Keratoconus in Down syndrome: Prevalence, risk factors, severity and corneal tomographic characteristics.

BACKGROUND: This study investigated the prevalence, risk factors and severity of corneal tomographic features of keratoconus in Down syndrome (DS). Additionally, previous studies indicate anomalous corneal features in DS, without keratoconus, this study characterised corneal features in DS without keratoconus. METHODS: This prospective observational study included participants with DS ≥10 years old. Keratoconus diagnosis, risk factors and corneal tomographic characteristics were recorded. Participants underwent slit-lamp biomicroscopy, Scheimpflug corneal tomography, corneal topography and autorefraction. A diagnosis of keratoconus (DS-KC), suspect keratoconus (DS-SK) and non-keratoconus (DS-NK) was made based on expert review of scans by three fellowship trained anterior segment ophthalmologists. Corneal tomography parameters from one eye of each participant were analysed. RESULTS: Keratoconus affected 50 (26.3%) of 190 participants, diagnosed by corneal tomography, topography or slit-lamp signs. Corneal hydrops affected 14.0% of DS-KC participants. Eye rubbing was a significant risk factor for keratoconus (p = 0.036). 175 (92%) participants could undertake corneal tomography of which tomography assessment alone identified 47 (26.9%) DS-KC participants, 64 (36.6%) DS-SK participants and 64 (36.6%) DS-NK participants. Significant differences (p < 0.001) were identified when the DS-KC, DS-SK and DS-NK groups were compared in maximum keratometry and posterior elevation at the thinnest point respectively: median (interquartile range) 50.20 (10.30D), 47.60 (1.95D), 46.50 (2.40D); 24.0 (38.00 µm), 10.00 (13.75 µm), 8.00 (6.00 µm). The DS-SK and DS-NK cohorts had similar minimum pachymetry, however, had several significantly different parameters among which included greater maximum keratometry, posterior elevation at the thinnest point in the DS-SK group. CONCLUSIONS: Keratoconus is common in DS. Keratoconus screening with corneal tomography is recommended for early detection.

Incomplete peripheral retinal vascularisation in retinopathy of prematurity: is it the consequence of changing oxygen saturation?

Background: We wish to determine the prevalence and risk factors of incomplete peripheral avascular retina (IPAR) in children screened for retinopathy of prematurity (ROP) and its association with oxygen saturation (SpO2) targets. Methods: A retrospective review of retinal images of premature infants born and screened for ROP in Auckland Region, New Zealand, between January 2013 and December 2017 was conducted. Images were reviewed to determine if avascular retina was present at their final ROP screening. The prevalence of peripheral avascular retina was compared among infants born prior to (Group 1) and after (Group 2) 2015 when the SpO2 target was increased. Infants with any concurrent ocular pathology or who had received ROP treatment were excluded. Results: In total, 62 (12.8%) of the total of 486 infants (247 in Group 1; 239 in Group 2) were found to have IPAR at their last ROP screening. Group 1 had more statistically significant infants with IPAR compared to Group 2 (39/247 infants and 23/239 infants respectively; p = 0.043). Conclusions: Incomplete peripheral retinal vascularisation occurred at a prevalence of 12.8% in infants at risk of ROP. Higher SpO2 targets did not increase the prevalence of incomplete peripheral retinal vascularisation. Low gestational age and low birth weight are likely risk factors for the development of avascular retina. Further research into the risk factors associated with incomplete peripheral retinal vascularisation and the associated long-term outcomes is needed.

Long-term visual outcomes of children screened for retinopathy of prematurity with telemedicine in New Zealand.

CLINICAL RELEVANCE: Children with a history of regressed retinopathy of prematurity (ROP) are at increased risk of peripheral avascular retina. Wide-field digital retinal imaging and telemedicine is an effective tool for ROP screening. Ophthalmologists and Optometrists should have a high level of clinical suspicion for peripheral retinal changes in children screened for ROP. BACKGROUND: Retinopathy of prematurity, a vaso-proliferative disorder of the pre-term retina, is a preventable cause of childhood visual impairment. The Auckland Regional Telemedicine ROP (ART-ROP) network, established in 2006, utilises wide-field digital imaging and telemedicine to screen at-risk infants for ROP. This prospective observational study reports the long-term ocular outcomes of ART-ROP network infants. METHODS: A comprehensive paediatric eye examination including cycloplegic autorefraction and wide-field retinal imaging was completed on all participants. Participants had been screened for ROP by the ART-ROP network between May 2008 and October 2011. RESULTS: A total of 69 children, with a mean age of 5 to 8 years old were assessed and divided into two groups: those with or without a history of ROP, 44 and 25 children, respectively. Infants with a history of ROP had significantly lower gestational age (26.6 ± 1.9 vs. 29.1 ± 1.6 weeks, p < 0.001) and birth weight (937 ± 237 vs. 1177 ± 311 grams, p = 0.001). No significant differences were detected between the two groups for visual acuity (p = 0.596), stereopsis (p = 0.219), refractive error (p = 0.472), or strabismus. Clinically significant refractive error was noted in 10 participants; none with moderate or high myopia. Retinal imaging exposed asymptomatic, persistent, peripheral avascular retina in four children, all of whom had a history of regressed ROP. CONCLUSION: Visual and ocular outcomes did not vary based on history of ROP, with no participant having reduced vision as a result of undetected or untreated ROP. Further research is required into the long-term implication of persistent avascular retina in regressed ROP.

Selected ocular dimensions of three penguin species.

Penguins (Spheniscidae) are a diverse clade of flightless, marine birds. Their eyes, likely a primary driver of behaviour, have been noted to have anatomic adaptations to their amphibious lifestyle. In particular, they have a relatively flat cornea, which would make the transition from a subaerial to a submarine environment require less accommodative effort. However, the ocular dimensions are not known for many penguin species, despite the diversity within the family, and their accommodative abilities have been the source of some dispute. In this study we undertook to establish the basic dimensions of the eye of the smallest, a mid-sized penguin and the second largest penguin. The power of the front surface of the cornea was inversely related to the size of both the eye and penguin, being 41.3 D in the little penguin (Eudyptula minor), a power greater than previously measured in any other penguin species, 26.3 D in the gentoo (Pygoscelis papua) and 19.1 D in the king penguin (Aptenodytes patagonicus). All other dimensions increased or decreased in line with the size of the eye. All penguins were able to achieve emmetropia in air. The gentoo appeared to be emmetropic underwater. A finding of central corneal thickening in some penguins may be artefactual. Calculations using the ocular dimensions demonstrated that the mean retinal illumination of an extended source of light in the little penguin eye is less than that of its larger, deeper-diving relatives.

Topographic screening reveals keratoconus to be extremely common in Down syndrome.

IMPORTANCE: Keratoconus disproportionately affects people with Down syndrome (DS). This is the first study of its kind in Australasia. BACKGROUND: To investigate the prevalence of keratoconus in DS. DESIGN: Cross-sectional study. PARTICIPANTS: Athletes with DS attending 2017 New Zealand Special Olympics National Summer Games. METHODS: Keratoconus was identified using corneal topography (TMS-4N, Tomey). Topography from both eyes was required to be included. Two independent quantitative criteria were used to indicate keratoconus. The first was keratoconus severity index ≥ 30%. The second, adapted from the literature, required at least four of eight topographic parameters to be abnormal. Data from the worse eye were analysed. Diagnosis in each group was subsequently confirmed qualitatively by three corneal fellowship-trained ophthalmologists. Those with a definitive diagnosis were grouped into Keratoconus Confirmed Group 1 (KCC1) and Keratoconus Confirmed Group 2 (KCC2), respectively. MAIN OUTCOME MEASURES: Keratoconus prevalence, severity, demographics. RESULTS: Of 110 athletes screened, N = 98 were included, mean age 30.0 ± 9.7 years. Using only topographic data, keratoconus was identified in 39 (39.8%) athletes by quantitative topographic criteria 1, and in 63 (64.3%) athletes by criteria 2. Keratoconus was confirmed by qualitative sub-specialist review in 30 (30.6%) (KCC1) and 38 (38.8%) (KCC2) athletes, respectively. Mean keratometry in groups KCC1 and KCC2 were 48.4 ± 3.2D and 48.2 ± 2.9D, respectively. Most were male (KCC1 63.3%, KCC2 76.3%) and of European ethnicity (KCC1 80%, KCC2 78.9%). CONCLUSIONS AND RELEVANCE: We report keratoconus in 30.6% to 38.8% of athletes with DS; therefore, we believe keratoconus screening is indicated in DS for early management.

Auckland regional telemedicine retinopathy of prematurity screening network: A 10-year review.

IMPORTANCE: Retinopathy of prematurity (ROP) is a potentially blinding condition affecting the retinae of premature infants. Effective screening is necessary for timely treatment. BACKGROUND: The Auckland Regional Telemedicine ROP (ART-ROP) network, utilizes wide-field digital imaging for ROP screening. This study reviews the ART-ROP network. DESIGN: Retrospective analysis of the ART-ROP database. PARTICIPANTS: Files of infants in ART-ROP from 2006 to 2015. METHODS: Data on infant demographics, ROP stage, treatment and outcome was collected. MAIN OUTCOME MEASURES: The efficacy of ART-ROP in the management of ROP. RESULTS: A review of 1181 infants across three neonatal intensive care units, was completed. Infants had a mean of four screening sessions with no infants who met ROP screening criteria being missed. Type 1 ROP was present in 83 infants, who had significantly lower average birth weight 786 ± 191 g compared to 1077 ± 285 g (P < .001), and gestational age 25.3 ± 1.7 weeks compared to 27.8 ± 2.2 weeks (P < .001) than the screened cohort. The number of infants requiring screening increased (R2 = .7993), yet treatment rates decreased (R2 = .9205) across the time period. Out-patient clinic follow-up was attended by 75.10% of infants screened and there was no missed ROP in those infants seen. CONCLUSIONS AND RELEVANCE: ART-ROP solely uses wide-field digital imaging for ROP diagnosis, and management, including discharge, of infants. This detailed review of ART-ROP indicates an increase in screening demand, but a decrease in the rate of type 1 ROP. The ART-ROP telemedicine model demonstrates real potential to address workforce shortage in ROP screening.

Persistent Avascular Retina in Infants With a History of Type 2 Retinopathy of Prematurity: To Treat or Not to Treat?

PURPOSE: To investigate persistent avascular retina in infants with type 2 retinopathy of permaturity (ROP) that persisted after 45 weeks' post-menstrual age when regular ROP screening ceased. METHODS: A prospective observational study where fundus fluorescein angiography (FFA) was completed on consecutive infants who had a history of type 2 ROP and avascular retina during ROP screening that persisted after 45 weeks' post-menstrual age. RESULTS: FFA was completed on 72 eyes of 36 infants (53% male), with a mean gestational age of 26.0 ± 2.2 weeks and a mean birth weight of 834.6 ± 216.3 grams. The mean age at discharge from ROP screening was 47.6 weeks' post-menstrual age. All patients had type 2 ROP at the worst stage of their disease, with predominantly stage 2 disease. FFA was performed at a mean age of 18.8 ± 10.3 months post-menstrual age. All patients had detectable avascular retina in peripheral zone II or III on FFA. Peripheral vessel leakage was present in 3 eyes of 2 infants (5.5%), who both subsequently received peripheral laser treatment. CONCLUSIONS: Premature infants with type 2 ROP may have persistent peripheral avascular retina with unknown long-term ocular complications, which can present management dilemmas. Retinal FFA is recommended to determine retinal ischemia and aid decision making for treatment in these cases. [J Pediatr Ophthalmol Strabismus. 2019;56(4):222-228.].

Clinical applicability of the Saccadic Vector Optokinetic Perimeter in children with and without visual impairment.

BACKGROUND: Common paediatric perimetry techniques require central fixation and subjective responses, which may be challenging for young or cognitively impaired children. The Saccadic Vector Optokinetic Perimeter (SVOP) was designed to overcome these challenges by using infra-red eye tracking to assess the visual field. This study assessed the clinical feasibility of SVOP in children without visual impairment, comparing it to current paediatric techniques, and in children with visual impairment. METHODS: Participants were recruited into two cohorts: children without visual impairment (visual acuity ≥ 6/7.5) and children with visual impairment (visual acuity ≤ 6/18). Children without visual impairment attempted the Goldmann perimeter, confrontation method, and SVOP. Children with visual impairment attempted SVOP, when clinically indicated, as part of a full ophthalmic assessment. Visual field results and test length were recorded. RESULTS: Twenty-three children without visual impairment (4-14 years old) attempted all three visual field assessments. Full results were recorded for 91 per cent of children with SVOP, 87 per cent with Goldmann, and 100 per cent with confrontation SVOP was significantly faster than Goldmann (p < 0.001) and confrontation (p = 0.003). Thirty-five children with visual impairment (3-19 years old) with visual acuity ranging from 6/9.5 to worse than 6/360 (mean of 0.8 ± 0.4 logMAR) attempted SVOP, with 26 children able to complete SVOP. DISCUSSION: This is the largest study to date of the clinical applicability of SVOP in children without visual impairment, as well as assessing the utility of SVOP in children with visual impairment. Further research is needed to assess the accuracy of SVOP in a range of paediatric ocular disorders. SVOP may potentially offer a visual field assessment method for children previously unable to complete current paediatric perimetry techniques.

Do picture-based charts overestimate visual acuity? Comparison of Kay Pictures, Lea Symbols, HOTV and Keeler logMAR charts with Sloan letters in adults and children.

PURPOSE: Children may be tested with a variety of visual acuity (VA) charts during their ophthalmic care and differences between charts can complicate the interpretation of VA measurements. This study compared VA measurements across four pediatric charts with Sloan letters and identified chart design features that contributed to inter-chart differences in VA. METHODS: VA was determined for right eyes of 25 adults and 17 children (4-9 years of age) using Crowded Kay Pictures, Crowded linear Lea Symbols, Crowded Keeler logMAR, Crowded HOTV and Early Treatment of Diabetic Retinopathy Study (ETDRS) charts in focused and defocused (+1.00 DS optical blur) conditions. In a separate group of 25 adults, we compared the VA from individual Kay Picture optotypes with uncrowded Landolt C VA measurements. RESULTS: Crowded Kay Pictures generated significantly better VA measurements than all other charts in both adults and children (p < 0.001; 0.15 to 0.30 logMAR). No significant differences were found between other charts in adult participants; children achieved significantly poorer VA measurements on the ETDRS chart compared with pediatric acuity tests. All Kay Pictures optotypes produced better VA (p < 0.001), varying from -0.38 ± 0.13 logMAR (apple) to -0.57 ± 0.10 logMAR (duck), than the reference Landolt C task (mean VA -0.19 ± 0.08 logMAR). CONCLUSION: Kay Pictures over-estimated VA in all participants. Variability between Kay Pictures optotypes suggests that shape cues aid in optotype determination. Other pediatric charts offer more comparable VA measures and should be used for children likely to progress to letter charts.