Prevalence and pattern of retinopathy of prematurity at two national referral hospitals in Uganda: a cross-sectional study.

BACKGROUND: Retinopathy of prematurity (ROP) is a leading cause of blindness in children and an ROP epidemic is predicted this decade in sub-Saharan Africa. With the increasing survival rate of preterm babies in Uganda, and no data on ROP prevalence, there is a need to assess the burden of ROP to inform preventive strategies and targeted screening. METHODS: We conducted a two-center cross-sectional study of preterm (< 37 weeks gestational age) infants from the neonatal units of Kawempe National Referral Hospital (KNRH) and Mulago Specialised Women and Neonatal Hospital (MSWNH) from August 2022 to October 2022. An ophthalmologist examined all participants using an indirect ophthalmoscope with a + 20D convex lens and captured digital images using a Volk iNview™ Fundus Camera. The collected data were entered into Epidata 4.2 and exported to Stata 14.0 for analysis. RESULTS: 331 preterm infants enrolled in this study. The oxygen received was unblended. The mean gestational age was 30.4 ± 2.7 weeks, and the mean birth weight was 1597 ± 509 g. 18/101 (17.8%) were found to have any ROP amongst the preterm infants recruited from MSWNH, 1/230 (0.4%) from KNRH [95% CI] had any stage of ROP (i.e. stage 5). Of these, 8 (42.1%) had stage 2 ROP. Infants with a birth weight below 1500 g were 10 times more likely to have ROP than those among infants with a birth weight more than 1500 g [AOR: 10.07 (2.71-37.44)]. Infants who were not fed exclusively on breast milk had higher odds of having ROP than those exclusively fed on breast milk [AOR: 7.82(1.92-31.82)]. CONCLUSION: 6% of preterm infants born in two tertiary hospitals in Uganda were found to have ROP. Lack of exclusive feeding on breast milk and birth weight of less than 1500 g were strong predictors of ROP. The higher prevalence of ROP in MSWNH calls for cautious use of oxygen among preterms. We recommend targeted ROP screening for those at risk.

Anesthesia management of laser photocoagulation for retinopathy of prematurity. A retrospective review of perioperative adverse events.

AIMS: The aim of this study was to report the incidence of perioperative adverse events occurring in infants undergoing diode laser photocoagulation of retinopathy of prematurity and to identify clinical risk factors that may affect the incidence. METHODS: This was a retrospective study of anesthetic and medical records of premature infants who were treated in the neonatal intensive care unit or an operating theater with laser photocoagulation in our institution between January 2014 and December 2019. Infants less than 38 weeks post-menstrual age or less than 2000 grams were considered high risk for complications. Electronic medical records were evaluated for clinical and demographic characteristics, comorbidities, and perioperative complications of anesthesia. RESULTS: Sixty-one infants (39 males, 22 females) underwent 72 laser treatments. The mean gestational age was 25.3 weeks (SD 1.6), and mean birth weight was 730 grams (SD 202). At treatment, the mean postmenstrual age was 37.5 weeks (SD 2.7) and weight was 2320 g (SD 610). Laser therapy was performed in an operating theater in 66 procedures (91.7%) and in the neonatal unit in 6 cases (8.3%). Twenty-nine (40.3%) laser surgeries occurred outside normal week-day daytime operating hours. Intraoperative hypotension occurred in 12 procedures (16.7%) but was not significantly different in high-risk infants (16.1% vs 16.7% OR 0.94 P = .94) or in procedures performed in-hours (16.3% vs 17.2% OR 0.93 P = .91). Post-extubation apnea occurred in 21 procedures (29%) but was not significantly different in high-risk infants (29.0% vs 27.3% OR 0.98 P = .34) or in procedures performed in-hours (27.9% vs 31.1% OR 0.86 P = .77). Infants remained intubated at the end of the procedure in 58 (80.5%) cases and 29 (40.3%) remained ventilated more than 24 hours after the procedure. CONCLUSION: The incidence of perioperative adverse events was not associated with patient's age, current weight, timing, or location of the procedure. Extubating infants at the end of the procedure is however associated with a high rate of apneas and bradycardia, and consideration should be given to keeping low weight infants undergoing prolonged procedures out-of-hours intubated.

Mosaic uniparental disomy results in GM1 gangliosidosis with normal enzyme assay.

Inherited metabolic disorders are traditionally diagnosed using broad and expensive panels of screening tests, often including invasive skin and muscle biopsy. Proponents of next-generation genetic sequencing have argued that replacing these screening panels with whole exome sequencing (WES) would save money. Here, we present a complex patient in whom WES allowed diagnosis of GM1 gangliosidosis, caused by homozygous GLB1 mutations, resulting in ß-galactosidase deficiency. A 10-year-old girl had progressive neurologic deterioration, macular cherry-red spot, and cornea verticillata. She had marked clinical improvement with initiation of the ketogenic diet. Comparative genomic hybridization microarray showed mosaic chromosome 3 paternal uniparental disomy (UPD). GM1 gangliosidosis was suspected, however ß-galactosidase assay was normal. Trio WES identified a paternally-inherited pathogenic splice-site GLB1 mutation (c.75+2dupT). The girl had GM1 gangliosidosis; however, enzymatic testing in blood was normal, presumably compensated for by non-UPD cells. Severe neurologic dysfunction occurred due to disruptive effects of UPD brain cells.

PERIPHERAL RETINAL DRUSEN-LIKE DEPOSITS IN GUCY2C CONGENITAL SECRETORY DIARRHEA SYNDROME.

PURPOSE: To report the presence of drusen in infancy, in a patient with Type 1 retinopathy of prematurity and a rare congenital sodium diarrhea secondary to a sporadic GUCY2C mutation. METHODS: A case report generated by review of clinical course, with imaging of 1 patient and literature review. RESULTS: A 1.075-kg infant born at gestation age 27 weeks was admitted to our institution with respiratory distress and secretory diarrhea. During screening for retinopathy of prematurity, peripheral drusen-like subretinal deposits were identified. There were no similar findings in either parent or family history of ocular pathologies. Their distribution is atypical for that seen in other causes of early onset drusen such as autosomal dominant drusen or Sorsby fundus dystrophy. Retinopathy of prematurity was identified, which progressed to Type 1, and was treated with bilateral indirect peripheral retinal photocoagulation at gestational age of 40 weeks. Fluorescein angiography was performed and was consistent with peripheral drusen. Optical coherence tomography of the central macula and an awake electroretinogram at 6 months were normal. Serial examinations confirmed no progression in the drusen-like deposits or in retinopathy of prematurity, with clinically appropriate visual development observed during close follow-up. CONCLUSION: We identify a unique ocular phenotype of retinal drusen-like deposits in an infant with a rare, sporadic GUCY2C mutation.

Identification of a recurrent mosaic KRAS variant in brain tissue from an individual with nevus sebaceous syndrome.

Nevus sebaceous syndrome (NSS) is a rare, multisystem neurocutaneous disorder, characterized by a congenital nevus, and may include brain malformations such as hemimegalencephaly or focal cortical dysplasia, ocular, and skeletal features. It has been associated with several eponyms including Schimmelpenning and Jadassohn. The isolated skin lesion, nevus sebaceous, is associated with postzygotic variants in HRAS or KRAS in all individuals studied. The RAS proteins encode a family of GTPases that form part of the RAS/MAPK signaling pathway, which is critical for cell cycle regulation and differentiation during development. We studied an individual with nevus sebaceous syndrome with an extensive nevus sebaceous, epilepsy, intellectual disability, and hippocampal sclerosis without pathological evidence of a brain malformation. We used high-depth gene panel sequencing and droplet digital polymerase chain reaction (PCR) to detect and quantify RAS/MAPK gene variants in nevus sebaceous and temporal lobe tissue collected during plastic and epilepsy surgery, respectively. A mosaic KRAS c.34G > T; p.(Gly12Cys) variant, also known as G12C, was detected in nevus sebaceous tissue at 25% variant allele fraction (VAF), at the residue most commonly substituted in KRAS Targeted droplet digital PCR validated the variant and quantified the mosaicism in other tissues. The variant was detected at 33% in temporal lobe tissue but was absent from blood and healthy skin. We provide molecular confirmation of the clinical diagnosis of NSS. Our data extends the histopathological spectrum of KRAS G12C mosaicism beyond nevus sebaceous to involve brain tissue and, more specifically, hippocampal sclerosis.

Retinopathy of prematurity: postmenstrual age at threshold in a transitional economy is similar to that in developed countries.

BACKGROUND: To analyse the timing of threshold disease in infants requiring treatment for retinopathy of prematurity in a transitional economy. DESIGN: Retrospective, observational, cohort study. SETTING: National Hospital of Paediatrics, Hanoi, Vietnam. STUDY POPULATION: Premature infants in the Neonatal ward requiring laser treatment for threshold retinopathy of prematurity. MAIN OUTCOME MEASURES: Chronological age and postmenstrual age at treatment. RESULTS: From January 2002 to November 2004, 42 infants from the National Hospital of Paediatrics required laser surgery for threshold retinopathy of prematurity. The mean +/- standard deviation (SD) of birth weight was 1369 +/- 184 g (range 1000-1700); the mean +/- SD of gestation at birth was 30 +/- 1.8 weeks (range 27-34); and the mean +/- SD of postmenstrual age at which treatment occurred in these infants was 36.2 +/- 2.5 weeks (range 31.4-42). A further 58 infants were transferred from other hospitals for laser surgery between January 2004 and October 2004. The mean +/- SD of birth weight was 1325.5 +/- 237.2 g (range 800-1900); the mean +/- SD of gestation at birth was 30 +/- 1.7 weeks (range 28-35); and the mean +/- SD of postmenstrual age at which treatment was given in these infants was 36.3 +/- 2.3 weeks (range 32.71-44.3). DISCUSSIONS: Despite the relative maturity of the gestation of these infants compared with infants in developed countries who develop severe retinopathy of prematurity, the timing of treatment for threshold disease appears to be related to postmenstrual age.

Discordant retinopathy of prematurity in twin anemia-polycythemia sequence.

We report the case of severe retinopathy of prematurity (ROP) in the donor twin with twin anemia-polycythemia sequence managed with the novel treatment of intrauterine blood transfusions. The fellow polycythemic twin was managed with intrauterine venesection and developed only mild ROP. Thus, despite intrauterine improvement of the twins' hemodynamic conditions, the risk of developing severe ROP remained in the donor twin.

New trends in childhood vision impairment in a developed country.

BACKGROUND: The Education Vision Assessment Clinic (EVAC) is a unique statewide service that reviews school children 4-18 years of age with low vision in Victoria, Australia, to determine their eligibility for educational support. The purpose of this study was to identify causes of vision impairment in students in Victoria using data from the EVAC. METHODS: Data collected from students who attended the EVAC at the Royal Victorian Eye and Ear Hospital, Melbourne, between the years 2003 and 2012 inclusive, were analyzed retrospectively. Participants were identified through the EVAC schedule of medical appointments. Medical records were reviewed for clinical and demographic information, including diagnosis of vision impairment and best-corrected visual acuity and/or visual fields. RESULTS: Of 543 students, 355 (65%) were eligible for educational assistance. Of those, 249 (70%) had best-corrected visual acuity between 20/60 and 20/200 and/or a field of vision of <20° to 10°, and 106 (30%) had a best-corrected visual acuity worse than 20/200 and/or a field of vision of <10°. Common causes of vision impairment were retinal dystrophies (24%), optic nerve pathology (14%), albinism (14%), and infantile motor nystagmus (10%). CONCLUSIONS: Treatable and potentially preventable causes of vision impairment, such as retinopathy of prematurity and cataract, caused <10% of vision impairment cases in Victorian school children. Analysis of demographic trends is essential to supporting efforts to ensure that students with low vision, from any socioeconomic background, receive specialist teaching services.

Analysis of the National Health and Nutrition Examination Survey. Comment on "Prevalence of visual impairment in the United States", by S Vitale, MF Cotch, and RD Sperduto. JAMA 295:2158-63, 2006.

CONTEXT: The prevalence of visual impairment in the U.S. public has not been surveyed nationally in several decades. OBJECTIVE: To estimate the number of U.S. individuals aged 12 years or older who have impaired distance vision due to uncorrected refractive error. DESIGN, SETTING, AND PARTICIPANTS: The National Health and Nutrition Examination Survey (NHANES), using a multistage probability sampling design, included a vision evaluation in a mobile examination center. Visual acuity data were obtained from 13,265 of 14,203 participants (93.4%) who visited the mobile examination center in 1999-2002. Visual impairment was defined as presenting distance visual acuity of 20/50 or worse in the better-seeing eye. Visual impairment due to uncorrected refractive error was defined as (presenting) visual impairment that improved, aided by automated refraction results, to 20/40 or better in the better-seeing eye. MAIN OUTCOME MEASURES: Presenting distance visual acuity (measured with usual corrective lenses, if any) and distance visual acuity after automated refraction. RESULTS: Overall, 1,190 study participants had visual impairment (weighted prevalence, 6.4%; 95% confidence interval [CI], 6.0-6.8%), and of these, 83.3% could achieve good visual acuity with correction (95% CI, 80.9-85.8%). Extrapolating these findings to the general U.S. population, approximately 14 million individuals aged 12 years or older have visual impairment (defined as distance visual acuity of 20/50 or worse), and of these, more than 11 million individuals could have their vision improved to 20/40 or better with refractive correction. CONCLUSIONS: Visual impairment due to uncorrected refractive error is a common condition in the United States. Providing appropriate refractive correction to those individuals whose vision can be improved is an important public health endeavor with implications for safety and quality of life.

Zone 1 retinopathy of prematurity in a transitional economy: a cautionary note.

PURPOSE: To describe three low risk infants in whom severe retinopathy of prematurity developed. DESIGN: A prospective, observational case series. METHODS: setting: National Hospital of Pediatrics, Hanoi, Vietnam. study population: Premature infants in the neonatal ward. observation procedure: Eye examinations. RESULTS: Severe retinopathy of prematurity occurred in three infants. All had zone 1 disease and other unusually severe findings, such as neovascularization of the disk. These infants would not be at risk for the development of such severe retinopathy of prematurity in countries with a developed economy. CONCLUSIONS: Unusual characteristics of retinopathy of prematurity may be occurring in countries with transitional economies. Screening programs should be implemented and should take into consideration the possibility that retinopathy of prematurity may occur in infants who fall outside the screening guidelines that are used in the developed world.

Scanning the ocular albinism 1 (OA1) gene for polymorphisms in congenital nystagmus by DHPLC.

BACKGROUND: Nystagmus is common to all types of albinism. Some subjects with nystagmus lack convincing signs of albinism, have no other visual pathway disease, and are classified as possessing congenital idiopathic nystagmus (CN). It has been postulated that CN may be a form of ocular albinism. METHODS: The presence of nystagmus, iris transillumination, and visual acuity were recorded in 39 CN and albino patients and their families. Physical characteristics were also noted. DNA from buccal swabs was obtained for use in denaturing high performance liquid chromatography (DHPLC) and chemical cleavage of mismatch (CCM) to scan several hotspots for X-linked ocular albinism (OA1) mutations. RESULTS: Two previously reported polymorphisms were confirmed: neither was found to be a causative mutation. CONCLUSION: No correlation was identified between nystagmus and OA1.

Green-laser induced maculopathy in a 15-year-old boy.

We report the case a 15-year-old boy who presented with retinopathy caused by a green-diode (class IIIB) laser. The patient was followed over a period of 8 weeks. Visual acuity on day 1 was 6/7.5, with central scotoma in the right eye, and 6/5 in the left eye. Macular optical coherence tomography of the right eye day 1 showed focal subfoveal disruption of the photoreceptor ellipsoid and myoid zones extending through the external limiting membrane to the outer nuclear layer. At week 8, visual acuity was 6/6 right eye and 6/5 in the left eye. Disruption of the ellipsoid and myoid layers, though still present, had improved.