Publications

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Silva RNE, Chiou CA, Wang M, Wang H, Shoji MK, Chou JC, D'Souza EE, Greenstein SH, Brauner SC, Alves MR, Pasquale LR, Shen LQ. Microvasculature of the Optic Nerve Head and Peripapillary Region in Patients With Primary Open-Angle Glaucoma. J Glaucoma 2019;28(4):281-288.Abstract
PURPOSE: To assess optic nerve head (ONH) and peripapillary microvasculature in primary open-angle glaucoma (POAG) of mild to moderate severity using swept-source optical coherence tomography angiography (OCTA). MATERIALS AND METHODS: In a cross-sectional study, swept-source OCTA images were analyzed for 1 eye from each of 30 POAG patients with glaucomatous Humphrey visual field loss and 16 controls. The anatomic boundary of ONH was manually delineated based on Bruch's membrane opening and large vessels were removed from en face angiography images to measure vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS), suggestive of flow, in the ONH and peripapillary region. POAG subgroup analysis was performed based on a history of disc hemorrhage (DH) matched by visual field mean deviation (MD). RESULTS: POAG (mean MD±SD, -3.3±3.0 dB) and control groups had similar demographic characteristics and intraocular pressure on the day of imaging. Groups did not differ in superficial ONH VD or flow indicated by IOS (P≥0.28). POAG eyes showed significantly lower VD (39.4%±4.0%) and flow (38.8%±5.6%) in deep ONH, peripapillary VD (37.9%±2.9%) and flow (43.6%±4.0%) compared with control eyes (44.1%±5.1%, 44.7%±6.9%, 40.7%±1.7%, 47.8%±2.5%, respectively; P≤0.007 for all). In the subgroup analysis, POAG eyes with (n=14) and without DH (n=16) had similar measured OCTA parameters (P>0.99 for all). CONCLUSIONS: The image processing methodology based on the anatomic boundary of ONH demonstrated compromised microvasculature in the deep ONH and peripapillary region in eyes with mild to moderate POAG, regardless of the history of DH.
Silva RNE, Shen LQ, Chiou CA, Shanbhag SS, Paschalis EI, Pasquale LR, Colby KA, Dohlman CH, Chodosh J, Alves MR. Glaucoma Management in Patients with Aniridia and Boston Type 1 Keratoprosthesis. Am J Ophthalmol 2019;Abstract
PURPOSE: To assess outcomes and glaucoma management in eyes with aniridia following Boston type 1 Keratoprosthesis (KPro) implantation. DESIGN: Retrospective, interventional comparative case series. METHODS: POPULATION: Patients with aniridia and patients with other preoperative diagnoses (excluding Stevens-Johnson syndrome, mucous membrane pemphigoid, and congenital disorders) who underwent KPro implantation at Massachusetts Eye and Ear with at least 2 years of follow-up. One eye per patient was selected based on the longer follow-up time. MAIN OUTCOME: Intermediate and long-term outcomes related to glaucoma. RESULTS: The aniridia (n=22) and comparison (n=61) groups had similar preoperative visual acuity (VA, mean ± standard deviation, 1.86±0.52 LogMAR, p=0.33) and follow-up time (65.6±26.3 months, p=0.25). Prior to KPro implantation, eyes with aniridia had more glaucoma (76.2%) and glaucoma surgery (57.1%) than comparison eyes (51.8%, p=0.053; 23.2%, p=0.005, respectively). More Ahmed valves were co-implanted with KPro in aniridia (47.6%) versus comparison eyes (17.9%, p=0.008). At final follow-up, more aniridia eyes had glaucoma (90.5%) than comparison eyes (64.3%, p=0.02), but the two groups had similar percentages of eyes with cup-to-disc ratio (CDR) >0.8 (23.8% vs. 30.4%, p=0.57) or CDR progression of ≥0.2 (42.9% vs. 44.6%, p=0.89, respectively). None of the eyes with prophylactic tube implantation developed glaucoma. Eyes with and without aniridia did not differ in post-KPro VA improvement (72.7%, 72.1%, p=0.96), and final VA (1.28±0.79 LogMAR, 1.23±0.98 LogMAR, p=0.51). CONCLUSION: Despite a higher glaucoma prevalence, eyes with aniridia achieved similar VA as comparison eyes with more than 5 years of mean follow-up time. Boston KPro offers satisfactory visual rehabilitation in aniridia when glaucoma is managed aggressively.
Silva PS, Aiello LP. Telemedicine and eye examinations for diabetic retinopathy: a time to maximize real-world outcomes. JAMA Ophthalmol 2015;133(5):525-6.
Silva PS, Zhang D, Jacoba CMP, Fickweiler W, Lewis D, Leitmeyer J, Curran K, Salongcay RP, Doan D, Ashraf M, Cavallerano JD, Sun JK, Peto T, Aiello LP. Automated Machine Learning for Predicting Diabetic Retinopathy Progression From Ultra-Widefield Retinal Images. JAMA Ophthalmol 2024;142(3):171-177.Abstract
IMPORTANCE: Machine learning (ML) algorithms have the potential to identify eyes with early diabetic retinopathy (DR) at increased risk for disease progression. OBJECTIVE: To create and validate automated ML models (autoML) for DR progression from ultra-widefield (UWF) retinal images. DESIGN, SETTING AND PARTICIPANTS: Deidentified UWF images with mild or moderate nonproliferative DR (NPDR) with 3 years of longitudinal follow-up retinal imaging or evidence of progression within 3 years were used to develop automated ML models for predicting DR progression in UWF images. All images were collected from a tertiary diabetes-specific medical center retinal image dataset. Data were collected from July to September 2022. EXPOSURE: Automated ML models were generated from baseline on-axis 200° UWF retinal images. Baseline retinal images were labeled for progression based on centralized reading center evaluation of baseline and follow-up images according to the clinical Early Treatment Diabetic Retinopathy Study severity scale. Images for model development were split 8-1-1 for training, optimization, and testing to detect 1 or more steps of DR progression. Validation was performed using a 328-image set from the same patient population not used in model development. MAIN OUTCOMES AND MEASURES: Area under the precision-recall curve (AUPRC), sensitivity, specificity, and accuracy. RESULTS: A total of 1179 deidentified UWF images with mild (380 [32.2%]) or moderate (799 [67.8%]) NPDR were included. DR progression was present in half of the training set (590 of 1179 [50.0%]). The model's AUPRC was 0.717 for baseline mild NPDR and 0.863 for moderate NPDR. On the validation set for eyes with mild NPDR, sensitivity was 0.72 (95% CI, 0.57-0.83), specificity was 0.63 (95% CI, 0.57-0.69), prevalence was 0.15 (95% CI, 0.12-0.20), and accuracy was 64.3%; for eyes with moderate NPDR, sensitivity was 0.80 (95% CI, 0.70-0.87), specificity was 0.72 (95% CI, 0.66-0.76), prevalence was 0.22 (95% CI, 0.19-0.27), and accuracy was 73.8%. In the validation set, 6 of 9 eyes (75%) with mild NPDR and 35 of 41 eyes (85%) with moderate NPDR progressed 2 steps or more were identified. All 4 eyes with mild NPDR that progressed within 6 months and 1 year were identified, and 8 of 9 (89%) and 17 of 20 (85%) with moderate NPDR that progressed within 6 months and 1 year, respectively, were identified. CONCLUSIONS AND RELEVANCE: This study demonstrates the accuracy and feasibility of automated ML models for identifying DR progression developed using UWF images, especially for prediction of 2-step or greater DR progression within 1 year. Potentially, the use of ML algorithms may refine the risk of disease progression and identify those at highest short-term risk, thus reducing costs and improving vision-related outcomes.
Silva PS, El-Rami H, Barham R, Gupta A, Fleming A, van Hemert J, Cavallerano JD, Sun JK, Aiello LP. Hemorrhage and/or Microaneurysm Severity and Count in Ultrawide Field Images and Early Treatment Diabetic Retinopathy Study Photography. Ophthalmology 2017;124(7):970-976.Abstract
OBJECTIVE: To evaluate detection of hemorrhage and/or microaneurysm (H/Ma) using ultrawide field (UWF) retinal imaging as compared with standard Early Treatment Diabetic Retinopathy Study (ETDRS) 7-field photographs (ETDRS photos). DESIGN: Single-site comparative study of UWF images and ETDRS photos. PARTICIPANTS: One hundred twenty-six eyes of 69 patients with no diabetic retinopathy (DR) or mild or moderate nonproliferative DR (NPDR). METHODS: Stereoscopic 200° UWF images and stereoscopic 35mm 30° 7-field color photographs were acquired on the same visit. Images were graded for severity and distribution of H/Ma. H/Mas were counted in ETDRS fields 2 to 7 in both ETDRS photos and UWF images. H/Mas in the UWF peripheral fields were also counted. MAIN OUTCOME MEASURES: Kappa (κ) and weighted κ statistics for agreement. Number of H/Ma within and outside ETDRS fields identified in UWF images and ETDRS photos. RESULTS: Distribution of DR severity by ETDRS photos was 24 (19.0%) no DR, 48 (38.1%) mild NPDR, and 54 (42.9%) moderate NPDR. A total of 748 of 756 fields (98.9%) were gradable for H/Mas on ETDRS photos and UWF images. Simple κ/weighted κ statistics for severity of H/Ma: all fields 0.61/0.69, field 2 0.70/0.77, field 3 0.62/0.73, field 4 0.50/0.62, field 5 0.54/0.65, field 6 0.64/0.70, and field 7 0.58/0.63 with overall exact agreement in 81.3% and within 1 step in 97.9% of fields. A greater proportion of fields was graded a more severe H/Ma level in UWF images than in the corresponding ETDRS photos (UWF: 12.7% vs. ETDRS: 6.5%). Evaluating comparable areas in UWF images and ETDRS photos (fields 2-7), a mean of 42.8 H/Mas were identified using ETDRS photos and 48.8 in UWF images (P = 0.10). An additional mean of 21.3 H/Mas (49.8% increase, P < 0.0001) were identified in the peripheral fields of the UWF images. CONCLUSIONS: There is good to excellent agreement between UWF images and ETDRS photos in determining H/Ma severity, with excellent correlation of H/Ma counts within ETDRS photo fields. UWF peripheral fields identified 49.8% more H/Ma, suggesting a more severe H/Ma in 12.7% of eyes. Given the additional lesions detected in peripheral fields and the known risks associated with H/Ma and peripheral lesions, quantification of H/Ma using UWF images may provide a more accurate representation of DR disease activity and potential greater accuracy in predicting DR progression.
Silva RNE, Chiou CA, Wang M, Devlin J, Li D, Lovelace S, Wang H, Greenstein SH, Brauner SC, Shen LQ. Quantification of the Peripapillary Microvasculature in Eyes with Glaucomatous Paracentral Visual Field Loss. Ophthalmol Glaucoma 2021;4(3):286-294.Abstract
PURPOSE: To quantify abnormalities in the peripapillary microvasculature in eyes with primary open-angle glaucoma (POAG) and paracentral visual field (VF) loss. DESIGN: Prospective, cross-sectional study. PARTICIPANTS: Thirty-three POAG patients, including 15 with paracentral VF loss and 18 with peripheral VF loss, and 31 control participants underwent swept-source OCT angiography (OCTA) of the peripapillary region. METHODS: The POAG groups were matched by VF mean deviation (MD). The peripapillary microvasculature from the internal limiting membrane to the retinal nerve fiber layer (RNFL) interface was quantified within a 0.70-mm annulus around Bruch's membrane opening after removal of large vessels. Both vessel density (VD) and the integrated OCTA by ratio analysis signal (IOS) suggestive of flow were measured. Regional VD and IOS were measured from the affected hemisphere corresponding to the VF hemifield of more severe loss, which was used to calculate the paracentral total deviation (PaTD), or total deviation within the central 10°. One eye per participant was included. MAIN OUTCOME MEASURES: Difference in peripapillary OCTA measurements between paracentral and peripheral VF loss groups and correlation of peripapillary VD and IOS with PaTD. RESULTS: The POAG groups had matched VF MD (-3.1 ± 2.5 dB paracentral vs. -2.3 ± 2.0 dB peripheral; P = 0.31), did not differ in average RNFL thickness (71.1 ± 14.7 μm vs. 78.1 ± 15.0 μm; P = 0.55), but differed in age (59.2 ± 9.6 years paracentral vs. 67.4 ± 6.6 years peripheral; P = 0.02). Compared with control participants, both paracentral and peripheral VF loss groups showed reduced VD (P < 0.001 and P = 0.009, respectively) and IOS (P < 0.001 and P = 0.01, respectively) in the affected hemisphere. Compared with POAG eyes with peripheral VF loss, the paracentral group showed reduced peripapillary VD (38.0 ± 2.0%, 35.0 ± 2.2%, respectively; P = 0.001) and IOS (44.3 ± 3.1%, 40.4 ± 4.0%, respectively; P = 0.02) in the affected hemisphere. Among all POAG eyes, peripapillary VD and IOS of the affected hemisphere correlated significantly with functional measurement of paracentral loss (PaTD, r = 0.40, P = 0.02; r = 0.45, P = 0.008; respectively). These correlations remained significant after adjusting for age (r = 0.41, P = 0.02; r = 0.47, P = 0.01; respectively). CONCLUSIONS: Regional peripapillary microvasculature showed decreased VD and flow in POAG with paracentral loss, supporting its importance in this glaucoma subtype.
Silva RNE, Taniguchi EV, Cruzat A, Paschalis EI, Pasquale LR, Colby KA, Dohlman CH, Chodosh J, Shen LQ. Angle Anatomy and Glaucoma in Patients With Boston Keratoprosthesis. Cornea 2020;39(6):713-719.Abstract
PURPOSE: To quantitatively analyze the angle anatomy in eyes with a Boston type 1 keratoprosthesis (KPro) using anterior segment optical coherence tomography (AS-OCT) and to assess the diagnostic ability of AS-OCT in KPro-associated glaucoma. METHODS: AS-OCT (RTVue) images from KPro eyes with and without glaucoma were reviewed. The angle opening distance at 500 μm from the scleral spur (AOD500), trabecular-iris angle at 500 μm from the scleral spur (TIA500), and trabecular-iris surface area at 500 μm from the scleral spur (TISA500) were measured by 2 observers masked to the diagnosis. The measurements for each visible quadrant were compared between KPro eyes with and without glaucoma. RESULTS: Twenty-two eyes with glaucoma and 17 eyes without glaucoma from 39 patients with KPro were included. Of the 4 quadrants imaged, the temporal angle was the most visible (79.5%) and angle measurements of the temporal quadrant were the only ones that differentiated the 2 groups: the mean AOD500, TIA500, and TISA500 were significantly lower in KPro eyes with glaucoma than without glaucoma (388.2 ± 234.4 μm vs. 624.5 ± 310.5 μm, P = 0.02; 26.1 ± 14.0 degrees vs. 39.1 ± 17.1 degrees, P = 0.03; and 0.15 ± 0.09 mm vs. 0.23 ± 0.12 mm, P = 0.03; respectively). The highest area under the receiver operating characteristic curve for detecting glaucoma was 0.75 for temporal TIA500 (95% confidence interval 0.57-0.94, P = 0.02) with 50% specificity at 80% of sensitivity and a cutoff value of 37 degrees. CONCLUSIONS: The temporal angle was the most visible on AS-OCT in eyes with a KPro. Significant narrowing of the temporal angle detected on AS-OCT was associated with glaucoma in these eyes.
da Silva S, Cepko CL. Fgf8 Expression and Degradation of Retinoic Acid Are Required for Patterning a High-Acuity Area in the Retina. Dev Cell 2017;42(1):68-81.e6.Abstract
Species that are highly reliant on their visual system have a specialized retinal area subserving high-acuity vision, e.g., the fovea in humans. Although of critical importance for our daily activities, little is known about the mechanisms driving the development of retinal high-acuity areas (HAAs). Using the chick as a model, we found a precise and dynamic expression pattern of fibroblast growth factor 8 (Fgf8) in the HAA anlage, which was regulated by enzymes that degrade retinoic acid (RA). Transient manipulation of RA signaling, or reduction of Fgf8 expression, disrupted several features of HAA patterning, including photoreceptor distribution, ganglion cell density, and organization of interneurons. Notably, patterned expression of RA signaling components was also found in humans, suggesting that RA also plays a role in setting up the human fovea.
Silva PS, Dela Cruz AJ, Ledesma MG, van Hemert J, Radwan A, Cavallerano JD, Aiello LM, Sun JK, Aiello LP. Diabetic Retinopathy Severity and Peripheral Lesions Are Associated with Nonperfusion on Ultrawide Field Angiography. Ophthalmology 2015;122(12):2465-72.Abstract

PURPOSE: To assess whether the presence of peripheral nonperfusion on ultrawide field (UWF) fluorescein angiography (FA) is associated with diabetic retinopathy (DR) severity and the presence of predominantly peripheral lesions (PPLs). DESIGN: Single-site, cross-sectional, retrospective study. PARTICIPANTS: Sixty-eight eyes of 37 diabetic subjects with or without DR and no history of prior panretinal laser photocoagulation. METHODS: Both 200° UWF images and UWF FA images were acquired at the same visit. Early Treatment Diabetic Retinopathy Study (ETDRS) templates were overlaid digitally based on disc and macula location onto stereographically projected UWF images. Images were evaluated for the presence of PPLs, defined as more than 50% of the graded lesion located outside the ETDRS field in each of the 5 extended fields. The UWF-FA images were evaluated by 2 masked, independent graders for extent of retinal nonperfusion area (NPA) and nonperfusion index (NPI; nonperfused/total gradable area). MAIN OUTCOME MEASURES: Association of NPA and NPI with DR severity and presence of PPLs. RESULTS: Distribution of DR severity was as follows: no DR, 8.8% eyes; mild nonproliferative DR (NPDR), 17.6%; moderate NPDR, 32.4%; severe NPDR, 17.6%; proliferative DR (PDR), 19.1%; and high-risk PDR, 4.4%; with PPL present in 61.8%. There was strong intragrader (r = 0.95) and intergrader (r = 0.86) agreement for NPA. Presence of PPLs was associated with increased NPA (191.8 mm(2) vs. 306.1 mm(2); P = 0.0019) and NPI (0.25 vs. 0.43; P = 0.0003). These relationships remained significant after adjusting for DR severity and diabetes duration. In eyes without PDR (n = 52), increasing NPA and NPI was associated with worsening DR (NPA, P = 0.001; NPI, P = 0.0003). NPA and NPI were not associated with clinically significant macular edema (NPA, P = 0.99; NPI, P = 0.67), nor correlated with visual acuity (NPA, r = 0.14, P = 0.23; NPI, r = 0.24, P = 0.05). CONCLUSIONS: Following a standardized protocol, the evaluation of UWF FA for NPA and NPI is reproducible. Both parameters are correlated highly with the presence of PPLs and DR severity. Given that the presence and extent of PPLs have been associated with increased risks of DR progression, the clinical identification of PPLs may reflect closely the extent of nonperfusion and ischemia, thus accounting for the increased risk of progression.

Silva PS, Liu D, Glassman AR, Aiello LP, Grover S, Kingsley RM, Melia M, Sun JK, Sun JK. ASSESSMENT OF FLUORESCEIN ANGIOGRAPHY NONPERFUSION IN EYES WITH DIABETIC RETINOPATHY USING ULTRAWIDE FIELD RETINAL IMAGING. Retina 2022;42(7):1302-1310.Abstract
PURPOSE: Evaluate association of retinal nonperfusion (NP) on ultrawide field (UWF) fluorescein angiography (FA) with diabetic retinopathy (DR) severity and predominantly peripheral lesions (PPL). METHODS: Multicenter observational study, 652 eyes (361 participants) having nonproliferative DR (NPDR) without center-involved diabetic macular edema in at least one eye. Baseline 200° UWF-color and UWF-FA images were graded by a central reading center for color-PPL and FA-PPL, respectively. UWF-FA was graded for NP index within concentric zones: posterior pole (<10 mm from fovea), midperiphery (10-15 mm), and far periphery (>15 mm). RESULTS: Baseline Early Treatment Diabetic Retinopathy Study DR severity was 31.7% no DR/mild NPDR, 24.1% moderate NPDR, 14.0% moderately severe NPDR, 25.6% severe/very severe NPDR, and 4.6% proliferative DR. Worse DR severity was associated with increased NP index overall (P = 0.002), in the posterior pole (P < 0.001), midperiphery (P < 0.001), and far periphery (P = 0.03). On average, 29.6% of imaged retinal NP was in the posterior pole, 33.7% in midperiphery, and 36.7% in far periphery. Increased NP index was associated with FA-PPL (P < 0.001) but not with color-PPL (P = 0.65). CONCLUSION: Approximately, 70% of NP in diabetic eyes is located outside the posterior pole. Increased NP is associated with the presence of FA-PPL, suggesting UWF-FA may better predict future DR worsening than UWF-color alone.
Silva MD, André C, Bispo PJM. Targeted Killing of Ocular Streptococcus pneumoniae by the Phage Endolysin MSlys. Ophthalmol Sci 2022;2(4):100193.
Silva PS, Gupta A, Ajlan RS, Schlossman DK, Tolson AM, Cavallerano JD, Aiello LP. Ultrawide field scanning laser ophthalmoscopy imaging of lipemia retinalis. Acta Ophthalmol 2017;Abstract
OBJECTIVE: To describe the characteristic retinal features of lipemia retinalis when using ultrawide field scanning laser ophthalmoscopy. MAIN POINTS: We report a case series of three subjects with ultrawide field retinal images showing cream discoloration of the fundus, light salmon-coloured posterior retinal vessels and greyish pink peripheral vasculature. On green-only imaging, many of the vessels appear light rather than typically dark. CONCLUSION: Lipemia retinalis is readily apparent on ultrawide field imaging and illustrates the alterations that systemic diseases may induce in the posterior and peripheral retinal vasculature. Ultrawide field imaging highlights the disparate vascular appearance of the posterior pole and retinal periphery in this condition.
Silva PS, Cavallerano JD, Sun JK, Soliman AZ, Aiello LM, Aiello LP. Peripheral lesions identified by mydriatic ultrawide field imaging: distribution and potential impact on diabetic retinopathy severity. Ophthalmology 2013;120(12):2587-2595.Abstract
OBJECTIVE: To assess diabetic retinopathy (DR) as determined by lesions identified using mydriatic ultrawide field imaging (DiSLO200; Optos plc, Scotland, UK) compared with Early Treatment Diabetic Retinopathy Study (ETDRS) 7-standard field film photography. DESIGN: Prospective comparative study of DiSLO200, ETDRS 7-standard field film photographs, and dilated fundus examination (DFE). PARTICIPANTS: A total of 206 eyes of 103 diabetic patients selected to represent all levels of DR. METHODS: Subjects had DiSLO200, ETDRS 7-standard field film photographs, and DFE. Images were graded for severity and distribution of DR lesions. Discrepancies were adjudicated, and images were compared side by side. MAIN OUTCOME MEASURES: Distribution of hemorrhage and/or microaneurysm (H/Ma), venous beading (VB), intraretinal microvascular abnormality (IRMA), and new vessels elsewhere (NVE). Kappa (κ) and weighted κ statistics for agreement. RESULTS: The distribution of DR severity by ETDRS 7-standard field film photographs was no DR 12.5%; nonproliferative DR mild 22.5%, moderate 30%, and severe/very severe 8%; and proliferative DR 27%. Diabetic retinopathy severity between DiSLO200 and ETDRS film photographs matched in 80% of eyes (weighted κ = 0.74,κ = 0.84) and was within 1 level in 94.5% of eyes. DiSLO200 and DFE matched in 58.8% of eyes (weighted κ = 0.69,κ = 0.47) and were within 1 level in 91.2% of eyes. Forty eyes (20%) had DR severity discrepancies between DiSLO200 and ETDRS film photographs. The retinal lesions causing discrepancies were H/Ma 52%, IRMA 26%, NVE 17%, and VB 4%. Approximately one-third of H/Ma, IRMA, and NVE were predominantly outside ETDRS fields. Lesions identified on DiSLO200 but not ETDRS film photographs suggested a more severe DR level in 10% of eyes. Distribution in the temporal, superotemporal, inferotemporal, superonasal, and inferonasal fields was 77%, 72%, 61%, 65%, and 59% for H/Ma, respectively (P<0.0001); 22%, 24%, 21%, 28%, and 22% for VB, respectively (P = 0.009); 52%, 40%, 29%, 47%, and 36% for IRMA, respectively (P<0.0001), and 8%, 4%, 4%, 8%, and 5% for NVE, respectively (P = 0.03). All lesions were more frequent in the temporal fields compared with the nasal fields (P<0.0001). CONCLUSIONS: DiSLO200 images had substantial agreement with ETDRS film photographs and DFE in determining DR severity. On the basis of DiSLO200 images, significant nonuniform distribution of DR lesions was evident across the retina. The additional peripheral lesions identified by DiSLO200 in this cohort suggested a more severe assessment of DR in 10% of eyes than was suggested by the lesions within the ETDRS fields. However, the implications of peripheral lesions on DR progression within a specific ETDRS severity level over time are unknown and need to be evaluated prospectively.
Sim DA, Keane PA, Tufail A, Egan CA, Aiello LP, Silva PS. Automated retinal image analysis for diabetic retinopathy in telemedicine. Curr Diab Rep 2015;15(3):14.Abstract

There will be an estimated 552 million persons with diabetes globally by the year 2030. Over half of these individuals will develop diabetic retinopathy, representing a nearly insurmountable burden for providing diabetes eye care. Telemedicine programmes have the capability to distribute quality eye care to virtually any location and address the lack of access to ophthalmic services. In most programmes, there is currently a heavy reliance on specially trained retinal image graders, a resource in short supply worldwide. These factors necessitate an image grading automation process to increase the speed of retinal image evaluation while maintaining accuracy and cost effectiveness. Several automatic retinal image analysis systems designed for use in telemedicine have recently become commercially available. Such systems have the potential to substantially improve the manner by which diabetes eye care is delivered by providing automated real-time evaluation to expedite diagnosis and referral if required. Furthermore, integration with electronic medical records may allow a more accurate prognostication for individual patients and may provide predictive modelling of medical risk factors based on broad population data.

Simavli H, Poon LY-C, Que CJ, Liu Y, Akduman M, Tsikata E, de Boer JF, Chen TC. Diagnostic Capability of Peripapillary Retinal Volume Measurements in Glaucoma. J Glaucoma 2017;26(6):592-601.Abstract
PURPOSE: To determine the diagnostic capability of spectral domain optical coherence tomography peripapillary retinal volume (RV) measurements. MATERIALS AND METHODS: A total of 156 patients, 89 primary open-angle glaucoma and 67 normal subjects, were recruited. Spectral domain optical coherence tomography peripapillary RV was calculated for 4 quadrants using 3 annuli of varying scan circle diameters: outer circumpapillary annuli of circular grids 1, 2, and 3 (OCA1, OCA2, OCA3). Area under the receiver operating characteristic curves and pairwise comparisons of receiver operating characteristic (ROC) curves were performed to determine which quadrants were best for diagnosing primary open-angle glaucoma. The pairwise comparisons of the best ROC curves for RV and retinal nerve fiber layer (RNFL) were performed. The artifact rates were analyzed. RESULTS: Pairwise comparisons showed that the smaller annuli OCA1 and OCA2 had better diagnostic performance than the largest annulus OCA3 (P<0.05 for all quadrants). OCA1 and OCA2 had similar diagnostic performance, except for the inferior quadrant which was better for OCA1 (P=0.0033). The pairwise comparisons of the best ROC curves for RV and RNFL were not statistically significant. RV measurements had lower rates of artifacts at 7.4% while RNFL measurements had higher rates at 42.9%. CONCLUSIONS: Peripapillary RV measurements have excellent ability for diagnosing not only glaucoma patients but also a subset of early glaucoma patients. The inferior quadrant of peripapillary annulus OCA1 demonstrated the best diagnostic capability for both glaucoma and early glaucoma. The diagnostic ability of RV is comparable with that of RNFL parameters in glaucoma but with lower artifact rates.
Simavli H, Que CJ, Akduman M, Rizzo JL, Tsikata E, de Boer JF, Chen TC. Diagnostic capability of peripapillary retinal thickness in glaucoma using 3D volume scans. Am J Ophthalmol 2015;159(3):545-56.e2.Abstract

PURPOSE: To determine the diagnostic capability of spectral-domain optical coherence tomography (SD OCT) peripapillary retinal thickness (RT) measurements from 3-dimensional (3D) volume scans for primary open-angle glaucoma (POAG). DESIGN: Cross-sectional study. METHODS: setting: Institutional. study population: 156 patients (89 POAG and 67 normal subjects). observation procedures: One eye of each subject was included. SD OCT peripapillary RT values from 3D volume scans were calculated for 4 quadrants of 3 different sized annuli. Peripapillary retinal nerve fiber layer (RNFL) thickness values were also determined. main outcome measures: Area under the receiver operating characteristic curve (AUROC) values, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios. RESULTS: The top 5 RT AUROCs for all glaucoma patients and for a subset of early glaucoma patients were for the inferior quadrant of outer circumpapillary annulus of circular grid (OCA) 1 (0.959, 0.939), inferior quadrant of OCA2 (0.945, 0.921), superior quadrant of OCA1 (0.890, 0.811), inferior quadrant of OCA3 (0.887, 0.854), and superior quadrant of OCA2 (0.879, 0.807). Smaller RT annuli OCA1 and OCA2 consistently showed better diagnostic performance than the larger RT annulus OCA3. For both RNFL and RT measurements, best AUROC values were found for inferior RT OCA1 and OCA2, followed by inferior and overall RNFL thickness. CONCLUSION: Peripapillary RT measurements from 3D volume scans showed excellent diagnostic performance for detecting both glaucoma and early glaucoma patients. Peripapillary RT values have the same or better diagnostic capability compared to peripapillary RNFL thickness measurements, while also having fewer algorithm errors.

Simcoe MJ, Shah A, Fan BJ, Choquet H, Weisschuh N, Waseem NH, Jiang C, Melles RB, Ritch R, Mahroo OA, Wissinger B, Jorgenson E, Wiggs JL, Garway-Heath DF, Hysi PG, Hammond CJ. Genome-Wide Association Study Identifies Two Common Loci Associated with Pigment Dispersion Syndrome/Pigmentary Glaucoma and Implicates Myopia in its Development. Ophthalmology 2022;129(6):626-636.Abstract
PURPOSE: To identify genetic variants associated with pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) in unrelated patients and to further understand the genetic and potentially causal relationships between PDS and associated risk factors. DESIGN: A 2-stage genome-wide association meta-analysis with replication and subsequent in silico analyses including Mendelian randomization. PARTICIPANTS: A total of 574 cases with PG or PDS and 52 627 controls of European descent. METHODS: Genome-wide association analyses were performed in 4 cohorts and meta-analyzed in 3 stages: (1) a discovery meta-analysis was performed in 3 cohorts, (2) replication was performed in the fourth cohort, and (3) all 4 cohorts were meta-analyzed to increase statistical power. Two-sample Mendelian randomization was used to determine whether refractive error and intraocular pressure exert causal effects over PDS. MAIN OUTCOME MEASURES: The association of genetic variants with PDS and whether myopia exerts causal effects over PDS. RESULTS: Significant association was present at 2 novel loci for PDS/PG. These loci and follow-up analyses implicate the genes gamma secretase activator protein (GSAP) (lead single nucleotide polymorphism [SNP]: rs9641220, P = 6.0×10-10) and glutamate metabotropic receptor 5 (GRM5)/TYR (lead SNP: rs661177, P = 3.9×10-9) as important factors in disease risk. Mendelian randomization showed significant evidence that negative refractive error (myopia) exerts a direct causal effect over PDS (P = 8.86×10-7). CONCLUSIONS: Common SNPs relating to the GSAP and GRM5/TYR genes are associated risk factors for the development of PDS and PG. Although myopia is a known risk factor, this study uses genetic data to demonstrate that myopia is, in part, a cause of PDS and PG.
Simmons NL, Robb RM, Tybor DJ, Gilbert AL. Older age and larger cyst size in children with spontaneous rupture of periorbital dermoid cysts. J AAPOS 2019;Abstract
We analyzed clinical and histopathologic data of 97 pediatric patients who underwent excision of dermoid cysts. On review, 16.5% of the sample population demonstrated localized chronic inflammatory changes, including the presence of giant cells and epithelial disruption. These features were considered indicative of prior cyst rupture. Age at time of initial presentation was significantly older and cyst size was significantly larger in patients with histopathologic signs of previous rupture. Longer time to presentation and time to excision were associated with increased odds of spontaneous rupture.
Simon SS, Chee YE, Haddadin RI, Veldman PB, Borboli-Gerogiannis S, Brauner SC, Chang KK, Chen SH, Gardiner MF, Greenstein SH, Kloek CE, Chen TC. Achieving target refraction after cataract surgery. Ophthalmology 2014;121(2):440-4.Abstract
PURPOSE: To evaluate the difference between target and actual refraction after phacoemulsification and intraocular lens implantation at an academic teaching institution's Comprehensive Ophthalmology Service. DESIGN: Retrospective study. PARTICIPANTS: We examined 1275 eye surgeries for this study. METHODS: All consecutive cataract surgeries were included if they were performed by an attending or resident surgeon from January through December 2010. Postoperative refractions were compared with preoperative target refractions. Patients were excluded if they did not have a preoperative target refraction documented or if they did not have a recorded postoperative manifest refraction within 90 days. MAIN OUTCOME MEASURES: The main outcome measure was percentage of cases achieving a postoperative spherical equivalent ± 1.0 diopter (D) of target spherical equivalent. RESULTS: We performed 1368 cataract surgeries from January through December of 2010. Of these, 1275 (93%) had sufficient information for analysis. Of the included cases, 94% (1196 of 1275) achieved ± 1.0 D of target refraction by 90 days after cataract surgery. CONCLUSIONS: This paper establishes a new benchmark for a teaching hospital, where 94% of patients achieved within 1.0 D of target refraction after cataract surgery. The refractive outcomes after cataract surgery at this academic teaching institution were higher than average international benchmarks.
Simpson FC, Islam MM, Buznyk O, Edin E, Groleau M, Kozak-Ljunggren M, Magrelli FM, AbuSamra DB, Argüeso P, Chodosh J, Liszka A, Fagerholm P, Griffith M. Electron-Beam Irradiated Recombinant Human Collagen-Phosphorylcholine Corneal Implants Retain Pro-Regeneration Capacity. Front Bioeng Biotechnol 2022;10:883977.Abstract
Sterilization of biodegradable, collagen-based implants is challenging as irradiation sterilization methods can alter their mechanical properties. Electron beam (EB) irradiation is a terminal sterilization method that has been used for biologically-derived implants. Here, recombinant human collagen type III-phosphorylcholine (RHCIII-MPC) hydrogels were irradiated with EB doses of 17, 19, or 21 kGy and their subsequent biocompatibility and ability to promote regeneration in rabbit corneas was evaluated. Unirradiated hydrogels stored in 1% chloroform in phosphate-buffered saline (C-PBS) were the controls. There were no significant differences between irradiated and non-irradiated samples in optical or physical properties (tensile strength, modulus, elasticity), or the ability to support cell growth. However, irradiated implants were more sensitive to high levels of collagenase than unirradiated controls and the C-PBS implants had increased cell growth compared to EB and controls at 72 h. Corneal implants e-beamed at 17 kGy or e-beamed and subsequently frozen (EB-F) to increase shelf-life showed no adverse biological effects of the irradiation. EB, EB-F, and C-PBS implanted corneas all rapidly re-epithelialized but showed mild neovascularization that resolved over 6 months. The regenerated neo-corneas were transparent at 6 months post-operation. In vivo confocal microscopy confirmed normal morphology for the epithelium, stroma, sub-basal nerves and unoperated endothelium. Histology showed that all the regenerated corneas were morphologically similar to the normal. Immunohistochemistry indicated the presence of a differentiated corneal epithelium and functional tear film. In conclusion, the e-beamed corneal implants performed as well as non-irradiated control implants, resulting in fully regenerated neo-corneas with new nerves and without blood vessels or inflammation that may impede vision or corneal function. Therefore, a complete validation study to establish EB irradiation as an effective means for corneal implant sterilization prior to clinical application is necessary as a next step.

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