Eva Larsson

Incidence of ROP in two consecutive Swedish population based studies.

Aims: To prospectively analyse the present incidence of ROP (retinopathy of prematurity) in a well defined geographical area in Sweden, and to compare it with that from a decade earlier in exactly the same area. Methods: Infants born between 1 August 1998 and 31 July 2000 with a birth weight of 1500 g or less were studied. They were screened for ROP from 5 weeks of postnatal age until the retina was entirely vascularised. The incidence of ROP, with its various stages, was compared with that of a previous (1988–90) population based study in the same geographical area. Results: The incidence of ROP in the present study was 36.4% (mild (18.2%) and severe ROP (18.2%)), which was similar to that of the previous study. Gestational age at birth remained the most important risk factor for ROP. We found a change in the distribution of ROP. The probability of ROP, particularly severe ROP, was highest in the most immature infants while it was lower in the least immature ones. Conclusions: The incidence of ROP remained the same in two consecutive population based studies. The more “mature” infants developed ROP, particularly severe ROP, less often, while the most immature infants had ROP more often, particularly severe ROP.

Screening for retinopathy of prematurity: evaluation and modification of guidelines

Aims: To evaluate current screening guidelines for ROP (retinopathy of prematurity) and to determine whether they can be modified. Methods: In accordance with the authors’ present criterion, infants born in Stockholm County, Sweden, from 1 August 1998 to 31 July 2000, with a gestational age of ≤32 weeks, were screened for ROP. The effectiveness of screening was studied. Results: The incidence of ROP was 25.5% in this study. A dropout group comprising almost 20% of the population studied (≤32 weeks), was never referred, were lost to follow up, or died before screening was completed. No infant with a gestational age of >31 weeks at birth developed severe ROP (stages 3–5) and no infant with a gestational age of >29 weeks was treated for ROP. Conclusion: 80% of infants in this population with a gestational age at birth of ≤32 weeks, the current screening criterion, were effectively screened for ROP. The authors recommend that the screening criterion be lowered to ≤31 weeks since no infant with severe ROP would have been missed.

Contrast sensitivity in 10 year old preterm and full term children: a population based study.

Aims: To determine the contrast sensitivity (CS) in 10 year old prematurely born children, previously included in a population based study on the incidence of retinopathy of prematurity (ROP), and in full term controls. Methods: This study included 205 prematurely born children and 215 children born at term, from the same geographical area and study period. CS was assessed monocularly with the Vistech 6500 test at five spatial frequencies (1.5–18 cycles/deg). Results: Prematurely born children had statistically significant lower CS at all frequencies, compared to full term ones. The mean differences in logarithmic CS were 0.03 (1.5 cycles/deg), 0.09 (3 cycles/deg), 0.10 (6 cycles/deg), 0.12 (12 cycles/deg), and 0.19 (18 cycles/deg). Even when the children with ROP and neurological disorders were excluded there was a difference between the two groups. Children who had been treated with cryotherapy had the lowest CS. Conclusion: CS was lower in 10 year old prematurely born children than in full term ones of the same age. Whether this finding affects their visual function in daily life is uncertain.

Central macular thickness is correlated with gestational age at birth in prematurely born children

Background/aim Previous studies have revealed various subnormal visual functions in prematurely born children. The present study aimed to determine the retinal macular thickness in prematurely born children and compare with children born at term. Methods The eyes of 65 prematurely born children aged 5–16 years were examined with Stratus optical coherence tomography (OCT) 3, and the results were compared with those of 55 children born at term. The retinal macular thickness in the nine EDTRS macular areas (A1–A9), the foveal minimum and the total macular volume were determined. Results The central macular thickness (A1 and foveal minimum) was significantly thicker in the prematurely born children than in those born at term. There was no correlation between macular thickness and visual acuity or refraction. Children with previous retinopathy of prematurity (ROP) had significantly thicker central maculae than those without it. Prematurely born children without previous ROP had significantly thicker central maculae than the control group. Multiple regression analyses showed that gestational age at birth was the only risk factor for a thick central macula. Conclusion Prematurely born children had thicker central maculae than those born at term. Regardless of ROP, the degree of prematurity was the most important risk factor for abnormal foveal development.

Peripheral and central visual fields in 11-year-old children who had been born prematurely and at term.

PURPOSE To examine the peripheral and central visual fields in children who had been born prematurely and at term. METHODS Four groups of 11-year-old children were examined: group 1 included 24 children who had been born at term (control group); group 2 included 20 children who had been born prematurely without ROP; group 3 included 22 children who had been born prematurely with untreated ROP (stages 2 and 3); and group 4 included 21 children who had been born prematurely and underwent cryotreatment for severe ROP. Their peripheral visual fields were examined with Goldmann perimetry. Static high-pass resolution perimetry was used to evaluate their central visual fields within 30 degrees. RESULTS The peripheral visual fields were constricted in children who had undergone cryotreatment (group 4), as compared with the other groups (1 to 3). We found no difference between the groups of children who had been born prematurely with or without ROP (groups 2 and 3) and the control group. The function of the central visual fields, expressed as neural capacity, was reduced in the children who had been born prematurely compared with the controls, significantly in their left eyes only. The children who underwent cryotreament did not differ from the other children who had been born prematurely in this respect. CONCLUSIONS The peripheral visual fields were constricted in children who had undergone cryotreatment. It is uncertain whether this was caused by the treatment or by severe ROP. The central visual fields showed a tendency of reduced neural capacity in the children who had been born prematurely, reflecting a reduced density of retinocortical neural channels. However, this was not related to ROP or cryotreatment.

Time to consider a new treatment protocol for aggressive posterior retinopathy of prematurity

Purpose:  To discuss treatment modalities for aggressive posterior retinopathy of prematurity (AP‐ROP).

Optical coherence tomography is helpful in the diagnosis of foveal hypoplasia

Purpose:  To investigate whether optical coherence tomography (OCT) is helpful in the diagnosis of foveal hypoplasia in children.

Retinal nerve fibre layer thickness in school-aged prematurely-born children compared to children born at term.

Aim To investigate the retinal nerve fibre layer (RNFL) with optical coherent tomography (OCT) in prematurely-born children. Methods 62 children born with a gestational age of ≤32 weeks, and a control group of 54 children born at term with normal birth weight (BW) were included in the study. 28 of the preterm children had retinopathy of prematurity (ROP) in the neonatal period; eight of them had severe ROP (stages 3–4). RNFL thickness was measured with Stratus OCT 3. Mean age at examination was 8.6 years in the preterm children and 10.1 years in the control group. Results There was a significant difference between the children born preterm and those born at term, regarding RNFL thickness in the superior (right eye (RE), p=0.043; left eye (LE), p=0.048) and the nasal quadrants (RE, p=0.006; LE, p<0.001), as well as average RNFL thickness (RE, p=0.016; LE, p=0.029). This difference was caused by the thinner RNFL in children with previous severe ROP (stages 3 and 4). Within the preterm group, the average RNFL thickness increased with larger BW (RE, p=0.050; LE, p=0.028), but there was no correlation with gestational age at birth. Conclusion The RNFL was reduced in prematurely-born children with severe ROP when compared to children born at term. It is hypothesised that severe retinopathy as well as ablation of the retina with laser treatment or cryotherapy may affect the axons of the ganglion cells and thus reduce RNFL thickness. Prematurely-born children with low BW had a thinner RNFL, suggesting a negative effect of low birth weight on neural development.

Outcome of Retinopathy of Prematurity

In prematurely born children, various visual and ophthalmologic sequelae occur because of both retinopathy of prematurity (ROP) and preterm birth per se. Several long-term follow-up studies have described the outcome of ROP. Visual impairment and blindness are well-known consequences, but the prevalence varies globally because of differing neonatal and ophthalmologic care. Improving treatment options and criteria for the treatment of ROP are continuously changing the ophthalmologic outcome. The anatomic outcome has improved with treatment, but good anatomic outcome in treated severe ROP does not always reflect the functional outcome. There is no consensus regarding long-term follow-up of prematurely born children.

Is quantitative spectral-domain superior to time-domain optical coherence tomography (OCT) in eyes with age-related macular degeneration?

Purpose:  The aim of this study was to determine the variability of macular map measurements, for two generations of optical coherence tomography (OCT) instruments, in eyes with wet age related macular degeneration (AMD) and low visual acuity.