Epidemiology of cataract in childhood: a global perspective

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.

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.

Surgical interventions for bilateral congenital cataract

BACKGROUND

Congenital cataracts are opacities of the lens in one or both eyes of children that cause a reduction in vision severe enough to require surgery. Cataract is the largest treatable cause of visual loss in childhood. Paediatric cataracts provide different challenges to those in adults. Intense inflammation, amblyopia and posterior capsule opacification can affect results of treatment. Two treatments commonly considered for congenital cataract are lensectomy and lens aspiration.

OBJECTIVES

The objective of this review was to assess the effects of surgical treatments for bilateral symmetrical congenital cataracts. Success was measured according to the vision attained and occurrence of adverse events.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, which contains the Cochrane Eyes and Vision Group Trials Register (2005, Issue 2), MEDLINE (1966 to June 2005), EMBASE (1980 to June 2005, week 27), LILACS (6 July 2005), the Science Citation Index and the reference list of the included studies. We also contacted trial investigators and experts in the field for details of further studies.

SELECTION CRITERIA

We included all prospective, randomised controlled trials that compared one type of cataract surgery to another, or to no surgery, in children with bilateral congenital cataracts aged 15 years or younger.

DATA COLLECTION AND ANALYSIS

Two authors extracted data. No meta-analysis was performed.

MAIN RESULTS

Four trials met the inclusion criteria. All trials were concerned with reducing the development of visual axis opacification (VAO). This was achieved with techniques that included an anterior vitrectomy or optic capture. Posterior capsulotomy alone was inadequate except in older children.

AUTHORS' CONCLUSIONS

Evidence exists for the care of children with congenital or developmental bilateral cataracts to reduce the occurrence of visual axis opacification. Further randomised trials are required to inform modern practice about other concerns including the timing of surgery, age for implantation of an intraocular lens and development of long-term complications such as glaucoma and retinal detachment.

Refractive and visual outcome of paediatric cataract surgery in the Ukraine

PURPOSE

To describe the refractive and visual outcomes after surgery for congenital or developmental cataract in the Ukraine.

METHODS

Cataract surgery was performed in 65 children aged 3-15 years. The cataracts were bilateral in 44 children and unilateral in 21. Examinations, including visual acuity (VA) and objective refraction using retinoscopy, were performed preoperatively and at 1 day, 6 months and 2 years postoperatively. Neither occlusion therapy nor spectacles were prescribed.

RESULTS

Almost all children (96%) gained in VA. In all, 40% of the bilateral cases achieved a corrected Snellen VA > or = 0.5 and 44% of the unilateral cases obtained a corrected VA > or = 0.2. The difference between VA (logMAR) preoperatively and 2 years postoperatively was statistically significant (p < 0.05). The bilateral cases showed a postoperative reduction in mean astigmatism from 3.9 D (1 day postoperatively) to 0.6 D (2 years postoperatively) (p < 0.001), while the unilateral cases showed a reduction from 4.2 D (1 day postoperatively) to 0.4 D (2 years postoperatively) (p < 0.001).

CONCLUSION

Good postoperative VA was achieved in the group with bilateral cataract. Surprisingly, even in the group with unilateral cataract, an increase in VA was obtained, despite the lack of postoperative correction with glasses or occlusion therapy.

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.

Clinical characteristics and surgical outcomes of pediatric cataract in Taiwan

PURPOSE

To report treatment of pediatric patients with cataract, and evaluate the efficiency of different surgical interventions.

METHOD

This study comprised a consecutive series of pediatric patients with congenital or developing cataract who received surgery between 1993 and 2002 at Chang Gung Memorial Hospital in Taiwan. Patients' demographics, cataract type, presenting symptoms, surgical intervention, postoperative visual acuity, and follow-up refractive changes were recorded.

RESULTS

Three hundred and ninety-nine eyes of 246 children were included; unilateral cataract was present 21.8% of the eyes. The age at surgery was ranged from 1 to 157 months. Eyes were grouped by surgical interventions performed: Group 1 included 98 eyes that had lensectomy. Group 2 included 89 eyes that had lensectomy and secondary intraocular lens implantation. Group 3 included 212 eyes that had lensectomy with primary intraocular implantation. The mean follow up time was 41.3 months. Finally, 23.1% group 1 patients, 42.1% group 2 patients, and 63.4% group 3 patients achieved visual acuity better than 20/60 (P=0.000). Upon analysis with multifactor regression, age at onset (P=0.011) was the only significant factor related to visual outcome. Complications such as after cataract and glaucoma occurred in 21.6% and 5.8% of all patients, respectively.

CONCLUSIONS

Intraocular lens implantation for children with congenital or developing cataract is an effective treatment for visual rehabilitation, even for those patients age 2 years and younger.

Cataracte congénitale

Cataract is a loss of lens transparency because of a protein alteration. Etiopathogenesis is poorly understood but new mutations of different developmental genes involved are found in 25% of cases. Frequency of onset, particularly when different ocular development anomalies occur, is related to the lens induction phenomena on the eye's anterior segment structure during embryologic development. Genetic transmission is often found on the dominant autosomal mode. Diagnosis is based on a complete and detailed examination of the eye, often with general anaesthesia. This condition predisposes children to later, sometimes serious amblyopia. Different clinical aspects can be observed: from cataract with ocular and/or systemic anomalies to polymalformative syndrome, skeletal, dermatological, neurological, metabolic, and genetic or chromosomal diseases. A general systematic pediatric examination is necessary. Congenital cataract requires first and foremost early diagnosis and a search for all etiologies. Surgical treatment is adapted case by case but it has progressed with the quality of today's intraocular lenses even if systematic implantation continues to be debated. Life-long monitoring is absolutely necessary.

Delay in presentation to hospital for surgery for congenital and developmental cataract in Tanzania

BACKGROUND

Childhood cataract is a leading cause of blindness in children in eastern Africa. High quality surgical services have been established at a few tertiary facilities in the region; however, there appears to be delay in presentation to hospital.

METHODS

Parents or guardians of all children presenting to KCMC Hospital or CCBRT Hospital with congenital (recognised since birth or within the first year) or developmental (cataract leading to reduction in vision after 1 year of age) cataract were interviewed regarding the actions taken (and timing of these) before coming to hospital. Demographic information was also collected. For analysis children were grouped as either late presenters (more than 12 months after recognition) or not late presenters (within 12 months of recognition) and predictors of late presentation were assessed.

RESULTS

Among 178 children (74 congenital cataract and 104 developmental cataract) analysed, the mean delay between recognition by the caregiver and presentation to hospital was 34 months, almost 3 years. The median delay was 18 months-9 months for congenital cataract and 24 months for developmental cataract. Long delay in presentation was associated with having developmental cataract, living far from the hospital, and low socio-educational status of the mother. Among children with congenital cataract, having another sibling increased the likelihood of early presentation.

CONCLUSION

Delay in presentation remains a significant problem for children needing surgery for congenital or developmental cataract. Parents who have multiple children may be more likely to seek early treatment, possibly because their expectations of achievable sight at a young age are based on previous experience of their older children. Educational efforts should aim to reach the most "unreachable" (those living the furthest from the hospital and having the lowest socio-educational status of the mother).

Cataracts in children

Bilateral congenital cataract is the most common cause of treatable childhood blindness. Nuclear cataract is usually present at birth and is nonprogressive, whereas lamellar cataract usually develops later and is progressive. Surgery must be performed promptly in cases with dense congenital cataract; if nystagmus has developed, the amblyopia is irreversible. A treatment regimen based on surgery within 2 months of birth combined with prompt optical correction of the aphakia and aggressive occlusion therapy with frequent follow-up has been successful in unilateral and bilateral cases. Both anterior and posterior capsulorhexes are performed in most children. Intraocular lens implantation can be performed safely in children older than 1 year. Anterior dry vitrectomy is recommended in preschool children to avoid after-cataract. Opacification of the visual axis is the most common complication of cataract surgery in children. Secondary glaucoma is the most sight-threatening complication and is common if surgery is performed early. Life-long follow-up is essential in these cases.

Pediatric cataract surgery in Nepal

PURPOSE

To describe the first pediatric cataract surgery case series report from Nepal.

SETTING

Tilganga Eye Center, Kathmandu, Nepal.

METHODS

This study comprised a consecutive series of 112 eyes of 85 children having cataract surgery with intraocular lens (IOL) implantation. General anesthesia of ketamine combined with peribulbar block was used in all patients. Patients' demographics, cataract type and presenting symptoms, surgical intervention, preoperative and postoperative visual acuities, and follow-up clinical examinations were recorded.

RESULTS

Seventy-three eyes (65.2%) of 53 patients had extracapsular cataract extraction with posterior capsulotomy, anterior vitrectomy, and posterior chamber IOL implantation (ECCE+PCAP+AV+PCIOL), and 39 eyes (34.8%) of 32 patients had cataract extraction and IOL implantation with an intact posterior capsule (ECCE+PCIOL). Of all patients, the mean age at surgery was 6.2 years +/- 4.3 (SD). The median age in the ECCE+PCAP+AV+PCIOL group was 4.7 years and in the ECCE+PCIOL group, 11.0 years. The mean follow-up was 5.4 +/- 5.3 months. The most common postoperative complication in the ECCE+PCIOL group was visual axis/posterior capsule opacification, which was seen in 18 eyes (46.2%) compared to 4 eyes (5.5%) in the ECCE+PCAP+AV+PCIOL group. Visual acuity improved with surgery in both groups. The leading cause of poor outcomes was deprivation amblyopia. There were no anesthesia-related complications.

CONCLUSIONS

Implantation of an IOL at the time of cataract extraction under combined systemic ketamine and peribulbar lidocaine anesthesia appeared to be well tolerated and produced significant visual improvement in pediatric patients in Nepal. Primary posterior capsulotomy and AV helped prevent visual axis opacification without a significant increase in complications.

Causes of childhood blindness: results from schools for the blind in south eastern Nigeria

AIM

This cross sectional study was undertaken to identify the major causes of childhood severe visual impairment/blindness (SVI/BL) among students in schools for the blind in south eastern Nigeria with a view to offering treatment to those with remediable blindness.

METHODS

142 students attending three schools for the blind in the study area were interviewed and examined using the World Health Organization programme for prevention of blindness (WHO/PBL) childhood blindness proforma.

RESULTS

By anatomical classification, the major causes of SVI/BL identified in the children (aged 15 years or less) were lesions of the lens (30.4%), corneal lesions (21.7%), whole globe lesions (mainly phthisis bulbi) (17.4%), and glaucoma/buphthalmos (10.9%). For the young adults (more than 15 years) these lesions accounted for 31.9%, 21.3%, 23.4%, and 8.5% of SVI/BL, respectively. For all the students, the commonest single diagnoses were cataract (23.5%) and corneal scarring (21.4%), of which 86.7% were caused by measles. By aetiological classification, childhood factors (38.6%) constituted the major cause of blindness: 37.0% in the children and 39.4% in the young adults. In 74.5% of all the students, blindness was considered avoidable.

CONCLUSIONS

A high proportion of childhood blindness in schools for the blind in south eastern Nigeria is avoidable. Development of paediatric ophthalmology in Nigeria to manage childhood cataract and glaucoma is advocated.

Paediatric cataract blindness in the developing world: surgical techniques and intraocular lenses in the new millennium

Paediatric cataract blindness presents an enormous problem to developing countries in terms of human morbidity, economic loss, and social burden. Managing cataracts in children remains a challenge: treatment is often difficult, tedious, and requires a dedicated team effort. To assure the best long term outcome for cataract blind children, appropriate paediatric surgical techniques need to be defined and adopted by ophthalmic surgeons of developing countries. The high cost of operative equipment and the uneven world distribution of ophthalmologists, paediatricians, and anaesthetists create unique challenges. This review focuses on issues related to paediatric cataract management that are appropriate and suitable for ophthalmic surgeons in the developing world. Practical guidelines and recommendations have also been provided for ophthalmic surgeons and health planners dealing with childhood cataract management in the developing world.

Outcome after treatment of congenital bilateral cataract

PURPOSE

To evaluate long-term functional outcome after treatment of dense congenital bilateral cataract.

METHODS

The records of 22 consecutive children operated on before the age of 12 months at St. Erik's Eye Hospital over a 5-year period (1991-96) were reviewed retrospectively. Linear Snellen visual acuity (VA) at last check, presence of stereoacuity, nystagmus, strabismus and other complications are accounted for. Subject age at last check ranged from 4 to 9 years.

RESULTS

Visual acuity could be estimated in 19 children: the median VA of the better eye was 0.4 (range: counting fingers - 0.8) and of the fellow eye 0.15 (range: amaurosis - 0.8). In nine otherwise healthy children who were operated on early (by 1 month of age), VA varied from 0.4 to 0.8 in the better eye. Four of these children achieved stereopsis. Pupillary block glaucoma developed in five eyes (in three children). Chronic glaucoma developed in eight eyes (in five children). Glaucoma occurred predominantly in children who underwent cataract extraction during the first week of life. Two of the latter had marked microphthalmos.

CONCLUSION

Good postoperative VA was achieved in most healthy children with dense bilateral congenital cataract when surgery was performed early (before 6-8 weeks of age). Chronic glaucoma developed predominantly when cataract extraction was performed during the first week of life.

Visual impairment and blindness in Europe and their prevention

The European region currently differs in many aspects, such as political, socioeconomic, and geographical. After substantial political changes at the beginning of the 1990s, the majority of central and eastern European countries started to rebuild their healthcare systems. It is apparent that eastern Europe represents a highly diverse region where the difference among countries broadens year after year. In highly industrialised countries of Europe, the leading causes of childhood serious visual loss are lesions of the central nervous system, congenital anomalies and retinal disorders. In the middle income countries of Europe, congenital cataract, glaucoma and, mainly, retinopathy of prematurity are highly expressed. The major cause of serious visual loss in adults in industrialised countries is age related macular degeneration. The other conditions comprise cataract, glaucoma, diabetic retinopathy, and uncorrected/uncorrectable refractive errors, along with low vision. In people of working age, diabetic retinopathy, retinopathy pigmentosa, and optic atrophy are the most frequently reported causes of serious visual loss. In the middle income countries of Europe, advanced cataract, glaucoma, and diabetic retinopathy are more frequently observed.

Multifocal intraocular lens implantation in pediatric cataract surgery

OBJECTIVE

To evaluate implantation of a zonal-progressive multifocal intraocular lens (IOL) in children.

STUDY DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

Thirty-five eyes of 26 pediatric patients aged 2 to 14 years with multifocal IOL implantation at one institution with more than 1 year of follow-up.

INTERVENTIONS

Standard surgical procedure comprised an anterior capsulorrhexis, lens material aspiration via two side-port incisions, temporal tunnel incision, and multifocal IOL (SA40-N; Allergan, Irvine, CA) implantation in all eyes. In 24 eyes (68%), a 5-mm posterior capsulorrhexis was created with forceps, followed by an anterior vitrectomy in 19 of those eyes (54%).

RESULTS

Twenty-six patients (35 eyes) had an average follow-up of 27.4 +/- 12.7 months (range, 12-58 months). At last follow-up, best-corrected distance visual acuity improved significantly (P = 0.001), 71% of eyes with a visual acuity of 20/40 or better and 31% of eyes with a visual acuity of 20/25 or better. In the 9 bilateral cases, spectacle dependency was moderate, with only 2 children (22%) reporting the permanent use of an additional near correction. The remaining children were either using distance-correction only (4 patients; 44%) or no glasses at all (3 patients; 33%). Stereopsis also improved significantly after multifocal IOL implantation (P = 0.01). Sixteen eyes (46%) experienced obscuration of the entrance pupil that required intervention, with 10 requiring a second intraocular surgery. Four eyes required an anterior membranectomy for persistent fibrinous membrane. Intraocular lens decentration requiring surgical intervention developed in six eyes.

CONCLUSIONS

Multifocal IOL implantation is a viable alternative to monofocal pseudophakia in this age group.

Results of cataract surgery in young children in east Africa

BACKGROUND

Cataract is the leading cause of blindness in children in east Africa. The results of surgery are poor, partly because of inadequate correction of aphakia.

METHODS

A retrospective survey of 118 eyes in 71 children with bilateral cataract. All eyes had implantation of an IOL at the time of cataract surgery. The average age at surgery was 3.5 years. 28 patients(39%) were less than 2 years old at the time of surgery on their first eye.

RESULTS

Preoperatively, 75.4% of eyes and 76.1% of patients were blind. A follow up of at least 3 months was available in 91 (77.1%) eyes. In these eyes, 44% had a latest corrected vision of 6/18 or better and 91.2% had a latest corrected vision of 6/60 or better. Eyes with zonular cataract, and eyes operated after the age of 2 years were more likely to obtain a vision of 6/18 or better. 3.3% of eyes and 1.8% of patients had an acuity of less than 3/60. Nystagmus was present in 42.3% of patients before surgery. In those patients followed up for a minimum of 6 months, 10.2% still had nystagmus. The most frequent complication was severe fibrinous uveitis, which occurred in 36 (30.5%) eyes. 62 (52.5%) eyes had a posterior capsulotomy at the time of cataract extraction. Of the remaining 56 eyes, 20 (35.7%) had so far required a posterior capsulotomy. The leading cause of poor visual outcome was amblyopia. Two patients developed severe complications related to the intraocular lens.

CONCLUSIONS

Insertion of a lens implant at the time of cataract extraction appears to be well tolerated in the short term, and may offer significant advantages in an African setting.

Surgical interventions for bilateral congenital cataract

BACKGROUND

Congenital cataracts are opacities of the lens in one or both eyes of children, causing a reduction in vision bad enough to require surgery. Cataract is the largest preventable cause of visual loss in childhood. Paediatric cataracts provide different challenges to those in adults. Intense inflammation, amblyopia and posterior capsule opacification can affect results of treatment. Two treatments commonly considered for congenital cataract are lensectomy and lens aspiration.

OBJECTIVES

The objective of this review is to assess the effects of surgical treatments for bilateral symmetrical congenital cataracts. Success is measured according to the vision attained and occurrence of adverse events.

SEARCH STRATEGY

We searched the Cochrane Controlled Trials Register - CENTRAL (which includes the Cochrane Eyes and Vision Group specialised register), MEDLINE, EMBASE, the Science Citation Index and the reference list of the included study. We also contacted trial investigators and experts in the field for details of further studies.

SELECTION CRITERIA

We included all prospective, randomised controlled trials that compared one type of cataract surgery to another or to no surgery, in children aged 15 years or younger with bilateral congenital cataracts.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted data. No meta-analysis was performed.

MAIN RESULTS

One trial met the inclusion criteria. This trial randomised 130 eyes of 65 children. Follow up of 56 children at three years found no difference in visual acuity between lensectomy and lens aspiration with primary capsulotomy. Secondary opacification developed at a higher rate in the lens aspiration group (66%) compared to the lensectomy group (2%).

REVIEWER'S CONCLUSIONS

The two methods of surgery for bilateral congenital cataracts in this review have good visual results but the incidences of side effects differ. Further randomised trials are required to inform modern practice.

Unseen blindness, unheard deafness, and unrecorded death and disability: congenital rubella in Kumasi, Ghana

OBJECTIVES

Although rubella serosusceptibility among women of reproductive age in West Africa ranges from 10% to 30%, congenital rubella syndrome has not been reported. In Ghana, rubella immunization and serologic testing are unavailable. Our objectives were to identify congenital rubella syndrome cases, ascertain rubella antibody seroprevalence during pregnancy, and recommend strategies for congenital rubella syndrome surveillance.

METHODS

Congenital rubella syndrome cases were identified through prospective surveillance and retrospective surveys of hospital records. A rubella serosurvey of pregnant urban and rural women was performed.

RESULTS

Eighteen infants born within a 5-month period met the congenital rubella syndrome case definitions, coinciding with a 9-fold increase in presentation of infantile congenital cataract. The congenital rubella syndrome rate for this otherwise unrecorded rubella epidemic was conservatively estimated to be 0.8 per 1000 live births. A postepidemic rubella immunity rate of 92.6% was documented among 405 pregnant women; susceptibility was significantly associated with younger age (P = .000) and ethnicity (northern tribes, P = .024).

CONCLUSIONS

Congenital rubella syndrome occurs in Ghana but is not reported. Information about congenital rubella syndrome and rubella in sub-Saharan Africa is needed to evaluate inclusion of rubella vaccine in proposed measles control campaigns.

After-cataract and secondary glaucoma in the aphakic infant rabbit

PURPOSE

To study the association between after-cataract and secondary glaucoma after lensectomy and 5-fluorouracil treatment in an experimental infant rabbit model.

SETTING

St Erik Eye Hospital, Karolinska Institute, Stockholm, Sweden.

METHODS

Lensectomy was performed in both eyes of 16 3-week-old rabbits. One randomly selected eye in each rabbit was injected with 2.5 mg of 5-fluorouracil (5-FU) at surgery and 5.0 mg the day after surgery to reduce the formation of after-cataract. Axial length, corneal thickness, corneal diameter, and intraocular pressure were measured preoperatively and 4 times during the 6 months following surgery. Six months after surgery, the wet weight of the after-cataract was determined.

RESULTS

In 16 aphakic eyes treated with 5-FU, no or a minimal amount (<0.001 g) of after-cataract developed. None of the eyes showed signs of secondary glaucoma. Of 16 aphakic eyes not treated with 5-FU, 10 developed considerable amounts of after-cataract (>0.10 g); 8 of these developed glaucoma. The other 6 eyes had no or minimal after-cataract and did not develop secondary glaucoma. The relationship between after-cataract and secondary glaucoma was statistically significant.

CONCLUSION

A significant relationship between the amount of after-cataract and the development of secondary glaucoma was found in aphakic infant rabbit eyes.

Long-term visual results in congenital cataract surgery associated with preoperative nystagmus

BACKGROUND

Congenital cataracts are the leading cause of preventable blindness in children. The prevalence of this disease is higher in developing countries. The incidence and visual outcome of patients who have undergone congenital cataract surgery in Mexico is not currently known. The purpose of this study is to evaluate the long-term visual results in Mexican children with bilateral congenital cataracts associated with preoperative nystagmus.

METHODS

In a tertiary-level hospital, the long-term visual results of 13 children (26 eyes) with bilateral congenital cataracts associated with preoperative nystagmus were evaluated. All patients had at least 5 years of follow-up after surgery, and all patients were subjected to an intentional ophthalmologic examination. Three types of visual function were evaluated: visual acuity, contrast sensitivity vision, and stereoscopic vision. Age at surgery was correlated with visual outcome. Optical rehabilitation and surgical complications were also analyzed.

RESULTS

Our group found five patients (38%) with acceptable visual acuity levels. Eight patients (62%) were legally blind according to World Health Organization (WHO) guidelines. Contrast sensitivity vision and stereopsis were severely affected in all patients. We also found a high correlation between timing of surgery, optical rehabilitation, and visual outcome.

CONCLUSIONS

Early diagnosis and treatment, in addition to adequate optical rehabilitation, are mandatory for preventing blindness secondary to congenital cataracts in developing countries. The current state of congenital cataract management in Mexico is also examined.

Pediatric cataracts

There have been major changes over the past 5 to 10 years in our understanding of both the chemical basis for and the surgical treatment of cataract in infants and children. Important questions that remain to be answered include the appropriate power and design selection criteria for intraocular lens implantation, as well as management of the posterior capsule and long-term refractive sequelae. In the past 10 years, there have been radical changes in the management of visually significant cataract in the infant and child. Whereas lens removal, subtotal posterior capsulectomy, vitrectomy, and aphakia were once the standard of care, many physicians now feel that small incisions, phacoemulsification technology, and intraocular lenses (IOLs) are best for these patients. Work is continuing to accumulate a significant body of evidence to evaluate results of these changes in technique and to develop optimal IOL designs and selection criteria for these specialized cataract patients.

Childhood blindness

PURPOSE

The objective of this study was to summarize available data regarding pediatric blinding diseases worldwide and to present the most up-to-date information on childhood blindness in the United States.

METHODS

We obtained data from a complete search of the world literature and from direct contact with each of the schools for the blind in the United States.

RESULTS

Five percent of worldwide blindness involves children younger than 15 years of age; in developing countries 50% of the population is in this age group. By World Health Organization criteria, there are 1.5 million children worldwide who are blind: 1.0 million in Asia, 0.3 million in Africa, 0.1 million in Latin America, and 0.1 million in the rest of the world. There are marked differences in the causes of pediatric blindness in different regions, apparently based on socioeconomic factors. In developing countries, 30% to 72% of such blindness is avoidable, 9% to 58% is preventable, and 14% to 31% is treatable. The leading cause is corneal opacification caused by a combination of measles, xerophthalmia, and the use of traditional eye medicine. There is no national registry of the blind in the United States, and most of the schools for the blind do not keep data regarding the cause of blindness in their students. From those schools that do have this information, the top 3 causes are cortical visual impairment, retinopathy of prematurity, and optic nerve hypoplasia. There has been a significant increase in both cortical vision loss and retinopathy of prematurity in the past 10 years.

CONCLUSIONS

There are marked regional differences in the prevalence and causes of pediatric blindness, apparently based on socioeconomic factors that limit prevention and treatment schemes. In the United States the 3 leading causes of pediatric blindness are cortical visual impairment, retinopathy of prematurity, and optic nerve hypoplasia. There is a need for more complete and more uniform data based on the established World Health Organization reporting format.