Yusuke Arai

Applying artificial intelligence to disease staging: Deep learning for improved staging of diabetic retinopathy

Purpose Disease staging involves the assessment of disease severity or progression and is used for treatment selection. In diabetic retinopathy, disease staging using a wide area is more desirable than that using a limited area. We investigated if deep learning artificial intelligence (AI) could be used to grade diabetic retinopathy and determine treatment and prognosis. Methods The retrospective study analyzed 9,939 posterior pole photographs of 2,740 patients with diabetes. Nonmydriatic 45° field color fundus photographs were taken of four fields in each eye annually at Jichi Medical University between May 2011 and June 2015. A modified fully randomly initialized GoogLeNet deep learning neural network was trained on 95% of the photographs using manual modified Davis grading of three additional adjacent photographs. We graded 4,709 of the 9,939 posterior pole fundus photographs using real prognoses. In addition, 95% of the photographs were learned by the modified GoogLeNet. Main outcome measures were prevalence and bias-adjusted Fleiss’ kappa (PABAK) of AI staging of the remaining 5% of the photographs. Results The PABAK to modified Davis grading was 0.64 (accuracy, 81%; correct answer in 402 of 496 photographs). The PABAK to real prognosis grading was 0.37 (accuracy, 96%). Conclusions We propose a novel AI disease-staging system for grading diabetic retinopathy that involves a retinal area not typically visualized on fundoscopy and another AI that directly suggests treatments and determines prognoses.

Correlations between choroidal abnormalities, Lisch nodules, and age in patients with neurofibromatosis type 1.

To evaluate correlations between choroidal abnormalities, Lisch nodules, and age in patients with neurofibromatosis type 1 (NF1), we examined ten cases with NF1 using near-infrared reflectance imaging. Patients ranged in age from 4 to 39 years. The angle used for near-infrared reflectance imaging was 55°. We counted the total number of choroidal abnormalities in an area within a 55° angle centered on the fovea and the total number of Lisch nodules on the iris by slit-lamp examination. No positive correlation was found between the number of Lisch nodules and patient age (Spearman’s rank correlation coefficient ρ=0.117, P=0.7414). Choroidal abnormalities tended to increase with age (ρ=0.6150), but this difference was not statistically significant (P=0.0650). A positive correlation was found between the number of choroidal abnormalities and Lisch nodules (ρ=0.783, P=0.0267). In conclusion, choroidal abnormalities tend to increase with patient age and are correlated with the number of Lisch nodules.

Changes in multiple cytokine concentrations in the aqueous humour of neovascular age-related macular degeneration after 2 months of ranibizumab therapy

Purpose To determine changes in multiple cytokine concentrations in the anterior chamber during the induction phase of ranibizumab treatment in patients with neovascular age-related macular degeneration (AMD). Methods This prospective study included 48 treatment-naïve neovascular AMD eyes of 48 patients who received three consecutive monthly injections of ranibizumab at the Japan Community Health Care Organization Tokyo Shinjuku Medical Center between November 2010 and August 2012. We collected ~0.2 mL aqueous humour before the first and third (2 months later) injections. Controls were 80 eyes with cataracts without retinal disease. The cytokines C-X-C motif chemokine ligand 1 (CXCL1), interferon-γ-induced protein 10 (IP-10), C-X-C motif chemokine ligand 12 (CXCL12), C-X-C motif chemokine ligand 13 (CXCL13), monocyte chemoattractant protein 1 (MCP-1), CCL11, C-C motif chemokine ligand 11 (CCL11), interleukin-6 (IL-6), interleukin-10 (IL-10) and matrix metalloproteinase 9 (MMP-9) were analysed using multiplex cytokine assays. Results Mean ages of the patients with AMD and controls were 73 and 75 years, respectively, and 31 (65%) and 37 (46%) subjects were men, respectively. Polypoidal choroidal vasculopathy was found in 27 eyes (56%). Mean concentrations of cytokines in aqueous humour in patients with neovascular AMD before the first and third ranibizumab injections were as follows (in pg/mL): CXCL1, 8.4 and 3.3; IP-10, 110 and 55; CXCL12, 480 and 240; CXCL13, 9.2 and 2.6; MCP-1, 620 and 220; CCL11, 7.1 and 2.8; IL-6, 5.9 and 1.6; IL-10, 0.15 and 0.015 (all p<0.0001), and MMP-9, 0.92 and 1.5 (p=0.0216), respectively. Concentrations of all cytokines decreased significantly after two consecutive ranibizumab injections, except for MMP-9, which increased significantly. Conclusions After two monthly consecutive antivascular endothelial growth factor injections, inflammatory cytokine levels in the aqueous humour of the eyes with AMD were strongly suppressed, while MMP-9 levels increased.

Bilateral endogenous Candida albicans subretinal abscess with suspected mixed bacterial infection

Purpose Candida albicans subretinal abscess is extremely rare. To our knowledge, only one unilateral case has been reported. Herein, we report one bilateral case. Mixed bacterial infection was also suspected based on broad-range real-time polymerase chain reaction. Methods A 64-year-old man being treated with oral corticosteroids for interstitial pneumonia visited us for visual loss in the left eye. Best corrected visual acuity (BCVA) was 20/20 in the right eye and 8/200 in the left eye. Funduscopy revealed round yellowish-white subretinal lesions with retinal hemorrhage in both eyes. Results Broad-range polymerase chain reaction of the vitreous fluid from the left eye showed a high copy count of bacterial 16s ribosome RNA. Despite large doses of antibiotics, the abscess expanded and vision decreased to light perception in the left eye. Exenteration of the left eye was performed followed by microscopic examination showing Gram-negative bacilli, and C. albicans was also cultured. Antibiotics and the maximum doses of antifungal drugs were administered. However, the abscess in the right eye expanded, and BCVA decreased to 2/200. Vitrectomy and silicone oil tamponade were performed. Vitreous fluid culture revealed C. albicans. At 16 months follow-up, BCVA was stable at 4/200 with healing of the subretinal abscess under silicone oil. Conclusion Since C. albicans subretinal abscess is extremely rare and there was a concurrent mixed bacterial infection, diagnostic procedures in our bilateral case were more complicated than usual. C. albicans infection should be included in the differential diagnosis of subretinal abscesses.

Visual acuity loss associated with excessive “dry macula” in exudative age-related macular degeneration

Purpose To investigate the correlation between visual acuity and central macular thickness (CMT) and choroidal thickness (CCT) in patients with wet age-related macular degeneration (AMD). Methods In this retrospective analysis, 14 eyes that received >10 ranibizumab injections (based on pro re nata [PRN] regimen) and maintained initial visual acuity gain were analyzed. The following 5 parameters were measured at the foveal center: CMT (distance from the inner limiting membrane [ILM] to Bruch’s membrane); central retinal thickness (CRT; distance from the ILM to the inner limit of the retinal pigment epithelium or subretinal fluid [SRF]); SRF thickness (SRFT); pigment epithelium detachment thickness (PEDT); and CCT. The correlation between the logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) and the 5 parameters was examined with generalized estimating equations. Results CMT, CRT, and CCT were negatively correlated with logMAR BCVA (P=0.031, 0.023, and 0.036, respectively) when only CMT values less than the thickness that maximized visual acuity for each eye were used for the analysis. Each 100-μm reduction in CMT, CRT, or CCT improved logMAR BCVA by −0.1, −0.08, or −0.07, respectively. SRFT and PEDT were not correlated with BCVA. The median CMT that maximized the visual acuity was 230 μm. Conclusion Dry macula with CMT <230 μm was associated with temporary decrease in visual acuity in AMD patients whose visual acuity was maintained with PRN regimen.

Intravitreal aflibercept for exudative age-related macular degeneration with good visual acuity: 2-year results of a prospective study

Purpose We report the 2-year outcomes of intravitreal aflibercept (IVA) for exudative age-related macular degeneration (AMD) with good visual acuity (VA) and examine the baseline factors associated with good visual outcome. Materials and methods This multicenter, prospective study evaluated 39 eyes (39 AMD patients) enrolled from August 2013 to August 2014 at 12 and 24 months. Only patients with initial best-corrected VA (BCVA) >0.3 logarithm of the minimum angle of resolution (20/40 Snellen) were eligible. Three consecutive monthly IVA injections were followed by 2 monthly injections for 12 months. Thereafter, patients received injections on a treat- and-extend regimen for up to 24 months. Outcome measures included BCVA and central macular thickness (CMT) at 12 and 24 months. Post hoc analysis, BCVA, and CMT were evaluated by AMD types (typical AMD [tAMD], type 1, and type 2 polypoidal choroidal vasculopathy [PCV]). Baseline characteristics and BCVA associations were evaluated with linear regression analysis and Student’s t-test. Results Mean age was 69 years and 26 of 39 eyes were male. tAMD, type 1 and type 2 PCV occurred in 18, 12, and 9 eyes, respectively. Baseline mean BCVA was 0.097 logarithm of the minimum angle of resolution (20/25 Snellen) and showed significant improvement to 0.058 (20/22 Snellen, P=0.03) at 12 months and 0.066 (20/23) at 24 months. CMT improved significantly from 320 (99) µm (mean [SD]) to 250 (93) µm (P=0.002) at 12 months and 240 (93) µm (P=0.0005) at 24 months. BCVA and CMT were not significantly different among the three groups. Only subretinal hemorrhage (SRH) was significantly associated with improved BCVA. BCVA change from baseline was −0.12 with SRH and −0.011 without SRH (P=0.017) at 12 months. Conclusion IVA showed good efficacy for exudative AMD with good VA at 24 months. tAMD and type 1 and 2 PCV showed similar prognosis. Baseline SRH predicted favorable long-term vision in AMD with good VA.

Stocker's line in pterygium

Pterygium is a fibrovascular proliferative disorder in which conjunctival tissue grows medially to cover the clear cornea. It is well known that outdoor work in situations with high light reflectivity enhances pterygium development. Surgical resection is not always necessary for patients without visual disturbance or cosmetic complaint. A 63yearold woman presented with a 5year history of a slow growing wingshaped ocular surface lesion in the left eye. Her best corrected visual acuity was 1.2 in the right eye and .9 in the left eye. On slitlamp examination showed marked pterygium that extend from the nasal side of bulbar conjunctiva onto the cornea in the left eye. A vertical gold leaflike line was also detected at the head of pterygium (Figure 1 arrow). Inferior conjunctival autograft transplantation was performed. One year after the surgery, there was no evidence of recurrence (Figure 2). Her left visual acuity improved to 1.2. A vertical line at the head of pterygium has been termed Stocker’s line.1–4 The lesion consisted of corneal linear iron deposition.3,4 Several