Ophthalmic Surgery, Lasers and Imaging Retina

Clinical Science 

Early Detection of Radiation Retinopathy in Pediatric Patients Undergoing External Beam Radiation Using Optical Coherence Tomography Angiography

Janelle Fassbender Adeniran, MD, PhD; Raafay Sophie, MD; Mehreen Adhi, MD; Aparna Ramasubramanian, MD

Abstract

BACKGROUND AND OBJECTIVE:

Detection of early vascular changes observed on optical coherence tomography angiography (OCTA) in children who have received external beam radiation and are at risk of developing radiation retinopathy (RR).

PATIENTS AND METHODS:

Eleven pediatric patients (20 eyes) with history of irradiation and nine healthy subjects (14 eyes) were retrospectively studied after dilated fundus exam and imaging.

RESULTS:

Four eyes of three patients had clinical RR. Eyes with radiation exposure but no RR had worse vision (no RR: logMAR 0.09 ± 0.14, Snellen 20/25) than controls (logMAR 0.01 ± 0.03, Snellen 20/21; P = .04) and increased superficial foveal avascular zone (FAZ) area (radiation: 0.31 ± 0.15 vs. control: 0.18 ± 0.10; P = .005). Eyes with RR had worse vision (RR: logMAR 0.34 ± 0.31, Snellen 20/44) than eyes with no RR (P = .001) and had increased deep FAZ (RR: 1.23 ± 0.40 vs. no RR: 0.68 ± 0.25; P = .01), but similar superficial FAZ (RR: 0.44 ± 0.28 vs. no RR: 0.31 ± 0.15; P = .42).

CONCLUSIONS:

Eyes with mildly decreased vision but no RR show superficial but not deep plexus changes. Eyes with RR have both superficial and deep plexus changes.

[Ophthalmic Surg Lasers Imaging Retina. 2019;50:145–152.]

Abstract

BACKGROUND AND OBJECTIVE:

Detection of early vascular changes observed on optical coherence tomography angiography (OCTA) in children who have received external beam radiation and are at risk of developing radiation retinopathy (RR).

PATIENTS AND METHODS:

Eleven pediatric patients (20 eyes) with history of irradiation and nine healthy subjects (14 eyes) were retrospectively studied after dilated fundus exam and imaging.

RESULTS:

Four eyes of three patients had clinical RR. Eyes with radiation exposure but no RR had worse vision (no RR: logMAR 0.09 ± 0.14, Snellen 20/25) than controls (logMAR 0.01 ± 0.03, Snellen 20/21; P = .04) and increased superficial foveal avascular zone (FAZ) area (radiation: 0.31 ± 0.15 vs. control: 0.18 ± 0.10; P = .005). Eyes with RR had worse vision (RR: logMAR 0.34 ± 0.31, Snellen 20/44) than eyes with no RR (P = .001) and had increased deep FAZ (RR: 1.23 ± 0.40 vs. no RR: 0.68 ± 0.25; P = .01), but similar superficial FAZ (RR: 0.44 ± 0.28 vs. no RR: 0.31 ± 0.15; P = .42).

CONCLUSIONS:

Eyes with mildly decreased vision but no RR show superficial but not deep plexus changes. Eyes with RR have both superficial and deep plexus changes.

[Ophthalmic Surg Lasers Imaging Retina. 2019;50:145–152.]

Introduction

Radiation retinopathy (RR) is a vision-threatening complication of irradiation. It manifests as macular edema, retinal hemorrhage / exudation, and neovascularization.1 Doses of 30 Gy to 35 Gy may cause retinopathy, but the incidence rises steeply above 50 Gy.2 Nevertheless, RR has been documented in bone marrow transplant (BMT) patients receiving total irradiation of no more than 12 Gy.3 Although manifest RR depends on multiple factors like age, dosage, fractionation, and use of eye shielding, there are currently no screening guidelines.

Studies suggest that RR is a vascular endothelial growth factor (VEGF)-mediated process driven by ischemia of the retinal vasculature.4 Fluorescein angiography can evaluate the retinal circulation in eyes with RR; however, it cannot differentiate the retinal capillary plexuses. Furthermore, the test involves intravenous dye injection, which is not without risk and is unpleasant for the patient, especially in the pediatric setting.

In contrast, optical coherence tomography angiography (OCTA) is a technique based on depth-resolved motion contrast imaging that operates by comparing fluctuations in signal amplitude due to movement of erythrocytes within blood vessels relative to the static surrounding tissue and non-invasively generates a three-dimensional OCT angiogram, allowing for assessment of the retinal and choroidal microvasculature at varying depths.5,6 Recent studies demonstrate the use of OCTA in grading RR,7 given its ability to subclinically detect both qualitative and quantitative changes in the retinal vasculature. These changes include an enlarged foveal avascular zone (FAZ) and decreased parafoveal capillary density involving both superficial and deep retinal capillary plexuses in patients who had received local radiation.8,9

There is a paucity of OCTA data in pediatric patients with RR, including those receiving external beam radiation. Typically, pediatric patients who present for evaluation of RR have undergone total body radiation (TBI) in addition to chemotherapy in preparation for BMT and / or have had cranial irradiation (CI) for extra-ocular tumors. The authors sought to noninvasively compare the retinal vasculature in pediatric patients who have undergone TBI and / or CI either with or without clinical RR to that of healthy control subjects using OCTA.

Patients and Methods

Subjects

A retrospective review of 11 pediatric patients (21 eyes; mean age ≤ 18 years old) with history of CI or TBI and nine healthy subjects (14 eyes) who presented for examination in the pediatric ophthalmology clinic at the Kentucky Lions Eye Center, University of Louisville School of Medicine. Dilated fundus examination was performed by a pediatric ophthalmologist (AR) to determine presence of clinical RR. Data gathered included patient demographics (age, race, sex) medical history including ocular diseases, and visual acuity (VA) for all subjects, as well as tumor / cancer details, treatments given, and radiation parameters for patients having undergone radiation treatment. The healthy subjects were included after they had OCTA and dilated fundus examination to rule out a chorioretinal condition.

This study adhered to the tenets of the Declaration of Helsinki and the Health Insurance Portability and Accountability Act of 1996. Approval was obtained from the institutional review board of the University of Louisville School of Medicine.

Optical Coherence Tomography Angiography Imaging and Image Processing

All subjects underwent imaging with the Cirrus high-definition (HD) Model 5000 (Carl Zeiss Meditec, Dublin, CA) with Angioplex software, which uses OCT microangiography complex algorithm and operates at an imaging speed of 68,000 A-scans per second. The built-in FastTrac technology reduces motion artifacts during image acquisition. The 3 mm × 3 mm angiography protocol was used to obtain the enface OCTA. The en face OCTA images were segmented for the superficial and deep retinal capillary plexuses using the built-in software function. JFA reviewed all images for segmentation accuracy prior to being exported into external software. Motion artifact or media opacity precluding analysis occurred in five eyes, resulting in exclusion from the study. Prior to exporting the en face OCTA of the deep retinal capillary plexus, projection artifacts from the superficial capillary plexus were removed. The OCTA images were used to analyze the FAZ area, FAZ circularity, and the parafoveal capillary density using external software.

Measurement of the Foveal Avascular Zone Area and Circularity

The size of the FAZ was measured at the superficial and deep retinal capillary plexuses using Image J software (National Institutes of Health, Bethesda, MD). Before FAZ measurement, image scale was set using a known pixel distance of 429 pixels for 3 mm, with a calculated pixel-to-millimeter ratio of 143 pixels per mm. Circularity was calculated from the FAZ using a preset Image J plugin (https://imagej.nih.gov/ij/plugins/circularity.html).

Measurement of Parafoveal Capillary Density

The parafoveal capillary density at the superficial and deep retinal capillary plexuses were measured using Adobe Photoshop CS6 (Adobe Systems, San Jose, CA). Each enface OCTA is a 429 × 429-pixel scan with a total pixel count of 184,041, which was exported without any post-acquisition editing, and rendered using Adobe red-green-blue (RGB) color scheme. Using the color range tool, the black (defined as RGB = 0-0-0) was selected and the inverse tool was used to select any color scheme other than black with a fuzziness factor greater than 140.8 The total number of pixels selected was then expressed as a percentage of the total number of pixels in the whole image.

Enhanced Depth Imaging and Choroidal Thickness Measurements

All subjects also underwent imaging with the HD 1-line raster with enhanced depth imaging (EDI) through the foveal center. These images were used to measure the subfoveal choroidal thickness in each eye. Choroidal thickness was measured in the usual fashion from the outer aspect of the retinal pigment epithelium / Bruch's membrane complex to the inner aspect of the choroidoscleral interface using the caliper function on the Cirrus software.

Statistical Analysis

All recorded data and statistical analyses were performed using SPSS Statistics Version 19 (IBM, Armonk, NY). Snellen VA was converted into logMAR for calculating averages. Comparison between groups was made using one-way analysis of variance with Bonferroni correction, or independent t-test for parametric data, and using Kruskal-Wallis H test with Bonferroni correction and Mann–Whitney U test for nonparametric data. Significance was considered when the P value was less than .05. Chi-square or Fisher's exact test was used to compare categorical data.

Results

Fourteen pediatric-aged eyes with no radiation exposure were examined for control (average age = 12.0 years ± 4 years; P = .60). Eleven pediatric patients with an average age of 11.5 years ± 4.46 years (Table 1) underwent either CI (n = 7; average age: 12.25 years ± 4.1 years) or fractionated TBI with BMT (n = 4; average age: 10.25 years ± 5.2 years). Radiation dose was 52.7 Gy and 18 Gy for patients receiving CI and TBI, respectively (P = .03; missing: n = 3). Three of 14 eyes (21.5%) of CI patients and one of eight (12.5%) eyes of TBI patients had RR (P = .06) (Table 1). Treatment indications, adjuvant chemotherapy, and follow-up since radiation exposure are included in Table 1. Average VA was similar at logMAR 0.18 ± 0.24 and logMAR 0.07 ± 0.07 in the CI and TBI groups, respectively (P = .4). Since all parameters were similar between groups, they are discussed hereafter as the radiation-exposure group (Table 2).

Indication for Patient Treatment and Treatments Received

Table 1:

Indication for Patient Treatment and Treatments Received

Vision and Image Analysis Results for Eyes Exposed to Radiation and Control Eyes

Table 2:

Vision and Image Analysis Results for Eyes Exposed to Radiation and Control Eyes

One eye without RR in the CI group could not be imaged due to media opacity, and one eye in the TBI with RR group was excluded due to significant motion artifact for total of 20 radiation-exposed eyes. Of normal patients, 14 eyes of nine patients had good quality images for grading. Mean VA for radiation-exposed and normal eyes was logMAR 0.14 ± 0.07 and logMAR 0.01 ± 0.03, respectively (P = .02).

Foveal Avascular Zone

In the radiation-exposed group, the area of the FAZ of the superficial capillary plexus was 0.33 ± 0.18 mm2, whereas the control group had an area of 0.18 ± 0.11 mm2, (P < .001). In the deep plexus, area of the FAZ in the radiation-exposed group measured 0.79 ± 0.36 mm2 whereas the control group had an area of 0.53 ± 0.16 mm2 (P = .03; Table 2).

Qualitative Anatomical Changes and Circularity

Most eyes in the radiation group (n = 15) had qualitative remodeling of the superficial capillary plexus defined by presence of microaneurysms (n = 2; Figure 1A), punched-out borders (n = 12; Figure 1B), enlarged intercapillary spaces (EICA) (n = 7; Figure 1C), or parafoveal capillary loops (n = 11; Figure 1D). Of the four eyes with clinical RR, three had three out of four of these characteristics, whereas one had four of four. Of the 16 eyes with no RR, 11 had qualitative changes. Six of eight exposed to CI had one of four characteristics, and two eyes had zero of four. Five of six eyes from patients receiving TBI had qualitative changes, three eyes had two of four characteristics, and two eyes of one patient had three of four. No eyes in the control group exhibited these changes.

Qualitative changes affecting the superficial capillary plexus in radiation-exposed eyes were evident, including microaneurysms (A), punched-out borders (B), enlarged intercapillary spaces (EICA) (C), and capillary loops (D).

Figure 1.

Qualitative changes affecting the superficial capillary plexus in radiation-exposed eyes were evident, including microaneurysms (A), punched-out borders (B), enlarged intercapillary spaces (EICA) (C), and capillary loops (D).

We hypothesized that measurement of circularity may give a more quantitative assessment of these changes. The radiation-exposed group had a circularity of 0.71 ± 0.15 and 0.76 ± 0.12 in the superficial and deep capillary plexuses, respectively. The control group measured 0.75 ± 0.11 and 0.83 ± 0.07 in the superficial and deep capillary plexuses, respectively. This was borderline significant in the deep (P = .05) but not the superficial plexus (Table 2).

Parafoveal Capillary Density

The superficial parafoveal capillary density in the radiation-exposed group (41.0% ± 5.3%) was decreased compared to the control eyes (45.4% ± 5.4%) (P = .02), whereas the deep capillary plexuses were not significantly different (20.7% ± 5.1% vs. 22.7% ± 5.5%; P = .31) (Table 2).

Choroidal Thickness

Choroidal thickness could be measured using EDI OCT (Figures 2A–2C). Altogether, eyes exposed to radiation had decreased choroidal thickness to eyes not exposed to radiation, but this did not reach significance (240.6 ± 59.2 vs. 276.9 ± 40.4; P = .09).

Choroidal thickness was measured in all images of radiation-exposed and control eyes. Although the choroid consistently measured thinner in the eyes with positive radiation retinopathy (RR) (n = 3), this did not reach statistical significance compared to eyes without clinical RR (n = 8) and control (n = 14) eyes.

Figure 2.

Choroidal thickness was measured in all images of radiation-exposed and control eyes. Although the choroid consistently measured thinner in the eyes with positive radiation retinopathy (RR) (n = 3), this did not reach statistical significance compared to eyes without clinical RR (n = 8) and control (n = 14) eyes.

Clinical Radiation Retinopathy Versus No Clinical Findings

Interestingly, eyes with radiation exposure but no clinical findings (no RR; n = 16) had decreased vision (no RR: logMAR 0.09 ± 0.14, Snellen 20/25 vs. control: logMAR 0.01 ± 0.03, Snellen 20/21; P = .04) (Table 3) and larger superficial plexus FAZ area (0.31 ± 0.15 vs. 0.18 ± 0.11; P = .005) (Figure 3B) compared to control eyes (Figure 3A). The deep plexus was not significantly larger (P = .08) (Figures 3D and 3E). The superficial capillary density was also decreased in eyes exposed to radiation but with no RR (42.2% ± 4.9%) compared to control eyes (45.4% ± 5.4%; P < .04) (Table 3).

Vision and Image Analysis Results for Eyes Diagnosed With Clinical Radiation Retinopathy, Eyes Without Clinical Signs Of Radiation Retinopathy, and Control Eyes

Table 3:

Vision and Image Analysis Results for Eyes Diagnosed With Clinical Radiation Retinopathy, Eyes Without Clinical Signs Of Radiation Retinopathy, and Control Eyes

Compared with the control eyes (A, D) and eyes without clinical radiation retinopathy (RR) (B, E), eyes with positive RR (C, F) had a larger foveal avascular zone (FAZ) and decreased parafoveal capillary density. Eyes with negative clinical RR compared to control eyes also had an enlarged FAZ and decreased parafoveal capillary density, but in the superficial plexus only (A, B).

Figure 3.

Compared with the control eyes (A, D) and eyes without clinical radiation retinopathy (RR) (B, E), eyes with positive RR (C, F) had a larger foveal avascular zone (FAZ) and decreased parafoveal capillary density. Eyes with negative clinical RR compared to control eyes also had an enlarged FAZ and decreased parafoveal capillary density, but in the superficial plexus only (A, B).

Four eyes of three patients with RR compared to no RR had decreased VA (RR: logMAR 0.34 ± 0.31, Snellen 20/44; P = .03) (Table 3) and larger FAZ area in the deep plexus only (1.23 ± 0.40 mm2 vs. 0.68 ± 0.25 mm2; P = .01) (Figure 3F). Eyes with RR compared to control eyes had increased FAZ area (superficial and deep) (Table 3; Figures 3A, 3C, 3D, and 3F) and decreased superficial plexus parafoveal capillary density (36.4% ± 4.9% [RR] vs. 45.4% ± 5.4% [control]) (Table 3). Although choroidal thickness (Figure 3B) was largely decreased in eyes with RR (183.7 μm ± 45.1 μm) compared to both eyes without clinical changes (256.8 μm ± 55.7 μm) and control eyes (276.9 μm ± 40.0 μm), this was not statistically significant (Table 3).

Discussion

Annually, 4,500 allogenic hematopeoetic stem cell transplantation are done in the United States in children younger than 20 years of age,10 and most receive TBI. The most common dose schedule for TBI is 12 Gy to 15 Gy given in fractions. The incidence of cranial radiation, on the other hand, is not known, as it is employed in various conditions like hematopoietic malignancy, intracranial tumors, and other head and neck tumors.11 Approximately 12,000 new cases of childhood cancer are diagnosed in the United States each year, and radiation treatment improves the survival of these patients.12

Herein, we used OCTA to detect preclinical RR in children and found interesting changes in asymptomatic eyes. Especially in the pediatric population, early detection of RR may have important clinical implications. We categorized patients receiving TBI or CI under one group for analysis as they had similar rates of RR, even though they had different known radiation doses.

Our findings show that eyes exposed to radiation but without clinical RR had a significantly enlarged superficial plexus FAZ area, decreased superficial parafoveal capillary density, and decreased VA compared to control eyes. Whether this means they will go on to develop clinical RR is not yet known. Interestingly, the superficial plexus was similar in eyes with RR versus no RR; however, the deep plexus was worse in eyes with clinical RR. Furthermore, eyes with no RR had a larger superficial plexus FAZ than control eyes but similar deep plexus FAZ. Accordingly, it may be the loss of vascularity in the deep plexus that ultimately leads to progression of RR.

Using the classification system proposed by Pulido et al.,7 the majority of these eyes would be classified as 1a or 1b, indicating findings on OCTA without significant cystoid macular edema (CME) or retinal thickening on OCT. Only four eyes could be classified as grade 4, where there was both clinical RR and findings on OCT.

Treatment of pediatric RR is typically initiated for neovascularization or vision-limiting CME (ie, laser photocoagulation for neovascularization versus intravitreal or sub-Tenon's steroids and intravitreal anti-VEGF agents for CME). No resulting VA difference between intravitreal steroid or anti-VEGF has been shown for treatment of RR-related CME.13 Pre-treating with anti-VEGF at the time of plaque removal for uveal melanoma and every 4 months for 2 years decreases the rate of development of RR by 50% according to Shah et al.1 Following cranially irradiated patients prospectively may elucidate whether a similar protocol may preserve vision long-term. At minimum, noninvasive detection of subclinical changes on OCTA may indicate future risk for clinically significant CME14 and could facilitate early treatment, or at least more frequent monitoring, especially in the pediatric population. It remains to be seen whether children exposed to radiation therapy will sustain better or worse visual prognosis than exposed adults in the long-run.

The limitation of our study is that as it was a retrospective study and, hence, the OCTA images before and after radiation are not available for comparison. A larger sample size and longitudinal follow-up of these patients is needed to further elucidate our findings. Furthermore, utilization of ultra-widefield angiography may aid in the earlier identification of patients at risk.

We know little about the long-term progression of pediatric RR. This disease entity is difficult to treat and may result in blindness for many children exposed to radiation. In this preliminary, retrospective study, we have demonstrated vascular changes in the superficial plexus on OCTA in eyes exposed to radiation but without clinical RR. Additionally, these children appear to have early but mild vision loss. Patients with superficial and deep plexus changes had clinical RR. Further prospective studies with long-term follow-up are needed to parse out the true implications of these early changes, as well as to decipher whether any preventive measures may be taken. It would also be important to determine if all patient receiving cranial radiation require routine ophthalmic screening as pediatric patients may not always complain of vision loss.

References

  1. Shah SU, Shields CL, Bianciotto CG, et al. Intravitreal bevacizumab at 4-month intervals for prevention of macular edema after plaque radiotherapy of uveal melanoma. Ophthalmology. 2014;121(1):269–275. doi:10.1016/j.ophtha.2013.08.039 [CrossRef]
  2. Parsons JT, Bova FJ, Mendenhall WM, Million RR, Fitzgerald CR. Response of the normal eye to high dose radiotherapy. Oncology (Williston Park). 1996;10(6):837–847; discussion 847–838, 851–832.
  3. Lopez PF, Sternberg P Jr, Dabbs CK, Vogler WR, Crocker I, Kalin NS. Bone marrow transplant retinopathy. Am J Ophthalmol. 1991;112(6):635–646. doi:10.1016/S0002-9394(14)77269-1 [CrossRef]
  4. Missotten GS, Notting IC, Schlingemann RO, et al. Vascular endothelial growth factor a in eyes with uveal melanoma. Arch Ophthalmol. 2006;124(10):1428–1434. doi:10.1001/archopht.124.10.1428 [CrossRef]
  5. de Carlo TE, Bonini Filho MA, Chin AT, et al. Spectral-domain optical coherence tomography angiography of choroidal neovascularization. Ophthalmology. 2015;122(6):1228–1238. doi:10.1016/j.ophtha.2015.01.029 [CrossRef]
  6. Salz DA, de Carlo TE, Adhi M, et al. Select features of diabetic retinopathy on swept-source optical coherence tomographic angiography compared with fluorescein angiography and normal eyes. JAMA Ophthalmol. 2016;134(6):644–650. doi:10.1001/jamaophthalmol.2016.0600 [CrossRef]
  7. Veverka KK, AbouChehade JE, Iezzi R, Pulido JS. Noninvasive grading of radiation retinopathy: The use of optical coherence tomography angiography. Retina. 2015;35(11):2400–2410. doi:10.1097/IAE.0000000000000844 [CrossRef]
  8. Shields CL, Say EA, Samara WA, Khoo CT, Mashayekhi A, Shields JA. Optical coherence tomography angiography of the macula after plaque radiotherapy of choroidal melanoma: Comparison of irradiated versus nonirradiated eyes in 65 patients. Retina. 2016;36(8):1493–1505. doi:10.1097/IAE.0000000000001021 [CrossRef]
  9. Say EA, Samara WA, Khoo CT, et al. Parafoveal capillary density after plaque radiotherapy for choroidal melanoma: Analysis of eyes without radiation maculopathy. Retina. 2016;36(9):1670–1678. doi:10.1097/IAE.0000000000001085 [CrossRef]
  10. Baird K, Cooke K, Schultz KR. Chronic graft-versus-host disease (GVHD) in children. Pediatr Clin North Am. 2010;57(1):297–322. doi:10.1016/j.pcl.2009.11.003 [CrossRef]
  11. Seung SK, Larson DA, Galvin JM, et al. American College of Radiology (ACR) and American Society for Radiation Oncology (ASTRO) Practice Guideline for the Performance of Stereotactic Radiosurgery (SRS). Am J Clin Oncol. 2013;36(3):310–315. doi:10.1097/COC.0b013e31826e053d [CrossRef]
  12. Childhood Cancer. National Cancer Institute website. https://www.cancer.gov/types/childhood-cancers. Updated January 28, 2019. Accessed March 1, 2019.
  13. Seibel I, Hager A, Riechardt AI, Davids AM, Böker A, Joussen AM. Antiangiogenic or corticosteroid treatment in patients with radiation maculopathy after proton beam therapy for uveal melanoma. Am J Ophthalmol. 2016;168:31–39. doi:10.1016/j.ajo.2016.04.024 [CrossRef]
  14. Mashayekhi A, Schonbach E, Shields CL, Shields JA. Early subclinical macular edema in eyes with uveal melanoma: Association with future cystoid macular edema. Ophthalmology. 2015;122(5):1023–1029. doi:10.1016/j.ophtha.2014.12.034 [CrossRef]

Indication for Patient Treatment and Treatments Received

Patient Age (Years) Treatment Indication Chemotherapy Radiation Dose Follow-Up (Months)
1* 16 CI Medulloblastoma None Unknown 156
2 8 CI Pilocyticastrocytoma None 50.4 Gy 36
3 14 CI Pilocyticastrocytoma Avastin 23 Gy 48
4 4 CI / BMT Medulloblastoma Carboplatin and thiotepa 54 Gy 6
5 12 CI Embryonal rhabdomyosarcoma Vincristine, dactinomycin, cyclophosphamide, ironitecan, temsirolimus 86.4 Gy 12
6* 17 CI Chondrosarcoma paranasal sinus None 75.6 60
7 7 CI Craniopharyngioma None 54 Gy 10
8 12 BMT / TBI Non-Hodgkin's Lymphoma Unknown Unknown 54
9 17 BMT / TBI Lymphoma Cyclophosphamide, etoposide and carmustine Unknown 96
10 7 BMT / TBI Leukemia Cyclophosphamide and etoposide 12 Gy 24
11* 13 BMT / TBI Leukemia Cyclophosphamide and etoposide 24 Gy 36

Vision and Image Analysis Results for Eyes Exposed to Radiation and Control Eyes

Group (Eyes) Visual Acuity (logMAR Average) Superficial FAZ (mm2) Deep FAZ (mm2) Circ (Superficial) Circ (Deep) PCD (Superficial, %) PCD (Deep, %) Choroidal Thickness*(μm)
Radiation (20) 0.141 ± 0.07 0.33 ± 0.18 0.79 ± 0.36 0.71 ± 0.15 0.76 ± 0.12 41.0 ± 5.3 20.7 ± 5.1 240.6 ± 60.9
Control (14) 0.014 ± 0.03 0.18 ± 0.11 0.53 ± 0.16 0.75 ± 0.11 0.83 ± 0.07 45.4 ± 5.4 22.7 ± 5.5 276.91 ± 40.0
Radiation vs. Control 0.02 0.01 0.02 0.36 0.05 0.02 0.31 0.09

Vision and Image Analysis Results for Eyes Diagnosed With Clinical Radiation Retinopathy, Eyes Without Clinical Signs Of Radiation Retinopathy, and Control Eyes

Group (Eyes) Visual Acuity (logMAR) FAZ, Superficial (mm2) FAZ, Deep (mm2) PCD, Superficial (%) Choroidal Thickness (μm)
Clinical RR (4) 0.34 ± 0.31 0.44 ± 0.28 1.23 ± 0.40 36.4 ± 4.9 183.7 ± 45.1
No RR (16) 0.09 ± 0.14 0.31 ± 0.15 0.68 ± 0.25 42.2 ± 4.9 256.8 ± 55.7
Control (14) 0.01 ± 0.03 0.18 ± 0.11 0.53 ± 0.16 45.4 ± 5.4 276.9 ± 40.0
RR vs. No RR 0.03 0.42 0.01 0.22 0.16
No RR vs. Control 0.04 0.005 0.08 0.04 0.13
RR vs. Control 0.001 0.03 0.004 0.03 0.22
Authors

From the University of Louisville School of Medicine, Department of Ophthalmology, Louisville, Kentucky.

Presented in poster format at the American Academy of Pediatric Ophthalmology and Strabismus Annual Meeting in March 2018 in Washington, DC.

Supported by an unrestricted institutional grant from Research to Prevent Blindness.

The authors report no relevant financial disclosures.

Address correspondence to Aparna Ramasubramanian, MD, University of Louisville, Department of Ophthalmology, 301 E. Muhammad Ali Blvd.,Louisville, KY 40202; email: Aparna.ramasubramanian@louisville.edu.

Received: June 19, 2018
Accepted: November 05, 2018

10.3928/23258160-20190301-03

Sign up to receive

Journal E-contents