Survey of childhood blindness and visual impairment in Botswana

Volume 14 Number 1 / February 2010 OCT was customized for the specific age of the patient and different scan protocols were tested. Results: When SD OCT parameters were corrected for age, image quality, field of image and ease of operation improved. The fovea could be imaged in 74% of the eyes imaged in the NICU group and 87% in the clinic group. No adverse events were reported. SD OCTwas more sensitive in detecting some pathologic changes when compared to masked concurrent clinical examination. ROP-related macular pathology, foveal hypoplasia and other retinal abnormalities were noted. Conclusions: SD OCT imaging can be optimized for the specific age of the patient and is useful to assess the macula in young children. Application of this technology complements clinical examination in the diagnosis of retinal pathologies in young children. 087 Inferior oblique muscles from patients with inferior oblique overaction: Examination of myosin heavy chain isoforms. Linda K. McLoon, Joost Felius, David R. Stager, David R. Stager Jr Purpose: Few studies have examined the potential changes in the inferior oblique muscles of patients who have been diagnosed with inferior oblique overaction. This study examined the percentage of fibers positive for fast, slow or embryonic myosin heavy chain isoforms (MHC) in patients with and without prior surgery compared to normal control inferior oblique muscles. Methods: Inferior oblique muscles, 6 with prior surgery, 4 without prior surgery and 3 controls, were frozen and prepared for immunohistochemical examination of fast MHC, slow MHC, or embryonic MHC isoforms. The percentage of myofibers positive for each isoform was determined morphometrically, and statistical significance was determined. Results: Several changes were evident in patient inferior oblique muscles compared to controls. The orbital layer of the EOM from both patient populations showed a 20% increase in fast MHC positive myofibers and almost a 50% decrease in slow MHC positive myofibers. There was a significant decrease in embryonic MHC expression in both orbital and global layers of the muscles from both patient populations, with decreases ranging from 12% to 50%. Discussion: Myosin heavy chain isoforms are responsible for shortening velocity in skeletal muscle. These data suggest that shortening velocity of the IO from the patients would be increased over normal IO muscles. Conclusions: There are many causes for alteration in eye position from normal. Understanding the adaptations of the EOM in various strabismus syndromes will allow for the development of new treatment modalities that can be tailored to subgroups of patients with similar maladaptations. 088 Oral propanolol for management of periocular infantile hemangioma. Tara Missoi, Gregg Lueder, Kenneth Gilbertson, Susan Bayliss Introduction: nfantile hemangiomas may occur on the eyelids and in the orbit. They can impair vision by inducing astigmatism, ptosis, and proptosis. Corticosteroids have been used to treat these lesions, but their use is associated with complications. Leaute-Labreze and colleagues recently reported successful treatment of hemangiomas with oral propanolol. We present our experience with oral propranolol for patients with periocular hemangiomas. Methods: We reviewed the records of 18 infants who were treated with oral propanolol (2 mg/kg/d) for periocular hemangiomas. Seven infants had previously not responded to corticosteroids (oral, intralesional injection, and/or topical). Seven patients were treated concurrently with occlusion for amblyopia. Results: Treatment with oral propranolol produced a rapid reduction in the size of all hemangiomas. The vision equalized in all patients

Journal of AAPOS

e23 treated for amblyopia. One patient (7%) suffered bradycardia and the propanolol was discontinued. Conclusions: Oral propanolol treatment is a very effective treatment for periocular hemangiomas. Patients should be monitored for systemic side effects while undergoing therapy. 089 The effects of D-penicillamine on a murine model of oxygen induced retinopathy. Annie Moreau, R. Micheal Siatkowski, Tammy L. Yanovitch, John D. Ash Purpose: A low rate of ROP was unexpectedly observed among Hungarian infants treated with intravenous d-penicillamine (DPA), a copper chelator, to prevent hyperbilirubinemia. This study was conducted to determine the effect of intraperitoneal and intravitreal DPA on retinal neovascularization in a murine model of oxygen-induced retinopathy. Methods: On postnatal day 7, 23 mice were injected subcutaneously with 300 or 600 mg/kg/day DPA x 3 days followed by 50 or 100 mg/kg/ day x 7 days, while a control cohort of 17 mice received subcutaneous Phosphate Buffered Solution (PBS). An additional 15 mice underwent intravitreal injection of 1 mL of 100 mg/mL DPA in the right eye, with 1 mL PBS intravitreally in the left eye as a control. They were placed in a 75% oxygen chamber x 7 days, room air x 3 days, and then sacrificed and enucleated. The retinas were stained and flatmounted to determine the severity of retinal neovascularization by quantifying neovascular buds (glomeruli and tubules). Results: After subcutaneous injection, the mean number of glomeruli and tubules was similar in the DPA (36 glomeruli, 6 tubules) and PBS (37 glomeruli, 3 tubules) groups (p 5 1.0). For the intravitreal phase, the DPA eyes had a mean of 13.97 neovascular buds (359 glomeruli, 60 tubules) versus a mean of 24.6 for the control eyes (566 glomeruli, 67 tubules, p 5 0.2). Conclusions: Neither intraperitoneal nor intravitreal injection of DPA significantly inhibit retinal neovascularization in a murine model of oxygen-induced retinopathy. This study does not support further investigation of this compound in human subjects. 090 Survey of childhood blindness and visual impairment in Botswana. Sudha Nallasamy, William V. Anninger, Graham E. Quinn, Oathokwa Nkomazana Introduction: In terms of blind-person years, the worldwide burden of childhood blindness is second only to cataracts. In developing countries, 30%-72% of childhood blindness is avoidable (preventable or treatable). Botswana is a middle-income country with poor access to ophthalmic care. We carried out this study to determine avoidable causes of childhood blindness and visual impairment (VI) in Botswana so a nationwide intervention could be planned. Methods: This study was carried out over 4 weeks in February to March 2009 in 8 cities in Botswana. Children with VI were recruited through a radio advertisement and local outreach programs. Children #15 years of age with visual acuity \20/60 in either eye were enrolled and examined. The World Health Organization/Prevention of Blindness Eye Examination Record for Children with Blindness and Low Vision was used to record data. Results: We enrolled 241 children, 79 with unilateral and 162 with bilateral VI. The most common causes of VI were refractive error, amblyopia, and cataract-related. Of unilateral cases, 89% were avoidable: 23% preventable (83% trauma-related) and 66% treatable (40% refractive error and 31% amblyopia). Of bilateral cases, 63% were avoidable: 5% preventable and 58% treatable (33% refractive error, 31% congenital cataracts, and 13% congenital glaucoma). Conclusions: Significant avoidable childhood blindness and VI exists. Refractive error, which is easily correctable with glasses, is the most common cause of bilateral VI, with cataracts a close second. Simple

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Volume 14 Number 1 / February 2010

measures can be made to reduce childhood VI in Botswana. A nationwide intervention is currently being planned. 091 Modification of Plusoptix referral criteria to enhance sensitivity and specificity. Niraj R. Nathan, Sean P. Donahue Purpose: To determine the impact of utilizing several different proposed sets of referral criteria on the specificity and sensitivity of the Plusoptix photoscreener for detecting amblyogenic factors. Methods: During a 2-month period, 149 children aged 9 months to 14 years were screened in the pediatric ophthalmology clinic setting. The estimated refractive error obtained by the Plusoptix instrument was compared to the results from a gold-standard pediatric ophthalmologic examination. Three previously-published sets of referral criteria were used, and their respective sensitivities and specificities to detect AAPOS Vision Screening Committee amblyogenic factors were calculated. Modifications of these criteria were also evaluated. The impact of these criteria on PPV given a prevalence of amblyogenic factors of 5% and 8% was determined. PPV (5% PPV (8% Sensitivity Specificity prevalence) prevalence) Manufacturer’s Matta (J AAPOS 2008;12:490) Arthur (J AAPOS 2009;13:51) Modification 1 (Anisometropia $ 1.5 D, Hyperopia $ 3.5 D, Myopia $3.0 D, Astigmatism $2.0 D, Anisocoria $1 mm) Modification 2 (Modified 1, increase cylinder to $2.5 D)

99% 97% 87% 86%

37% 46% 75% 84%

8% 9% 16% 22%

12% 13% 24% 32%

85%

89%

30%

41%

Results: Both modified criteria resulted in a marked increase in specificity with very little change in sensitivity, indicating that almost all children referred solely for cylinder values between 1.5 and 2.5 D were false positives. Conclusions: The manufacturer's criteria have excellent sensitivity but unacceptably low specificity; other criteria increase specificity with minimal effect on sensitivity and should be considered for field use. 092 Subclinical foveal hypoplasia in normal children detected by OCT. Susana Noval, Sharon F. Freedman, Sanjay Asrani, Mays A. ElDairi Introduction: Foveal hypoplasia is usually associated with significant visual dysfunction and an absent foveal reflex on biomicroscopy. Optical coherence tomography(OCT) easily provides accurate images of the foveal anatomy. Among a group of normal children having OCT for the development of a normative database (Arch Ophthalmol 2009;127), we identified a few with underdeveloped foveal architecture despite normal clinical examination. This study's purpose is to characterize the prevalence and features of subclinical foveal hypoplasia in the eyes of normal children. Methods: Stratus OCT (OCT-3; Carl-Zeiss-Meditec) macular scans from 286 clinically normal children were examined for those with an unidentifiable foveal depression, and these cases were characterized. Results: Three females and 6 males aged 4-12 (mean, 8  SD 2.9) years out of the 286 (mean age, 8.63.1) subjects enrolled in this prospective IRB-approved study were identified to have bilateral shallow foveal depression by OCT. Eight children (of 154) were white (5.4% prevalence); one (of 6) was of mixed ethnicity (white/black,17% prevalence). Mean visual acuity was 0.110.11 logMAR units (20/25),

median was 20/20. For 9 right eyes vs 286 normals, mean foveal thickness (mm) was 231.4  8.8 vs 188.8  25.0 (p\0.0001); similarly mean macular volume (mm3) was 6.89  0.38 vs 6.94  0.35 (p 5 0.7). Two of these children had strabismus, and one was successfully treated for unilateral amblyopia. All were thought to have a foveal pit on indirect ophthalmoscopy. Conclusions: 3.1% of clinically normal children had an anatomically underdeveloped foveal pit on OCT, despite having normal visual function and ophthalmic examination. Ongoing study will reexamine these children three years later, with both OCT-3 and spectral-domain-OCT to assess for longitudinal changes in foveal anatomy. 093 Changes in optic nerve sheath diameter after lumbar puncture in children. Mary Catherine Olson, David L. Rogers, Rae R. Fellows, Emily de los Reyes Purpose: To demonstrate the response of the optic nerve sheath to changes in intracranial pressure before and after lumbar puncture (LP) as measured by B-scan ultrasound. Methods: This is a prospective, blinded, clinical study. Ten consecutive patients 18 years or younger scheduled for a diagnostic and/or therapeutic LP were recruited for the study. Immediately prior to lumbar puncture, each patient had three B-scan measurements of the optic nerve sheath diameter (ONSD) of each eye. The measurements were taken 3 mm posterior to the anterior surface of the optic nerve. The LP was then performed and both opening and closing pressures and volume of cerebral spinal fluid (CSF) removed were recorded. After the LP, the B-scan measurement of the ONSD was repeated. Measurements were compared using the paired t-test. Results: Mean average ONSD OD pre-LP was 5.084 mm (SD 1.03) and post-LP was 4.63 mm (SD 0.76). Mean average ONSD OS pre-LP was 5.16 (SD 0.83) and post-LP was 4.55 (SD 0.47). There was no statistically significant difference between the ONSD OD and OS. There was a statistically significant decrease in ONSD OU (p 5 0.0002 OD and p 5 0.0034 OS) after LP. There is a positive trend correlating average difference in pre-and post-LP ONSD and amount of CSF drained. Conclusions: All patients had a decrease in the size of the ONSD after LP. This demonstrates that reducing the CSF pressure in the spinal column will have the immediate effect of reducing the optic nerve sheath diameter. 094 Longitudinal study of optic cup progression in children. Hee-Jung S. Park, Christian Hampp, Joseph L. Demer Purpose: To determine the normative rate of cup-to-disc-ratio (C:D) progression in children, and to determine the effect of prematurity and low birth weight on this rate. Design: Retrospective, longitudinal cohort study. Method: In a single pediatric ophthalmology practice, a single examiner evaluated optic cup size by serial ophthalmoscopy over at least five years in 92 patients (184 eyes). Patients with intraocular surgery or optic nerve disease were excluded. We performed cross-sectional analysis of C:D per year of age and used linear regression to compare C:D progression between preterm and term-born children, and low vs normal birth weight children. Results: Children without evidence of optic nerve disease exhibited progressive optic cupping. In term-born children, mean C:D increased by 0.0079 per year. Rate of mean C:D progression was double in children born preterm: 0.0168 (p 5 0.049, comparison to term) per year of age. A similar, nonsignificant trend is observed when comparing low birth weight (LBW) to normal (p 5 0.131). Discussion: This is the first longitudinal study examining the rate of optic cup enlargement in a pediatric population. We demonstrate

Journal of AAPOS