Unilateral Infantile Cataract Research Articles

Long-term strabismus outcomes after unilateral infantile cataract surgery in the Infant Aphakia Treatment Study

To characterize long-term strabismus outcomes in children in the Infant Aphakia Treatment Study (IATS).

Long-term strabismus outcomes after unilateral infantile cataract surgery in the Infant Aphakia Treatment Study

To characterize long-term strabismus outcomes in children in the Infant Aphakia Treatment Study (IATS). This study was a secondary data analysis of long-term ocular alignment characteristics of children aged 10.5 years who had previously been enrolled in a randomized clinical trial evaluating aphakic management after unilateral cataract surgery between 1 and 6 months of age. In the IATS study, 96 of 109 children (88%) developed strabismus through age 10.5 years. Half of the 20 children who were orthophoric at distance through age 5 years maintained orthophoria at distance fixation at 10.5 years. Esotropia was the most common type of strabismus prior to age 5 years (56/109 [51%]), whereas exotropia (49/109 [45%]) was the most common type of strabismus at 10.5 years (esotropia, 21%; isolated hypertropia, 17%). Strabismus surgery had been performed on 52 children (48%), with 18 of these (35%) achieving microtropia <10Δ. Strabismus was equally prevalent in children randomized to contact lens care compared with those randomized to primary intraocular lens implantation (45/54 [83%] vs 45/55 [82%]; P = 0.8). Median visual acuity in the study eye was 0.56 logMAR (20/72) for children with orthotropia or microtropia <10Δ versus 1.30 logMAR (20/400) for strabismus ≥10Δ (P = 0.0003). Strabismus-in particular, exotropia-is common irrespective of aphakia management 10 years following infant monocular cataract surgery. The delayed emergence of exotropia with longer follow-up indicates a need for caution in managing early esotropia in these children. Children with better visual acuity at 10 years of age are more likely to have better ocular alignment.

Visual Rehabilitation in Pediatric Aphakia.

The management of childhood cataract begins at the initial contact with the family and typically extends far into the child's future. Decisions affecting long-term care and visual outcomes are often made in these initial preoperative encounters. Treatment will vary depending on whether the cataract is unilateral or bilateral and whether it is infantile onset or later. Thorough discussion of the treatment options is needed, especially with description of the life-long management issues for the child. Visual outcomes will vary, with the best visual acuity results being observed in older children with bilateral cataracts. Visual rehabilitation of children with unilateral cataract requires use of a contact lens or an intraocular lens (IOL) for the best result with a chance for binocularity. Only about 50% of eyes with unilateral infantile cataract will develop vision of better than 20/200. For bilateral cataracts, both contacts and IOLs can be used, as well as aphakic glasses. Excellent visual outcomes are typical unless glaucoma develops, which occurs in up to 30% of cases. Cataract surgery after 1 year of age is associated with substantially better visual outcomes. The use of an IOL is most commonly accepted and performed for cataract in one or both eyes after 1 year of age. Prior to 1 year of age, significantly more secondary surgical procedures are required to manage opacification of the optical axis with the use of an IOL compared with the use of surgery and contact lens correction. Amblyopia therapy for unilateral cataract needs be continuous from the time of surgery until at least 8 years of age. It is often difficult to perform this therapy over such a long time period, with compliance with less than 30% of prescribed time during infancy at 5 years after surgery.

Baseline Characteristics of the Infant Aphakia Treatment Study Population: Predicting Recognition Acuity at 4.5 Years of Age

To identify patient baseline characteristics that predict recognition acuity at 4.5 years of age in the Infant Aphakia Treatment Study, a study of patients with monocular infantile cataracts. We analyzed baseline characteristics of the 114 infants enrolled in the Infant Aphakia Treatment Study to determine which were most predictive of visual outcome at 4.5 years of age. All infants underwent cataract surgery between 1 and 7 months of age. Monocular acuity was assessed at 4.5 years of age by a traveling examiner using the Amblyopia Treatment Study HOTV protocol. Age at cataract surgery was weakly associated with visual acuity (Spearman rank correlation coefficient = 0.19, P = 0.041) with median visual acuity better among the younger patients (28-48 days: 0.50 logMAR, 49-210 days: 1.10 logMAR, P = 0.046). Patients from families with private insurance had significantly better median visual acuity (0.60 vs. 1.40 logMAR, P = 0.0004). No other baseline characteristic revealed a significant bivariate relationship with visual acuity. A multiple linear regression relating visual acuity to all baseline characteristics demonstrated that only the availability of private insurance was statistically significant, accounting for 12% of the variance. This analysis concurs with previous studies that early surgery is important for good visual outcomes in patients with unilateral infantile cataracts. The fact that only one baseline variable (private insurance) contributed to the multivariate analysis, accounting for 12% of the variance, suggests that predicting visual outcome for these patients is complicated at best, and cannot be estimated from baseline characteristics alone. (ClinicalTrials.gov number, NCT00212134.).

Nystagmus and related fixation instabilities following extraction of unilateral infantile cataract in the Infant Aphakia Treatment Study (IATS).

To study eye movements in a large group of children after the removal of unilateral infantile cataract, and to compare fixation instabilities between treatment groups with or without IOL implantation. The Infant Aphakia Treatment Study (IATS) is a randomized, multicenter clinical trial comparing IOL to contact lens (CL) treatment with a unilateral infantile cataract in participants who underwent cataract surgery at 1 to 6 months of age. At age 4.5 years, eye movements were recorded in 103 participants, using a high-speed video camera while the child performed a fixation task. The recordings were inspected by masked readers for the presence of fixation instabilities (nystagmus and saccadic oscillations). Overall, fixation instabilities were observed in 50 (60%) of 83 children who had evaluable recordings, with no differences between treatment groups (27 [64%] of 42 in the IOL group, 23 [56%] of 41 in the CL group; P = 0.51). Nystagmus was seen in 38% and saccadic oscillations in 31%, with no differences between treatment groups (P > 0.33). Children without a fixation instability had better visual acuity (P = 0.04). Nystagmus and saccadic oscillations are well-known consequences of infantile cataracts, presumably the result of visual deprivation during the critical period of visual development. After early cataract extraction, successful optical correction may reduce further form deprivation and minimize the incidence of these fixation instabilities. In this study, no differences in the presence of fixation instabilities were found between the two treatment strategies (CL or IOL) for optical correction after cataract removal. (ClinicalTrials.gov number, NCT00212134.).

Atoll sign in posterior lenticonus: A case report of bilateral posterior lenticonus with review of literature

Posterior lenticonus is a rare progressive disease characterized by protrusion of posterior lens capsule along with lens cortex into the vitreous cavity. Posterior lenticonus is more common but present unilaterally unlike anterior lenticonus, which presents bilaterally. Posterior lenticonus is a common cause of unilateral infantile cataract but is a very rare cause of bilateral cataract. Diagnosis is mainly clinical but can be difficult in asymptomatic patients; oil drop sign (in mild posterior lenticonus) and fish tail sign (lenticular cortex hanging in vitreous cavity after posterior capsular dehiscence) are described in posterior lenticonus. We are proposing an atoll sign in advanced case of posterior lenticonus with intact posterior capsule on slit lamp examination. The positive atoll sign will have more favorable prognosis since posterior capsule is intact, hence posterior chamber intraocular lens implantation will be more feasible with better visual prognosis as was the case with our patient.

Assessment of Risk Factors for Infantile Cataracts Using a Case-Control Study: National Birth Defects Prevention Study, 2000–2004

To identify risk factors for infantile cataracts of unknown etiology. Case-control study. Case infants (n = 152) and control infants (n = 4205) enrolled in the National Birth Defects Prevention Study for birth years 2000-2004. Multivariate analysis was performed exploring associations for risk factors for bilateral and unilateral infantile cataracts of unknown etiology. Infantile cataracts of unknown etiology. Maternal interviews were completed for 43 case infants with bilateral and 109 with unilateral infantile cataracts of unknown etiology. Very low birth weight (<1500 g) was associated with both unilateral (adjusted odds ratio [OR], 6.0; 95% confidence interval [CI], 2.2-16.3) and bilateral (OR, 13.2; 95% CI, 4.2-41.1) cataracts, whereas low birth weight (1500-2499 g) was only associated with bilateral cataracts (OR, 3.3; 95% CI, 1.3-8.1). Infants with unilateral cataracts were more likely to be born to primigravid women (OR, 1.6; 95% CI, 1.0-2.7) than women with > or =2 previous pregnancies, although this was of borderline significance. Although not significant, effect estimates were elevated suggesting a possible association between unilateral cataracts and maternal substance abuse during pregnancy, and between bilateral cataracts and urinary tract infection during pregnancy and aspirin use during pregnancy. Very low birth weight is associated with both bilateral and unilateral cataracts, whereas low birth weight is associated with bilateral cataracts and primigravidity with unilateral cataracts. Other associations, although not statistically significant, suggest risk factors that merit further research.

Amblyopia after unilateral infantile cataract extraction after six weeks of age

To determine interocular grating acuity difference in children treated for unilateral infantile cataract. A group of 27 children previously treated for unilateral infantile cataract, had their monocular visual acuity measured by sweep visual evoked potentials. Interocular grating acuity difference was calculated as the absolute subtraction of monocular acuity scores. Lens status, opacity severity and eye alignment were considered for analysis. Mean interocular grating acuity difference obtained from unilateral cataract patients was 0.58 +/- 0.20 logMAR. This result was significantly larger than 0.10 logMAR used as normative data. Children with severe opacities had a more pronounced amblyopia than the moderate ones. No significant correlation between amblyopia and strabismus or aphakia was found. Interocular acuity difference in this group of unilateral congenital cataract was more pronounced than previous reports, mainly because of delay in diagnosis, surgery and optical correction.

Ocular motor outcomes after bilateral and unilateral infantile cataracts

We wished to study how the severity and duration of early onset visual deprivation affects eye alignment and ocular stability. Thirty-three patients (aged 1 week to 12.8 years) with infantile cataracts (16 bilateral, 17 unilateral) were examined for periods up to 61 months. Twenty-three patients were considered to have cataracts, which were a major obstacle to vision (major form deprivation), 9 of whom underwent surgery within 8 weeks of birth (mean and SD = 5.2 ± 2.3 weeks) and 10 after 8 weeks (mean and SD = 33.9 ± 29.7 months). Eye alignment and fixation stability was measured using infrared recording systems and video. Visual acuity was assessed using forced-choice preferential looking techniques in the neonates and infants and with optotypes in the children. Fifteen of the 23 (65%) patients who experienced major form deprivation exhibited a nystagmus, of which 11 (73%) were manifest latent nystagmus (MLN). Nineteen of the 23 (85%) had strabismus. Of the nine patients who underwent early surgery (⩽8 weeks), two displayed a preoperative nystagmus whilst between 10 and 39 months post-operatively 8 (89%) exhibited a nystagmus. Of the group of 10 patients with minor cataracts only 2 (1 late surgery, 1 no surgery) had nystagmus and 2 strabismus. We conclude that following optimal post-operative management of infantile cataracts a sustained nystagmus—typically an MLN—is the most likely ocular motor outcome, even when the period of deprivation is as short as 3 weeks.

Factors that influence the visual outcome in cases of infantile unilateral cataract

Aim: To review retrospectively the records of a cohort of patients who presented before 6 months of age with unilateral cataract and identify factors that influenced the visual outcome. Method: The records of children with unilateral infantile cataract, who had been examined since 1993 following the establishment of a new occlusion protocol, were reviewed. For analysis the children were divided into two groups: group A with visual acuity of 0.6 logMAR or better and group B with visual acuity of Results: Thirty-two children met the inclusion criteria; 8 transferred to other hospitals leaving 24 cases for analysis. There were 11 (46%) children in group A with visual acuity ranging from 0.6 to 0.04 logMAR and 13 (54%) children in group B with visual acuity ranging from NPI, to 0.74 logMAR. The median age at surgery was 8.5 weeks (13 weeks, group A; 7 weeks, group B). There was a greater Incidence of ophthalmic complications in group B. Nystagmus was present in 9 (38%) children, 8 of who were in group B, and this was a significant factor in visual outcome (p = 0.013). Compliance with the occlusion protocol was also a significant factor in visual outcome (p = 0.016). Further analysis indicated an association between occlusion compliance, visual outcome and distance from home (p = 0.035). Conclusion: A high incidence of ophthalmic complications, a delay in establishing daily contact lens wear and a failure to achieve 'good' compliance with occlusion therapy were associated with a poor visual outcome.

Non-syndromic posterior lenticonus a cause of childhood cataract: evidence for X-linked inheritance.

When an X-linked pedigree of posterior lenticonus with cataract was identified further evidence for X-linked inheritance of this condition was sought. Forty-three cases of posterior lenticonus were identified from a database of 354 children with cataract. Two children with the X-linked syndromes of Lowe and Nance-Horan and 3 children with Fanconi syndrome have been excluded from further analysis. None of the children was deaf. None of the non-syndromic cases had microcornea. There were 38 cases of non-syndromic posterior lenticonus (approximately 11%). There were 15 children from 13 pedigrees and 23 apparently sporadic cases. Of the 106 cases on the database with unilateral cataract 15 had posterior lenticonus (approximately 14%). Eleven of 13 pedigrees were compatible with X-linked inheritance or autosomal dominant inheritance with variable expression. However, in 2 pedigrees there was father to son transmission. Posterior lenticonus is a common cause of unilateral infantile cataract, but is thought to be a rare cause of bilateral cataracts. This study suggests that posterior lenticonus is responsible for a significant proportion of childhood cataracts (approximately 14% of unilateral and approximately 9% of bilateral cases). Posterior lenticonus is generally thought to occur as a sporadic condition. This study demonstrates that there is a family history of early-onset cataract in a significant number of bilateral cases (approximately 58%).

Stereopsis and binocular vision after surgery for unilateral infantile cataract

Purpose: To assess the prevalence and level of binocular function in children with unilateral congenital or very early infantile cataract. Methods: We retrospectively reviewed the charts of all patients with unilateral congenital or very early infantile cataract who underwent operation before 4 months of age, at the W. K. Kellogg Eye Center/University of Michigan Hospitals, from 1985 to 1995. Amblyopia was treated with a reduced patching schedule consisting of 1 hour per day per month of age for the first 6 months of life, in an attempt to improve binocular function by allowing more hours of binocular interaction during the presumed critical period for development of binocular cortical pathways. Results: Thirteen patients met the inclusion criteria. Seven patients had persistent hyperplastic primary vitreous (PHPV) cataract and 6 had non-PHPV cataract. Overall, visual acuity of 20/80 or better developed in 69% of patients; 100% of eyes with non-PHPV cataract achieved visual acuity of 20/60 or better. Stereopsis of 400 arc seconds or better was detectable in 62% of patients, including 3 with PHPV cataract and 3 who required strabismus surgery in the first year of life. Three children had better than 150 arc seconds of stereopsis. The incidence of large-angle strabismus was 54%. Conclusions: Binocular cooperation, including gross and fine stereopsis, can develop in children with unilateral aphakia as a result of early removal of infantile cataracts. A less-strenuous patching schedule than has been historically advocated may foster this process, while restoring and maintaining good central visual acuity in patients with excellent compliance with contact lens and occlusion regimens. (J AAPOS 1999;3:109-13)

Posterior Chamber Lens Implantation in Infants and Juveniles

Extracapsular cataract extraction with posterior chamber intraocular lens implantation was performed in 23 eyes (21 patients) of infants and juveniles. Four children with unilateral infantile cataract were operated on at the age of 3 or younger. Nine older children (11 eyes), all of them with bilateral juvenile cataract, were operated when older than 3. Seven children had traumatic cataracts: surgery was performed at the age of 3 or younger in three of them, and above this age in four. One patient aged 13 had a cataract due to heterochromic iridocyclitis. Final visual acuity results, binocularity, surgical complications and the need for additional surgery for secondary cataract development were analysed in relation to the age at surgery and the type of cataract. A visual acuity of 6/12 or better was achieved in 82.6% of the operated eyes. Stereopsis was found in 47.6% of the patients. Inflammation with fibrinous exudate, aqueous flare and cells in the anterior chamber appeared postoperatively in 57% of eyes, and were more common among the infant age group, but subsided with suitable anti-inflammatory treatment. Opacification of the posterior capsule was found within 3 months of surgery in 43.5% of the eyes, and was more common in the infants. Treatment with Nd-YAG laser was useful in the older children; in infants the opening made by laser in the posterior capsule did not last and a clear visual axis was achieved only after pars plana anterior vitrectomy and posterior central capsulectomy. The final results were excellent in patients with juvenile and traumatic cataracts. In those with unilateral infantile cataracts the results were considered encouraging.

Complications of Implant Surgery in Children

Rapid recognition and appropriate therapy will prevent or remediate most of the complications occurring in children after cataract aspiration and IOL implantation. Some of the complications of pediatric IOL implantations are related to the increased scleral pliability and decreased rigidity which predispose scleral collapse, vitreous loss, flat anterior chamber and corneal endothelial damage. A second group of complications is associated with the enhanced inflammatory and fibrotic responses peculiar to a child's eye. This group includes operative striate keratitis and iridocyclitis, late IOL precipitates, secondary and postpseudophakos membranes, iris erosion and synechiae formation, and IOL tilt and displacement. Although the intraocular lens is a possible means of visual rehabilitation for children with traumatic cataracts or unilateral infantile cataracts, its long-term risk/benefit ratio must still stand the test of time.

The Need for Intraocular Lens Implantation in Children

The intraocular lens offers an additional experimental parameter to be considered for the visual rehabilitation of children with traumatic or unilateral infantile cataracts. The disadvantages of aphakic spectacles or contact lens and amblyopia have committed many of these eyes to the status of visual cripples. In this series of 41 patients, with a maximum of 24 months follow-up, it has been concluded that the IOL may be successfully implanted.

Intraocular Lenses in Children

The intraocular lens offers an experimental alternative to be considered for the visual rehabilitation of children with traumatic or unilateral infantile cataracts. The disadvantages of aphakic spectacles or contact lenses and amblyopia have committed many of these eyes to the status of visual cripples. In this series of 41 patients with a maximum of 24 months follow-up, it has been concluded that an IOL may be successfully implanted. I wish to reemphasize that vitreous involvement does not preclude IOL implantation providing all the vitreous is removed from the anterior chamber by the conclusion of the operation. Discissions of secondary membranes should be performed if there is any doubt as to the clarity of the membrane. All patients should be repeatedly refracted and the over-refraction prescribed to assure that the child is obtaining the best possible form vision to the aphakic eye. Bifocals are encouraged for near work. Vigorous occlusion therapy is undertaken in all patients exhibiting signs of amblyopia.