Characterization of Punctate Inner Choroidopathy Using Enhanced Depth Imaging Optical Coherence Tomography Javier Zarranz-Ventura, MD, PhD,1,2,3 Dawn A. Sim, FRCOphth,2 Pearse A. Keane, MD, FRCOphth,1,2 Praveen J. Patel, MD, FRCOphth,1,2 Mark C. Westcott, MD, FRCOphth,1 Richard W. Lee, PhD, FRCOphth,1,2,4 Adnan Tufail, MD, FRCOphth,1,2 Carlos E. Pavesio, MD, FRCOphth1,2 Purpose: To perform qualitative and quantitative analyses of retinal and choroidal morphology in patients with punctate inner choroidopathy (PIC) using enhanced depth imaging optical coherence tomography (EDI-OCT). Design: Cross-sectional, consecutive series. Participants: A total of 2242 patients attending 2 tertiary referral uveitis clinics at Moorfields Eye Hospital were screened; 46 patients with PIC diagnosis were identified, and 35 eyes (35 patients) had clinically inactive PIC had EDI-OCT images that met the inclusion criteria. Methods: Punctate inner choroidopathy lesions were qualitatively assessed for retinal features, such as (1) focal elevation of the retinal pigment epithelium (RPE), (2) focal atrophy of the outer retina/RPE, and (3) presence of sub-RPE hyperreflective deposits and choroidal features: (a) presence of focal hyperreflective dots in the inner choroid and (b) focal thinning of the choroid adjacent to PIC lesions. Quantitative analyses of the retina, choroid, and choroidal sublayers were performed, and associations with clinical and demographic data were examined. Main Outcome Measures: Prevalence of each lesion pattern and thickness of retinal and choroidal layers. Results: A total of 90 discrete PIC lesions were captured; 46.6% of PIC lesions consisted of focal atrophy of the outer retina and RPE; 34.4% consisted of sub-RPE hyperreflective deposits; and 18.8% consisted of localized RPE elevation with underlying hyporeflective space. Focal hyperreflective dots were seen in the inner choroid of 68.5% of patients, with 17.1% of eyes presenting focal choroidal thinning underlying PIC lesions. By excluding high myopes, patients with “atypical” PIC had reduced retinal thickness compared with patients with “typical” PIC (246.65
30.2 vs. 270.05
24.6 mm; P ¼ 0.04), and greater disease duration was associated with decreases in retinal thickness (r ¼ 0.53; P ¼ 0.01). A significant correlation was observed between best-corrected visual acuity and foveal retinal thickness (r ¼ 0.40; P ¼ 0.03). Conclusions: In a large series of patients with clinically inactive PIC, one fifth of the lesions analyzed revealed RPE elevation with underlying hyporeflective space, described before as a sign of activity and suggesting subclinical inflammation. Retinal thickness seems to be associated with disease type and duration of disease in nonehighly myopic eyes. Improved visualization of the inner choroid using EDI-OCT may allow noninvasive assessment of inflammatory status. Ophthalmology 2014;-:1e8 ª 2014 by the American Academy of Ophthalmology. Supplemental material is available at www.aaojournal.org.

Punctate inner choroidopathy (PIC), a disease that typically affects young myopic women, is characterized by the development of multiple, small, yellow-white spots in the posterior pole of each eye.1e3 These “PIC lesions” are thought to occur at the level of the inner choroid and retinal pigment epithelium (RPE) and develop in the absence of clinically apparent intraocular inflammation. After a few weeks, these acute PIC lesions resolve, leaving atrophic spots with variable pigmentation. In many patients, such resolution leads to improvement or resolution of visual symptoms. However, in approximately 40% of patients, more severe visual loss subsequently occurs, primarily due to development of choroidal neovascularization (CNV).1e4  2014 by the American Academy of Ophthalmology Published by Elsevier Inc.

In recent years, the advent of intravitreal anti-angiogenic therapies has greatly improved the treatment options for patients with PIC who develop CNV.4e9 Despite this, the underlying pathophysiology of the disorder remains poorly understood. For example, during the acute phase, patients often have photopsia and visual field defects out of proportion to lesion size and extent,1,10 thus suggesting the presence of more widespread disease than is clinically evident (in fact, widespread focal areas of choroidal hypofluorescence may be seen on indocyanine green angiography).11 Furthermore, in the continued absence of clinicopathologic correlative studies, the nature of the acute PIC lesionsdand their role in CNV developmentdremains unclear (on fluorescein ISSN 0161-6420/14/$ - see front matter http://dx.doi.org/10.1016/j.ophtha.2014.03.011

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Ophthalmology Volume -, Number -, Month 2014 angiography, these lesions show early hyperfluorescence with late staining).3 However, recent advances in optical coherence tomography (OCT) imaging offer some exciting opportunities to address these issues. In patients with uveitic disease, OCT is most commonly used for the evaluation of cystoid macular edema,12,13 although its use for diagnosis and phenotyping has increased in recent years.14 A recent case report described the evolution of an acute multifocal choroiditis without inflammation that was PIC-like.15 Despite this, the OCT features of PIC have not been extensively evaluated. For the most part, the use of OCT in PIC studies has been restricted to assessment of treatment response in patients with CNV.5,7,16 More recently, a small number of studies have attempted to evaluate PIC lesion characteristics in the absence of CNV.17e19 Although these studies have used the latest generation of spectral domain OCT technology, the rarity of the disease means that their patient numbers are small (i.e., case reports or small case series). Furthermore, as a result of limitations with conventional OCT scanning, these studies have been unable to comprehensively evaluate disease features of the choroid. Given that PIC has long been regarded as a disease of the inner choroiddthus the namedthis represents a significant shortcoming. In 2008, however, Spaide et al,20 described a method by which OCT scanning protocols could be modified to permit direct visualization of the choroid, socalled enhanced depth imaging (EDI) OCT.20 Since this seminal work, EDI-OCT has been used to evaluate the choroid in a variety of conditions, with examples including high myopia and Vogt-Koyanagi-Harada (VKH) disease.21,22 In this report, we describe the use of EDI-OCT to perform an enhanced characterization of morphologic abnormalities in a large cohort of patients with PIC. Furthermore, we apply customized image analysis software to perform quantitative analysis of retinal and choroidal thickness in this cohort of patients with PIC. To avoid bias in the assessment and interpretation of retinal and choroidal parameters in EDI-OCT scans, only patients with clinically inactive PIC were included in the study.

Methods Inclusion Criteria and Clinical Demographic Data Clinical and imaging data were collected retrospectively from patients attending 2 tertiary referral uveitis clinics (M.C.W., C.E.P.) over a 5-month period. Patients with a clinical diagnosis of PIC who had undergone EDI-OCT according to a set protocol were included. The criteria used for the diagnosis of PIC at Moorfields Eye Hospital have been described in detail elsewhere.2 Briefly, eyes with “typical” PIC had predominantly small lesions confined to the vascular arcades, whereas those eyes with “atypical” PIC demonstrated larger lesions with a peripapillary distribution. Clinical and demographic data were obtained from patient records and included age, sex, refraction (high myopia was defined as 6 diopters [D]), best-corrected visual acuity (BCVA), type of disease, disease duration, disease activity, current systemic treatment, previous intravitreal treatments with antievascular

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endothelial growth factor drugs, and history of CNV. This study was approved by the local ethics committee for Moorfields Eye Hospital and was conducted in adherence to the tenets set forth in the Declaration of Helsinki.

Enhanced Depth Imaging-Optical Coherence Tomography Image Acquisition Protocol All OCT image sets were acquired using the Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) with custom EDI scanning protocols. This device allows for near infrared (NIR) fundus photographs, with a 55 field of view, to be obtained simultaneously with registered OCT images. Each EDI-OCT image set consisted of 7 OCT B-scans obtained in a 20 5 horizontal raster pattern centered in the fovea; each individual B-scan was generated from 50 averaged scans (Fig 1, available at www.aaojournal.org). For inclusion in the study, all OCT image sets had to be of sufficient quality to allow visualization of the retinal and choroidal layers for qualitative and quantitative analyses. In the case of the accompanying NIR fundal images, inclusion required the optic disc and vasculature to be in optimal confocal plane with well-defined edges.

Image Analysis Qualitative Analysis. The number of visible PIC lesions was then counted using macula-centered NIR fundal images (55 field of view). Only those lesions that were included in the 7 raster OCT scans covering the 20 5 scanned area were selected for analysis. The OCT lesions that could be interpreted as previously active CNV were classified as “definitely CNV” or “questionably CNV”; were correlated with previous clinical records, color fundus photographs, and fluorescein angiography images; and were excluded from qualitative analysis. Location of definite CNV lesions was addressed with these clinical data as subfoveal, juxtafoveal, and extrafoveal for subgroup analysis purposes. Each PIC lesion included in OCT image sets was then evaluated for the following changes in retinal morphology: (1) focal elevation of the RPE (with underlying hyporeflective space between the RPE and Bruch’s membrane and increased penetration of light through the inner choroid), (2) focal atrophy of the outer retina/RPE, and (3) presence of sub-RPE deposits (with hyperreflective signal within the lesion). These retinal features have been described in OCT studies of PIC.17e19 Choroidal morphology was then assessed, including (1) presence of focal hyperreflective dots in the inner choroid and (2) focal thinning of the choroid adjacent to PIC lesions. No choroidal features have been consistently reported in OCT in patients with PIC. Examples of each retinal and choroidal morphologic feature are illustrated in Figure 2. Quantitative Analysis. Quantitative analysis of EDI-OCT images was performed using custom software (OCTOR; Doheny Image Reading Center, Los Angeles, CA). This software first allows manual delineation of any morphologic compartment of interest and then provides detailed quantitative analysis of this compartment. Its use has been described and validated in previous reports.23e26 For the purposes of this study, boundaries for the neurosensory retina, RPE plus subretinal deposits, and choroid were manually segmented in the 7-line raster EDI-OCT scans covering a 20 5 area centered in the foveal region (Fig 3B). The choroidal layer was further subdivided into Haller’s large vessel and Sattler’s medium vessel layers (on OCT, the walls of blood vessels appear hyperreflective, and their lumens appear hyporeflective) (Fig 3C). Haller’s large vessel layer was defined as a space consisting of large hyporeflective areas (where the luminal-to-vessel wall ratio is >50%). The outer boundary of this space is the choroidal-scleral junction, and the

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Novel EDI-OCT Features of Punctate Inner Choroidopathy

Figure 2. Qualitative analysis of punctate inner choroidopathy (PIC) lesions by optical coherence tomography. A, Retinal pigment epithelium (RPE) elevation with underlying hyporeflective space between the RPE and Bruch’s membrane and increased penetration of light through the inner choroid. B, Focal disruption of outer retinal layers and RPE atrophy, with increased penetration of light through the inner choroid. C, Sub-RPE deposit with hyperreflective signal within the lesion (similar reflectivity to RPE). D, Multiple hyperreflective dots in the inner choroid. E, Focal choroidal thinning localized beneath atrophic PIC lesion.

inner boundaries are the edges of the large vessel walls. Sattler’s medium vessel layer has a mottled appearance on OCT, consisting of equivalent hyporeflective and hyperreflective areas (a lumen-to-vessel wall ratio of 50%). Sattler’s layer also included the thin layer of choriocapillaris because current OCT technology does not allow for delineation of these layers separately25,27 and Sattler’s layer is demarcated by the inner boundary of Haller’s layer wall and the outer border of the RPE. The mean thickness (micrometer) of these layers was calculated both at the foveal center (fovea was defined as Early Treatment Diabetic Retinopathy Study central subfield) and across the entirety of the OCT scanning area (i.e., a 20 5 horizontal raster pattern centered on the fovea, macula was defined as total scanned area).

Statistical Analysis Descriptive, frequency statistics, and the chi-square test were used to assess qualitative variables. In cases of bilateral disease, a single eye was selected using permuted block randomization for analysis. Normality of quantitative variables was examined using histograms. Snellen BCVA was converted to logarithm of the minimum angle of resolution (logMAR) equivalents for the purposes of statistical analysis. Subgroup analysis also was performed in eyes with high myopia, defined as a refractive error 6 D. The independent-samples t test, Pearson’s correlation coefficient, and partial correlation coefficient were used when variables were normally distributed, and the ManneWhitney U test and Spearman’s correlation coefficient were used when nonparametric tests were required. A P value less than 0.05 was considered statistically significant. All statistical analyses were performed using SPSS 15.0 software (SPSS Inc., Chicago, IL).

Results Baseline Characteristics and Clinical Features Electronic records of 2242 patients with uveitis were screened, and 46 patients with a clinical diagnosis of PIC were identified. Thirtyfive eyes from 35 patients had EDI-OCT images that met the inclusion criteria. The baseline characteristics and clinical features of this patient cohort are summarized in Table 1 (available at ww.aaojournal.org). The mean age
standard deviation was 40.1
9.4 years (range, 21e60 years), with an 8:1 female-to-male ratio (82.8%). The mean refractive error was 4.5
4.1 D, BCVA was 0.33
0.47 logMAR units (Snellen equivalent of 20/47
4.7 lines), and mean duration of disease was 61.0
48.6 months. Twenty-four patients presented with bilateral disease (68.5%), and 11 patients had unilateral disease (31.4%). Of the total cohort, 29 patients (82.8%) had a history of CNV; in 22 of these patients CNV development was unilateral, whereas in the remaining 7 patients bilateral CNV occurred. No differences were observed in CNV characteristics or location among the study groups. In the current study, no patients had active CNV at EDI-OCT acquisition or in the preceding 3 months. Eighteen patients (51.4%) were receiving immunosuppressive therapies (oral steroids in 14 [40.0%]; oral steroids plus second-line agents [mycophenolate and azathioprine] in 3 [8.6%]; second-line agent [mycophenolate] in 1 [2.8%]), and 17 patients (48.6%) were no longer receiving treatment. For subgroup analysis purposes, eyes with systemic treatment at the moment of the scan are defined as “treated” eyes, and eyes without systemic treatment are defined as “untreated” eyes. No significant differences between typical and atypical disease were seen for baseline characteristics, CNV frequency, CNV location, or treatment modality.

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Figure 3. Segmentation protocol for quantitative analysis with OCTOR (Doheny Image Reading Center, Los Angeles, CA). A, Raw enhanced depth imaging optical coherence tomography image. B, Boundaries segmented manually with OCTOR: internal limiting membrane, inner boundary of retinal pigment epithelium (RPE), outer boundary of RPE plus sub-RPE deposits, boundary between Sattler’s medium vessel layer and Haller’s large vessel layer, and outer boundary of choroid. C, Spaces of interest defined by above boundaries: retina, RPE plus sub-RPE deposits, and choroid (subsequently subdivided into Sattler’s medium vessel layer and Haller’s large vessel layer). Pink ¼ internal limiting membrane; blue ¼ inner boundary of RPE; orange ¼ outer boundary of RPE plus sub-RPE deposits; yellow ¼ boundary between Sattler’s medium vessel layer and Haller’s large vessel layer; purple ¼ outer boundary of choroid.

Qualitative Analysis of Retinal and Choroidal Morphology In total, 142 PIC lesions were counted from the NIR fundal images. Of these, 90 lesions (63%) were also captured by the 20 5 OCT scanning protocol and included in the qualitative analysis. Retinal Morphology. Among the 3 lesion patterns analyzed, 46.6% of all PIC lesions (42/90) showed focal atrophy of the outer retina, in particular the photoreceptor inner segment/outer segment junction and RPE (Fig 2B). This focal disruption also was associated with atrophic changes affecting the overlying outer nuclear and outer plexiform layers. Some 34.4% of PIC lesions (31/90) consisted of sub-RPE deposits (Fig 2C), and 18.8% (17/ 90) consisted of localized RPE elevations (Fig 2A). In the subgroup analyses, untreated eyes had a trend toward a greater number of sub-RPE deposits (47.0% [16/34] untreated vs. 26.7% [15/56] treated; P ¼ 0.05). Conversely, a trend toward a greater presence of outer retinal atrophy was observed in treated eyes (35.3% [12/34]) compared with untreated eyes (53.6% [30/56]) (P ¼ 0.09) (Table 2, available at www.aaojournal.org; Figs 2 and 4). Choroidal Morphology. Focal hyperreflective dots were seen in Sattler’s medium vessel layer in 68.5% of patients (24/35) (Fig 2D). They were most commonly located directly beneath or adjacent to PIC lesions but were also observed in areas distant from lesions (Fig 4A). These hyperreflective dots appear to be located adjacent to vessel walls or on the luminal surface and were not observed within the hyporeflective luminal vascular

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spaces (Fig 4B). No hyperreflective dots were noted in Haller’s large vessel layer. This feature was more common in eyes with typical PIC (87.5% [14/16]) compared with atypical PIC (57.9% [11/19]), but this difference did not reach statistical significance (P ¼ 0.05). Focal areas of thinning, spanning large and medium vessel layers of the choroid, were observed in 17.1% (6/35) of the eyes (Fig 2E). In most of these cases, these areas were associated with PIC lesions containing outer retinal layer disruption and atrophy (Table 2, available at www. aaojournal.org; Figs 2 and 4).

Quantitative Analysis of Retinal and Choroidal Morphology The mean retinal thickness was 256.04
32.9 mm, and the mean choroidal thickness was 210.52
103.44 mm. The results stratified by disease type and refractive status are included in Tables 3 and 4 (available at www.aaojournal.org). Retinal Thinning in Atypical Disease. The retina was significantly thinner in eyes with atypical PIC (243.73
35.36 mm) compared with typical PIC (270.66
23.22 mm) (P ¼ 0.01). When highly myopic eyes were excluded from analysis, this difference remained significant (246.65
30.2 vs. 270.05
24.6 mm; P ¼ 0.04) (Tables 3 and 4, available at www.aaojournal.org). Thinning of the Choroid and Haller’s Large Vessel Layer in Atypical Punctate Inner Choroidopathy and Highly Myopic Eyes. The choroid was significantly thinner in eyes with atypical PIC (177.77
100.98 mm) versus eyes with typical PIC

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Novel EDI-OCT Features of Punctate Inner Choroidopathy

Figure 4. Clinical cases. A, A 29-year-old woman with bilateral quiescent typical disease: left eye, 5.5 diopters (D), best-corrected visual acuity (BCVA) 0.2 logarithm of the minimum angle of resolution (logMAR), 10 months since the last flare-up, receiving 7.5 mg of oral prednisolone at scan acquisition. Focal disruption and atrophy of outer retinal layers and retinal pigment epithelium (RPE) (*), with increased penetration of light (thick arrow), are seen inferonasal to the fovea. Diffuse hyperreflective dots appear temporal and nasal to the atrophic area (thin arrows). B, A 31-year-old woman with bilateral quiescent typical disease: right eye, 0.5 D, BCVA 0.8 logMAR, 17 months since the last flare-up, not receiving treatment at scan acquisition. An RPE elevation with an underlying sub-RPE hyporeflective space between the RPE and Bruch’s membrane and increased penetration of light through the inner choroid are seen inferotemporal to the fovea (thick arrow). Although the disease status was clinically classified as quiescent, this finding has been reported as a sign of activity in punctate inner choroidopathy lesions. Nasal to this lesion, an area of subretinal hyperreflective deposit consistent with an old subfoveal choroidal neovascularization reported in previous clinical notes also is seen (*); these lesions were systematically excluded from qualitative analysis. Multiple focal hyperreflective dots are seen in the inner choroid (Sattler’s medium vessel layer) on the nasal side of the scan and posterior to previous lesions temporally (thin arrows).

(249.42
95.10 mm) (P ¼ 0.03). This difference was maintained in Haller’s large vessel layer (114.96
61.93 mm in atypical PIC versus 167.68
65.92 mm in typical PIC; P ¼ 0.02). However, when highly myopic eyes were excluded from analysis, this difference was not significant (229.09
98.96 vs. 268.85
84.75 mm; P ¼ 0.29). In eyes with high myopia, the thickness of the choroid and Haller’s and Sattler’s layers was significantly lower compared with eyes with low myopia (P