Objective: To examine the relationship between subclinical diabetic macular edema (DME) and the development of clinically significant macular edema (CSME) in nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes. Methods: A prospective, monocenter, observational study was designed to follow patients/eyes with type 2 diabetes and NPDR (Early Treatment Diabetic Retinopathy Study levels 20 and 35) with no prior laser treatment for 2 years or until development of CSME. Ophthalmologic examinations, including best-corrected visual acuity, fundus photography and optical coherence tomography (OCT), were performed at baseline, 6 months and a final visit. Results: A total of 348 patients completed study follow-up; 26 eyes developed CSME. Six out of 32 eyes/patients presenting subclinical DME at baseline developed CSME (18.7%), while 20 out of 316 eyes without subclinical DME developed CSME (6.3%). Eyes/patients with subclinical DME presented a risk for DME progression 3.686 times higher than that of eyes/patients without subclinical DME (95% confidence interval 1.221-7.988). Conclusions: Subclinical DME in eyes with NPDR identified by center point thickness measured on a Stratus OCT is a good predictor of CSME development.

Keywords:
Subclinical diabetic macular edema, Center point thickness, Optical coherence tomography, Clinically significant macular edema, Nonproliferative diabetic retinopathy, Type 2 diabetes
1.
Paunescu LA, Schuman JS, Price LL, Stark PC, Beaton S, Ishikawa H, Wollstein G, Fujimoto JG: Reproducibility of nerve fiber thickness, macular thickness, and optic nerve head measurements using StratusOCT. Invest Ophthalmol Vis Sci 2004;45:1716-1724.
2.
Krzystolik MG, Strauber SF, Aiello LP, Beck RW, Berger BB, Bressler NM, Browning DJ, Chambers RB, Danis RP, Davis MD, Glassman AR, Gonzalez VH, Greenberg PB, Gross JG, Kim JE, Kollman C; Diabetic Retinopathy Clinical Research Network: Reproducibility of macular thickness and volume using Zeiss optical coherence tomography in patients with diabetic macular edema. Ophthalmology 2007;114:1520-1525.
3.
Brown JC, Solomon SD, Bressler SB, Schachat AP, DiBernardo C, Bressler NM: Detection of diabetic foveal edema: contact lens biomicroscopy compared with optical coherence tomography. Arch Ophthalmol 2004;122:330-335.
4.
Browning DJ, Fraser CM, Clark S: The relationship of macular thickness to clinically graded diabetic retinopathy severity in eyes without clinically detected diabetic macular edema. Ophthalmology 2008;115:533-539.
5.
Bressler NM, Miller KM, Beck RW, Bressler SB, Glassman AR, Kitchens JW, Melia M, Schlossman DK; Diabetic Retinopathy Clinical Research Network: Observational study of subclinical diabetic macular edema. Eye (Lond) 2012;26:833-840.
6.
Sng CC, Cheung CY, Man RE, Wong W, Lavanya R, Mitchell P, Aung T, Wong TY: Influence of diabetes on macular thickness measured using optical coherence tomography: the Singapore Indian Eye Study. Eye (Lond) 2012;26:690-698.
7.
Browning DJ, Fraser CM: The predictive value of patient and eye characteristics on the course of subclinical diabetic macular edema. Am J Ophthalmol 2008;145:149-154.
8.
Photocoagulation for diabetic macular edema. Early Treatment Diabetic Retinopathy Study report number 1. Early Treatment Diabetic Retinopathy Study research group. Arch Ophthalmol 1985;103:1796-1806.
9.
Early Treatment Diabetic Retinopathy Study design and baseline patient characteristics. ETDRS report number 7. Ophthalmology 1991;98(5 suppl):741-756.
10.
Bressler NM, Edwards AR, Antoszyk AN, Beck RW, Browning DJ, Ciardella AP, Danis RP, Elman MJ, Friedman SM, Glassman AR, Gross JG, Li HK, Murtha TJ, Stone TW, Sun JK; Diabetic Retinopathy Clinical Research Network: Retinal thickness on Stratus optical coherence tomography in people with diabetes and minimal or no diabetic retinopathy. Am J Ophthalmol 2008;145:894-901.
11.
Sheetz MJ, Aiello LP, Davis MD, Danis R, Bek T, Cunha-Vaz J, Shahri N, Berg PH; MBDL and MBCU Study Groups: The effect of the oral PKC β inhibitor ruboxistaurin on vision loss in two phase 3 studies. Invest Ophthalmol Vis Sci 2013;54:1750-1757.
12.
Aiello LP, Vignati L, Sheetz MJ, Zhi X, Girach A, Davis MD, Wolka AM, Shahri N, Milton RC; PKC-DRS and PKC-DRS2 Study Groups: Oral protein kinase c β inhibition using ruboxistaurin: efficacy, safety, and causes of vision loss among 813 patients (1,392 eyes) with diabetic retinopathy in the Protein Kinase C β Inhibitor-Diabetic Retinopathy Study and the Protein Kinase C β Inhibitor-Diabetic Retinopathy Study 2. Retina 2011;31:2084-2094.
13.
Lobo CL, Bernardes RC, Figueira JP, Faria de Abreu JR, Cunha-Vaz JG: Three-year follow-up of blood retinal barrier and retinal thickness alterations in patients with type 2 diabetes mellitus and mild nonproliferative retinopathy. Arch Ophthalmol 2004;122:211-217.
14.
Cunha-Vaz J, Bernardes R, Lobo C: Blood-retinal barrier. Eur J Ophthalmol 2011;21(suppl 6):S3-S9.
15.
van Dijk HW, Verbraak FD, Kok PH, Stehouwer M, Garvin MK, Sonka M, DeVries JH, Schlingemann RO, Abràmoff MD: Early neurodegeneration in the retina of type 2 diabetic patients. Invest Ophthalmol Vis Sci 2012;53:2715-2719.
© 2013 S. Karger AG, Basel
2013
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