Browsing by Author "Prakalapakorn, S. Grace"

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    Plasma Levels of Bevacizumab and Vascular Endothelial Growth Factor After Low-Dose Bevacizumab Treatment for Retinopathy of Prematurity in Infants
    (American Medical Association, 2022) Hartnett, M. Elizabeth; Wallace, David K.; Dean, Trevano W.; Li, Zhuokai; Boente, Charline S.; Dosunmu, Eniolami O.; Freedman, Sharon F.; Golden, Richard P.; Kong, Lingkun; Prakalapakorn, S. Grace; Repka, Michael X.; Smith, Lois E.; Wang, Haibo; Kraker, Raymond T.; Cotter, Susan A.; Holmes, Jonathan M.; Ophthalmology, School of Medicine
    Importance: Intravitreal bevacizumab effectively treats severe retinopathy of prematurity (ROP), but it enters the bloodstream and may reduce serum vascular endothelial growth factor (VEGF), potentially causing detrimental effects on developing organs in the premature infant. Objective: To evaluate the association of intravitreal bevacizumab with plasma bevacizumab and VEGF concentrations at 2 and 4 weeks after predefined, de-escalating doses of intravitreal bevacizumab were administered to infants with severe ROP. Design, setting, and participants: This phase 1 dose de-escalation case series study was conducted at 10 US hospitals of ophthalmology institutions from May 21, 2015, to May 7, 2019. Blood samples were collected 2 and 4 weeks after intravitreal bevacizumab injection. Participants included 83 premature infants with type 1 ROP in 1 or both eyes and no previous ROP treatment. Data were analyzed from April 2017 to August 2021. Interventions: Study eyes received a single bevacizumab injection of 0.250 mg, 0.125 mg, 0.063 mg, 0.031 mg, 0.016 mg, 0.008 mg, 0.004 mg, or 0.002 mg. When the fellow eye required treatment, one dose higher was administered. Total dose administered at baseline was defined as the sum of doses given to each eye within 3 days of initial study-eye injection. Main outcomes and measures: Plasma bevacizumab concentration at 2 and 4 weeks after injection and the percentage change in plasma VEGF concentrations from pretreatment levels. Results: A total of 83 infants (mean [SD] age, 25 [2] weeks; 48 boys [58%]) were included in this study. Higher doses of bevacizumab administered at baseline were associated with higher plasma bevacizumab concentrations at 2 weeks (ρ, 0.53; 95% CI, 0.31-0.70) and 4 weeks (ρ, 0.44; 95% CI, 0.18-0.64). Plasma VEGF concentrations decreased by 50% or more from pretreatment levels in 40 of 66 infants (61%) at 2 weeks and 31 of 61 infants (51%) at 4 weeks, but no association was observed between the total dose of bevacizumab administered at baseline and percentage change in plasma VEGF concentrations 2 weeks (ρ, -0.04; 95% CI, -0.28 to 0.20) or 4 weeks (ρ, -0.17; 95% CI, -0.41 to 0.08) after injection. Conclusions and relevance: Results of this phase 1 dose de-escalation case series study revealed that bevacizumab doses as low as 0.002 mg were associated with reduced plasma VEGF levels for most infants at 2 and 4 weeks after intravitreal administration; however, no association was observed between total bevacizumab dose administered and reductions in plasma VEGF levels from preinjection to 2 weeks or 4 weeks. Additional studies are needed to evaluate the long-term effects of low-dose bevacizumab on neurodevelopment and retinal structure.
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    Prophylactic laser versus continued surveillance after initial bevacizumab treatment for retinopathy of prematurity
    (Science Direct, 2021-05-06) Hong, Gloria J.; Stinnett, Sandra S.; Freedman, Sharon F.; Wallace, David K.; Prakalapakorn, S. Grace; Ophthalmology, School of Medicine
    Guidelines on managing infants after initial anti-vascular endothelial growth factor (VEGF) treatment (eg, bevacizumab) for retinopathy of prematurity (ROP) are limited. We found that following initial bevacizumab treatment for ROP, prophylactically lasering infant eyes before hospital discharge reduced the number and duration of outpatient ROP screening examinations compared with following infants, per current United States (US) ROP screening guidelines.
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    Quantitative comparison of blood vessel changes after treatment of retinopathy of prematurity with laser versus bevacizumab
    (Elsevier, 2022-12) Wang, Weiliang; Hong, Gloria J.; Stinnett, Sandra S.; Freedman, Sharon F.; Wallace, David K.; Prakalapakorn, S. Grace; Ophthalmology, School of Medicine
    Current therapies for treatment-indicated (type 1) retinopathy of prematurity mainly consist of laser photocoagulation and intravitreal anti-vascular endothelial growth factor (eg, bevacizumab) injection. The first visible signs of acute-phase regression are typically vascular, including decreased plus disease. Using a semiautomated computer program, we quantitatively compared posterior pole vascular changes following treatment with laser versus bevacizumab and found that in the first month following treatment, vascular dilation and tortuosity significantly decreased following either treatment modality, but tortuosity decreased earlier and faster after bevacizumab.
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    Quantitatively comparing weekly changes in retinal vascular characteristics of eyes eventually treated versus not treated for retinopathy of prematurity
    (Elsevier, 2021) Hong, Gloria J.; Koerner, Jagger C.; Weinert, Marguerite C.; Stinnett, Sandra S.; Freedman, Sharon F.; Wallace, David K.; Riggins, J. Wayne; Gallaher, Keith J.; Prakalapakorn, S. Grace; Ophthalmology, School of Medicine
    Purpose To quantitatively compare retinal vascular characteristics over time in eyes eventually treated versus not treated for retinopathy of prematurity (ROP), using ROPtool analysis of narrow-field retinal images. Methods This longitudinal study used prospectively collected narrow-field retinal images of infants screened for ROP, prior to treatment, if needed. Images were analyzed using a methodology that combines quadrant-level measures from several images of the same eye. For the longitudinal analysis, one examination per postmenstrual age (PMA) was included per eye. We compared the following ROPtool indices and their change per week between eyes eventually treated versus not treated for ROP: tortuosity index (TI), dilation index (DI), sum of adjusted indices (SAI), and tortuosity-weighted plus (TWP). Analysis was performed on three levels: eye (mean value/eye), quadrant (highest quadrant value/eye), and blood vessel (highest blood vessel value/eye). Results Of 832 examinations (99 infants), 745 images (89.5%) had 3-4 quadrants analyzable by ROPtool. On the eye level, ROPtool indices differed between eyes eventually treated versus not treated at PMA of 33-35 and 37 weeks for TI, SAI, and TWP, and at PMA of 33-34 and 37 weeks for DI (P ≤ 0.0014), and change per week differed between eyes eventually treated versus not treated only for SAI at PMA of 32 weeks (P < 0.001). Conclusions Quantitative analysis of retinal vascular characteristics using ROPtool can help predict eventual need for treatment for ROP as early as 32 weeks PMA. ROPtool index values were more useful than change in these indices to predict eyes that would eventually need treatment for ROP.