Pediatric cataract surgery in Nepal

Universal newborn eye screening: a systematic review of the literature and review of international guidelines

Background

This systematic review assessed the effectiveness of universal screening for newborn eye abnormalities compared with no screening in improving infant vision and health outcomes.

Methods

We searched CENTRAL (Cochrane Library), MEDLINE, Embase, Global Health, Global Index Medicus, clinical trials databases, and bibliographies of relevant articles. We included randomized and observational studies of all newborns, regardless of illness or risk factors, that compared universal screening for any eye abnormality by eight weeks of age with no universal screening. Two authors independently selected studies, extracted data, and evaluated the risk of bias. We used GRADE to assess the certainty of evidence. We also reviewed available recommendations on newborn eye screening.

Results

Fourteen studies were identified but only three compared universal red reflex screening with no screening. Findings suggest that universal red reflex testing in maternity wards (MWs) may increase the number of newborns with congenital cataracts referred for eye care from MWs or well-baby clinics (WBCs) in the first year of life (risk ratio (RR) = 9.83, 95% confidence interval (CI) = 1.36-71.20; low certainty evidence). However, the effect of screening in WBC is uncertain (RR = 6.62, 95% CI = 0.87-50.09). The effect of MW or WBC screening on referral from any health care facility (MWs, WBCs, paediatrician clinic, other) in the first year is uncertain (MW screening: RR = 1.22, 95% CI = 0.63-2.39; WBC screening: RR = 0.97, 95% CI = 0.46-2.05). However, referral or surgery by 6 weeks of age may be higher with universal MW screening (early referral: RR = 4.61, 95% CI = 1.12-19.01; early surgery: RR = 8.23, 95% CI = 1.13-59.80; low certainty evidence). The effect of WBC screening on early referral and surgery is uncertain (early referral: RR = 1.98, 95% CI = 0.43-9.19; early surgery: RR = 3.97, 95% CI = 0.50-31.33; very low certainty evidence). Universal red reflex testing may increase clinical conjunctivitis (OR = 1.22, 95% CI = 1.01-1.47; low certainty evidence) but the effect on confirmed bacterial conjunctivitis is uncertain (OR = 1.20, 95% CI = 0.76-1.90; very low-certainty evidence). Nine guidelines recommended universal newborn eye screening using red reflex testing.

Conclusions

Evidence supports the role of red reflex testing shortly after birth to increase early identification, referral, and surgery for congenital cataracts.

Bilateral paediatric cataract surgery - outcomes of 298 children from Kinshasa, the Democratic Republic of the Congo

INTRODUCTION

The leading cause of childhood blindness globally is paediatric cataract. Bilateral cataract surgery can help to improve visual performance and to diminish the burden of childhood blindness.

OBJECTIVE

To report in a retrospective observational cohort study the long-term outcomes of 298 children who had bilateral cataract surgery with IOL implantation from 2001-2016 in Kinshasa.

METHODS

A standardized surgical treatment of paediatric cataract was practiced on 298 children. Patient's follow-up, complications, and visual outcomes were recorded and analysed.

RESULTS

The mean age was 5.7 ± 4.3 years and males were predominant (64.9%). Most of children were living mainly in urban poorest areas (96.3%). Strabismus, nystagmus and microcornea were encountered in 20.1%, 25.1% and 8.7% of children, respectively. Using WHO criteria most of patients were classified as blind preoperatively and 81.9% of them had improved visual outcomes after surgery. Main reasons for reduced vision during follow-up were secondary cataract (5.7%), IOL decentration (1.2%), retinal detachment (1.2%), and secondary glaucoma (1.5%).

CONCLUSION

In spite of the post conflict challenges, elimination of cataract blindness in children remains a priority. Children present at a late age for surgery and long term follow-up is poor. There is need for program strengthening in these areas.

Causes of delayed presentation of pediatric cataract: A questionnaire-based prospective study at a tertiary eye care center in central rural India

Purpose

To find out the sociodemographic, sociocultural, and socioeconomic factors leading to delay in pediatric cataract surgery and its impact on final visual outcome.

Methods

A prospective interview-based analytical cohort study was conducted on 156 children aged 0-16 years with either unilateral or bilateral congenital/developmental cataracts. Caregivers were interviewed using a pretested validated questionnaire. Time intervals between recognition by a caregiver to consultation were denoted as Delay-1 and between consultations to surgical intervention as Delay-2. Spearman's rank correlation was used to determine the presence of correlation between causes of delay and visual outcome.

Results

The mean age of presentation was 7.78 ± 4.34 years. Mothers were the first informant of the problem (n = 110, 70.5%). Out of 156 children, only 8 (5.1%) children presented to the hospital within 1 month by caregivers and 26 (16.7%) children underwent surgery within 2 months of advice. About 22 (14.1%) children had total cumulative delay of 1-6 months, 11 (7%) had delay of 6-12 months, and 115 (73.71%) had delay of >12 months. The most common cause identified for Delay-1 was unawareness in 41 cases (26.28%), however, for Delay-2 major factor responsible was cost (n = 38, 24.35%). The median preoperative visual acuity was 1.31 logMAR and median postoperative visual acuity at 4 weeks was 0.61 logMAR. (P < 0.001) Less age at surgery, upper socioeconomic status, less time delay, and better preoperative vision were positively correlated to better visual outcomes.

Conclusion

Delay in presentation for childhood cataract surgery remains a significant problem in central rural India. Delay in surgery is multifactorial which includes unawareness, cost, misdiagnosis, self-treatment, distance from the hospital, lack of family support, and poor socioeconomic status.

Pediatric cataract surgery with hydrophilic acrylic intraocular lens implantation in Nepalese children

Purpose

To assess the outcome of cataract surgery with hydrophilic acrylic intraocular lens (IOL) implantation in children with congenital and developmental cataracts.

Method

A retrospective review of medical records of children with congenital or developmental cataracts who underwent cataract surgery with hydrophilic IOL implantation, from January 2011 to December 2014 in a tertiary eye hospital in Nepal. Primary posterior capsulotomy, anterior vitrectomy, and IOL implantation was done in children 8 years or younger, while older children underwent only lens aspiration and IOL implantation.

Results

A total of 178 eyes of 120 children underwent cataract surgery with primary IOL implantation. Mean age at the time of surgery was 6.9 years (range: 3 months to 15 years). Average follow-up time was 13.7 (±5.9) months. Associated ocular anomalies were present in 84 (47.1%) eyes. Postoperative complications were found in 33 eyes (18.13%) with inflammatory membrane being the most common (10.1%). Two eyes (1.1%) developed endophthalmitis. Second intervention was needed in 12 (6.5%) eyes. Preoperative vision of less than 6/60 was present in 105 eyes (57.69%). Final best corrected visual acuity of 6/12 or better was found in 81 (44.5%) eyes.

Conclusion

Our study shows that hydrophilic IOL is suitable for use in children. Results of this study are comparable with other studies on pediatric cataract surgeries using hydrophobic acrylic intraocular lenses. Low cost hydrophilic lens implantation is an effective approach in managing pediatric cataract surgery in developing countries like Nepal.

Infantile cataract: comparison of two surgical approaches

OBJECTIVE

To compare the results of 2 cataract extraction techniques with primary intraocular lens (IOL) implantation in children.

DESIGN

Retrospective comparative case series study.

METHODS

This study included children with congenital or developmental cataract. In all cases, anterior capsulorhexis, lens aspiration, posterior continuous curvilinear capsulorhexis, and primary IOL implantation were performed. We compared 2 surgical approaches. In the first approach, after IOL implantation in the bag, posterior optic capture (OC) was performed without anterior vitrectomy (OC technique); in the second approach, anterior vitrectomy was performed without OC of the IOL (AV technique). Patient demographic data as well as ethnic origin, child's age at cataract diagnosis, child's age at surgery, axial length, IOL power in diopters, visual acuity, visual axis opacification, and complications were assessed.

RESULTS

One hundred twenty-three eyes were included for surgical approach outcomes comparison; 21 eyes underwent the OC surgical approach and 102 the AV surgical approach. The mean patient age at surgery was 57.3 ± 47.1 months. The mean follow-up was 63.13 months (range 12-202 months). Epithelial lens reproliferation was the major adverse event in our series, affecting 21.1% of patients' eyes; the mean time to epithelial lens reproliferation development was 90 ± 9.70 months. There was no statistically significant difference between the two groups in best spectacle-corrected visual acuity or epithelial lens reproliferation incidence.

CONCLUSIONS

In our case series we did not find any difference between surgical techniques.

Visual outcomes of dense pediatric cataract surgery in eastern China

Purpose

To evaluate the visual outcomes of dense pediatric cataract surgery in eastern China.

Methods

Medical records of children who underwent surgery for dense unilateral or bilateral pediatric cataract in Shandong Provincial Hospital between January 2007 and December 2012 were collected. Patients who cooperated with optical correction and aggressive patching of the sound eye and who had a minimum postoperative follow-up of more than 2 years were included. Risk factors for poor visual outcomes were analyzed.

Results

Of the 105 eligible patients (181 eyes), 76 had bilateral cataract, and 29 unilateral. With a mean follow up of 46.77 mo (range 24.0~96.0 mo), the final best corrected visual acuity (BCVA) of 158 eyes were recorded, and 4.43% (7/158) achieved 0.1 logarithm of the minimum angle of resolution (logMAR) or better; 15.19% (24/158) obtained a BCVA between 0.1 logMAR and 0.3 logMAR; 18.99%, (30/158) between 0.3 logMAR and 0.5 logMAR; 46.84% (74/158), between 0.5 logMAR and 1 logMAR; 14.55%, worse than 1 logMAR. The mean BCVA of the patients who underwent lensectomy before 3 months of age was significantly better than that of patients who underwent lensectomy between 3 and 12 months (p = 0.001). In the same lensectomy age groups, the final BCVA of the children in the bilateral and unilateral groups did not differ significantly (P>0.05). Lensectomy after 3 months of age, postoperative complications, strabismus and nystagmus were shown to be risk factors for poor visual outcomes.

Conclusions

Lensectomy before 3 months of age, IOL implantation, proper managing of postoperative complications, early optical correction and aggressive postoperative patching of the sound eye would increase the final BCVA for patients with dense pediatric cataract.

Access to controlled medicines for anesthesia and surgical care in low-income countries: a narrative review of international drug control systems and policies

PURPOSE

This article describes the functioning of the international drug control system, its integration into national legislation and policy, and the collective impact on access to medicines.

SOURCE

We conducted a review of the three international drug control conventions, peer-reviewed articles, and grey literature known to the authors that describes national and international drug control systems and their impact on access to controlled medicines. This review was supplemented with literature derived from a structured search of MEDLINE^® for articles relating to medical uses of ketamine in low- and middle-income countries conducted to strengthen an advocacy campaign. We illustrate the impact of the drug control system on access to medicines through an analysis of current levels of availability of opioids in many countries as well as through a description of the ongoing advocacy work to ensure the availability of ketamine for medical care in low-income countries.

PRINCIPAL FINDINGS

The complexity of the international drug control system, along with health providers' lack of knowledge regarding key provisions, presents a barrier to improving access to safe anesthesia care in low- and middle-income countries. Fifteen of the 46 essential medicines of potential relevance to perioperative care are listed under one or more of the schedules of the three international drug control conventions and, subsequently, are required to be under national controls, potentially decreasing their availability for medical use.

CONCLUSION

Improving the capacity and quality of anesthesia care in low- and middle-income countries requires attention to improving access to controlled medicines. Anesthesiologists and others involved in global health work should collaborate with policymakers and others to improve national and international drug control legislation to ensure that attempts to thwart illicit drug trafficking and use do not compromise availability of controlled medicines.

Outcomes of Pediatric Cataract Surgery in the Copperbelt Province of Zambia

PURPOSE

To study the outcomes of pediatric cataract surgeries in children operated on in the Copperbelt Province of Zambia and the barriers to accessing surgery.

METHODS

All children who had congenital, developmental, and traumatic cataracts operated on by lens aspiration, primary posterior capsulotomy, and anterior vitrectomy with posterior chamber intraocular lens implantation from 2012 to 2013 and followed up beyond 6 months were studied. Each child underwent a comprehensive preoperative evaluation. An active, assisted follow-up was done and parents were asked about reasons for delay between presentation and surgery.

RESULTS

One hundred two eyes of 70 children met the inclusion criteria of the study. Preoperatively, 76 of 77 (98.7%) eyes in the congenital and developmental cataract group had presenting visual acuity of worse than 6/60. This improved postoperatively, with 19 (29.7%) eyes having best corrected visual acuity (BCVA) of better than 6/18, 23 (35.9%) having BCVA of 6/24 to 6/60, and 22 (34.4%) having BCVA of worse than 6/60. Older age (P = .005), better preoperative vision (P = .045) at presentation, unilaterality (P = .012), and delay between presentation and surgery (P = .004) were predictors of a better postoperative outcome. On multivariate analysis, only age was significant (P = .025). Distance and cost of travel and surgery were the causes of delay in presentation. In the patients with traumatic cataracts, 17 of 25 (68%) had BCVA of better than 6/18, 6 (24%) had BCVA between 6/24 and 6/60, and 2 (8%) had BCVA of worse than 6/60 at the 6-month follow-up. The most common causes of injury were being struck by sticks and stones (10 children, 25%).

CONCLUSIONS

Visual outcomes after pediatric cataract surgery in Zambia were comparable and satisfactory. Cost of treatment was a barrier, but delay did not adversely affect outcome. [J Pediatr Ophthalmol Strabismus. 2016;53(5):311-317.].

Visual Outcome and Related Factors in Bilateral Total Congenital Cataract Patients: 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.

Surgery for sight: outcomes of congenital and developmental cataracts operated in Durban, South Africa

PURPOSE

To study the visual outcomes of congenital and developmental cataract surgery and determine variables for presentation for pediatric cataract surgery in KwaZulu Natal province of South Africa.

METHODS

Care-givers of children presenting with cataract to a quaternary centre were asked when they first detected the condition. The reasons for delay between detection and surgery were studied. The children underwent a comprehensive eye examination and then appropriate surgery. They were prospectively followed up for 3 months and visual acuity and stereopsis were noted. Delay in presentation for surgery and visual outcomes were co-related with demographic and clinical factors.

RESULTS

Eighty-three non-traumatic cataract surgeries in 50 children were studied. Twenty-six (52%) were males, mean age was 3 years 10 months (SD 3yrs 4 months). The mean delay between identification and surgery was 20.7 months (SD 18 months). Twenty-six (52%) children had >15 months interval between diagnosis and surgery. Only mother's occupation was significantly associated with delay (P=0.017). Post-surgery 17/69 (24.7%) had visual acuity ≥6/18, 20/69 (29.0%) had vision between 6/24-6/60, whereas 32/69 (46.3%) had visual acuity ≤6/60. The final vision was associated with age (P=0.031), delay between diagnosis and surgery (P<0.001), type of surgery (P=0.046) and preoperative vision (P<0.001).

CONCLUSION

Although the children's vision improved substantially, a longer follow-up and amblyopia treatment would be necessary to optimize the visual outcome, which depended on age and preoperative vision. Health promotion activities aimed at mothers are important in improving visual outcomes.

Pediatric cataract surgery in National Eye Centre Kaduna, Nigeria: outcome and challenges

PURPOSE

To assess the outcomes of congenital/developmental cataract from a tertiary eye care hospital in Northwest Nigeria.

MATERIALS AND METHODS

A retrospective chart review was performed of all patients diagnosed with congenital or developmental cataract who underwent surgery from January 2008 to December 2009. Data were collected on patient demographics, preoperative characteristics, intraoperative complications, and postoperative outcomes as well as complications.

RESULTS

A total of 181 eyes of 102 patients underwent surgery. There were 95 (52.5%) right eyes. There were 64 (62.7%) males. The mean age of the patients was 6.88 ± 7.97 years. Fifty-four (51.3%) patients were below 3 years old. Most (62%) patients had congenital cataract with a history of onset within the first year of life [39 (62.9%) patients]. Amblyopia, nystagmus, and strabismus were the most frequent ocular comorbidities accounting for 50.3%, 36.5%, and 35.4% of eyes respectively. The majority (84.3%) of the patients had surgery within 6 months of presentation. All patients underwent manual small incision cataract surgery (MSICS). Seventy-nine (77.5%) patients underwent simultaneous bilateral surgery. Intraocular lens implantation was performed in 83.4% eyes. The most common early and late postoperative complication was, posterior capsular opacity which occurred in 65 eyes of 43 children. In these cases, moderate visual acuity was predominant visual outcome.

CONCLUSION

Treatment of pediatric cataract in our setting is complicated by demographic factors which results in late presentation and consequently, late treatment of children. Short-term visual outcome is fair. Data on long term postoperative outcomes could not be acquired due to poor follow-up.

Cataract surgery outcomes in bangladeshi children

PURPOSE

To measure visual acuity (VA) outcomes, complication rates, and the social impact of cataract surgery in a cohort who underwent surgery as children in Bangladesh.

DESIGN

Case series.

PARTICIPANTS

A total of 471 of 850 children from 6 Bangladeshi districts who had been identified as cataract blind using key informants (KIs) between 2004 and 2009 during the Bangladesh Childhood Cataract Campaign (BCCC) together with all those children not included in the BCCC database but in the Child Sight Foundation (CSF) database who had been identified as cataract blind.

METHODS

The subjects and families were contacted again by KIs and transported to local examination centers, where parents and subjects were administered a questionnaire and subjects underwent full ocular examination. Where operative data were available (15%), they were analyzed in conjunction with questionnaire and examination findings. Statistical analysis was performed using SPSS Statistics (IBM, Armonk, NY).

MAIN OUTCOME MEASURES

Presenting and best-corrected visual acuities (BCVAs), cause(s) of poor outcome, postoperative refraction, and school attendance.

RESULTS

A total of 407 of the participants had undergone bilateral surgery as children, with a mean follow-up of 8.8 years. The mean age at examination was 16 years (range, 5-28 years; standard deviation [SD], 4.6 years); 63% of those examined were male; 22% had a binocular presenting VA of >20/60; and 53% were severely visually impaired or blind (VA <20/200). After refraction, 33% had VA >20/60 in their better eye and 33% had VA <20/200. Factors that predicted poor VA in multivariate logistic regression analysis were nystagmus (P < 0.001), longer delay in presentation (P < 0.001), and magnitude of absolute spherical equivalent refractive error (P<0.001). Some 50% had nystagmus, and 69% of those currently aged ≤16 years were attending school. Better acuity was associated with school attendance (P < 0.001), whereas gender was not.

CONCLUSIONS

Approximately one third of all participants had a BCVA of ≥20/60 in their better eye. Amblyopia and nystagmus limited visual outcome, indicating the need for earlier detection and treatment. This is the first study to show the link between pediatric cataract outcome and access to education, a millennium development goal.

Cataract surgery in infants with microphthalmos

PURPOSE

To report the postoperative outcomes of cataract surgery in microphthalmic eyes of infants.

METHODS

This prospective observational study was carried out on 20 infants with microphthalmos with visually significant cataract. Microphthalmos was defined as axial length of the globe 16.50 mm or less. We excluded eyes with ocular trauma, inflammation, posterior hyperplastic primary vitreous or a tractional retinal detachment, aniridia, or chorioretinal coloboma. All the infants enrolled in this study underwent phacoaspiration with primary posterior capsulotomy, anterior vitrectomy, and peripheral iridectomy. Intraocular lens was not implanted in these children. Post-operative evaluation included refractive errors, irregularity of pupil, posterior synechiae, visual axis obscuration, and intraocular pressure. These children were followed up for a minimum of 12 months.

RESULTS

We evaluated 37 eyes of 20 infants, of whom 17 infants had bilateral and three infants had unilateral cataract. The mean age of the children and the mean axial length at the time of surgery were 3.78 ± 2.25 months and 15.76 ± 0.56 mm respectively. The complications observed were irregularity of pupil in seven eyes (18.9 %), glaucoma in five eyes (13.5 %), posterior synechiae in two eyes (5.2 %), visual axis obscuration due to posterior capsule opacification (PCO) in two eyes (5.2 %) and phthisis in one eye (2.7 %).

CONCLUSION

Infants achieved a favorable outcome after phacoaspiration with primary posterior capsulotomy with anterior vitrectomy. However, these children must be followed up to detect and treat postoperative complications such as visual axis obscuration, posterior synechiae, and glaucoma to achieve optimal outcome.

Results of late surgical intervention in children with early-onset bilateral cataracts

BACKGROUND

Cataracts are a major cause of childhood blindness globally. Although surgically treatable, it is unclear whether children would benefit from such interventions beyond the first few years of life, which are believed to constitute 'critical' periods for visual development.

AIMS

To study visual acuity outcomes after late treatment of early-onset cataracts and also to determine whether there are longitudinal changes in postoperative acuity.

METHODS

We identified 53 children with dense cataracts with an onset within the first half-year after birth through a survey of over 20,000 rural children in India. All had accompanying nystagmus and were older than 8 years of age at the time of treatment. They underwent bilateral cataract surgery and intraocular lens implantation. We then assessed their best-corrected visual acuity 6 weeks and 6 months after surgery.

RESULTS

48 children from the pool of 53 showed improvement in their visual acuity after surgery. Our longitudinal assessments demonstrated further improvements in visual acuity for the majority of these children proceeding from the 6-week to 6-month assessment. Interestingly, older children in our subject pool did not differ significantly from the younger ones in the extent of improvement they exhibit.

CONCLUSIONS AND RELEVANCE

Our results demonstrate that not only can significant vision be acquired until late in childhood, but that neural processes underlying even basic aspects of vision like resolution acuity remain malleable until at least adolescence. These data argue for the provision of cataract treatment to all children, irrespective of their age.

A pilot study to evaluate incorporating eye care for children into reproductive and child health services in Dar-es-Salaam, Tanzania: a historical comparison study

Background

Many blinding eye conditions of childhood are preventable or treatable, particularly in developing countries. However, primary eye care (PEC) for children is poorly developed, leading to unnecessary visual loss. Activities for control by health workers entail interventions for systemic conditions (measles, vitamin A deficiency), identification and referral of children with sight threatening conditions and health education for caregivers. This pilot study evaluated integrating a package of activities to promote child eye health into Reproductive and Child Health (RCH) services in Dar-es-Salaam, Tanzania.

Methods

Design: historical comparison study. Fifteen Clinical Officers and 15 nurses in 15 randomly selected RCH clinics were trained in PEC for children in July 2010. They were given educational materials (poster and manual) and their supervisors were orientated. Knowledge and practices were assessed before and 3 weeks after training. One year later their knowledge and practices were compared with a different group of 15 Clinical Officers and 15 nurses who had not been trained.

Results

Before training staff had insufficient knowledge to identify, treat and refer children with eye diseases, even conjunctivitis. Some recommended harmful practices or did not know that cataract requires urgent referral. Eye examination, vitamin A supplementation of mothers after delivery and cleaning the eyes at birth with instillation of antibiotics (Crede’s prophylaxis) were not routine, and there were no eye-specific educational materials.

Three weeks after training several clinics delivering babies started Crede’s prophylaxis, vitamin A supplementation of women after delivery increased from 83.7% to 100%, and all staff included eye conditions in health education sessions. At one year, trained staff were more likely to correctly describe, diagnose and treat conjunctivitis (z=2.34, p=0.04)(30%-vs-60.7%). Mystery mothers observed health education sessions in 7/10 RCH clinics with trained staff, five (71.4%) of which included eye conditions.

Conclusions

Primary eye care for children in Dar-es-Salaam is inadequate but training RCH staff can improve knowledge in the short term and change practices. Attendance by mothers and their children is high in RCH clinics, making them ideal for delivery of PEC. Ongoing supportive supervision is required to maintain knowledge and practices, as well as systems to track referrals.

Barriers to follow-up for pediatric cataract surgery in Maharashtra, India: how regular follow-up is important for good outcome. The Miraj Pediatric Cataract Study II

BACKGROUND

Regular follow up and amblyopia treatment are essential for good outcomes after pediatric cataract surgery.

AIM

To study the regularity of follow-up after cataract surgery in children and to gauge the causes of poor compliance to follow up.

SUBJECTS

262 children (393 cataracts) who underwent cataract surgery in 2004-8.

MATERIALS AND METHODS

The children were identified and examined in their homes and a "barriers to follow-up" questionnaire completed. Demographic data collected, visual acuity estimated, and ocular examination performed.

STATISTICAL ANALYSIS

SPSS version 19.

RESULTS

Of the 262 children, only 53 (20.6%) had been regularly following up with any hospital, 209 (79.4%) had not. A total of 150 (57.3%) were boys and the average age was 13.23 years (Std Dev 5 yrs). Poor follow up was associated with the older age group ( P < 0.001), less education of mother ( P = 0.012), father's occupation ( P = 0.031), how much money spent on travel ( P = 0.033) and was it paid or free surgery ( P = 0.001). It was not related to gender, numbers of children in family, ordinal status of child, and social strata. Distance and cost were major barriers, as was the inability of the eye care center to communicate the importance of follow up. A prospective follow-up visit showed that 93 children needed Nd: YAG LASER capsulotomy, 5 needed low vision aids, 4 contact lens, and 162 a change of spectacles. The average visual acuity improved in 150 (38.8%) eyes >1 line with regular follow-up.

CONCLUSION

Regular follow-up is important and improves vision; eye care practitioners need to take special efforts to ensure better follow-up.

Dual approach using vitrectorhexis combined with anterior vitrectomy in pediatric cataract surgery

Purpose. To evaluate efficacy and safety of vitrectorhexis method for both anterior and posterior capsules combined with anterior vitrectomy in children with cataract. Methods. A retrospective chart review was performed for 19 children with cataract operated at a tertiary referral center. Dual approach including anterior and posterior segments was used during the surgery in terms of capsulotomy, intraocular lens (IOL) implantation, and anterior vitrectomy. Results. A total of 23 eyes of 19 patients were enrolled in the study. The mean age of the children was 39.4 ± 2.2 months (5–78). The mean postoperative followup duration was 20.6 ± 7.8 months (3–32). Intraoperative tear was observed only in one of 23 (4.3%) eyes during anterior capsulotomy. All of the patients had a clear visual axis and showed no IOL decentration. Conclusions. Dual approach using vitrectorhexis and anterior vitrectomy is an easy-to-perform technique that seems safe and effective in the short term for younger children.

Clinical and cost impact of a pediatric cataract follow-up program in western Nepal and adjacent northern Indian States

BACKGROUND

High-quality, comprehensive pediatric cataract surgery programs have recently developed in low-income countries, but postoperative care has lagged. This study evaluated the post-cataract surgery follow-up program implemented in March 2011 at the Lumbini Eye Institute in Bhairahawa, Nepal, which included a full-time pediatric counselor and program director, a specific database, a tracking system, and cell phone reminders.

METHODS

Baseline data for all cataract surgical patients <16 years of age were obtained retrospectively from hospital administrative records for 2009, the year prior to program introduction, and prospectively for all cases between March 1, 2011, and February 28, 2012. The statistical significance of the difference in the proportion of children attending follow-up in 2009 versus 2011-12 was calculated, and the overall program costs for 2011-12 was determined based on hospital records.

RESULTS

In 2011-12, 334 children (248 males [74%]) underwent cataract surgery, including 89 Nepali (27%) and 245 Indian (73%) children. The proportion of boys was significantly higher in 2011-12 compared to 2009, but there were no differences in terms of age or distance to hospital. In 2009, 87%, 60%, and 37% attended their first, second, and third follow-up visits, respectively. Follow-up rates improved significantly to 96%, 81%, and 57%, respectively, after the implementation of the postoperative follow-up program. The 2011-12 program is estimated to have cost US$17,444.

CONCLUSIONS

The new post-cataract surgery program resulted in improved follow-up at relatively little additional cost.

Long term outcomes of bilateral congenital and developmental cataracts operated in Maharashtra, India. Miraj pediatric cataract study III

AIM

To study long term outcome of bilateral congenital and developmental cataract surgery.

SUBJECTS

258 pediatric cataract operated eyes of 129 children.

MATERIALS AND METHODS

Children who underwent pediatric cataract surgery in 2004-8 were traced and examined prospectively in 2010-11. Demographic and clinical factors were noted from retrospective chart readings. All children underwent visual acuity estimation and comprehensive ocular examination in a standardized manner. L. V. Prasad Child Vision Function scores (LVP-CVF) were noted for before and after surgery.

STATISTICS

Statistical analysis was done with SPSS version 16 including multi-variate analysis.

RESULTS

Children aged 9.1 years (std dev 4.6, range 7 weeks-15 years) at the time of surgery. 74/129 (57.4%) were boys. The average duration of follow-up was 4.4 years (stddev 1.6, range 3-8 years). 177 (68.6%) eyes had vision <3/60 before surgery, while 109 (42.2%) had best corrected visual acuity (BCVA) >6/18 and 157 (60.9%) had BCVA >6/60 3-8 years after surgery. 48 (37.2%) had binocular stereoacuity <480 sec of arc by TNO test. Visual outcome depended on type of cataract (P = 0.004), type of cataract surgery (P < 0.001), type of intra-ocular lens (P = 0.05), age at surgery (P = 0.004), absence of post-operative uveitis (P = 0.01) and pre-operative vision (P < 0.001), but did not depend on delay (0.612) between diagnosis and surgery. There was a statistically significant improvement for all the 20 questions of the LVP-CVF scale (P < 0.001).

CONCLUSION

Pediatric cataract surgery improved the children's visual acuity, stereo acuity and vision function. Developmental cataract, use of phacoemulsification, older children and those with better pre-operative vision had betterlong-termoutcomes.

Visual outcomes of bilateral congenital and developmental cataracts in young children in south India and causes of poor outcome

CONTEXT

Bilateral pediatric cataracts are important cause of visual impairment in children.

AIM

To study the outcome of bilateral pediatric cataract surgery in young children.

SETTING AND DESIGN

Retrospective case series in a tertiary center.

MATERIALS AND METHODS

Records of pediatric cataracts operated between January 2001 and December 2003, with a minimum follow-up of 3 months, were reviewed retrospectively.

STATISTICAL METHODS

Independent sample t-test, Fisher's exact test, and logistic regression using SPSS (Statistical Package for Social Science, Chicago, USA) version 12.

RESULTS

215/257 (83.7%) patients had a minimum follow-up of 3 months. The mean age of presentation to the hospital was 53 months (range: 0-168 months). Congenital cataract was present in 107 patients (58.2%) and developmental cataract in 77 patients (41.8%). The mean age at surgery was 55.2 months (range: 1-168 months). Out of 430 eyes, 269 (62.6%) had an intraocular lens implanted. The mean duration of follow-up was 13.1 months (range: 3-38 months). Pre-operatively, 102 patients (47.3%) had visual acuity <6/60, in the better eye, compared to 37 patients (17.2%) post-operatively ( P < 0.001). Eighty-five patients (39.5%) had visual acuity >6/18. The most common early post-operative complication was fibrinous uveitis in 57 eyes (13.3%) and the most common delayed post-operative complication was posterior capsular opacification in 118 eyes (27.4%). The most important prognostic factor for poor outcome was congenital cataract (odds ratio [OR]: 26.3; 95% confidence interval [CI], 4.4-158.5) and total cataract (OR: 4.8; 95% CI, 1.3-17).

CONCLUSION

Nearly half of the eyes had visual acuity >6/18. The outcome was poorer in congenital cataracts, especially those operated after >1 year of age.

Bilateral pediatric cataract surgery: outcomes of 390 children from Nepal and Northern India

PURPOSE

To report the outcomes of bilateral pediatric cataract surgery from eastern Nepal and northern India.

METHODS

Preoperative, intraoperative, and postoperative data of 390 children who underwent surgery bilaterally between 2007 and 2009 were analyzed.

RESULTS

Forty-two (10.8%) children came from Nepal and 348 (89.2%) from India (mainly Bihar State). Intraocular lens (IOL) implantation with posterior capsule opening and anterior vitrectomy were achieved in 386 (99.0%) children bilaterally. Median age at surgery was 7 years and 69.2% were male. At first presentation, 243 (62.3%) of the children were blind (< 3/60 in the better eye). After more than 1 year, 53.5% had a normal visual status (range: 6/6 to 6/18), 5.6% of children were still blind, and mean refractive error spherical equivalent was +1.0 ± 2.4 diopters. Astigmatism changed from suture-induced with the rule at discharge to against the rule within 3 weeks of surgery. Mean long-term astigmatic error was 1.0 ± 0.9 diopters after 1 year. Glaucoma was rare.

CONCLUSIONS

Even in a setting with limited resources, successful, cost-effective, high-volume surgery for pediatric cataract is possible. Despite late presentation and limited follow-up, more than half achieved good outcomes after more than 1 year. Only 5.6% remained blind due to amblyopia or eye anomalies. Bilateral surgery during one hospital stay, IOL implantation with undercorrection according to age, aggressive surgery to prevent secondary cataract, intensive anti-inflammatory therapy, and provision of durable, high-quality spectacles to take home all proved beneficial because many children cannot attend for regular follow-up.

Causes, epidemiology, and long-term outcome of traumatic cataracts in children in rural India

Purpose:

To describe preoperative factors, long-term (>3 years) postoperative outcome and cost of traumatic cataracts in children in predominantly rural districts of western India.

Subjects:

Eighty-two traumatic cataracts in 81 children in a pediatric ophthalmology department of a tertiary eye-care center.

Materials and Methods:

Traumatic cataracts operated in 2004–2008 were reexamined prospectively in 2010–2011 using standardized technique. Cause and type of trauma, demographic factors, surgical intervention, complications, and visual acuity was recorded.

Statistical Analysis:

Data analysis done by using SPSS (Statistical package for social sciences) version 17.0 We have used Chi-square test, Fisher's exact test, paired t-test to find the association between the final vision and various parameters at 5% level of significance; binary logistic regression was performed for visual outcome ≥6/18 and ≥6/60.

Results:

The children were examined in a 3–7 year follow-up (4.35 ± 1.54). Average age at time of surgery was 10.4 ± 4.43 years (1.03 to 18). Fifty (61.7%) were boys. Forty (48.8%) were blunt and 32 (39%) were sharp trauma. The most common cause was wooden stick 23 (28.0%) and sharp thorn 14 (17.1%). Delay between trauma and presentation to hospital ranged from same day to 12 years after the injury with median of 4 days. The mean preoperative visual acuity by decimal notation was 0.059 ± 0.073 and mean postoperative visual acuity was 0.483 ± 0.417 (P < 0.001). Thirty-eight (46.3%) had best corrected visual acuity (BCVA) ≥6/18 and 51 (62.2%) had BCVA ≥ 6/60. In univariable analysis, visual outcome (≥6/18) depended on type of surgery (P = 0.002), gender (P = 0.028), and type of injury (P = 0.07)–sharp trauma and open globe injury had poorer outcomes; but not on age of child, preoperative vision, and type of surgeon. On multivariable binary logistic regression, only gender was significant variable. Of the 82 eyes, 18 (22%) needed more than one surgery. The parents spent an average of 2250 ($45) for the surgery and 55 (66.4%) were from lower socio-economic class.

Conclusion:

The postoperative visual outcomes varied and less than half achieved ≥ 6/18.

Advances in the management of the surgical complications for congenital cataract

The greatest concern in children with cataracts is irreversible visual loss. The timing of congenital cataract surgery is critical for the visual rehabilitation. Cataract surgery in children remains complex and challenging. The incidence of complications during or after operation is higher in children than adults. Some complications could be avoided by meticulous attention to surgical technique and postoperative care, and others were caused by more exuberant inflammatory response associated with surgery on an immature eye or the intrinsic eyes abnormalities. Utilizing of advanced techniques and timely applying topical corticosteroids and cycloplegic agents can reduce the occurrence of visual axis opacification. Operation on children with strabismus or nystagmus, and applying occlusion therapy on amblyopic eyes can balance the visual inputs to the two eyes. Diagnosis of glaucoma following congenital cataract surgery requires lifelong surveillance and continuous assessment of the problem. So cataract surgeries in children are not the end of journey, but one step on the long road to visual rehabilitation. This paper describes recent evidence from the literature regarding the advance of management after congenital cataract surgery.

Comparison of hospital versus rural eye cAMP based pediatric cataract surgery

Purpose:

To compare the outcomes of pediatric cataract surgery with intraocular lens (IOL) implantation in an eye camp setting and tertiary care center.

Materials and Methods:

Children aged 5-16 years with visually significant cataract underwent phacoaspiration with IOL implantation in an eye camp (eye camp group) or tertiary care center (TCC group). All surgeries incorporated contemporary microsurgical techniques with implantation of polymethyl-methacrylate (PMMA) IOL. Major postoperative complications were managed at a tertiary care center. Postoperative complications, visual acuity and compliance were evaluated using the Chi-square test. A P value less then 0.05 was considered as statistically significant.

Results:

The cohort comprised 59 children in the eye camp group and 48 children in the TCC group. Thirty two of fifty nine (54.23%) eyes in the eye camp group and 30/48 (62.5%) eyes in the TCC group achieved 20/40 or better best corrected visual acuity (BCVA) postoperatively. Postoperatively, 36 (61%) eyes in the eye camp group and 22 (45.83%) eyes in the TCC group required Nd: YAG laser capsulotomy or a pars plana membranectomy. (P> 0.05) The most striking feature was loss to follow up. In the eye camp group, loss to follow was 20% at one year, 49% at two years, 62% at 3 years and 67% at 4 years compared to 12.5, 21, 27 and 33% respectively in the TCC group (P<0.05, all cases).

Conclusions:

The outcomes of camp and tertiary care center (hospital) based pediatric cataract surgery were similar. However, the major drawback of camp based surgery was loss to follow up which eventually affected the management of amblyopia and postoperative complications.

Eye conditions and blindness in children: priorities for research, programs, and policy with a focus on childhood cataract

The major causes of blindness in children encompass intrauterine and acquired infectious diseases, teratogens and developmental and molecular genetics, nutritional factors, the consequences of preterm birth, and tumors. A multidisciplinary approach is therefore needed. In terms of the major avoidable causes (i.e., those that can be prevented or treated) the available evidence shows that these vary in importance from country to country, as well as over time. This is because the underlying causes closely reflect socioeconomic development and the social determinants of health, as well as the provision of preventive and therapeutic programs and services from the community through to tertiary levels of care. The control of blindness in children therefore requires not only strategies that reflect the local epidemiology and the needs and priorities of communities, but also a well functioning, accessible health system which operates within an enabling and conducive policy environment. In this article we use cataract in children as an example and make the case for health financing systems that do not lead to 'catastrophic health expenditure' for affected families, and the integration of eye health for children into those elements of the health system that work closely with mothers and their children.

Technological advances in pediatric cataract surgery

PURPOSE

Managing pediatric cataracts is often challenging. It is technically difficult to perform surgery in these small complaint eyes and there is higher prevalence of postoperative complications. The outcomes of surgery depend on technique and technology. The purpose of this study is to review the current literature on technological advances in pediatric cataract surgery.

METHODS

Review of literature on management of pediatric cataract surgery.

RESULTS

The advent of vitrectomy machines and intraocular lenses (IOLs) has revolutionized pediatric cataract surgery. "Vitrectorhexis" has become a good alternative to manual capsulorhexis. Primary management of posterior capsule and limited anterior vitrectomy has reduced the incidence of visual axis opacification. Primary IOL implantation is becoming a standard of care in the youngest children. Single piece Acrysof® is preferred for in-the-bag implantation and 3-piece Acrysof® for sulcus implantation. Newer IOLs are being evaluated in pediatric eyes. Precise measurement of intraocular lens power and predicting refractive change are major challenges in long term care of children after surgery.

CONCLUSION

New technology and surgical techniques have refined pediatric cataract surgery. It is critical to focus our efforts on precise biometry measurements, IOL power calculation, and designing IOLs that may address refractive changes in the growing pediatric eye.

Cost of pediatric cataract surgery in Maharashtra, India

AIM

To calculate the direct cost of pediatric cataract surgery, from the provider's perspective.

METHODS

The direct cost was calculated using standard costing methods in a pediatric ophthalmology department of a comprehensive community eye care center in western India. Fixed costs included those of the building, interior decoration, out patient department's equipment, operation theater equipment, personnel, administration and hospital maintenance. The consumable costs included materials used during surgery. Only direct costs were considered.

RESULTS

The average direct costs were Indian rupees (Rs.) 69 ($1.77) for an outpatient department consultation, Rs.606 ($15.53) for operation theater equipment use, and Rs. 2 427($62.23) for personnel. The consumable costs ranged from Rs.1 452 ($37.23) to 15 267 ($391.46), depending on the protocol used. The net average cost of pediatric cataract surgery ranged from Rs. 4 722 ($122) to Rs. 18 537 ($475) per eye.

CONCLUSION

Cataract surgery is cost intensive for children with cataract. Pediatric ophthalmologists should decide about most cost effective standards of care to rationalize consumable cost.

Delayed presentation of cataracts in children: are they worth operating upon?

PURPOSE

Childhood cataract is an important cause of avoidable blindness in children. The study aimed to investigate the outcome of surgery in cataracts with delayed presentation which had been operated upon as new pediatric ophthalmology centers were set up in India.

METHODS

This was a retrospective interventional case series from a community eye care center in Western India. Demographic, surgical, pre-operative and post-operative details were obtained from the patients records and entered into Microsoft excel and statistical analysis conducted using SPSS-11 software (SPSS, Chicago, IL). Vision was tested 6 weeks after surgery. The predictors of good vision (> or =6/18) were identified by regression analysis. If the interval between detection of cataract in children and their presentation for surgery was more than 18 months for developmental and 6 months for congenital the cataract was defined having a delayed presentation.

RESULTS

Five hundred and twenty nine eyes of 437 children aged 2 months to 16 years were operated upon in 2004-2006. Preoperative vision was <3/60 in 405 (76.6%) eyes with cataract. Of these 529, 242 eyes were with delayed presentation of cataract (83 congenital and 149 other). 102 had up to 5 years, 91 had 6-10 years and 49 had >11 yrs delay in presentation. At 6 weeks following surgery, vision was > or = 6/18 in 36/93 (38.7%) of eyes with delayed presenting cataracts, as compared to 94/244 (38.5%) > or =6/18 in those without.

CONCLUSION

Surgery for cataracts with delayed presentation helps to regain functional vision, which can be used for navigation and low vision aids.

Determinants of pediatric cataract program outcomes and follow-up in a large series in Mexico

PURPOSE

To report determinants of outcomes and follow-up in a large Mexican pediatric cataract project.

SETTING

Hospital Luis Sanchez Bulnes, Mexico City, Mexico.

METHODS

Data were collected prospectively from a pediatric cataract surgery program at the Hospital Luis Sanchez Bulnes, implemented by Helen Keller International. Preoperative data included age, sex, baseline visual acuity, type of cataract, laterality, and presence of conditions such as amblyopia. Surgical data included vitrectomy, capsulotomy, complications, and use of intraocular lenses (IOLs). Postoperative data included final visual acuity, refraction, number of follow-up visits, and program support for follow-up.

RESULTS

Of 574 eyes of 415 children (mean age 7.1 years +/- 4.7 [SD]), IOLs were placed in 416 (87%). At least 1 follow-up was attended by 408 patients (98.3%) (mean total follow-up 3.5 +/- 1.8 months); 40% of eyes achieved a final visual acuity of 6/18 or better. Children living farther from the hospital had fewer postoperative visits (P = .04), while children receiving program support had more visits (P = .001). Factors predictive of better acuity included receiving an IOL during surgery (P = .04) and provision of postoperative spectacles (P = .001). Predictive of worse acuity were amblyopia (P = .003), postoperative complications (P = .0001), unilateral surgery (P = .0075), and female sex (P = .045).

CONCLUSIONS

The results underscore the importance of surgical training in reducing complications, early intervention before amblyopia (observed in 40% of patients) can develop, and vigorous treatment if amblyopia is present. The positive impact of program support on follow-up is encouraging, although direct financial support may pose a problem for sustainability. More work is needed to understand reasons for worse outcomes in girls.

Pediatric cataract extraction with intraocular lens implantation: visual acuity outcome when measured at age four years and older

PURPOSE

Assessment of visual outcome of pediatric eyes that underwent cataract extraction with primary intraocular lens (IOL) implantation at a single center.

METHODS

A retrospective review of charts of 510 consecutive pediatric patients that underwent cataract extraction was performed. Exclusion criteria were traumatic cataract, secondary IOL implantation, retinopathy of prematurity, severe developmental delay, age less than 4 years at last follow-up, and follow-up less than 6 months. In bilateral cases, only right eye data were included.

RESULTS

One hundred thirty-nine eyes met inclusion criteria. Median age at surgery was 5.12 years (range, 0.03-16.92); median age at last follow-up was 9.05 years, and median follow-up was 3.65 years. Sixty-six of 139 (47.5%) patients had unilateral cataracts compared with 73/139 (52.5%) bilateral cases. The median visual acuity of all eyes was 20/30, with median visual acuity of unilateral and bilateral cases being 20/40 and 20/25, respectively. Older patients achieved better visual acuity (unilateral cases: p = 0.003; bilateral cases: p = 0.07). Eyes with a greater interocular axial length difference achieved poorer visual acuity. Forty-five patients had a final visual acuity worse than 20/40. Of these, 34 (76%) had a diagnosis of amblyopia as the sole cause. Nineteen of 139 (13.7%) eyes had final visual acuity worse than 20/200. Eighteen patients required strabismus surgery, and 22 required additional intraocular surgery.

CONCLUSIONS

Better visual acuity was associated with bilateral cataract, older age at surgery, and normal interocular axial length difference. Amblyopia was the major cause of residual visual deficit.

Predictors of poor follow-up in children that had cataract surgery

BACKGROUND

Centers for high quality cataract surgery for children have been developed in a number of sub-Saharan African countries. Surgery, however, is only the first stage of a long, often complex, rehabilitation program. There are indications that follow-up in these settings is poor. In a setting with a high quality surgical service an active program to identify and manage children with cataract and a newly developed low vision program, we sought to measure routine follow-up and to determine the factors associated with good or poor follow-up.

METHODS

This prospective study included all children (under the age of 16 years) having surgery for congenital, developmental, or traumatic cataract at KCMC Hospital between March 2003 and October 2004. Standardized data was collected pre-, intra-, and postoperation. Follow-up was assessed at two weeks and ten weeks.

RESULTS

Among the 154 children included 35.1% had congenital cataract, 32.5% had developmental cataract, and 31.8% had traumatic cataract. Overall, 66.9% attended two-week follow-up and 42.9% attended ten-week follow-up. Multivariate analysis revealed that sex (being a boy), close proximity to a hospital, and minimal delay in presentation for surgery all independently predicted good follow-up at two weeks. Only distance from a hospital and preoperative vision (not blind in operative eye) predicted good ten-week follow up.

DISCUSSION

Current follow-up practices are inadequate. Significant investment in surgical interventions may not lead to improved visual rehabilitation or quality of life, if investments in follow-up are not increased. Linking individual children, their families, and the hospital needs to be approached systematically, if follow-up is to be improved. Improved hospital-based counseling should focus on families who bring their child late for surgery and with girls.

The use of peribulbar anaesthesia in paediatric cataract surgery (age 7-15 years) in a mobile eye camp in China

AIM

To evaluate the feasibility and acceptability of the use of peribulbar anaesthesia (PA) in paediatric cataract surgery in rural areas in China, where there are limitations in expertise and equipment for general anaesthesia (GA).

METHODS

We prospectively evaluated the feasibility and acceptability of carrying out paediatric cataract surgery under PA in children aged 7-15 years. Informed consent was obtained from the subjects and their parents. Children were assessed for their suitability for PA. Peribulbar anaesthesia was given as a peribulbar block using a 2% lidocaine, 0.5% bupivacaine-hyaluronidase mixture administered before lens aspiration with intraocular lens implantation. The acceptability of the PA was evaluated by questionnaire.

RESULTS

A total of 19 patients were recruited. Their mean age was 12 +/- 2 years (range 7-15 years). None required conversion to GA. All subjects regarded PA as either totally acceptable (63.2%) or acceptable (36.8%). The mean pain scores (from 0 to 100) during the injection and surgery were 28 +/- 26 and 6 +/- 8, respectively. Seventeen patients (89.5%) said they would prefer PA if choices in anaesthesia were offered again.

CONCLUSIONS

Peribulbar anaesthesia can be considered as a viable option in selected children undergoing cataract surgery when facilities for safe and optimal general anaesthesia are unavailable.