent refraction, uncorrected and best-corrected spectacle visual acuity, or the parameters of vector analysis. All toric IOL alignment errors were within 10° of the intended axis, and among them, about 42% of eyes in the digital group and 61% of eyes in the manual group had a rotation of 0–2° (P = 0.038). Trefoil in the manual group decreased postoperatively compared with the digital group (P = 0.012). Other aberration analyses did not reveal any statistical differences between groups. Conclusions: Accurate slit-beam manual marking and digital image-guided marking are equally effective for toric IOL alignment.

Background: In cataract surgery, calculating intraocular lens (IOLs) power in patients who have previously received corneal refractive surgery on the same eye presents a clinical challenge. This study aims to compare the accuracy of the Haigis-L, Barrett True-K, and Shammas-PL formulas in predicting the IOL power in eyes following corneal refractive surgery. Methods: This study analyzed 32 eyes belonging to 28 patients who underwent cataract surgery and IOL implantation after previously undergoing myopic corneal refractive surgery. The IOL power was calculated using the Haigis-L, Barrett True-K, and Shammas-PL formulas, and the accuracy of the three formulas was compared. Results: The Haigis-L, Barrett True-K, and Shammas-PL formulas had a mean arithmetic IOL prediction error of −0.65, −0.39, and −0.46, respectively. The mean numerical errors of the three formulas were significantly different from zero (P<0.001). The smallest median absolute refraction prediction error (median =0.40) belonged to the Barrett True-K formula, which was significantly smaller than that of the Haigis-L formula (median =0.57, P0.05). There was no significant difference in the percentage of eyes within either ±0.50 D or ±1.00 D of the predicted refraction error across the three formulas. Conclusions: The Barrett True-K formula can predict IOL power in eyes that have previously undergone myopic corneal refractive surgery better than the Haigis-L formula.

Objective To provide a reference for future policy and measure formulation by conducting a detailed analysis of the burden of vision loss due to cataract by year, age, and gender in China from 1990 to 2019. Methods Data on the prevalence and disability-adjusted life-years (DALYs) due to cataract in China and neighboring and other G20 countries were extracted from the 2019 Global Burden of Disease (GBD) study to observe the changing trends of vision loss. Results The number and rate of all-age prevalence and DALYs for cataract in China increased significantly from 1990 to 2019. The age-standardized DALYs rate witnessed a slowly declining trend by 10.16%. And the age-standardized prevalence increased by 14.35% over the 30-year period. Higher prevalence and DALYs were observed in female population from 1990 through 2019, with little improvement over the decades(all p < 0.001). The disease burden of cataract is higher in middle-aged and elderly people. Blindness accounted for the largest proportion of vision impairment burden caused by cataract in China. The age-standardized prevalence and DALY rate of cataract in China were lower than those in India and Pakistan, but higher than those in Russia, South Korea, North Korea, Singapore, and Japan. Conclusions In the past 30 years, although the age-standardized DALYs rate has decreased slightly in China, the all-age prevalence and DALYs have both increased. This study highlights the importance of reducing cataract burden by providing timely and easily accessible quality care, especially in females and the elderly population.