AQUEOUS HUMOR CYTOKINE LEVELS AS BIOMARKERS OF DISEASE SEVERITY IN DIABETIC MACULAR EDEMA.

PURPOSE: To determine whether aqueous cytokine levels correlate with disease severity in diabetic macular edema. METHODS: A prospective cross-sectional study of 49 adults with diabetes mellitus, centre-involving diabetic macular edema and central subfield macular thickness ≥310 µm on spectral domain optical coherence tomography. Clinical examination and aqueous sampling were carried out before an initial injection of ranibizumab. Multiplex immunoassay of sample was carried out for vascular endothelial growth factor, placental growth factor, transforming growth factor beta, intercellular adhesion molecule-1, interleukin (IL)-2, IL-3, IL-6, IL-8, IL-10, IL-17, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, and epidermal growth factor. Multivariate robust regression models were constructed, and adjusted for age, lens status, or severity of retinopathy, and size of foveal avascular zone. RESULTS: Spectral domain optical coherence tomography macular volume was an excellent measure of disease severity, correlating strongly with central subfield macular thickness (P < 0.001), best-corrected Snellen visual acuity (P < 0.001), and baseline diabetic retinopathy severity (P = 0.01). Elevated aqueous intercellular adhesion molecule-1 correlated with greater macular volume (P = 0.002). No aqueous cytokine, including VEGF, correlated with central subfield macular thickness. There was an association between IL-10 levels and best-corrected Snellen visual acuity (P = 0.03). CONCLUSION: Aqueous intercellular adhesion molecule-1 correlates with disease severity as measured by macular volume on spectral domain optical coherence tomography, and IL-10 is associated with BCVA. Intercellular adhesion molecule-1 may be a clinically useful biomarker for diabetic macular edema severity.

VOLUMETRIC ASSESSMENT OF THE RESPONSIVENESS OF PIGMENT EPITHELIAL DETACHMENTS IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION TO INTRAVITREAL BEVACIZUMAB.

PURPOSE: To determine baseline factors that can predict the response of pigment epithelial detachments (PEDs) in neovascular age-related macular degeneration to treatment with intravitreal bevacizumab (IVB). METHODS: Patients with newly diagnosed neovascular age-related macular degeneration and PED who were treated exclusively with IVB were included. Response to treatment was defined by change in PED volume (determined using spectral-domain optical coherence tomography). PEDs were classified as either predominantly serous or fibrovascular. Multivariable regression and receiver operating characteristic analyses were performed. RESULTS: A total of 48 eyes were identified (mean follow-up time 73 weeks). Overall, the response to the first IVB treatment was predictive of the response to treatment at the final visit (P = 0.015). Serous PEDs had a greater decrease in volume at the final visit (P = 0.008). With respect to both PED types, a decrease in PED volume of 21% after the first IVB treatment was predictive of an overall decrease in volume of 30% at the final visit (sensitivity 83%, specificity 76%). CONCLUSION: In neovascular age-related macular degeneration, serous PEDs respond more favorably to IVB than fibrovascular PEDs. Overall, for both types of PED, the response to the first treatment is predictive of the final response to treatment. Taken together, the results would suggest that if there is less than 21% reduction in PED volume after the first IVB treatment, and/or the PED is predominantly fibrovascular, then switching to another antivascular endothelial growth factor agent should be considered.

Choroidal degeneration in birdshot chorioretinopathy.

PURPOSE: The purpose of the study was to determine if progressive choroidal changes occur in birdshot chorioretinopathy (BSCR). METHODS: Retrospective chart review of all patients with BSCR who were seen over a 3-year period. Controls consisted of healthy age-matched and gender-matched patients. Choroidal thickness at baseline and final follow-up visit was measured with the use of optical coherence tomography. Results were analyzed using univariate and multivariable statistical models. RESULTS: A total of 11 patients (22 eyes) with BSCR were identified. The majority of BSCR eyes (86%) had clinically inactive disease. Follow-up ranged from 2 months to 27 months. Mean age was 55 years. Patients with BSCR had significantly thinner choroid compared with controls (P < 0.001). Furthermore, the rate of choroid thinning for patients diagnosed with BSCR (2.68 µm per month) was significantly higher than that of controls (0.27 µm per month) (P = 0.003). There was no statistically significant difference in the rate of choroidal thinning between the two eyes of patients with BSCR (P = 0.859), indicating that the choroidal thinning was symmetrical. CONCLUSION: Despite having clinically inactive uveitis, eyes with BSCR can develop progressive choroidal thinning. The clinical relevance of this choroidal thinning, or degeneration, remains to be fully elucidated.

Exacerbation of choroidal and retinal pigment epithelial atrophy after anti-vascular endothelial growth factor treatment in neovascular age-related macular degeneration.

PURPOSE: To study the progression of retinal pigment epithelium (RPE) and choroidal atrophy in patients with neovascular age-related macular degeneration (AMD) and to assess for a possible association with the number and type of anti-vascular endothelial growth factor treatments. METHODS: Patients with neovascular AMD and a minimum of 1-year follow-up were reviewed. Fellow eyes with nonneovascular AMD were used as control eyes. Retinal pigment epithelial atrophy area and choroidal thickness were determined using spectral-domain optical coherence tomography. Multivariable regression models were used for statistical analyses. RESULTS: A total of 415 eyes were included in the study, with a mean follow-up of 2.2 years. Eyes with neovascular AMD had greater progression of RPE atrophy and choroidal atrophy compared with those with nonneovascular AMD (P < 0.001). Progression of RPE atrophy and choroidal atrophy was independently associated with the total number of injections of bevacizumab and ranibizumab (all P values ≤ 0.001). In the subgroup of 84 eyes with neovascular AMD and without RPE atrophy at baseline, only bevacizumab was associated with the progression of RPE atrophy (P = 0.003). This study likely lacked statistical power to detect an association with ranibizumab in this subgroup. CONCLUSION: Retinal pigment epithelial atrophy and choroidal atrophy in neovascular AMD seem to be exacerbated by anti-vascular endothelial growth factor treatment. Possible differences between bevacizumab and ranibizumab require further investigation.

Optical coherence tomography-based correlation between choroidal thickness and drusen load in dry age-related macular degeneration.

PURPOSE: Spectral domain optical coherence tomography can be used to measure both choroidal thickness and drusen load. The authors conducted an exploratory study using spectral domain optical coherence tomography to determine if a correlation between choroidal thickness and drusen load exists in patients with dry age-related macular degeneration. METHODS: Forty-four patients with dry age-related macular degeneration were recruited. The drusen area and volume were determined using the automated software algorithm of the spectral domain optical coherence tomography device, and choroidal thickness was measured using enhanced depth imaging. Correlations were determined using multivariable and univariable analyses. RESULTS: The authors found an inverse correlation between choroidal thickness and drusen load (r = -0.35, P = 0.04). Drusen load was also correlated with visual acuity (r = 0.32, P = 0.04). A correlation between choroidal thickness and visual acuity was suggested (r = -0.22, P = 0.21). CONCLUSION: Spectral domain optical coherence tomography can be used to assess the correlation between drusen load and choroidal thickness, both of which show a relationship with visual acuity. The measurement of these outcomes may serve as important outcome parameters in routine clinical care and in clinical trials for patients with dry age-related macular degeneration.

Inflammatory ocular adverse events with the use of oral bisphosphonates: a retrospective cohort study.

BACKGROUND: There have been several published reports of inflammatory ocular adverse events, mainly uveitis and scleritis, among patients taking oral bisphosphonates. We examined the risk of these adverse events in a pharmacoepidemiologic cohort study. METHODS: We conducted a retrospective cohort study involving residents of British Columbia who had visited an ophthalmologist from 2000 to 2007. Within the cohort, we identified all people who were first-time users of oral bisphosphonates and who were followed to the first inflammatory ocular adverse event, death, termination of insurance or the end of the study period. We defined an inflammatory ocular adverse event as scleritis or uveitis. We used a Cox proportional hazard model to determine the adjusted rate ratios. As a sensitivity analysis, we performed a propensity-score-adjusted analysis. RESULTS: The cohort comprised 934,147 people, including 10,827 first-time users of bisphosphonates and 923,320 nonusers. The incidence rate among first-time users was 29/10,000 person-years for uveitis and 63/10,000 person-years for scleritis. In contrast, the incidence among people who did not use oral bisphosphonates was 20/10,000 person-years for uveitis and 36/10,000 for scleritis (number needed to harm: 1100 and 370, respectively). First-time users had an elevated risk of uveitis (adjusted relative risk [RR] 1.45, 95% confidence interval [CI] 1.25-1.68) and scleritis (adjusted RR 1.51, 95% CI 1.34-1.68). The rate ratio for the propensity-score-adjusted analysis did not change the results (uveitis: RR 1.50, 95% CI 1.29-1.73; scleritis: RR 1.53, 95% CI 1.39-1.70). INTERPRETATION: People using oral bisphosphonates for the first time may be at a higher risk of scleritis and uveitis compared to people with no bisphosphonate use. Patients taking bisphosphonates must be familiar with the signs and symptoms of these conditions, so that they can immediately seek assessment by an ophthalmologist.

Oral fluoroquinolones and the risk of retinal detachment.

CONTEXT: Fluoroquinolones are commonly prescribed classes of antibiotics. Despite numerous case reports of ocular toxicity, a pharmacoepidemiological study of their ocular safety, particularly retinal detachment, has not been performed. OBJECTIVE: To examine the association between use of oral fluoroquinolones and the risk of developing a retinal detachment. DESIGN, SETTING, AND PATIENTS: Nested case-control study of a cohort of patients in British Columbia, Canada, who had visited an ophthalmologist between January 2000 and December 2007. Retinal detachment cases were defined as a procedure code for retinal repair surgery within 14 days of a physician service code. Ten controls were selected for each case using risk-set sampling, matching on age and the month and year of cohort entry. MAIN OUTCOME MEASURE: The association between retinal detachment and current, recent, or past use of an oral fluoroquinolone. RESULTS: From a cohort of 989,591 patients, 4384 cases of retinal detachment and 43,840 controls were identified. Current use of fluoroquinolones was associated with a higher risk of developing a retinal detachment (3.3% of cases vs 0.6% of controls; adjusted rate ratio [ARR], 4.50 [95% CI, 3.56-5.70]). Neither recent use (0.3% of cases vs 0.2% of controls; ARR, 0.92 [95% CI, 0.45-1.87]) nor past use (6.6% of cases vs 6.1% of controls; ARR, 1.03 [95% CI, 0.89-1.19]) was associated with a retinal detachment. The absolute increase in the risk of a retinal detachment was 4 per 10,000 person-years (number needed to harm = 2500 computed for any use of fluoroquinolones). There was no evidence of an association between development of a retinal detachment and ß-lactam antibiotics (ARR, 0.74 [95% CI, 0.35-1.57]) or short-acting ß-agonists (ARR, 0.95 [95% CI, 0.68-1.33]). CONCLUSION: Patients taking oral fluoroquinolones were at a higher risk of developing a retinal detachment compared with nonusers, although the absolute risk for this condition was small.

Subconjunctival sirolimus in the treatment of diabetic macular edema.

BACKGROUND: Diabetic macular edema (DME) is a leading cause of blindness in the developed world. Sirolimus has been shown to inhibit the production, signaling, and activity of many growth factors relevant to the development of diabetic retinopathy. This phase I/II study assesses the safety of multiple subconjunctival sirolimus injections for the treatment of DME, with some limited efficacy data. METHODS: In this phase I/II prospective, open-label pilot study, five adult participants with diabetic macular edema involving the center of the fovea and best-corrected ETDRS visual acuity score of ≤74 letters (20/32 or worse) received 20 µl (440 µg) of subconjunctival sirolimus at baseline, month 2 and every 2 months thereafter, unless there was resolution of either retinal thickening on OCT or leakage on fluorescein angiography. Main outcome measures included best-corrected visual acuity and central retinal thickness on OCT at 6 months and 1 year, as well as safety outcomes. RESULTS: Repeated subconjunctival sirolimus injections were well-tolerated, with no significant drug-related adverse events. There was no consistent treatment effect related to sirolimus; one participant experienced a 2-line improvement in visual acuity and 2 log unit decrease in retinal thickness at 6 months and 1 year, two remained essentially stable, one had stable visual acuity but improvement of central retinal thickness of 1 and 3 log units at 6 months and 1 year respectively, and one had a 2-line worsening of visual acuity and a 1 log unit increase in retinal thickness at 6 months and 1 year. Results in the fellow eyes with diabetic macular edema, not treated with sirolimus, were similar. CONCLUSIONS: Subconjunctival sirolimus appears safe to use in patients with DME. Assessment of possible treatment benefit will require a randomized trial.

Finasteride for chronic central serous chorioretinopathy.

PURPOSE: To evaluate the safety and efficacy of finasteride, an inhibitor of dihydrotestosterone synthesis, in the treatment of chronic central serous chorioretinopathy. METHODS: Five patients with chronic central serous chorioretinopathy were prospectively enrolled in this pilot study. Patients were administered finasteride (5 mg) daily for 3 months, after which study medication was withheld and patients were observed for 3 months. Main outcome measures included best-corrected visual acuity, central subfield macular thickness, and subretinal fluid volume as assessed by optical coherence tomography. Serum dihydrotestosterone, serum testosterone, and urinary cortisol were also measured. RESULTS: There was no change in mean best-corrected visual acuity. Mean center-subfield macular thickness and subretinal fluid volume reached a nadir at 3 months and rose to levels that were below baseline by 6 months. The changes in both optical coherence tomography parameters paralleled those in serum dihydrotestosterone level. In four patients, center-subfield macular thickness and/or subretinal fluid volume increased after discontinuation of finasteride. In the remaining patient, both optical coherence tomography parameters normalized with finasteride and remained stable when the study medication was discontinued. CONCLUSION: Finasteride may represent a novel medical treatment for chronic central serous chorioretinopathy. Larger controlled clinical trials are needed to further assess the efficacy of finasteride for the treatment of central serous chorioretinopathy.

Relationship between photoreceptor outer segment length and visual acuity in diabetic macular edema.

PURPOSE: The purpose of this study was to quantify photoreceptor outer segment (PROS) length in 27 consecutive patients (30 eyes) with diabetic macular edema using spectral domain optical coherence tomography and to describe the correlation between PROS length and visual acuity. METHODS: Three spectral domain-optical coherence tomography scans were performed on all eyes during each session using Cirrus HD-OCT. A prototype algorithm was developed for quantitative assessment of PROS length. Retinal thicknesses and PROS lengths were calculated for 3 parameters: macular grid (6 x 6 mm), central subfield (1 mm), and center foveal point (0.33 mm). Intrasession repeatability was assessed using coefficient of variation and intraclass correlation coefficient. The association between retinal thickness and PROS length with visual acuity was assessed using linear regression and Pearson correlation analyses. The main outcome measures include intrasession repeatability of macular parameters and correlation of these parameters with visual acuity. RESULTS: Mean retinal thickness and PROS length were 298 mum to 381 microm and 30 microm to 32 mum, respectively, for macular parameters assessed in this study. Coefficient of variation values were 0.75% to 4.13% for retinal thickness and 1.97% to 14.01% for PROS length. Intraclass correlation coefficient values were 0.96 to 0.99 and 0.73 to 0.98 for retinal thickness and PROS length, respectively. Slopes from linear regression analyses assessing the association of retinal thickness and visual acuity were not significantly different from 0 (P > 0.20), whereas the slopes of PROS length and visual acuity were significantly different from 0 (P < 0.0005). Correlation coefficients for macular thickness and visual acuity ranged from 0.13 to 0.22, whereas coefficients for PROS length and visual acuity ranged from -0.61 to -0.81. CONCLUSION: Photoreceptor outer segment length can be quantitatively assessed using Cirrus HD-OCT. Although the intrasession repeatability of PROS measurements was less than that of macular thickness measurements, the stronger correlation of PROS length with visual acuity suggests that the PROS measures may be more directly related to visual function. Photoreceptor outer segment length may be a useful physiologic outcome measure, both clinically and as a direct assessment of treatment effects.

Fundus autofluorescence changes in cytomegalovirus retinitis.

PURPOSE: The purpose of this study was to describe fundus autofluorescence imaging features of cytomegalovirus (CMV) retinitis and to correlate fundus autofluorescence features with clinical activity. METHODS: A retrospective case series was undertaken to evaluate nine eyes of six patients with active CMV retinitis. Patients were evaluated with a comprehensive ophthalmic examination, fundus autofluorescence imaging, and fundus photography. Oral valganciclovir, intravitreal ganciclovir, intravitreal foscarnet, or an ganciclovir implant was administered as clinically indicated. RESULTS: In all nine eyes with active CMV retinitis, a hyperautofluorescent signal on fundus autofluorescence imaging was correlated spatially with the border of advancing CMV retinitis. Stippled areas of alternating hyperautofluorescence and hypoautofluorescence were observed in regions of retinal pigment epithelium atrophy from prior CMV retinitis. In three eyes with subtle CMV reactivation, a hyperautofluorescent border was helpful in the detection and localization of active CMV retinitis. In another patient, diffuse, punctate hyperautofluorescence after intravitreal ganciclovir and foscarnet was a concern for medication-related toxicity. CONCLUSION: Fundus autofluorescence imaging was valuable in highlighting areas of active CMV retinitis in all patients in this series, including two patients with subtle clinical features. Fundus autofluorescence may be useful as an adjunctive imaging modality for the detection of CMV activity and aid in our understanding of the structural changes during episodes of CMV retinitis.

Complementary angiographic and autofluorescence findings in pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is a systemic disease with characteristic findings on fundus examination. The fundus findings may be difficult to detect with ophthalmoscopy. A case report is described as follows. A PXE patient had subtle retinal findings on fundoscopy that were more prominently seen using a combination of both fundus autofluorescence (FAF) imaging and indocyanine green (ICG) angiography. The fundus features visualized using each of these two modalities appeared different from each other. FAF imaging and ICG angiography may be able to more prominently detect pathology at the level of the retinal pigment epithelium and Bruch's membrane, respectively. The use of these imaging modalities together may be complementary and useful in the evaluation of patients with PXE.

INCREASED PHOTORECEPTOR OUTER SEGMENT VOLUME FOLLOWING SYSTEMIC TREATMENT OF BIRDSHOT CHORIORETINOPATHY.

PURPOSE: Retinal degeneration in birdshot chorioretinopathy can be quantified using spectral domain optical coherence tomography by measuring the photoreceptor outer segment (PROS) volume. The purpose of this study was to determine if the PROS volume in BSCR responds to systemic immunomodulatory therapy (IMT). METHODS: Retrospective chart review with analysis of PROS volume derived from spectral domain optical coherence tomography. RESULTS: We identified a total of three patients who met our inclusion criteria. At baseline, all patients had abnormal PROS and/or ellipsoid layer findings on spectral domain optical coherence tomography. After systemic immunomodulatory therapy, these abnormalities improved, and PROS volume increased, in all patients (P < 0.05). CONCLUSION: PROS volume can increase after systemic treatment of birdshot chorioretinopathy. This SD-OCT parameter may serve as a useful marker of retinal degeneration in BSCR, and may be a useful outcome measure in monitoring treatment response in birdshot chorioretinopathy.

Visual acuity outcomes after cataract surgery in patients with age-related macular degeneration: age-related eye disease study report no. 27.

OBJECTIVE: To evaluate visual acuity outcomes after cataract surgery in patients with varying degrees of age-related macular degeneration (AMD). DESIGN: Cohort study. PARTICIPANTS: A total of 4757 participants enrolled in the Age-Related Eye Disease Study (AREDS), a prospective, multicenter, epidemiological study of the clinical course of cataract and AMD and a randomized controlled trial of antioxidants and minerals. METHODS: Standardized lens and fundus photographs, performed at baseline and annual visits, were graded by a centralized reading center using standardized protocols for severity of AMD and lens opacities. History of cataract surgery was obtained every 6 months. Analyses were conducted using multivariate logistic regression. MAIN OUTCOME MEASURE: The change in best-corrected visual acuity (BCVA) after cataract surgery compared with preoperative BCVA. RESULTS: Visual acuity results were analyzed for 1939 eyes that had cataract surgery during AREDS. The mean time from cataract surgery to measurement of postoperative BCVA was 6.9 months. After adjustment for age at surgery, gender, type, and severity of cataract, the mean change in visual acuity at the next study visit after the cataract surgery was as follows: Eyes without AMD gained 8.4 letters of acuity (P<0.0001), eyes with mild AMD gained 6.1 letters of visual acuity (P<0.0001), eyes with moderate AMD gained 3.9 letters (P<0.0001), and eyes with advanced AMD gained 1.9 letters (P = 0.04). The statistically significant gain in visual acuity after cataract surgery was maintained an average of 1.4 years after cataract surgery. CONCLUSIONS: On average, participants with varying severity of AMD benefited from cataract surgery with an increase in visual acuity postoperatively. This average gain in visual acuity persisted for at least 18 months.

Tachyphylaxis after intravitreal bevacizumab for exudative age-related macular degeneration.

PURPOSE: To describe tachyphylaxis to intravitreal bevacizumab (IVB) in patients with exudative age-related macular degeneration (AMD). METHODS: We retrospectively reviewed the records of 59 consecutive patients treated with IVB at the National Eye Institute over a 14-month period and identified cases demonstrating loss of treatment efficacy as revealed by spectral domain optical coherence tomography. We defined tachyphylaxis as a loss of therapeutic response to IVB 28 +/- 7 days after administration in an eye that had previously demonstrated a therapeutic response in the same time interval. RESULTS: Five patients (six eyes) were identified as developing tachyphylaxis after repeated treatment with IVB. High-dose IVB (2.50 mg) did not restore therapeutic response in these patients. Bilateral tachyphylaxis to IVB was seen after an episode of unilateral postinjection anterior uveitis. After the first treatment of IVB, the median time taken to develop tachyphylaxis was 100 weeks (range: 31-128 weeks), and the median number of IVB treatments to the development of tachyphylaxis was 8 treatments (range: 5-10 treatments). CONCLUSION: Tachyphylaxis can occur after long-term intravitreal use of bevacizumab in patients with AMD. The precise mechanism of tachyphylaxis is unclear, but both local and/or systemic factors may be involved.

Evaluating the cost-effectiveness of anterior uveitis investigation by Canadian ophthalmologists.

BACKGROUND: To evaluate the cost-effectiveness of anterior uveitis investigation by Canadian ophthalmologists and to assess the role of implementing national clinical guidelines for such investigation. METHODS: Based on data extracted from the Canadian National Uveitis Survey (CNUS, 2007 version), the cost of investigating a patient with anterior uveitis, according to current practice patterns of Canadian ophthalmologists, was determined and grouped across 4 clinical scenarios: (i) nongranulomatous anterior uveitis in an adult, (ii) granulomatous anterior uveitis in an adult, (iii) granulomatous anterior uveitis with suspected sarcoidosis in an adult or a child, and (iv) nongranulomatous anterior uveitis in a child. Similarly, the cost of investigating a patient with anterior uveitis as per published evidence-based guidelines was determined and compared with the current practice pattern using a cost-minimization model, sensitivity analyses, and Monte Carlo simulations. RESULTS: Ophthalmologists were found to consistently order more tests than recommended by evidence-based guidelines, across each of the scenarios studied (p < 0.05). Overall, complete blood count, erythrocyte sedimentation rate, C-reactive protein, antinuclear antibody, and rheumatoid factor were the most commonly ordered extraneous tests that were not included in the evidence-based guidelines for the routine investigation of anterior uveitis. Also, there were significant differences in the cost of investigating a patient with anterior uveitis when compared with those predicted by adhering to evidence-based clinical practice guidelines. Cost minimization and sensitivity analyses revealed that published guidelines imparted cost savings when compared with current practice patterns across the 4 clinical scenarios studied (p < 0.01). The maximum additional cost was associated with investigating nongranulomatous anterior uveitis in an adult, where a minimal additional cost of $75 per patient was spent. For granulomatous anterior uveitis in an adult, the additional cost was approximately $40, whereas the additional cost for investigating an adult or a child with suspected sarcoidosis was $36. Only $11 of additional cost was spent in the workup of a child with nongranulomatous anterior uveitis. When applied to the Canadian population, adherence to the Clinical Practice Guidelines recommended by the CNUS may result in cost savings of $600,000 per year to the Canadian health care system. INTERPRETATION: Adherence to the evidence-based Clinical Practice Guidelines recommended by the CNUS may result in significant cost savings, with virtually no loss of sensitivity in the routine investigation of anterior uveitis in Canada.

Normal Variation of Photoreceptor Outer Segment Volume With Age, Gender, Refractive Error, and Vitreomacular Adhesion.

BACKGROUND AND OBJECTIVE: Thickness and volume changes of the photoreceptor outer segment (PROS) layer on spectral-domain optical coherence tomography (SD-OCT) images are associated with various disease states. However, there are limited data on normal anatomical variation. This study evaluates the correlation of PROS volume with age, gender, refractive error, and presence of vitreomacular adhesion (VMA) in healthy subjects. PATIENTS AND METHODS: SD-OCT scans of 68 normal eyes were analyzed. The ellipsoid zone and the apical retinal pigment epithelium boundary were segmented using an automated algorithm. The PROS volume was calculated as the region bounded by these two layers within a 6-mm diameter circle centered at the fovea. A general linear model was used for statistical analysis. RESULTS: PROS volume increased with age to a significant degree (P = .013). Gender, refractive error, and presence of VMA were insignificant factors. CONCLUSION: PROS volume, as measured on routine SD-OCT, increases with age in healthy subjects, after adjusting for gender, refractive error, and VMA. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:523-527.].

Aqueous Humor Cytokine Levels and Anatomic Response to Intravitreal Ranibizumab in Diabetic Macular Edema.

Importance: Variability in response to anti-vascular endothelial growth factor (VEGF) treatment in diabetic macular edema (DME) remains a significant clinical challenge. Biomarkers could help anticipate responses to anti-VEGF therapy. Objectives: To investigate aqueous humor cytokine level changes in response to intravitreal ranibizumab therapy for the management of DME, and to determine the association between baseline aqueous levels and anatomic response. Design, Setting, and Participants: In this prospective multicenter cohort study, 49 participants with diabetes mellitus complicated by center-involving DME, with a central subfield thickness of 310 µm or greater on spectral-domain optical coherence tomography (SD-OCT), were recruited from December 22, 2011, to June 13, 2013 and statistical analysis were performed from March 1, 2017, to June 1, 2017. A total of 48 participants proceeded to follow-up. Interventions: Participants received monthly injections of ranibizumab, 0.5 mg, for 3 months. Aqueous fluid for cytokine analysis was obtained at baseline and repeated at the 2-month visit. Multiplex immunoassay was carried out in duplicate for VEGF, placental growth factor, transforming growth factor beta 2, intercellular adhesion molecule 1 (ICAM-1), interleukin 6 (IL-6), IL-8, IL-10, vascular intercellular adhesion molecule, and monocyte chemoattractant protein 1. Main Outcomes and Measures: Baseline and 2-month change in aqueous cytokine levels, 3-month change in SD-OCT central subfield thickness and macular volume (MV), and the statistical association between baseline aqueous cytokine levels and these measures of anatomic response to ranibizumab in center-involving DME. Results: Among the 48 participants, the mean (SD) age was 61.9 (7.1) years and 36 participants (75.0%) were men. The following cytokines were lower at month 2 vs baseline: ICAM-1 (median change, -190.88; interquartile range [IQR], -634.20 to -26.54; P < .001), VEGF (median change, -639.45; IQR, -1040.61 to -502.61; P < .001), placental growth factor (median change, -1.31; IQR, -5.99 to -0.01; P < .001), IL-6 (median change, -38.61; IQR, -166.72 to -2.80; P < .001), and monocyte chemoattractant protein 1 (median change, -90.13; IQR, -382.74 to 109.47; P = .01). When controlling for age, foveal avascular zone size, and severity of retinopathy, multiple linear regression determined that increasing baseline aqueous ICAM-1 was associated with a favorable anatomic response, in terms of reduced SD-OCT MV at 3 months (every additional 100 pg/mL of baseline ICAM-1 was associated with a reduction of 0.0379 mm3; P = .01). Conversely, increasing baseline aqueous VEGF was associated with a less favorable SD-OCT MV response at 3 months (every additional 100 pg/mL of baseline VEGF was associated with an increase of 0.0731 mm3; P = .02) and was associated with lower odds of being a central subfield thickness responder (odds ratio, 0.868; 95% CI, 0.755-0.998). Conclusions and Relevance: Elevated aqueous ICAM-1 and reduced VEGF levels at baseline are associated with a favorable anatomic response to ranibizumab in DME, although there is not always direct correlation between anatomic and visual acuity response.