Roger Bowell

Intraocular lenses in children: changes in axial length, corneal curvature, and refraction

AIM To assess changes in axial length, corneal curvature, and refraction in paediatric pseudophakia. METHODS 35 eyes of 24 patients with congenital or developmental lens opacities underwent extracapsular cataract extraction and posterior chamber intraocular lens implantation. Serial measurements were made of axial length, corneal curvature, objective refraction, and visual acuity. RESULTS For patients with congenital cataracts (onset <1 year age) the mean age at surgery was 24 weeks. Over the mean follow up period of 2.7 years, the mean increase in axial length of 3.41 mm was not significantly different from the value of an expected mean growth of 3.44 mm (pairedt test, p=0.97) after correction for gestational age. In the developmental cataract group (onset >1 year of age) the mean age at surgery was 6.4 years with a mean follow up of 2.86 years. This group showed a mean growth in axial length of 0.36 mm that was not significantly different from an expected value of 0.47 mm (paired t test, p = 0.63). The mean preoperative keratometry was 47.78 D in the congenital group and 44.35 D in the developmental group. At final follow up the mean keratometry in the congenital group was 46.15 D and in the developmental group it was 43.63 D. In eyes followed for at least 2 years, there was an observed myopic shift by 24 months postoperatively of 3.26 D in the congenital cases (n=10) and 0.96 D in the developmental cases (n=18). CONCLUSION The pattern of axial elongation and corneal flattening was similar in the congenital and developmental groups to that observed in normal eyes. No significant retardation or acceleration of axial growth was found in the eyes implanted with IOLs compared with normal eyes. A myopic shift was seen particularly in eyes operated on at 4–8 weeks of age and it is recommended that these eyes are made 6 D hypermetropic initially with the residual refractive error being corrected with spectacles.

Long term follow up of primary trabeculectomy for infantile glaucoma

BACKGROUND--The treatment for infantile glaucoma is surgical. Treatment options include goniotomy, trabeculotomy, combined trabeculotomy-trabeculectomy, and trabeculectomy. METHODS--Patients who had a follow up of 5 years or longer after primary trabeculectomy were examined to determine the long term stability in infantile glaucoma. RESULTS--In eyes with primary infantile glaucoma 92.3% achieved control of their glaucoma with a single trabeculectomy; 100% achieved control with two trabeculectomies; 85.7% of eyes with secondary infantile glaucoma achieved control with a single trabeculectomy. There were no serious complications experienced in either group. CONCLUSION--Primary trabeculectomy is a safe and successful operation for infantile glaucoma.

Optic nerve hypoplasia, encephalopathy, and neurodevelopmental handicap.

Abnormalities of the central nervous system are frequently described in optic nerve hypoplasia. In a longitudinal study of 46 consecutive children (32 term, 14 preterm) with bilateral optic nerve hypoplasia 32 (69.5%) had associated neurodevelopmental handicap. Of these, 90% had structural central nervous system abnormalities on computed tomographic brain scans. Neurodevelopmental handicap occurred in 62.5% of the term and 86% of the preterm infants respectively. Term infants had a greater incidence of ventral developmental midline defects and proportionately fewer maternal and/or neonatal complications throughout pregnancy, while encephaloclastic lesions were commoner among the premature infants. An association of optic nerve hypoplasia with the twin transfusion syndrome and prenatal vascular encephalopathies is described.

Ocular complications in homocystinuria--early and late treated.

Homocystinuria due to cystathionine-beta-synthetase deficiency is an autosomal recessive disorder of methionine metabolism with an incidence in Ireland of 1 in 52,544 births. Ocular complications in untreated patients include ectopia lentis, secondary glaucoma, optic atrophy, and retinal detachment. There are no characteristic signs or symptoms in infancy, and early detection relies on screening of newborn babies. Nineteen patients with homocystinuria were studied; 14 received dietary treatment and vitamin supplementation starting in the newborn period. Of these, none developed ectopia lentis after a mean follow-up of 8.2 years, compared with a 70% dislocation rate in untreated patients with a similar follow-up period. Ectopia lentis developed and progressed in five patients diagnosed later in life, despite tight biochemical control. The risk of ocular complications in homocystinuria can be substantially reduced in patients started on treatment within six weeks of birth.

Advanced cicatricial retinopathy of prematurity--outcome and complications.

AIMS: To assess the outcome and complications of patients with advanced retinopathy of prematurity (ROP). METHODS: All patients with eyes achieving stage 4 or 5 retinopathy of prematurity were reviewed. Twenty one eyes were diagnosed during ROP screening in maternity hospitals and 10 eyes were of infants transferred for treatment. RESULTS: Thirty one eyes of 17 patients were included. Thirteen eyes were treated for acute disease but progressed to stage 4 or 5; seven had cryotherapy and six diode laser photocoagulation. Cataract was found in 17 eyes (54.8%), glaucoma in seven eyes (22.6%), microphthalmos in 15 (48.4%), and corneal opacification in four eyes (12.9%). Fifteen eyes had surgical procedures; two (6.5%) had trabeculectomy, four (12.9%) had lensectomy, and nine (29%) retinal detachment repair. Transferred infants had their initial eye examination later than infants in hospitals screened by the authors and 80% of them had progressed beyond threshold ROP by the time they were transferred for treatment. Twenty nine eyes (93.6%) had visual acuities of 3/60 or less and only two eyes (6.5%) achieved 6/18 or less. CONCLUSION: The visual outcome of the eyes undergoing retinal re-attachment surgery was disappointing. Cataract, microphthalmos, and glaucoma were the most frequent complications, and surgical intervention was often required. The need for children who are blind as a result of ROP to have long term follow up is shown.

Ophthalmic findings in classical galactosaemia--prospective study.

Thirty three children with classical galactosaemia diagnosed through newborn screening are considered. It is concluded that cataract formation has a direct relationship with poor dietary control. Erythrocyte galactose-1-phosphate (Gal-1-P) levels do not correspond to cataract formation unless many times higher than normal. The value of crystalline lens biomicroscopy is confirmed as a useful method for monitoring the dietary and biochemical control in classical galactosaemia.

Ophthalmic Findings in Classical Galactosemia-A Screened Population

Classical galactosemia due to a deficiency of galactose-1-phosphate-uridyl transferase, is an autosomal recessive disorder of galactose metabolism with an incidence in Ireland of one in 30,000 births. It can result in cataract formation through the accumulation of galactitol within the lens. Seventeen children with transferase deficient galactosemia were studied. Early diagnosis followed by a galactose-free diet and tight biochemical control prevented cataract formation in 13 cases after a mean follow-up of 6.3 years. Cataracts did not regress in all patients commenced on diet by 6 weeks but early treatment prevented progression. The ophthalmologist may play an important role in the monitoring of patients with this disease as the recognition of new lens opacities by slit-lamp biomicroscopy may be the most sensitive initial index of inadequate biochemical control.

Uniocular childhood blindness : a prospective study

PURPOSE This prospective study examines uniocular blindness among children younger than 16 attending a large pediatric ophthalmology department. The aim was to identify the causes of uniocular blindness and determine how much is preventable. We defined blindness according to the World Health Organization definition of vision worse than or equal to 3/60. METHODS All children who attended the department and were blind in one eye during the period of the study were included. A history was taken, visual acuity was assessed by an age-appropriate method, and an ocular examination was carried out. When necessary, the child also was seen by an orthoptist or pediatrician. RESULTS A total of 71 patients were identified. At the time of diagnosis, the patients varied in age from a few weeks to 15 years. The causes were classified into one of the following diagnostic categories: chromosomal/genetic (8.5%), prenatal (47.9%), perinatal (7.0%), or childhood (36.6%). Many cases are prenatal in origin and are not preventable. Other causes that are difficult to prevent include retinoblastoma, toxocariasis, and trauma. One cause, amblyopia, may be preventable or treatable in most instances if detected early. CONCLUSIONS Most cases of uniocular blindness are not preventable; however, protective glasses should be encouraged to prevent injury to the good eye.

Congenital ocular motor apraxia: An inability to unlock the vestibulo-ocular reflex

The authors report ten cases of congenital ocular motor apraxia. Two patients had Cockaynes syndrome. One patient had succinic semialdehyde dehydrogenase deficiency. One patient had vermian hypoplasia of the cerebellum. Four patients had precocious head movements with abnormal limb tremor in the first two days of life.Based on their findings the authors postulate that head thrusts are the result of a failure to unlock the vestibulo-ocular reflex from the object of regard rather than a strategy to assist horizontal gaze.

Cataracts in children with classical galactosaemia and in their parents

Classical galactosaemia (McKusick 23040) is an autosomal recessive multisystem disorder caused by a deficiency of galactose-l-phosphate uridyl transferase (GPUT) (Kalckar et al., 1956). The incidence in Ireland is 1:30 000 live births (Cahalane and Naughten, 1983). Early detection and treatment may prevent the development of its major complications: cataracts, jaundice, hepatomegaly and mental retardation (Donnell and Bergren, 1975). The rationale for newborn screening is based on this experience. The reports of an association between GPUT heterozygosity and an increased risk of visually significant pre-senile cataracts are conflicting (Wilson and Donnell, 1958; Skalka and Prchal, 1978) in a group of patients in whom therapeutic implications may be important. We describe the ophthalmic findings in a group of children with classical galactosaemia (homozygous) and their parents (obligate heterozygotes).