Graefes Arch Clin Exp Ophthalmol DOI 10.1007/s00417-015-3206-9
RETINAL DISORDERS
Spectral-domain optical coherence tomography findings of tractional retinal elevation in patients with diabetic retinopathy Yu Cheol Kim 1 & Jae Pil Shin 2
Received: 12 June 2015 / Revised: 5 October 2015 / Accepted: 22 October 2015 # Springer-Verlag Berlin Heidelberg 2015
Abstract Purpose To evaluate the clinical and morphological characteristics as well as the surgical outcomes of tractional retinal elevation (TRE) in patients with proliferative diabetic retinopathy (PDR) by analyzing spectral-domain optical coherence tomography (SD-OCT). Methods SD-OCT images of 26 eyes (24 patients) who visited our clinic because of TRE and PDR from August 2011 to August 2014 were reviewed. According to the presence or absence of tractional retinal detachment (TRD), patients were classified into group 1 (without TRD) or group 2 (with TRD), and the clinical characteristics and surgical outcomes of the two groups were compared. Furthermore, we categorized the SD-OCT morphological components into sponge, cystoid, saw tooth, bridging columnar, and TRD and compared the characteristics among patients who had different components. Results Group 1 had 18 eyes and group 2 had eight eyes. No differences in age, best corrected visual acuity (BCVA), or spherical equivalent were observed between the two groups, but group 2 had longer axial length than that of group 1 (p= 0.02). A large variety of combined OCT findings was found in group 1 compared to that in group 2. TRD was the least combined form with the other morphological components. This study was presented in part as a poster at the annual meeting of the Association for Research in Vision and Ophthalmology in 2013. * Yu Cheol Kim
[email protected] 1
Department of Ophthalmology, Keimyung University School of Medicine Dongsan Medical Center, 56, Dalseong-ro, Jung-gu, Daegu 41931, Korea
2
Department of Ophthalmology, School of Medicine, Kyungpook National University, Daegu, Korea
Although 92 % of eyes with the bridging columnar component had the cystoid component, TRD and tractional retinoschisis (TRS, bridging columnar morphology) were combined in only one eye. Conclusion Diabetic TRE may progress to TRD or TRS, which are mutually exclusive. They may progress to TRD in eyes with a long axial length, and cystoid macular edema seems to develop into TRS.
Keywords Diabetic retinopathy . Optical coherence tomography . Retinal detachment . Retinoschisis
Early vitreous liquefaction and shrinkage in patients with diabetic retinopathy can lead to vitreous traction and, particularly, proliferative diabetic retinopathy (PDR), which is fibrovascular proliferation on the vitreoretinal interface that induces retinal traction and various complications. In the past, patients with retinal vessels elevated concavely by traction were diagnosed with tractional retinal detachment (TRD). However, some TRD cases with retinal breaks did not progress to rhegmatogenous retinal detachment, suggesting that some of these cases should have been diagnosed as retinoschisis [1–3]. Lincoff et al. [4] defined all these PDR cases as tractional retinal elevation (TRE) and classified them into TRD and tractional retinoschisis (TRS). After the development of optical coherence tomography (OCT), TRS was reported to be more common than TRD in TRE [5]. However, studies about what determines progression to TRD or TRS using spectral-domain optical coherence tomography (SD-OCT) and research about the influence of macular edema on retinal traction are insufficient, compared with those about the influence of retinal traction on macular edema.
Graefes Arch Clin Exp Ophthalmol
Therefore, we classified TRE according to the presence or absence of TRD on SD-OCT and investigated factors affecting the correlation and prognosis according to SD-OCT morphological features.
Methods and materials SD-OCT images of 24 patients (26 eyes) with PDR who were diagnosed with TRE (Fig. 1) by fundus examination and scheduled for pars plana vitrectomy from August 2011 to August 2014 were reviewed retrospectively. This study was approved by the institutional review board of Dongsan Medical Center. Horizontal and vertical linear scans (B-scan mode) and cube scans (raster mode) centered on the fovea were taken using OCT/SLO® (OTI, Ophthalmic Technology Co., Toronto, ONT, Canada) with a 29.7° width and analyzed with all scan findings.
Fig. 1 Fundus finding of diabetic tractional retinal elevation. a fundus photograph, b fluorescein angiogram
Eyes with other ocular diseases affecting visual acuity and retinal morphology and those with a history of pars plana vitrectomy were excluded from this study. Visual acuity was checked with a Snellen chart and converted to LogMAR. The postoperative best corrected visual acuity (BCVA) in the statistics was measured at the last visit. Each axial length was measured ten times with an A-scan ultrasonic biometer (Axis-II PR®; Quantel Medical, Inc., Cournon d’Auvergne Cedex, France), and the mean values, excluding the lowest and highest values, were adopted. Intraocular pressure (IOP) was measured with a Goldmann applanation tonometer. The enrolled eyes were classified into group 1 (18 eyes) without TRD identified on SD-OCT or group 2 (8 eyes) with TRD. Sex, age, diabetes duration, axial length, spherical equivalent (SE), involvement of the fovea, preoperative IOP, preoperative and postoperative BCVA, lens state, intraoperative internal limiting membrane peeling, improvement in BCVA after surgery, and percentage of patients with final BCVA>20/50 were evaluated and analyzed. The SD-OCT findings identified by TRE were divided into five morphological components of sponge edema, cystoid edema, saw tooth, bridging columnar (TRS), and TRD (Fig. 2). We evaluated which morphological components composed each patient’s image and analyzed the correlations. The definitions of sponge and cystoid edema were based on the macular edema classifications of Otani et al. [6]. Sponge edema morphology was defined as diffuse retinal thickening showing a relative homogenous intraretinal change. Cystoid edema was defined as retinal thickening showing intraretinal hyporeflective cystoid spaces larger than 150 μm (Fig. 2a). Saw-tooth appearance was defined as a saw-like bumpy retinal surface (Fig. 2b). Columnar bridging appearance was defined as columns bridging split retinas, which is called retinoschisis (Fig. 2c). Bridges on the retinal surface or retinal pigment epithelium (RPE) were excluded. TRD was defined as a separated sensory retina from the RPE, with a distinct border and relative concave curvature (Fig. 2d). Localized convex retinal detachment without traction was considered serous retinal detachment, not TRD. All OCT findings were analyzed with the five morphological components, not classified into one dominant component, and we analyzed whether each morphological component was comorbid or mutually exclusive. Broad traction [≥1 disc diameter (DD)] and narrow traction (
