Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2014  |  Volume : 27  |  Issue : 1  |  Page : 174-177

Optical coherence tomography as a prognostic tool for visual improvement after management of diabetic macular edema


Department of Ophthalmology, Faculty of Medicine, Menoufia University, Al-Menoufia, Egypt

Date of Submission16-Apr-2013
Date of Acceptance12-Jun-2013
Date of Web Publication20-May-2014

Correspondence Address:
Marwa A Zaky Galal
MSc, Department of Ophthalmology, Faculty of Medicine, Menoufia University, Shebin El-Kom, Al-Menoufia, 11160
Egypt
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/1110-2098.132794

Rights and Permissions
  Abstract 

Objectives
The aim of the study was to evaluate the role of optical coherence tomography (OCT) as a prognostic tool for visual improvement after management of diabetic macular edema (DME).
Background
OCT provides an easy quantitative assessment of the relationship between DME and visual acuity.
Patients and methods
Fifty eyes affected with DME were treated and followed up for 6 months. The main outcome measures were best corrected visual acuity (BCVA) and central macular thickness (CMT) in addition to photoreceptor integrity changes, which were measured using OCT at 1 month and 6 months after treatment.
Result
After treatment of DME, follow-up at 1 month revealed that the mean CMT was significantly higher among patients in the panretinal photocoagulation (PRP) + intravitreal triamcinolone acetonide (IVTA) + grid group compared with the patients in the grid + PRP group (P = 0.001), focal + PRP group (P = 0.01), and focal management group (P = 0.008). The mean BCVA was significantly lower among patients in the grid + IVTA group compared with patients in the grid + PRP group (P = 0.03), focal + PRP group (P = 0.02), and focal treatment group (P = 0.008). After 6 months of treatment, there was no significant difference between the mean values of CMT (P = 0.46) or BCVA (P = 0.07) with respect to different ways of management. With respect to the photoreceptor integrity at 1 month follow-up, the mean CMT was significantly lower in the intact (P = 0.001) and disrupted (P = 0.01) groups compared with that in the absent photoreceptor integrity group, whereas the mean BCVA was significantly higher in the intact group than in the absent (P = 0.001) and disrupted (P = 0.001) photoreceptor integrity groups. At 6 months, the mean CMT of the absent photoreceptor integrity group was significantly higher than that of the intact group (P = 0.03), and the mean BCVA was significantly higher in the intact group than that in the disrupted photoreceptor integrity group (P = 0.01).
Conclusion
CMT measured using OCT and the status of photoreceptor layer significantly provide an objective guideline for predicting the visual improvement in eyes with DME after treatment.

Keywords: Central macular thickness, diabetic macular edema, optical coherence tomography, photoreceptor layer


How to cite this article:
Wagdy FM, Sarhan AE, Elmorsy OA, Zaky Galal MA, Nassar MK. Optical coherence tomography as a prognostic tool for visual improvement after management of diabetic macular edema. Menoufia Med J 2014;27:174-7

How to cite this URL:
Wagdy FM, Sarhan AE, Elmorsy OA, Zaky Galal MA, Nassar MK. Optical coherence tomography as a prognostic tool for visual improvement after management of diabetic macular edema. Menoufia Med J [serial online] 2014 [cited 2020 Feb 16];27:174-7. Available from: http://www.mmj.eg.net/text.asp?2014/27/1/174/132794


  Introduction Top


Optical coherence tomography (OCT) is an accurate tool for early diagnosis, analysis, and monitoring of diabetic retinopathy, with high repeatability and resolution. It allows not only the qualitative diagnosis of diabetic macular edema (DME) but also the quantitative assessment of DME [1].

OCT is particularly valuable in analyzing vitreomacular relationship and detecting serous detachment that is not detectable with biomicroscopy [2].

OCT features of DME were classified into four patterns: diffuse retinal thickening, cystoid macular edema, serous retinal detachment, and vitreomacular interface abnormalities [3]. OCT provides easy measurement of objective macular thickness and quantitative assessment of the relationship between DME and visual acuity (VA) [4].

Laser treatment for diabetic retinopathy is still the gold standard in the treatment of focal and diffuse DME and proliferative diabetic retinopathy (PDR). When treated properly, the 5-year risk for blindness is reduced by 90% in patients with PDR, and the risk for visual loss from macular edema is reduced by 50% [5].

Intravitreal injection such as intravitreal triamcinolone acetonide (IVTA) injection or antivascular endothelial growth factor such as pegaptanib Macugen (American biotechnology company, Foster City, California, USA.), bevacizumab Avastin, and ranibizumab Lucentis (Genentech/Roche enentech, Inc. South San Francisco, California, United States) are increasingly used to treat patients with macular edema resulting from a variety of conditions such as diabetes, pseudophakia, and idiopathic cystoid macular edema [6].

Pharmacologic inhibition of vascular endothelial growth factor has been suggested as a promising treatment strategy for DME [7].


  Patients and methods Top


This study included 50 patients with DME aged between 30 and 65 years (28 male patients and 22 female patients). The study included both insulin-dependent (one patient) and noninsulin-dependent (49 patients) patients; 30 patients with non-PDR and 20 with PDR. The duration of diabetes ranged from 11 to 20 years. Patients with any type of DME detected by clinical examination either in association with non-PDR or PDR were included in the study, whereas patients with advanced cataract, significant corneal opacities, prior vitreoretinal surgeries, retinal diseases other than diabetic retinopathy, ocular hypertension or glaucoma, and major ocular surgery, including cataract extraction within 6 months before the study, were excluded.

All patients were examined with respect to the measurement of best corrected visual acuity (BCVA) using the Landolt broken ring chart that converted it to decimal from the VA notation table, and fundus fluorescein angiography was performed at presentation.

Spectral domain OCT was used, Heidelberg Spectralis (Heidelberg Engineering, Heidelberg, Germany), for all patients. Two examination modalities were used: 'macular cube' and 'line scan'. A macular cube generates a cube of data through a 6-mm 2 grid (6.0 × 6.0 mm). Retinal thickness was then displayed as a two-dimensional color-coded map of retinal thickness in the posterior pole, with brighter colors indicating the areas of increased retinal thickness, and as a numeric average of nine early treatment diabetic retinopathy study (ETDRS) type area for quantitative evaluation.

OCT was performed at presentation, 1 month, and 6 months, and central macular thickness (CMT) was measured automatically using an OCT retinal mapping software. The photoreceptor layer was analyzed as either present with a completely visible inner segment/outer segment (IS/OS) or disrupted IS/OS or even absence of the IS/OS.

Management of DME was carried out either with argon laser photocoagulation, focal or grid, or with IVTA Kenacort (Bristol-Myers Squibb, New York City, USA) 40 mg, 4 mg in 0.1 ml/injection in the operation theater under strict asepsis.

Patients were examined at 1 month and 6 months with respect to BCVA, CMT, and photoreceptor integrity.

Results were collected, tabulated, and statistically analyzed using an IBM compatible personal computer with the SPSS statistical package version 20 (SPSS Inc., Chicago, Illinois, USA).

Pearson's correlation was used to express the correlation between two normally distributed variables, whereas Spearman's correlation was used to express the correlation between not normally distributed variables. A P value of less than 0.05 was considered statistically significant.


  Results Top


This study included 50 patients: 28 (56.0%) male and 22 (44.0%) female. The mean age among the studied group was 53.16 years and the mean duration of diabetes was 12.62 years.

The mean CMT among the studied group at presentation was 324.46 ± 106.36 μm and the mean BCVA (in decimal) was 0.21 ± 0.12.

Management of DME was carried out, and at 1 month the mean CMT was significantly higher among patients in the panretinal photocoagulation (PRP) + IVTA + grid group compared with patients in the grid+PRP group (P = 0.001), focal + PRP group (P = 0.01), and focal management group (P = 0.008). The mean VA was significantly lower among patients in the grid + IVTA group compared with patients in the grid + PRP group (P=0.03), focal + PRP group (P = 0.02), and focal treatment group (P = 0.008) [Table 1].
Table 1: Comparison between the mean values of central macular thickness and best corrected visual acuity with respect to the management at 1 month

Click here to view


After 6 months, there was no significant difference between the mean values of CMT (P = 0.46) or VA (P = 0.07) with respect to different ways of management [Table 2].
Table 2: Comparison between the mean values of central macular thickness and best corrected visual acuity with respect to the management at 6 months

Click here to view


The mean CMT was significantly lower in the intact (P = 0.001) and disrupted (P = 0.01) groups compared with the absent photoreceptor integrity group, whereas the mean VA was significantly higher in the intact group compared with the absent (P = 0.001) and disrupted (P = 0.00) photoreceptor integrity groups at 1-month follow-up [Table 3]. At 6 months the mean CMT in the absent photoreceptor integrity group was significantly higher than that in the intact group (P = 0.03), and the mean VA was significantly higher in the intact group than that in the disrupted photoreceptor integrity group (P = 0.01) [Table 4].
Table 3: Comparison between the mean values of central macular thickness and best corrected visual acuity with respect to the photoreceptor integrity at 1 month

Click here to view
Table 4: Comparison between the mean values of central macular thickness and best corrected visual acuity with respect to the photoreceptor integrity at 6 months among the studied group

Click here to view



  Discussion Top


This study shows that there was a significant negative correlation between the mean values of CMT and VA with respect to the management at 1 month among the studied groups.

This was similar to the study by Sutter et al. [8], who reported that IVTA was effective in improving VA and reducing DME and was also in agreement with the study by Soliman et al. [9], who found that 1-month macular laser treatment was critical for establishing the outcome of macular laser treatment in DME.

The present study shows that there was no significant correlation between the mean values of VA, CMT, and the management modality at 6 months follow-up.

The same findings were obtained by Schmid et al. [10], who showed that there was no significant change in VA, although OCT revealed a significant change in retinal thickness during 6 months follow-up period after treatment of DME using macular grid laser.

This was in contrast to the study by Gillies et al. [11], who suggested that the beneficial effect of IVTA in eyes with DME persists up to 5 years.

This study shows that the mean CMT at 6 months in the absent photoreceptor integrity group was significantly higher than that in the intact group, whereas the mean VA was significantly higher in the intact group than that in the disrupted photoreceptor integrity group.

This was in agreement with the study by Maheshwary et al. [12], who considered the rupture of the IS/OS junction as an important predictor of VA in patients with DME.

In addition, these results agreed with the study by Hannouche et al. [13], who concluded that the photoreceptor integrity was correlated with the CMT. Patients with continuous photoreceptor integrity showed lower CMT and significantly better BCVA (P < 0.001) than patients with disrupted photoreceptor integrity; also, patients with disrupted photoreceptor integrity showed higher CMT (P < 0.001) and worse VA.

Otani et al. [14] also reported that the integrity of these structures was more related to the BCVA than CMT, as it is more directly related to visual function.

This was in agreement with the study by Blumenkranz et al. [15] and Deαk et al. [16], who suggested a strong and reliable correlation between the measurements of the outer photoreceptor layer and VA. In addition, Shin et al. [17] showed that VA was closely associated with the IS/OS integrity, whereas CMT had no significant correlation with photoreceptor integrity in patients with DME.


  Conclusion Top


Early diagnosis of DME is vital to the preservation of VA. OCT is a promising new imaging technique that can improve the diagnosis and clinical management in patients with DME.

CMT and integrity of the photoreceptor IS/OS layer are significant predictors of VA in patients with DM, which may help to predict the outcome after treatment and to choose the best treatment modality.


  Acknowledgements Top


Conflicts of interest

None declared.

 
  References Top

1.Özdek S, Erdinc M, Gürelik G, Aydin B. Optical coherence tomography assessment of diabetic macular edema: comparison with fluorescein angiographic and clinical findings. Ophthalmologica 2005; 219 :86-92.  Back to cited text no. 1
    
2. Recchia F, Ruby A, Carvalho R. Pars plana vitrectomy with removal of the internal limiting membrane in the treatment of persistent diabetic macular edema. Am J Ophthalmol 2005; 139 :447-454.  Back to cited text no. 2
    
3. Kim B, Smith S, Kaiser P. Optical coherence tomographic patterns of diabetic macular edema. Am J Ophthalmol 2006; 142 :405-412.  Back to cited text no. 3
    
4. Browning DJ, Glassman A, Aiello L, Beck R, Brown D, Fong D, et al. Relationship between optical coherence tomography-measured central retinal thickness and visual acuity in diabetic macular oedema. Ophthalmology 2007; 114 :525-536.  Back to cited text no. 4
    
5. Comer GM, Ciulla TA. Current and future pharmacological intervention for diabetic retinopathy. Expert Opin Emerg Drugs 2005; 10 :441-455.  Back to cited text no. 5
    
6. Jonas J, Kreissig I, Degenring R. Intravitreal triamcinolone acetonide for treatment of intraocular proliferative, exudative and angiogenic diseases. Prog Retin Eye Res 2005; 5 :587-611.  Back to cited text no. 6
    
7. Arevalo JF, Fromow-Guerra J, Quiroz-Mercado H, Sanchez JG Wu L, Maia M, et al. Primary intravitreal bevacizumab (Avastin) for diabetic macular edema. Results from the Pan-American Collaborative Retina Study Group at 6-month follow-up. Ophthalmology 2007; 114 :743-750.  Back to cited text no. 7
    
8. Sutter FK, Simpson JM, Gillies MC. Intravitreal triamcinolone for diabetic macular edema that persists after laser treatment: three-month efficacy and safety results of a prospective, randomized, double-masked, placebo-controlled clinical trial. Ophthalmology 2004; 111 :2044-2049.  Back to cited text no. 8
    
9. Soliman W, Sander B, Soliman KA, Yehya S, Rahamn MS, Larsen M. The predictive value of optical coherence tomography after grid laser photocoagulation for diffuse diabetic macular oedema, Acta Ophthalmol 2008; 86 :284-291.  Back to cited text no. 9
    
10.1Schmid KE, Neumaier-Ammerer B, Stolba U, Binder S. Effect of grid laser photocoagulation in diffuse diabetic macular oedema in correlation to glycosylated haemoglobin (HbA1c). Graefes Arch Clin Exp Ophthalmol 2006; 244 :1446-1452.  Back to cited text no. 10
    
11.1Gillies MC, Simpson JM, Gaston C, Hunt G, Ali H, Zhu M, Sutter F. Five-year results of a randomized trial with open-label extension of triamcinolone acetonide for refractory diabetic macular edema. Ophthalmology 2009; 116 :2182-2187.  Back to cited text no. 11
    
12.1Maheshwary AS, Oster SF, Yuson RM, Cheng L, Mojana F, Freeman WR. The association between percent disruption of the photoreceptor inner segment outer segment junction and visual acuity in diabetic macular edema. Am J Ophthalmol 2010; 150 :63-67.  Back to cited text no. 12
    
13.1Hannouche RZ, Avila MP, Isaac DL, Silva RS, Rassi AR. Correlation between central subfield thickness, visual acuity and structural changes in diabetic macular edema. Arq Bras Oftalmol 2012; 75 :183-187.  Back to cited text no. 13
    
14.1Otani T, Yamaguchi Y, Kishi S. Correlation between visual acuity and foveal microstructural changes in diabetic macular edema. Retina 2010; 30 :774-780.  Back to cited text no. 14
    
15.1Blumenkranz MS, Haller JA, Kuppermann BD, Williams GAIp M, Davis M, et al. Correlation of visual acuity and macular thickness measured by optical coherence tomography in patients with persistent macular edema. Retina 2010; 30 :1090-1094. Comment in Retina. 2011; 31 :815; author reply 815-816  Back to cited text no. 15
    
16.1Deák GG, Bolz M, Ritter M, Prager S, Benesch T, Schmidt-Erfurth U. Diabetic Retinopathy Research Group Vienna A systematic correlation between morphology and functional alterations in diabetic macular edema. Invest Ophthalmol Vis Sci 2010; 51 :6710-6714.  Back to cited text no. 16
    
17.1Shin HJ, Lee SH, Chung H, Kim HC. Association between photoreceptor integrity and visual outcome in diabetic macular edema. Graefes Arch Clin Exp Ophthalmol 2012; 250 :61-70.  Back to cited text no. 17
    



 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Patients and methods
Results
Discussion
Conclusion
Acknowledgements
References
Article Tables

 Article Access Statistics
    Viewed1063    
    Printed11    
    Emailed0    
    PDF Downloaded154    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]