Duoru Lin

10-Year Overview of the Hospital-Based Prevalence and Treatment of Congenital Cataracts: The CCPMOH Experience

A review of 6 years of hospitalization charts from Zhongshan Ophthalmic Center (ZOC) revealed that congenital cataracts (CC) accounted for 2.39% of all cataract in-patient cases and that the age at surgery was decreasing before the establishment of the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH) in December 2010. We aimed to investigate data from the 4 years (January 2011 to December 2014) following the establishment of the CCPMOH, compared, and combined with data from the previous study period (January 2005 to December 2010) to generate a 10-year overview of the hospital-based prevalence and treatment of CC. In the 4-year period after CCPMOH establishment, the prevalence of CC was 2.01% in all hospitalizations, and was 2.78% in all cataract in-patients. Most of the eligible CC in-patients (71%) lived in south China. The ratio of boys to girls was 1.42:1. Nearly 2/3 of the patients underwent cataract extraction with primary intraocular lens (IOL) implantation at a mean age of 78.40±51.45 months, and cataract extraction surgeries without IOL implantation were performed in the remaining 1/3 of patients at a mean age of 10.03±15.92 months. After CCPMOH establishment, an increased incidence of CC was revealed, and the CC in-patients were younger than the patients in the previous period. The 10-year overview (2421 CC in-patients from 206630 hospitalizations) revealed upward trends in both the number and the prevalence of CC and a further reduction in age at surgery. In conclusion, the data from 4-year period after CCPMOH establishment and the 10-year overview showed upward trends in the hospital-based prevalence of CC cases and a further reduction in age at surgery, likely reflecting the effects of the CCPMOH establishment and providing useful information for further CC studies and a valuable foundation for the prevention and treatment of this cause of childhood blindness.

Prevalence of Corneal Astigmatism and Anterior Segmental Biometry Characteristics Before Surgery in Chinese Congenital Cataract Patients

The prevalence and the distribution characteristics of corneal astigmatism (CA) and anterior segment biometry before surgery in Chinese congenital cataract (CC) patients are not completely understood. This study involved 400 CC patients from the Zhongshan Ophthalmic Center enrolled from February 2011 to August 2015. Data on CA, keratometry, central corneal thickness (CCT) and anterior chamber depth (ACD) were measured by the Pentacam Scheimpflug System. The mean age of patients was 54.27 months, and the ratio of boys to girls was 1.53:1. The mean CA was 2.03 diopters (D), and 39.25% of subjects had CA values ≥2 D. The most frequent (71.8%) diagnosis was with-the-rule astigmatism. Oblique astigmatism was present in 16.2% of cases, and 12% of cases had against-the-rule astigmatism. The mean keratometry measurement of cataractous eyes in bilateral patients was significantly larger than that in unilateral patients. Girls had a larger mean keratometry but a thinner CCT than did boys. The CA, CCT, and ACD of cataractous eyes were significantly larger than those of non-cataractous eyes in unilateral patients. The CA, mean keratometry, CCT, and ACD in CC patients varied with age, gender, and laterality. Fully understanding these characteristics may help inform guidelines and treatment decisions in CC patients.

Distribution of Axial Length before Cataract Surgery in Chinese Pediatric Patients

Axial length (AL) is a significant indicator of eyeball development, but reports on the overall status of axial development in congenital cataract (CC) patients and its relationship with patient demographics, such as age, sex, and laterality, are rare. We prospectively investigated the AL of 1,586 patients ≤18 years old and undergoing cataract surgery in China from January 2005 to December 2014. Of these 3,172 eyes, a logarithmic correlation between AL and age in CC patients was calculated, and an age of approximately 2 years was found to be a turning point in the growth rate of AL. A considerable variation was observed in CC patients of the same age. Furthermore, 2–6 years old boys had longer AL than girls. The AL of affected eye in unilateral patients was longer than that of the contralateral eye in 2–6 years age group and longer than that of eye in bilateral CC patients in all age groups. These findings indicate that the development of the length of eyeballs in CC patients is influenced by multiple factors in addition to age. A full understanding of the distribution of AL may provide a useful reference for judging the timing of surgery in CC patients.

A Novel Congenital Cataract Category System Based on Lens Opacity Locations and Relevant Anterior Segment Characteristics.

Purpose We compared the anterior segment characteristics of congenital cataract (CC) patients with lens opacities in different locations and proposed a modified, simple CC category system. Methods Cataractous eyes of CC patients were classified into four groups based on the locations of lens opacities shown in slit-lamp examinations and by a 3-dimensional anterior segment imaging system as follows: total, anterior, interior, and posterior cataracts. The mean keratometry value, corneal astigmatism (CA), central corneal thickness (CCT), and anterior chamber depth (ACD) of eyes in different groups were compared. Results We included a total of 428 CC patients. Half of the patients with an anterior cataract had the complication of a pupillary residual membrane. Among the patients with posterior lentiglobus cataracts, 90.38% had unilateral involvement. Patients with total, anterior, or interior cataracts had larger keratometry values than those with either posterior cataracts or clear lens. Congenital cataract patients had greater CA and CCT values than those with a clear lens. The largest CA was presented in patients with anterior cataracts, and the value decreased gradually with more posterior locations of lens opacities. Eyes with total and anterior cataracts had smaller ACDs, and eyes with interior and posterior cataracts had greater ACDs than eyes with a clear lens. Conclusions Cataractous eyes in CC patients with lens opacities in different locations presented distinct anterior segment characteristics. The modified CC category system, based on the relationships among the locations of lens opacities and anterior segment characteristics, may be beneficial for CC diagnosis and treatment.

Patient participation in free cataract surgery: a cross-sectional study of the low-income elderly in urban China

Objectives To explore the characteristics of the low-income elderly who underwent free cataract surgery and to determine the degree of patient satisfaction with the free cataract surgery programme in urban China. Methods A free cataract surgery management workflow was designed as a poverty relief project in Guangzhou. In this study, participants who underwent free cataract surgery between January and August 2014 received a telephone interview based on a structured questionnaire. Data were collected on patient demographics, resources, health conditions, reasons for undergoing the free surgery and overall evaluation of the free cataract surgery programme. Results Among the 833 participants, the mean surgical age was 76.85±7.46 years (95% CI 76.34 to 77.36), and the male to female ratio was 385:448. The majority (94.31%, 746/791) of patients resided in the main urban districts. Patients underwent surgery 61.08±60.15 months (95% CI 56.17 to 66.00) after becoming aware of the cataract, although 66.83% of them reported that their daily lives were influenced by cataracts. Only 21.5% of the respondents underwent physical examinations that included regular eye screening, and only 6.30% were highly educated patients. Financial problems were the primary reason cited by patients for participating in the free surgery programme. Those patients with a monthly family income of 1000–2999¥ (US

Timing and approaches in congenital cataract surgery: a randomised controlled trial

161–482) per capita constituted the largest patient population. The free clinics in the parks and the free cataract surgery were highly rated (9.46 and 9.11 of 10 points) by the beneficiaries. Conclusions The telephone survey revealed a high level of patient satisfaction regarding the free cataract surgery programme. Most of the patients who participated in the programme resided in major urban districts and had poor health awareness and a low level of education. The information provided by this study is crucial for improving and expanding the management of free cataract surgery programmes. Trial registration number NCT02633865; Post-results.

Visual Outcome and Related Factors in Bilateral Total Congenital Cataract Patients: A Prospective Cohort Study.

BACKGROUND The optimum timing of surgery and the approach that should be used during congenital cataract surgery are controversial and present challenges for paediatric cataract surgeons in China. The aim of this study was to compare visual prognoses and postoperative adverse effects of paediatric cataract surgery done at different times and using different surgical approaches. METHODS In this prospective, randomised controlled trial, we recruited Chinese patients aged 3 months or younger who were diagnosed with bilateral diffuse or total cataracts, but who did not have coexisting ocular, systemic or neurological diseases. Patients were randomly assigned into two surgical timing groups: a 3-month-old and a 6-month-old. Each eye had one of three randomly assigned surgical procedures: lens aspiration, lens aspiration with posterior continuous curvilinear capsulorhexis, and lens aspiration with posterior continuous curvilinear capsulorhexis and anterior vitrectomy. Long-term visual acuity and incidence of postoperative secondary glaucoma and severe posterior capsular opacification were the primary outcomes. χ2 tests, Fishers exact tests and Kruskal-Wallis tests were used to compare the outcomes between groups. Generalised Estimating Equation with a working covariance matrix of unstructured correlations was integrated into the multivariate linear regression to explore the relationship between long-term visual acuity and the incidence of complications. The research protocol was approved by the Institutional Review Board and Ethics Committee of Sun Yat-sen University. Informed written consent was obtained from at least one family member of each participating patient, and the study was done according to the Declaration of Helsinki. This trial is registered with ClinicalTrials.gov, number NCT02581046. FINDINGS We recruited 61 patients (30 girls, 31 boys) to our study. 4 children were excluded from the final analysis because their parents declined participation. A total of 57 participants (114 eyes) with a mean follow-up of 48·7 months were included in the final analysis. Long-term visual acuity in patients who underwent surgery aged 6 months (0·81 [SD 0·28]) was better than that of patients who had surgery aged 3 months (0·96 [0·30], p=0·02) and incidence of posterior capsular opacification during the 6 months following surgery was positively correlated with long-term visual acuity (β=-0·080, p=0·036). Two (2/95, 2%) eyes with a confirmed diagnosis of secondary glaucoma were in the 3-month-old group, and additional surgical interventions were done in these patients to lower the intraocular pressure. For patients who had surgery aged 6 months, the incidence of severe posterior capsular opacification was significantly higher in the lens aspiration group than other two groups (lens aspiration, 8/15 [53%]; lens aspiration with posterior continuous curvilinear capsulorhexis, 3/21 [14%]; and lens aspiration with posterior continuous curvilinear capsulorhexis and anterior vitrectomy, 3/16 [19%]; p=0·03). INTERPRETATION It was safer and more effective for Chinese bilateral diffuse congenital cataract patients to have surgery of lens aspiration with posterior continuous curvilinear capsulorhexis with or without anterior vitrectomy at 6 months of age than at 3 months of age. FUNDING National Basic Research Program (973; 2015CB964600); Natural Science Foundation of Guangzhou (91546101, 81300750); Clinical Research and Translational Medical Center for Pediatric Cataract in Guangzhou, China.

Developmental profile of ocular refraction in patients with congenital cataract: a prospective cohort study.

This study is to evaluate the visual outcome and identify its crucial related factors in children undergoing cataract surgery for bilateral total congenital cataract (CC). This prospective study included consecutive bilateral total cataract patients undergoing primary surgery at Zhongshan Ophthalmic Center (ZOC), Guangzhou, China from Jan 2010 to May 2014. Visual outcome was estimated by best-corrected visual acuity (BCVA) at last follow-up. Potential related factors, including gender, age at last follow-up, age at primary surgery, surgical procedure, postoperative complications (PCs), frequency of follow-up and changes in spectacles were evaluated. Eighty-eight children (176 eyes) were included in the cohort. The mean post-operative BCVA (logMAR) was 1.07 ± 0.53 at the mean follow-up duration 31.07 ± 19.36 months. Multivariable generalized estimating equations (GEEs) showed BCVA was significantly associated with PCs, age at last follow-up and age at primary surgery. Partial correlation analysis indicated age at primary surgery was positively correlated with BCVA controlling for the other factors, both for the whole age range (R = 0.415, P < 0.001) and age >6 months (R = 0.867, P < 0.001). Better visual acuity was related to early primary surgery and low PC occurrence in children with bilateral total CC. Timely surgical intervention and strict control of PCs would be potential steps to achieving better visual outcome.

Construction and implications of structural equation modeling network for pediatric cataract: a data mining research of rare diseases

BACKGROUND Refractive status is crucial to visual function and can change throughout life. For patients with congenital cataract, the developmental profile of refraction is complicated owing to the potential influence of diverse clinical manifestations and various treatments, and has not yet been fully characterised. METHODS In this prospective cohort study, we enrolled patients with congenital cataract from the Childhood Cataract Program of the Chinese Ministry of Health (CCPMOH). Two experienced cataract surgeons (YL and WC) did cataract removal or intraocular lens (IOL) implantation at Zhongshan Ophthalmic Center. Patients were followed up at 1 week, 1 month, and 3 months postoperatively, then every 3 months thereafter. Follow-up refraction assessments were conducted with objective retinoscopy and cycloplegia, and were performed by experienced independent optometrists. We compared refraction status (presented as spherical equivalent), and the rate of myopic shift between bilateral and unilateral congenital cataract with linear mixed model (LMM) analysis, then compared the range of myopic shift between bilateral and unilateral congenital cataract with multivariate linear regression Ethical approval was provided by the institutional review board of the Zhongshan Ophthalmic Center (Guangzhou, China). Parents of participating children provided written informed consent. FINDINGS Between Jan 1, 2010, and Oct 31, 2013, we enrolled 1258 participants, all of whom underwent cataract removal and/or intraocular lens (IOL) implantation. By study completion on Oct 31, 2015, 1164 (93%) participants had attended at least one follow-up visit and had refraction status recorded (6585 follow-ups total). Median follow-up was 3 years (IQR 2·5-4·5 years). Spherical equivalent measurements decreased by 1·36 D (SD 0·06) per year between 0·5 years and 4 years of age in bilateral and unilateral congenital cataract aphakic patients. The spherical equivalent of unilateral aphakia was 0·67 D (SD 0·31) smaller than that of bilateral aphakia after correcting for age and sex (p=0·0325). Spherical equivalents in congenital cataract pseudophakia decreased by 0·28 D (SD 0·02) between 1·5 years and 18 years of age (p<0·0001). Spherical equivalents in unilateral pseudophakia did not differ from bilateral pseudophakia (p=0·2996). With the current strategy for IOL calculation, the spherical equivalent in congenital cataract pseudophakia reached emmetropia around 6 years of age, while the healthy eyes of unilateral congenital cataract reached emmetropia at 9-10 years. The rate of myopic shift peaked in both young childhood and early adolescence in all participants. The range of myopic shift in the unilaterally congenital cataract affected eyes was correlated with age at refraction measurement, cataract removal, and IOL implantation, as well as with sex. INTERPRETATION Factors that dictate the range of myopic shift in unilateral congenital cataract seem to be different from those in bilateral congenital cataract, indicating differences in the aetiopathogenesis and refractive prognosis between bilateral and unilateral congenital cataract. Refraction data from patients with congenital cataract are of clinical significance to the guidelines for congenital cataract treatment, especially for IOL calculation concerning the laterality of congenital cataract. FUNDING National Natural Science Foundation of China (number 81300750), the Ministry of Science and Technology of China Grants (973 program, 2015CB964600), the Key Research Plan for the National Natural Science Foundation of China (number 91546101) and the Guangdong Provincial Natural Science Foundation for Distinguished Young Scholars of China (number 2014A030306030).

Impairments of Visual Function and Ocular Structure in Patients With Unilateral Posterior Lens Opacity

BackgroundThe majority of rare diseases are complex diseases caused by a combination of multiple morbigenous factors. However, uncovering the complex etiology and pathogenesis of rare diseases is difficult due to limited clinical resources and conventional statistical methods. This study aims to investigate the interrelationship and the effectiveness of potential factors of pediatric cataract, for the exploration of data mining strategy in the scenarios of rare diseases.MethodsWe established a pilot rare disease specialized care center to systematically record all information and the entire treatment process of pediatric cataract patients. These clinical records contain the medical history, multiple structural indices, and comprehensive functional metrics. A two-layer structural equation model network was applied, and eight potential factors were filtered and included in the final modeling.ResultsFour risk factors (area, density, location, and abnormal pregnancy experience) and four beneficial factors (axis length, uncorrected visual acuity, intraocular pressure, and age at diagnosis) were identified. Quantifiable results suggested that abnormal pregnancy history may be the principle risk factor among medical history for pediatric cataracts. Moreover, axis length, density, uncorrected visual acuity and age at diagnosis served as the dominant factors and should be emphasized in regular clinical practice.ConclusionsThis study proposes a generalized evidence-based pattern for rare and complex disease data mining, provides new insights and clinical implications on pediatric cataract, and promotes rare-disease research and prevention to benefit patients.