Ocular morbidity in very low birth-weight infants with intraventricular hemorrhage

Optic atrophy in prematurity: pathophysiology and clinical features

Optic atrophy is an important cause of visual impairment in children, and the aetiological profile has changed over time. Technological advancements led by neuroimaging of the visual pathway and imaging of the optic nerve with optical coherence tomography have accelerated the understanding of this condition. In the new millennium, an increasing prevalence of prematurity as a cause of optic atrophy in children has been highlighted. This new shift has been linked with increasing rates of premature births and improved neonatal survival of preterm infants. The available literature is limited to hospital and registry-based cohorts with modest sample sizes, methodological heterogeneity and selection bias limitations. Larger studies that are better designed are required to better understand the contribution of prematurity to the disease burden. In addition to considering other life-threatening aetiologies, screening for premature birth should be covered as part of a comprehensive history when evaluating a child with paediatric optic atrophy.

[Anatomo-functional state of the central retina in premature infants with intraventricular hemorrhage and retinopathy of prematurity]

OBJECTIVE

Assessment of the anatomo-functional state of the central retina in children with intraventricular hemorrhage (IVH) and retinopathy of prematurity (ROP) in the long-term period.

MATERIAL AND METHODS

We examined 51 patients (102 eyes) born 25-34 weeks' of gestation (birth weight 700-2290 g), aged 8.83±3.5 years, and 18 children (36 eyes) born prematurely aged 10.8±3.2 years. The children underwent standard ophthalmologic examination, optical coherence tomography (OCT) and visual evoked potentials (VEP).

RESULTS

Retinal thickness (RT) and retinal volume (RV) in the fovea of premature infants with PH and/or IVH are significantly higher than in healthy full-term infants, which correlates with lower visual acuity (p<0.05). RT and RV in the fovea has an inverse proportional relationship with gestational age (GA), (p<0.05). According to the results of VEP, moderate organic changes in the conduction tract of the visual analyzer are noted in 45% of premature infants (p<0.05).

CONCLUSION

The process of macula formation is affected by many perinatal and postnatal factors, namely: GA, birth weight, ROP, hypoxic-ischemic CNS diseases, and refractive disorders.

[Modern possibilities of diagnosing lesions of the visual analyzer in perinatal lesions of the central nervous system in full-term and premature infants]

The article provides an overview of current neuro-ophthalmological diagnostic capabilities in patients with perinatal lesions. The main attention is paid to the diagnosis of patients with periventricular leukomalacia and peri- and intraventricular hemorrhages. The most relevant methods of neuro-ophthalmological diagnosis in hypoxic-ischemic CNS lesions are covered. The functions and peculiarities of blood supply of the germinal matrix are described. The importance of the use of optical coherence tomography and visual evoked potential recording in full-term and premature infants with visual pathway and/or visual cortex lesions in brain lesions is discussed. The conclusion emphasizes the need for an interdisciplinary approach in the examination of children with perinatal CNS lesions.

Strabismus at Age 2 Years in Children Born Before 28 Weeks' Gestation: Antecedents and Correlates

Children born very preterm are at greater risk of ophthalmic morbidities, including strabismus, than children born at term. We evaluated perinatal factors associated with strabismus at age 2 years in a large population of infants delivered before 28 weeks' gestation. A total of 996 infants in the multicenter ELGAN (Extremely Low Gestational Age Newborn) study who had a retinal exam in infancy and a developmental assessment at 2 years corrected age are included. Their mothers were interviewed about the pregnancy, and both mother and newborn charts were reviewed. Certified examiners administered the Bayley Scales of Infant Development-II and performed an examination of ocular alignment. Time-oriented logistic regression risk models were created to evaluate the associations of characteristics and exposures with the development of strabismus. Overall, 14% (n = 141) of the children had strabismus at 2 years, and 80% of strabismic children had esotropia. Characteristics associated with strabismus were birth before 26 weeks' gestation, severe fetal growth restriction, and maternal history of aspirin ingestion. Associated postnatal factors included a SNAP-II (Score for Neonatal Acute Physiology) illness severity value ≥ 30, brain ventriculomegaly, type I retinopathy of prematurity, and ventilator-dependent severe bronchopulmonary dysplasia. Strabismus in very preterm populations is associated with a number of antenatal and postnatal antecedents as well as clinical and imaging correlates indicative of brain damage in these children. Routine ophthalmologic assessments in the early years can allow appropriate and timely interventions.

Prevalence and course of strabismus through age 6 years in participants of the Early Treatment for Retinopathy of Prematurity randomized trial

PURPOSE

To present strabismus data for children who participated in the Early Treatment for Retinopathy of Prematurity (ETROP) randomized trial.

METHODS

The prevalence of strabismus, categorized as present or absent, was tabulated for all children with history of high-risk prethreshold retinopathy of prematurity (ROP) who participated in the ETROP randomized trial and were examined at 9 months to 6 years of age. Relationships among strabismus and demographic measures, eye characteristics, and neurodevelopmental factors were analyzed.

RESULTS

Among the 342 children evaluated at 6 years, the prevalence of strabismus was 42.2%. Even with favorable acuity scores in both eyes, the prevalence of strabismus was 25.4%, and with favorable structural outcomes in both eyes the prevalence of strabismus was 34.2%. Of children categorized as visually impaired as the result of either ocular or cerebral causes, 80% were strabismic at the 6-year examination. Of 103 study participants who were strabismic at 9 months, 77 (74.8%) remained so at 6 years. Most strabismus was constant at both the 9-month (62.7%) and the 6-year examination (72.3%). After multiple logistic regression analysis, risk factors for strabismus were abnormal fixation behavior in one or both eyes (P < 0.001), history of amblyopia (P < 0.003), unfavorable structural outcome in one or both eyes (P = 0.025), and history of anisometropia (P = 0.04). Strabismus surgery was performed for 53 children. By 6 years, the cumulative prevalence of strabismus was 59.4%.

CONCLUSIONS

Most children with a history of high-risk prethreshold ROP develop strabismus at some time during the first 6 years of life.

RetCam image analysis of optic disc morphology in premature infants and its relation to ischaemic brain injury

AIMS

To assess optic disc characteristics in premature infants with and without ischaemic brain injury and to evaluate the role of optic disc morphology in dating the injury.

METHODS

RetCam fundal images, cranial ultrasounds and magnetic resonance imaging (MRI) of 109 premature infants were analysed. The study cohort was divided into subgroups depending on the presence or absence of periventricular leucomalacia (PVL) and intraventricular haemorrhage (IVH). The control group consisted of infants with normal neuroimaging at term and 2 years of age. Using the image analysis software of the RetCam, optic disc diameter (ODD), optic disc area (ODA), and optic cup area (OCA) were measured at 33-34 weeks gestational age. As serial cranial ultrasonography had been performed, it was possible to date the brain injury in those infants with periventricular white matter (PVWM) damage.

RESULTS

Although there was a trend towards reducing ODD, ODA, and OCA with increasing severity of IVH, only the IVH 4 group differed significantly from the controls for these parameters (p = 0.002, p = 0.02, and p = 0.04, respectively). 44.4% of infants with grade 4 IVH had small discs. Only one patient had a large cup in a normal sized disc; this patient had IVH 4. In patients with PVWM damage, the median time of insult was 27 weeks in those with small discs and 28 weeks in those with normal discs. This difference was not significant (p = 0.23).

CONCLUSIONS

Premature infants with IVH 4 have an increased incidence of optic nerve hypoplasia. We found no association between disc morphology and timing of brain injury.

Treated threshold stage 3 versus spontaneously regressed subthreshold stage 3 retinopathy of prematurity: a study of motility, refractive, and anatomical outcomes at 6 months and 36 months

AIM

To compare the visual acuity (VA), spherical equivalent refractive error, motility, and anatomical outcomes in children with treated regressed threshold stage 3 retinopathy of prematurity (ROP) and those with spontaneously regressed subthreshold stage 3 ROP.

METHOD

6 month and 3 year data collected from infants examined between 1989 and 1999 with regressed stage 3 ROP, with or without treatment were retrospectively reviewed.

RESULTS

85 infants were included in this study. 40 eyes received cryotherapy, 81 eyes laser photocoagulation, and 34 eyes had spontaneously regressed subthreshold stage 3 ROP. Grating acuity score > or =2 cycles/degree (c/d) at 6 months was predictive of optotype acuity > or =6/9 in 69% of eyes and a score <2 c/d at 6 months was predictive of acuity < 6/9 in 88% of eyes. Eyes with subthreshold stage 3 ROP were twice as likely to have VA of 6/9 or better at 36 months than the treated eyes. The mean spherical equivalent refractive error at 36 months was -6.5 dioptres (D) (-21.5D to +1.38D) in cryotherapy treated eyes, -2.4D (-13D to +4D) in the laser group, and -0.22D (-9D to +2.25D) in the subthreshold group. Eyes within the treated groups were more myopic than the eyes within the spontaneously regressed group (p = 0.005). At 36 months, 42 out of the 85 infants (that is, 49%) had strabismus (44% in the cryotherapy group, 26% in the laser group, and 25% in the subthreshold group). There was a statistically significant association between the presence of strabismus and anisometropia (p = 0.016) and strabismus and intraventricular haemorrhage (IVH) (p = 0.005). There was a statistically significant difference in the incidence of strabismus between mild and moderate and severe grade IVH (p = 0.01). Eight out of 40 eyes in the cryotherapy group and six out of the 81 eyes in the laser group developed macular ectopia. None of the eyes in the spontaneously regressed group had macular dragging.

CONCLUSIONS

In this study, the grating acuity at 6 months was a good predictor of the 3 year optotype acuity in all groups. Eyes with spontaneously regressed subthreshold stage 3 ROP were associated with better vision at 3 years of age and a lesser degree of myopia compared to the treated groups. Strabismus developed predominantly in the treated groups and was frequently associated with neurological damage and/or anisometropia. The spontaneously regressed subthreshold stage 3 group had a better anatomical outcome compared to the groups in which the retinopathy regressed following treatment.

Ophthalmological problems of the premature infant

Preterm infants are more likely than term infants to have significant abnormalities of all parts of the visual system leading to reduced vision. The most common problem is retinopathy of prematurity (ROP). The frequency and severity of this disorder is inversely related to gestational age. Damage ranges from minor to catastrophic. Preterm infants also have higher rates of amblyopia, strabismus, refractive error, and cortical visual impairment. The later problem is largely associated with neonatal brain injury. Years later, these children may develop glaucoma and retinal detachments.

Retinopathy of prematurity and other ocular problems in premature infants weighing less than 1500 g at birth

PURPOSE

To estimate the incidence of retinopathy of prematurity and other ocular problems in a population of preterm infants.

METHODS

This retrospective study included all infants with gestational age (GA) <32 weeks and birth weight (BW) <1500 g cared for in the neonatal intensive care unit (NICU) over a period of nine years (1992-2000). Ophthalmological examination was started the 4th week of life and included refractive examination, examination of the cornea and funduscopy under mydriasis. An ocular motility test was done after the 2nd month.

RESULTS

The study included 194 infants. Stage I and II retinopathy occurred in 51 infants but regressed spontaneously. Five of the 194 (2.5%) had to undergo cryopexy. Optic disc atrophy was observed in association with peri-intraventricular hemorrhage (PIIVH) (grade IV) in seven infants. Fifteen infants (7.7%) had retinal hemorrhages which were absorbed by three months of age. Almost 20% of the study infants developed high refractive errors and 13.4% strabismus.

CONCLUSIONS

Not only retinopathy of prematurity, but other serious ocular problems were observed in this population of preterm infants. The role of PIIVH III-IV in the pathogenesis of certain ocular problems needs further elucidation.

Ocular outcomes in low birth weight premature infants with intraventricular hemorrhage

PURPOSE

To study ocular outcomes in very low birth weight premature infants with intraventricular hemorrhage.

METHODS

Parents of 490 consecutive very low birth weight (less than 1500 g) premature infants who were discharged from the neonatal intensive care unit of our hospital between 1994 and 1996 were asked to enroll their child/children in this cross-sectional study. Sixty infants (12%) were recruited and had complete masked ophthalmologic examinations at 12 months corrected gestational age. The medical records of each infant were reviewed after the eye examination was complete. The occurrence of intraventricular hemorrhage and other perinatal comorbidities was documented. Ocular outcomes of infants with no or low-grade (grades I-II) hemorrhages were compared with those of infants with high-grade (grades III-IV) intraventricular hemorrhage.

RESULTS

Of the 60 infants examined, 17 (28%) had neonatal intraventricular hemorrhage. Eleven (18%) had high-grade intraventricular hemorrhage, and 49 (82%) had no or low-grade hemorrhage. Of the 11 infants with high-grade intraventricular hemorrhage, 8 (73%) had strabismus compared with 7 (14%) of 49 infants with no or low-grade hemorrhages who developed strabismus (P<0.001). The high-grade group also had a larger proportion of infants with ocular motility defects (P=0.008), nystagmus (P<0.001), optic nerve atrophy (P<0.001), and abnormal retinal findings (P=0.039). Additionally, these infants were more likely to have stage 3 or worse retinopathy of prematurity (P=0.003).

CONCLUSIONS

These results confirm the findings of our earlier retrospective study, and suggest that the occurrence of high-grade intraventricular hemorrhage in the early postnatal period places these infants at significant risk for adverse ocular outcomes. These infants require close ophthalmologic surveillance.

Perinatal cortical and subcortical visual loss: mechanisms of injury and associated ophthalmologic signs

PURPOSE

To determine whether term and preterm injuries to the retrogeniculate visual system are associated with recognizable patterns of ophthalmologic abnormalities and whether these patterns can be attributed to cortical (gray matter) or subcortical (white matter) injury.

DESIGN

A retrospective case series.

PARTICIPANTS

One hundred children with clinical and neuroimaging signs of perinatal posterior visual pathway injury who were examined at Arkansas Children's Hospital Eye Clinic between 1989 and 1999.

METHODS

We reviewed magnetic resonance images or computed tomographic scans from 50 children with cortical (predominantly or exclusively involving cortical gray matter) and 50 children with subcortical (predominantly or exclusively involving subcortical white matter) perinatal injury to the retrogeniculate visual system. Ophthalmologic abnormalities were analyzed retrospectively in each group.

MAIN OUTCOME MEASURES

Conjugate gaze deviation, type of strabismus, abnormal eye movements, and optic disc morphology.

RESULTS

Horizontal conjugate gaze deviation, exotropia, and a normal optic disc appearance were significantly more common in cortical than in subcortical visual loss. Tonic downgaze, esotropia, and optic nerve hypoplasia (with or without coexisting pallor) were significantly more common in subcortical than in cortical visual loss.

CONCLUSIONS

Perinatal cortical and subcortical visual loss produce differing profiles of ophthalmologic dysfunction. A reclassification of periventricular leukomalacia and other forms of retrogeniculate white matter injury as subcortical visual loss would increase diagnostic specificity.

Heredity versus abnormalities in pregnancy and delivery as risk factors for different types of comitant strabismus

PURPOSE

To elucidate risk factors for different types of comitant strabismus, the incidence of heredity and abnormalities in pregnancy and delivery was compared among different types of strabismus.

METHODS

Between May 1998 and January 1999, a prospective clinical study of 500 consecutive patients with comitant strabismus at a referral-based university hospital was performed using data collected from questionnaires and interviews. Inclusion criteria were infantile esotropia (168 patients), accommodative and partially accommodative esotropia (97 patients), microesotropia (15 patients), acquired esotropia (12 patients), intermittent or constant exotropia (205 patients), and congenital exotropia (3 patients). Exclusion criteria were strabismus associated with systemic and central nervous system abnormalities and organic eye diseases.

RESULTS

Family history was significantly more prevalent in intermittent or constant exotropia and accommodative or partially accommodative esotropia than in infantile esotropia (P<.0001 and P=.0267, respectively, Fisher's exact test). In contrast, abnormalities in pregnancy and delivery were noted at a significantly higher rate in infantile esotropia than in accommodative or partially accommodative and in intermittent or constant exotropia (P=.003 and P=.0215, respectively). Patients with infantile esotropia were significantly younger at the survey than those with the other two types of strabismus (P=.0004 and P<.0001). No significant difference was found in the number of siblings, birthweight, maternal age at delivery, or maternal cigarette smoking or alcohol drinking among these three types of strabismus.

CONCLUSION

Heredity and abnormalities in pregnancy and delivery are two major risk factors for comitant strabismus and contribute at different levels to the development of infantile esotropia, accommodative or partially accommodative esotropia, and intermittent or constant exotropia.

Ocular significance of intraventricular haemorrhage in premature infants

AIM

To document ocular outcome in premature infants with intraventricular haemorrhages (IVH).

METHODS

68 preterm infants with IVH were examined.

RESULTS

Mean gestational age was 28.1 weeks (range 24-35). Mean birth weight was 1045.9 g (630-2240). Mean follow up was 54.6 months (6-150). IVH is graded from 1 to 4 based on the severity of haemorrhages. The incidence of ocular abnormalities was compared between low grade IVH (grade 1 and 2) and high grade IVH (grade 3 and 4). Of the 68 infants with IVH, ROP occurred in 33 infants (48.5%); 13 (43.3%) had low grade IVH; 20 (52.6%) had high grade IVH. Strabismus developed in 30 infants (44.1%); 14 (46.6%) had low grade IVH; 16 (42.1%) had high grade IVH. Infants with high grade IVH were at significant greater risk than infants with low grade IVH for the development of optic atrophy (31.5% v 16.6%), hydrocephalus (57.8% v 10%).

CONCLUSION

This study highlights the serious significance of all grades of IVH with the higher incidence of optic atrophy and hydrocephalus with high grade IVH.

Severity of neonatal retinopathy of prematurity is predictive of neurodevelopmental functional outcome at age 5.5 years. Behalf of the Cryotherapy for Retinopathy of Prematurity Cooperative Group

OBJECTIVE

The purpose of this study was to assess the relation between neonatal retinopathy of prematurity (ROP) in very low birth weight infants and neurodevelopmental function at age 5.5 years.

METHODS

Longitudinal follow-up of children occurred in 2 cohorts of the Multicenter Cryotherapy for Retinopathy of Prematurity Study. The extended natural history cohort followed 1199 survivors of <1251 g birth weight from 5 centers. The threshold randomized cohort (ThRz) followed 255 infants <1251 g from 23 centers who developed threshold ROP and who consented to cryotherapy to not more than 1 eye. At 5.5 years both cohorts had ophthalmic and acuity testing and neurodevelopmental functional status determined with the Functional Independence Measure for Children (WeeFIM).

RESULTS

Evaluations were completed on 88.7% of the extended natural history cohort; 87% had globally normal functional skills (WeeFIM: >95). As ROP severity increased, rates of severe disability increased from 3.7% among those with no ROP, to 19.7% of those with threshold ROP. Multiple logistic regression analysis demonstrated that better functional status was associated with favorable visual acuity, favorable 2-year neurological score, absence of threshold ROP, having private health insurance, and black race. Evaluations were completed on 87.4% of the ThRz children. In each functional domain, the 134 children with favorable acuity in their better eye had fewer disabilities than did the 82 children with unfavorable acuity: self-care disability 25.4% versus 76.8%, continency disability 4.5% versus 50.0%, motor disability 5.2% versus 42.7%, and communicative-social cognitive disability 22.4% versus 65.9%, respectively.

CONCLUSION

Severity of neonatal ROP seems to be a marker for functional disability at age 5. 5 years among very low birth weight survivors. High rates of functional limitations in multiple domains occur in children who had threshold ROP, particularly if they have unfavorable visual acuity.

Intraventricular haemorrhage and stage 3 retinopathy of prematurity

BACKGROUND/AIMS

A recent report has highlighted the decreasing prevalence in recent years of severe intraventricular haemorrhage (IVH) in very low birthweight (VLBW) infants (<1500 g). This study attempted to identify the severity of the grade of IVH in infants with stage 3 retinopathy of prematurity (ROP), and to re-examine the association between threshold ROP and IVH.

METHODS

This was a retrospective study carried out over 3 years, between December 1995 and December 1998 of neonates admitted to a single neonatal intensive care unit. 28 infants with stage 3 ROP were identified from the ROP screening database. Cranial ultrasound scans were available on 24 of these infants. The scans were reviewed and the severity of IVH was graded from grade 1 to grade 4. The birth weight, sex, ethnic origin, and gestational age of the babies were recorded. The number of infants progressing to threshold disease and the treatment provided was documented.

RESULTS

The 24 infants had a median gestational age of 26 weeks (range 24-28 weeks) and a median birth weight of 762.5 g (range 540-1010 g). 17 infants were treated for threshold disease. 13 infants (54.2%) had IVH, of these eight (61.5%) had grade 1, two (15.4%) had grade 2, one (7.7%) had grade 3, and two (15.4%) had grade 4. 12 of the 13 infants (92.3%) with IVH had treatment with laser or cryotherapy for ROP compared with five of the remaining 11 infants (p = 0.023, Fisher's exact test). These data provide little evidence of any association between IVH and each of ethnic origin (p = 0.856), sex (p = 1), birth weight, or gestational age (p = 0.56 and p = 0.06 respectively) in infants with stage 3 ROP.

CONCLUSIONS

These data provide strong evidence (p = 0. 023) of an association between the presence of IVH and treatment of threshold ROP. Although the numbers in this study are small the majority of infants with stage 3 ROP had grade 1 IVH, which heralds a more favourable neurological outcome. An association between the severity of ROP and severity of IVH was not demonstrated. With improvements in neonatal care and a reduction in the prevalence of severe IVH, there appears to be a weakening of the previously reported association between severe IVH and severe ROP. However, the presence of even a minor grade of IVH may be a significant risk factor for threshold ROP once stage 3 disease is encountered.

The incidence of ophthalmologic interventions in children with birth weights less than 1251 grams. Results through 5 1/2 years. Cryotherapy for Retinopathy of Prematurity Cooperative Group

OBJECTIVE

This study aimed to report the frequency of ophthalmologic surgical and medical therapies provided to children with birth weights less than 1251 g who had all stages of retinopathy of prematurity (ROP). In addition, this study aimed to report the initial age at which such procedures are provided and to report the frequency of cerebrospinal fluid shunts.

DESIGN

Observational case series with prospective data collection.

PARTICIPANTS

Children from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) with birth weights less than 1251 g served as subjects. Group A included 257 children from all 23 CRYO-ROP study centers who had threshold ROP, who had participated in the randomized trial of cryotherapy, and who had survived to age 1 year. Group B included 1208 children from 5 of the 23 study centers who had varying severity of ROP (69 had threshold ROP) and who had participated in a 5 1/2-year study of the natural history of ROP.

MAIN OUTCOME MEASURES

Investigators documented medical and surgical ophthalmologic interventions through age 5 1/2 years as well as cerebrospinal fluid shunting surgery for hydrocephalus through age 2 years.

RESULTS

Group A was composed of 257 children with threshold ROP who underwent 226 ocular interventions in addition to cryotherapy (0.9 intervention per child). The most common treatments performed on the randomized cohort of children were vitrectomy (26% of patients), lensectomy (18%), amblyopia therapy (20%), and strabismus surgery (10%). Cataract surgery not associated with vitrectomy was performed infrequently (2%) and was performed equally often in treated and control eyes. Amblyopia therapy was prescribed as often for treated as for control eyes. Cerebrospinal fluid shunts were placed in 11% of these children. Group B was composed of 1208 natural history patients who underwent 239 ophthalmologic interventions (0.4 intervention per child). Strabismus surgery was the most commonly performed procedure for the natural history cohort of children (6% of the children). Amblyopia therapy was prescribed for 7% of the natural history patients. Cerebrospinal fluid shunts were required by 3% of the natural history infants, more often in children with more severe ROP.

CONCLUSIONS

These premature infants underwent a large number of ophthalmologic treatments during the first 5 1/2 years of life. The long-term costs of both extreme prematurity and ROP include not only the initial ablative therapy for ROP and societal loss due to blindness that still occurs in some cases, but also the ongoing costs of caring for eye problems.