Visual outcomes of cataract surgery performed by supervised novice surgeons during training in rural China

To assess the outcomes of cataract surgery performed by novice surgeons during training in a rural programme. Design: Retrospective study. Participants: Three hundred thirty-four patients operated by two trainees under supervision at rural Chinese county hospitals. Methods: Two trainees performed surgeries under supervision. Visual acuity, refraction and examinations were carried out 3 months postoperatively. Main Outcome Measures: Postoperative uncorrected visual acuity, pinhole visual acuity, causes of visual impairment (postoperative uncorrected visual acuity<6/18) Results: Among 518 operated patients, 426 (82.2%) could be contacted and 334 (64.4% of operated patients) completed the examinations. The mean age was 74.1±8.8 years and 62.9% were women. Postoperative uncorrected visual acuity was available in 372 eyes. Among them, uncorrected visual acuity was ≥6/18 in 278 eyes (74.7%) and <6/60 in 60 eyes (16.1%), and 323 eyes (86.8%) had pinhole visual acuity≥6/18 and 38 eyes (10.2%) had pinhole visual acuity<6/60. Main causes of visual impairment were uncorrected refractive error (63.9%) and comorbid eye disease (24.5%). Comorbid eye diseases associated with pinhole visual acuity<6/60 (n=23, 6.2%) included glaucoma, other optic nerve atrophy, vitreous haemorrhage and retinal detachment. Conclusions: The findings suggest that hands-on training remains safe and effective even when not implemented in centralized training centres. Further refinement of the training protocol, providing postoperative refractive services and more accurate preoperative intraocular lens calculations, can help optimize outcomes. © 2012 The Authors Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

Causes and five-year incidence of blindness and visual impairment in urban southern China:The Liwan Eye Study

PURPOSE. We determined the causes and five-year incidence of blindness and visual impairment (VI) in an adult, urban Chinese population. METHODS. Participants underwent a comprehensive eye examination at baseline in 2003 and then five years later. The World Health Organization (WHO) and United States (US) definitions were used to define incident blindness (WHO visual acuity [VA] < 20/400 in the better-seeing eye, US VA ≤ 20/200) and incident VI (WHO VA < 20/60-20/400, US VA < 20/40->20/200). RESULTS. Among 1405 baseline participants, 924 (75%) of 1232 survivors (87.7%) participated in the 5-year follow-up. The incidences of VI and blindness were 5.38% (95% confidence interval [CI] 3.99% ~ 7.07%) and 0.33% (95% CI 0.07% ~ 0.95%), respectively, based on the WHO definition, and 9.85% (95% CI 7.96% ~ 12.0%) and 1.42% (95% CI 0.76% ~ 2.41%), respectively, based on the US definition. Incidence of blindness and VI (WHO definition) increased significantly with older age (P < 0.001) and poorer baseline presenting VA in the worse-seeing eye (P < 0.001). The leading cause of best-corrected VI (WHO definition) was cataract (64.6%), whereas the main causes of presenting VI were refractive error (40.4%) and cataract (38.4%). CONCLUSIONS. The incidence of VI in urban Southern China is high. The major causes are unoperated cataract and undercorrected refractive error, reflecting the need for better surgical and refractive care, even in this urban setting. © 2013 The Association for Research in Vision and Ophthalmology, Inc.

Five-year incidence and postoperative visual outcome of cataract surgery in urban southern China:The liwan eye study

Purpose. To determine the 5-year incidence and visual outcome of cataract surgery in an adult urban Chinese population. Methods. A comprehensive eye examination was performed at baseline and 5 years later on subjects participating in a population-based study. Incident cataract surgery was defined as having undergone surgery in either eye during the 5-year period. Postoperative visual impairment (PVI) was defined as visual acuity (VA) <6/18 based on both presenting VA (PVA) and best corrected VA (BCVA) in the operated eye. Results. Among the 1405 baseline participants, 75% (924) of survivors were seen at the 5-year follow-up visit. Forty-four returning participants (62 eyes) had undergone incident cataract surgery, an incidence of 4.84% (95% confidence interval [CI] - [3.53, 6.44]). Detailed medical and surgical records were available for 54/62 (87.1%) eyes, and of these, 5/ 54 (24.1%) had an immediate preoperative visual acuity <6/ 120. All recorded surgeries were performed at tertiary-level hospitals with phacoemulsification and foldable intraocular lens implantation. Those undergoing cataract surgery were more educated (P < 0.05) and had poorer baseline PVA in the worse-seeing eye (P < 0.001) than 54 persons with baseline PVA <6/18 due to cataract who had not had surgery. Among the 62 operated eyes, 22.6% (14/62) had PVI based on PVA and 9.6% (6/62) based on BCVA. Conclusions. Despite somewhat lower incidence, outcomes of cataract surgery in urban southern China are comparable with developed countries and better than for rural China. In urban China, emphasis should be on improving access to surgery. (Invest Ophthalmol Vis Sci. 2012;53:7936-7942) © 2012 The Association for Research in Vision and Ophthalmology, Inc.

Visual symptoms and retinal straylight after laser peripheral iridotomy: the Zhongshan Angle-Closure Prevention Trial.

OBJECTIVE: To assess the impact of laser peripheral iridotomy (LPI) on forward-scatter of light and subjective visual symptoms and to identify LPI parameters influencing these phenomena. DESIGN: Cohort study derived from a randomized trial, using an external control group. PARTICIPANTS: Chinese subjects initially aged 50 or older and 70 years or younger with bilateral narrow angles undergoing LPI in 1 eye selected at random, and age- and gender-matched controls. METHODS: Eighteen months after laser, LPI-treated subjects underwent digital iris photography and photogrammetry to characterize the size and location of the LPI, Lens Opacity Classification System III cataract grading, and measurement of retinal straylight (C-Quant; OCULUS, Wetzlar, Germany) in the treated and untreated eyes and completed a visual symptoms questionnaire. Controls answered the questionnaire and underwent straylight measurement and (in a random one-sixth sample) cataract grading. MAIN OUTCOME MEASURES: Retinal straylight levels and subjective visual symptoms. RESULTS: Among 230 LPI-treated subjects (121 [58.8%] with LPI totally covered by the lid, 43 [19.8%] with LPI partly covered by the lid, 53 [24.4%] with LPI uncovered by the lid), 217 (94.3%) completed all testing, as did 250 (93.3%) of 268 controls. Age, gender, and prevalence of visual symptoms did not differ between treated subjects and controls, although nuclear (P<0.01) and cortical (P = 0.03) cataract were less common among controls. Neither presenting visual acuity nor straylight score differed between the treated and untreated eyes among all treated persons, nor among those (n = 96) with LPI partially or totally uncovered. Prevalence of subjective glare did not differ significantly between participants with totally covered LPI (6.61%; 95% confidence interval [CI], 3.39%-12.5%), partially covered LPI (11.6%; 95% CI, 5.07%-24.5%), or totally uncovered LPI (9.43%; 95% CI, 4.10%-10.3%). In regression models, only worse cortical cataract grade (P = 0.01) was associated significantly with straylight score, and no predictors were associated with subjective glare. None of the LPI size or location parameters were associated with straylight or subjective symptoms. CONCLUSIONS: These results suggests that LPI is safe regarding measures of straylight and visual symptoms. This randomized design provides strong evidence that treatment programs for narrow angles would be unlikely to result in important medium-term visual disability.

Causes and prevalence of visual impairment among adults in the United States.

OBJECTIVES: To estimate the cause-specific prevalence and distribution of blindness and low vision in the United States by age, race/ethnicity, and gender, and to estimate the change in these prevalence figures over the next 20 years. METHODS: Summary prevalence estimates of blindness (both according to the US definition of < or =6/60 [< or =20/200] best-corrected visual acuity in the better-seeing eye and the World Health Organization standard of < 6/120 [< 20/400]) and low vision (< 6/12 [< 20/40] best-corrected vision in the better-seeing eye) were prepared separately for black, Hispanic, and white persons in 5-year age intervals starting at 40 years. The estimated prevalences were based on recent population-based studies in the United States, Australia, and Europe. These estimates were applied to 2000 US Census data, and to projected US population figures for 2020, to estimate the number of Americans with visual impairment. Cause-specific prevalences of blindness and low vision were also estimated for the different racial/ethnic groups. RESULTS: Based on demographics from the 2000 US Census, an estimated 937 000 (0.78%) Americans older than 40 years were blind (US definition). An additional 2.4 million Americans (1.98%) had low vision. The leading cause of blindness among white persons was age-related macular degeneration (54.4% of the cases), while among black persons, cataract and glaucoma accounted for more than 60% of blindness. Cataract was the leading cause of low vision, responsible for approximately 50% of bilateral vision worse than 6/12 (20/40) among white, black, and Hispanic persons. The number of blind persons in the US is projected to increase by 70% to 1.6 million by 2020, with a similar rise projected for low vision. CONCLUSIONS: Blindness or low vision affects approximately 1 in 28 Americans older than 40 years. The specific causes of visual impairment, and especially blindness, vary greatly by race/ethnicity. The prevalence of visual disabilities will increase markedly during the next 20 years, owing largely to the aging of the US population.

Visual outcomes and astigmatism after sutureless, manual cataract extraction in rural China: study of cataract outcomes and up-take of services (SCOUTS) in the caring is hip project, report 1.

OBJECTIVE: To study the visual acuity and astigmatism of persons undergoing cataract extraction by local surgeons in rural China. METHODS: Visual acuity, keratometry, and refraction were measured 10 to 14 months postoperatively for all cataract cases during 4 months in Sanrao, China. RESULTS: Among 313 eligible subjects, 242 (77%) could be contacted, of whom 176 (73%) were examined. Of those who were examined, mean +/- SD age was 69.3 +/- 10.5 years, 66.5% were female, 35 had been operated on bilaterally at Sanrao, and 85.2% had a preoperative presenting visual acuity of 6/60 or worse. Presenting and best-corrected postoperative acuity in the eye that was operated on were 6/18 or better in 83.4% and 95.7%, respectively. Among 27 fellow eyes operated on elsewhere, 40.7% had a presenting acuity of 6/18 or better and 40.7% were blind (P < .001). Mean +/- SD postoperative astigmatism did not differ between 211 eyes that were operated on (-1.13 +/- 0.84 diopters) and 109 eyes that were not (-1.13 +/- 1.17 diopters; P = .27). Presence of operative complications (8.5%) and older age were associated with worse vision; bilateral surgery was associated with better vision. CONCLUSIONS: These results confirm the effectiveness of skill transfer in this setting, with superior outcomes to most studies in rural Asia and to eyes in this cohort operated on at other facilities.

Correction of moderate myopia is associated with improvement in self-reported visual functioning among Mexican school-aged children.

PURPOSE: To quantify the impact on self-reported visual functioning of spectacle provision for school-aged children in Oaxaca, Mexico. METHODS: The Refractive Status Vision Profile (RSVP), a previously validated tool to measure the impact of refractive correction on visual functioning, was adapted for use in rural children and administered at baseline and 4 weeks (27.3 +/- 4.4 days) after the provision of free spectacles. Visual acuity with and without correction, age, sex, and spherical equivalent refraction were recorded at the time of follow-up. RESULTS: Among 88 children (mean age, 12 years; 55.7% girls), the median presenting acuity (uncorrected or with original spectacles), tested 4 weeks after the provision of free spectacles, was 6/9 (range, 6/6-6/120). Significant improvements in the following subscales of the RSVP were seen for the group as a whole after the provision of free spectacles: function, 11.2 points (P = 0.0001); symptoms, 14.3 points (P < 0.0001); total score, 10.3 points (P = 0.0001). After stratification by presenting vision in the better-seeing eye, children with 6/6 acuity (n = 22) did not have significant improvement in any subscale; those with acuity of 6/7.5 to 6/9 (n = 34) improved only on function (P = 0.02), symptoms (P = 0.005), and total score (P = 0.003); and those with acuity of 6/12 or worse improved on total score (P < 0.0001) and all subscales. Subjects (n = 31) with uncorrected myopia of -1.25 D or more had a mean improvement in total score of 15.9 points (P < 0.0001), whereas those with uncorrected myopia between -0.50 and -1.00 D inclusive (n = 53) had a mean improvement of 8 points (P = 0.01). CONCLUSIONS: Provision of spectacles to children in this setting had a significant impact on self-reported function, even at modest levels of baseline visual disability. The correlation between presenting vision/refraction and improvement and the failure of children 6/6 at baseline to improve offer evidence for a real effect.

Distribution and visual impact of postoperative refractive error after cataract surgery in rural China: study of cataract outcomes and up-take of services report 4.

PURPOSE: To model the possible impact of using average-power intraocular lenses (IOLs) and evaluate the postoperative refractive error in patients having cataract surgery in rural China.SETTING: Rural Guangdong, China.METHODS: Patients having cataract surgery by local surgeons were examined and visual function was assessed 10 to 14 months after surgery. Subjective refraction at near and distance was performed bilaterally by an ophthalmologist. Patients had a target refraction of -0.50 diopter (D) based on ocular biometry.RESULTS: Of the 313 eligible patients, 242 (77%) could be contacted and 176 (74% of contacted patients, 56% overall) were examined. Examined patients had a mean age of 69.4 +/- 10.5 years. Of the 211 operated eyes, 73.2% were within +/-1.0 D of the target refraction after surgery. The best presenting distance vision was in patients within +/-1.0 D of plano and the best presenting near vision, in those with mild myopia (<-1.0 D to > or =2.0 D) (P= .005). However, patients with hyperopia (>+1.0 D) reported significantly better adjusted visual function than those with emmetropia or myopia (<-1.0 D). When the predicted use of an average-power IOL (median +21.5 D) was modeled, predicted visual acuity was significantly reduced (P= .001); however, predicted visual function was not significantly altered (P>.3).CONCLUSIONS: Accurate selection of postoperative refractive error was achieved by local surgeons in this rural area. Based on visual function results, aiming for mild postoperative myopia may not be suitable in this setting. Implanting average-power IOLs significantly reduced postoperative presenting vision, but not visual function.

Visual disability, visual function, and myopia among rural chinese secondary school children: the Xichang Pediatric Refractive Error Study (X-PRES)--report 1.

PURPOSE: To evaluate visual acuity, visual function, and prevalence of refractive error among Chinese secondary-school children in a cross-sectional school-based study. METHODS: Uncorrected, presenting, and best corrected visual acuity, cycloplegic autorefraction with refinement, and self-reported visual function were assessed in a random, cluster sample of rural secondary school students in Xichang, China. RESULTS: Among the 1892 subjects (97.3% of the consenting children, 84.7% of the total sample), mean age was 14.7 +/- 0.8 years, 51.2% were female, and 26.4% were wearing glasses. The proportion of children with uncorrected, presenting, and corrected visual disability (< or = 6/12 in the better eye) was 41.2%, 19.3%, and 0.5%, respectively. Myopia < -0.5, < -2.0, and < -6.0 D in both eyes was present in 62.3%, 31.1%, and 1.9% of the subjects, respectively. Among the children with visual disability when tested without correction, 98.7% was due to refractive error, while only 53.8% (414/770) of these children had appropriate correction. The girls had significantly (P < 0.001) more presenting visual disability and myopia < -2.0 D than did the boys. More myopic refractive error was associated with worse self-reported visual function (ANOVA trend test, P < 0.001). CONCLUSIONS: Visual disability in this population was common, highly correctable, and frequently uncorrected. The impact of refractive error on self-reported visual function was significant. Strategies and studies to understand and remove barriers to spectacle wear are needed.

Impact of posterior subcapsular opacification on vision and visual function among subjects undergoing cataract surgery in rural China: Study of Cataract Outcomes and Up-Take of Services (SCOUTS) in the Caring is Hip Project, report 5.

AIM: To study the effect of posterior capsular opacification (PCO) on vision and visual function in patients undergoing cataract surgery in rural China, and to compare this with the effect of refractive error. METHODS: Patients undergoing cataract surgery in at least one eye by local surgeons in a rural setting between 8 August and 31 December 2005 were examined with slit lamp grading of PCO 10-14 months after surgery. Subjects with any PCO associated with best-corrected visual acuity of 6/7.5 or worse, or with grade 2+ or worse PCO without visual decrement, were offered YAG laser capsulotomy. Vision and self-reported visual function were assessed, and various demographic and clinical factors potentially associated with PCO were recorded. RESULTS: Of 313 patients operated on within the study window, 239 (76%) could be contacted by telephone; study examinations were performed on 176 (74%). Examined subjects had a mean (SD) age of 69.4 (10.5) years, 116 (67%) were female, and 149 (86%) had been blind (presenting visual acuity < or = 6/60) in the operated eye before surgery. PCO of grade 1 or above was present in 34 of 204 operated eyes (16.7%). Those with PCO had significantly worse presenting vision (p = 0.007) but not visual function (p>0.3) than those without PCO. Women had a significantly higher prevalence of PCO (20.9%) than did men (8.6%, p<0.05). Of 19 eyes undergoing capsulotomy with best-corrected visual acuity measured the next day, 13 (68%) improved by one or more lines, and seven (37%) improved by two or more lines. Despite a higher uptake of capsulotomy (95%) as opposed to refraction (35%) in this cohort, the yield in terms of eyes with poor presenting visual acuity (< 6/18) that could be improved was higher for refraction (26% = 9/35) than for capsulotomy (9% = 3/35). CONCLUSION: The prevalence of PCO and impact on vision and visual function in this cohort was modest 1 year after surgery. However, PCO prevalence increases with time. Follow-up of this cohort is underway to determine the effectiveness of this early intervention in identifying and treating subjects who will eventually experience clinically significant PCO.

A population-based study of visual impairment among pre-school children in Beijing: the Beijing study of visual impairment in children.

PURPOSE: To evaluate the prevalence and causes of visual impairment among Chinese children aged 3 to 6 years in Beijing. DESIGN: Population-based prevalence survey. METHODS: Presenting and pinhole visual acuity were tested using picture optotypes or, in children with pinhole vision < 6/18, a Snellen tumbling E chart. Comprehensive eye examinations and cycloplegic refraction were carried out for children with pinhole vision < 6/18 in the better-seeing eye. RESULTS: All examinations were completed on 17,699 children aged 3 to 6 years (95.3% of sample). Subjects with bilateral correctable low vision (presenting vision < 6/18 correctable to >or= 6/18) numbered 57 (0.322%; 95% confidence interval [CI], 0.237% to 0.403%), while 14 (0.079%; 95% CI, 0.038% to 0.120%) had bilateral uncorrectable low vision (best-corrected vision of < 6/18 and >or= 3/60), and 5 subjects (0.028%; 95% CI, 0.004% to 0.054%) were bilaterally blind (best-corrected acuity < 3/60). The etiology of 76 cases of visual impairment included: refractive error in 57 children (75%), hereditary factors (microphthalmos, congenital cataract, congenital motor nystagmus, albinism, and optic nerve disease) in 13 children (17.1 %), amblyopia in 3 children (3.95%), and cortical blindness in 1 child (1.3%). The cause of visual impairment could not be established in 2 (2.63%) children. The prevalence of visual impairment did not differ by gender, but correctable low vision was significantly (P < .0001) more common among urban as compared with rural children. CONCLUSION: The leading causes of visual impairment among Chinese preschool-aged children are refractive error and hereditary eye diseases. A higher prevalence of refractive error is already present among urban as compared with rural children in this preschool population.

Cataract surgical outcomes, visual function and quality of life in four rural districts in Vietnam.

BACKGROUND: To evaluate cataract surgical outcomes in four rural districts of Ha Tinh Province, Vietnam. DESIGN: Cross-sectional study. PARTICIPANTS: Post-cataract surgery patients sampled randomly from facilities in four rural districts of Ha Tinh Province >3 months after surgery. MAIN OUTCOME MEASURES: Postoperative visual acuity (VA), visual function and quality of life. RESULTS: Among 412 patients, the mean age was 74.5 ± 9.4 years, 67% (276) were female, and 377 (91.5%) received intraocular lenses (IOL). Nearly two-thirds of patients had no postoperative visits after discharge. Postoperatively, more than 40% of eyes had presenting VA <6/18, while 20% remained <6/60. The mean self-reported visual function and quality of life for all patients were 68.7 ± 23.8 and 73.8 ± 21.6, respectively. Most patients (89.5%) were satisfied with surgery and the majority (94.4%) would recommend surgery to others. One-third of patients paid ≥$US50 for surgery. In multiple regression modelling, older age (P < 0.01), intraoperative complications (P < 0.01) and failure to receive an IOL (P < 0.01) were associated with postoperative VA <6/60. CONCLUSION: Satisfaction with surgery was high, and many patients were willing to pay for their operations. Poor visual outcomes were common; however, and better surgical training is needed to reduce complications and their impact on visual outcomes. More intensive postoperative follow-up may also be beneficial. © 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists.

Lighting conditions and optical filters effects on visual performance of speleologists exposed to cave environments

The aim of this study is to evaluate lighting conditions and speleologists’ visual performance using optical filters when exposed to the lighting conditions of cave environments. A crosssectional study was conducted. Twenty-three speleologists were submitted to an evaluation of visual function in a clinical lab. An examination of visual acuity, contrast sensitivity, stereoacuity and flashlight illuminance levels was also performed in 16 of the 23 speleologists at two caves deprived of natural lightning. Two organic filters (450 nm and 550 nm) were used to compare visual function with and without filters. The mean age of the speleologists was 40.65 (± 10.93) years. We detected 26.1% participants with visual impairment of which refractive error (17.4%) was the major cause. In the cave environment the majority of the speleologists used a head flashlight with a mean illuminance of 451.0 ± 305.7 lux. Binocular visual acuity (BVA) was -0.05 ± 0.15 LogMAR (20/18). BVA for distance without filter was not statistically different from BVA with 550 nm or 450 nm filters (p = 0.093). Significant improved contrast sensitivity was observed with 450 nm filters for 6 cpd (p = 0.034) and 18 cpd (p = 0.026) spatial frequencies. There were no signs and symptoms of visual pathologies related to cave exposure. Illuminance levels were adequate to the majority of the activities performed. The enhancement in contrast sensitivity with filters could potentially improve tasks related with the activities performed in the cave.