Microaneurysm formation rate as a predictive marker for progression to clinically significant macular edema in nonproliferative diabetic retinopathy.

PURPOSE: To evaluate the predictive value of microaneurysm (MA) formation rate concerning the development of clinically significant macular edema (CSME) in patients with mild-to-moderate nonproliferative diabetic retinopathy as evaluated by an automated analysis of central field fundus 30° photographs. METHODS: Two hundred and eighty-seven eyes were included in the study. Photographs obtained at Day 0, at 6, and 12 months were analyzed using the RetmarkerDR software (Critical Health SA) in a masked manner, and the MA formation rate was documented. A threshold of a calculated MA formation rate of 2 or more was chosen to consider a patient "positive." The ability to predict CSME development was then calculated for a period of up to 5 years. HbA1c values, blood pressure, or duration of diabetes were also evaluated. RESULTS: The study population consisted of 89 male and 59 female patients with a mean age of 57.6 years, a mean HbA1c of 7.8, and a mean duration of diabetes of 12.3 years. Forty-seven of 287 eyes (16.4%) developed CSME during follow-up. An increased MA formation rate of >2 MA was clearly associated with development of CSME. Using the automated analysis and a threshold of 2 or more new MA, the authors were able to identify 70.2% of the eyes that developed CSME during follow-up ("true positive") and using a threshold of up to 2 new MA, 71.7% of the patients that did not develop CSME ("true negative"). No significant differences concerning baseline and 1-year HbA1c levels within patient eyes that developed CSME compared with patient eyes below or over the calculated threshold of 2 MA (P = 0.554 and P = 0.890, respectively) were seen. The positive and negative predictive value was calculated to be 33% versus 92.5%, sensitivity was 70%, and specificity was 72%. CONCLUSION: Using the RetmarkerDR software, the authors were able to identify patients with higher risk to develop CSME during follow-up using a threshold of 2 or more MA formation rate. Together with the high negative predictive value, the automated analysis may help to determine the individual risk of a patient to develop sight-threatening complications related to diabetic retinopathy and schedule individual screening intervals.

Screening for Diabetic Retinopathy in the Central Region of Portugal. Added Value of Automated 'Disease/No Disease' Grading.

Purpose: To describe the procedures of a nonmydriatic diabetic retinopathy (DR) screening program in the Central Region of Portugal and the added value of the introduction of an automated disease/no disease analysis. Methods: The images from the DR screening program are analyzed in a central reading center using first an automated disease/no disease analysis followed by human grading of the disease cases. The grading scale used is as follows: R0 - no retinopathy, RL - nonproliferative DR, M - maculopathy, RP - proliferative DR and NC - not classifiable. Results: Since the introduction of automated analysis in July 2011, a total of 89,626 eyes (45,148 patients) were screened with the following distribution: R0 - 71.5%, RL - 22.7%, M - 2.2%, RP - 0.1% and NC - 3.5%. The implemented automated system showed the potential for human grading burden reduction of 48.42%. Conclusions: Screening for DR using automated analysis allied to a simplified grading scale identifies DR vision-threatening complications well while decreasing human burden. © 2014 S. Karger AG, Basel.

Microaneurysm turnover in diabetic retinopathy assessed by automated RetmarkerDR image analysis--potential role as biomarker of response to ranibizumab treatment.

PURPOSE: To evaluate the influence of a ranibizumab treatment on microaneurysm (MA) turnover in diabetic retinopathy. METHODS: Sixty-nine eyes were included in this retrospective study. We compared a group of 33 eyes with ranibizumab treatment for diabetic macular edema to 36 eyes with nonproliferative diabetic retinopathy only. Nonmydriatic ultra-widefield scanning laser ophthalmoscopy (Optomap) images were obtained at a mean 4.76 ± 1.69 days prior to the first ranibizumab injection (baseline) and again 35.94 ± 2.44 days after the third consecutive injection in a 4-week interval. In untreated controls, images were obtained at baseline and 97.81 ± 3.16 days thereafter. Images were analyzed using the RetmarkerDR software (Critical Health SA, Coimbra, Portugal), and the turnover of MAs was documented and analyzed. Thereafter, MA turnover was correlated with central retinal thickness (CRT) as assessed by OCT. RESULTS: At baseline, patients in the treatment group had 5.64 ± 0.75 MAs. One month after 3 ranibizumab injections, measured MAs decreased to 4.03 ± 0.66. In the untreated control group, the initial number of 3.36 ± 0.6 MAs remained almost unchanged over 3-4 months (2.89 ± 0.57 MAs). Dynamic analysis showed that after ranibizumab treatment 3.06 ± 0.5 new MAs appeared, while 5.09 ± 0.79 disappeared. In the control group, 2.11 ± 0.4 new MAs appeared and 2.61 ± 0.48 disappeared. MA turnover was significantly higher with ranibizumab compared to the control group (8.15 ± 1.14 vs. 4.72 ± 0.81, p < 0.001). Consistently, CRT decreased from 444 to 330 µm in the ranibizumab group, while there was no change in the control group (291 vs. 288 µm). CONCLUSION: The treatment of macular edema using ranibizumab does not only reduce macular thickness, but also has an impact on the turnover of MAs in diabetic retinopathy. RetmarkerDR analysis showed that more pre-existent MAs disappeared than new MAs developed, and the absolute number of MAs also decreased.

Automated diabetic retinopathy imaging in Indian eyes: a pilot study.

AIM: To evaluate the efficacy of an automated retinal image grading system in diabetic retinopathy (DR) screening. MATERIALS AND METHODS: Color fundus images of patients of a DR screening project were analyzed for the purpose of the study. For each eye two set of images were acquired, one centerd on the disk and the other centerd on the macula. All images were processed by automated DR screening software (Retmarker). The results were compared to ophthalmologist grading of the same set of photographs. RESULTS: 5780 images of 1445 patients were analyzed. Patients were screened into two categories DR or no DR. Image quality was high, medium and low in 71 (4.91%), 1117 (77.30%) and 257 (17.78%) patients respectively. Specificity and sensitivity for detecting DR in the high, medium and low group were (0.59, 0.91); (0.11, 0.95) and (0.93, 0.14). CONCLUSION: Automated retinal image screening system for DR had a high sensitivity in high and medium quality images. Automated DR grading software's hold promise in future screening programs.

Ocular Risk Factors for Exudative AMD: A Novel Semiautomated Grading System.

Purpose. To evaluate the contribution of the ocular risk factors in the conversion of the fellow eye of patients with unilateral exudative AMD, using a novel semiautomated grading system. Materials and Methods. Single-center, retrospective study including 89 consecutive patients with unilateral exudative AMD and ≥3 years of followup. Baseline color fundus photographs were graded using an innovative grading software, RetmarkerAMD (Critical Health SA). Results. The follow-up period was 60.9 ± 31.3 months. The occurrence of CNV was confirmed in 42 eyes (47.2%). The cumulative incidence of CNV was 23.6% at 2 years, 33.7% at 3 years, 39.3% at 5 years, and 47.2% at 10 years, with a mean annual incidence of 12.0% (95% CI = 0.088-0.162). The absolute number of drusen in the central 1000 and 3000 µ m (P < 0.05) and the absolute number of drusen ≥125 µm in the central 3000 and 6000 µm (P < 0.05) proved to be significant risk factors for CNV. Conclusion. The use of quantitative variables in the determination of the OR of developing CNV allowed the establishment of significant risk factors for neovascularization. The long follow-up period and the innovative methodology reinforce the value of our results. This trial is registered with ClinicalTrials.gov NCT00801541.