Table of Contents  
Year : 2018  |  Volume : 26  |  Issue : 2  |  Page : 111-117

Macular changes in diabetic patients using optical coherence tomography and fundus photography

Department of Ophthalmology, UP University of Medical Sciences, Saifai, Uttar Pradesh, India

Date of Web Publication13-Feb-2019

Correspondence Address:
Dr. Reena Sharma
House No. 199, Civil Lines, Etawah, Uttar Pradesh
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/njo.njo_1_18

Rights and Permissions

Aim: To identify and compare macular changes in patients with diabetic mellitus (DM) using optical coherence tomography (OCT) and fundus photography (FP). Setting and Design: This prospective comparative study was conducted at a tertiary care center. Materials and Methods: We examined 200 eyes of 107 diabetic patients with slit-lamp biomicroscopy, color FP using TOPCON fundus camera, and cirrus OCT. Fasting blood sugar (FBS), postprandial blood sugar (PPBS), and hemoglobin A1c (HbA1c) were measured. The clinical diabetic retinopathy (DR) and OCT findings were compared. Statistical Analysis: SPSS version 20, using Pearson’s Chi-square test, Student’s t-test, and analysis of variance. Results: Mean age of patients was 53.59 ± 10.8 years, with 68.2% males. Only six (5.5%) patients had type 1 DM. Mean FBS, PPBS, and HbA1c were 137.08 ± 34.4 mg/dL, 218.13 ± 70.5 mg/dL, and 6.65% ± 2.8%, respectively. The mean HbA1c of patients with OCT changes (7.08% ± 2.9%) was higher than those with normal OCT (5.52 ± 2.18) (P value < 0.001, t statistic—0.001). The retinopathy was found in 55 eyes (27.50%) on OCT and 74 (37%) eyes on FP. Of 126 eyes with normal fundus, 75 eyes (59.52%) had OCT changes. The mean central foveal, parafoveal, and perifoveal macular thickness in OCT were 260.95 ± 65.16, 322.78 ± 47.96, 281.73 ± 36.77 μm, respectively. The eyes with retinopathy had increased foveal (P < 0.001) and peripheral (parafoveal and perifoveal) thicknesses (P < 0.001). Conclusion: The OCT showed changes in the absence of clinical retinopathy in 59.2% eyes (P value < 0.001), indicating a role in detecting subclinical retinopathy. The eyes with clinical retinopathy however had a thicker fovea, implicating a more severe disease and retinopathy. Higher HbA1c values were associated with higher chances of OCT changes.

Keywords: Diabetic retinopathy, fundus photography, optical coherence tomography

How to cite this article:
Sami I, Sharma R, Sharma N, Sharma BD, Singh B. Macular changes in diabetic patients using optical coherence tomography and fundus photography. Niger J Ophthalmol 2018;26:111-7

How to cite this URL:
Sami I, Sharma R, Sharma N, Sharma BD, Singh B. Macular changes in diabetic patients using optical coherence tomography and fundus photography. Niger J Ophthalmol [serial online] 2018 [cited 2023 Jan 30];26:111-7. Available from:

  Introduction Top

Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both (American Diabetes Association).[1] This chronic hyperglycemia of diabetes is associated with damage to various organs, including the retina. Diabetic retinopathy (DR), one of the most frequent complications of diabetes, is a major public health problem with significant socioeconomic implications, affecting approximately 50% of diabetic patients, and remains a leading cause of blindness.[2],[3],[4],[5] Patients with DR are 25 times more likely to become blind than nondiabetics.[6] The incidence of retinopathy increases with duration of the disease and the majority of patients developed some retinopathy after 20 years.[7]

Optical coherence tomography (OCT) is an innovation in ophthalmology; it is a noninvasive, fast, and noncontact investigation that gives two-dimensional cross-sectional images of the retina layers and provides quantitative measurements of the retinal thickness.[8],[9] It has evolved through generations to a resolution up to 4 µm and high level of reproducibility.[10] It has evolved from a research tool to a procedure commonly used for the diagnosis and monitoring of patients with macular disease[11] in the clinic.

OCT can be used either to qualitatively assess retinal features or to make quantitative measurements, which is especially important in the early stages of DR when the structural changes are not yet evident with slit-lamp biomicroscopy or by doing fundus fluorescein angiography.[12],[13] The purpose of the study was to identify and compare the macular changes in diabetic patients using OCT and fundus photography (FP).

  Subjects and Methods Top

The present study was a prospective, observational study conducted in patients with DM presenting to the ophthalmology outpatient department for regular fundus evaluation. The study included 200 eyes of 107 patients. Patients with DM with age between 20 and 80 years and willing to be the part of this study were included. Eyes with significant media opacities precluding a good OCT signal, macular edema due to other causes (such as age-related macular degeneration, posterior uveitis, retinal vascular occlusions, retinitis pigmentosa, and some medications) and eyes with other ocular pathologies were excluded.

All patients underwent clinical evaluation by a physician with a review of the medical history. Information about the type of diabetes, duration of diabetes, smoking, alcohol intake, current medications and any history of systemic, and ocular disease was collected. The laboratory investigations [fasting and postprandial blood glucose, glycosylated hemoglobin A1c (HbA1c)] were performed in all cases.

Visual acuity was tested using Snellen’s visual acuity chart and anterior segment examined using a slit lamp (Haag-Streit USA, Inc., Mason, Ohio, USA). Fundus evaluation was performed using a 90D lens with slit-lamp biomicroscope and Heine indirect ophthalmoscope after instilling 0.8% tropicamide and 5% phenylephrine eye drops. FP (color stereoscopic) was taken using the TOPCON TRC 50IA 35° fundus camera (TOPCON, Tokyo, Japan). The FPs were examined by a masked examiner and the DR was graded according to the early treatment DR study classification.

The macular cube scans of 512 × 128 protocol were taken with the spectral domain OCT (Cirrus™ HD-OCT 4000; Carl Zeiss Meditec, Dublin, California, USA). The software, patented by Carl Zeiss Meditec, measured the retinal thickness to produce data for further analysis. The scans were taken three times to get scans with the highest signal intensity, no centration error, and minimal segmentation error. Only scans with signal strengths ≥7 and without artifact were included. Of the macular scan, the central macular thickness, average of the four-quadrant macular thicknesses in the inner (1–3 mm) and outer (3–6 mm) rings, was used for analyses. The data were analyzed using SPSS version 20 (IBM SPSS Inc., Chicago, USA). Discrete data were analyzed using Pearson’s χ2 test for nonnormal distribution and continuous data were analyzed using Student’s t test and analysis of variance.

  Results Top

The study included 200 eyes of 107 patients. The mean age of the patients was 53.59 ± 10.89 years. Of these 107 patients, 73 (68.22%) were males and 34 (31.77%) were females. There were six (5.6%) patients (11 eyes) with type 1 DM and 101 (94.4%) patients (189 eyes) with type 2 DM. The mean duration of diabetes in the study patients was 6.67 ± 5.40 years (range 1–29 years, median 4.00 years).

The mean fasting blood sugar (FBS), postprandial blood sugar (PPBS), and HbA1c in the patients were 137.1 ± 34.4 mg/dL (range 79.9–325.0 mg/dL), 218.1 ± 70.5 mg/dL (range 113.6–542.0 mg/dL), and 6.6% ± 2.9% (range 2.8%–14.2%), respectively.

On OCT, normal macular thickness scan was found in 145 eyes (72.50%), whereas changes in scan were seen in 55 eyes. The mean central macular thickness of patients with normal OCT scan was 246.29 + 4.97 μm (230–256 μm), and that of cases with OCT changes was 265 + 75.47 μm (43–659 μm). The mean HbA1c of the patients with normal OCT was 5.52% ± 2.18%, and in the patients with OCT changes, it was 7.08% ± 2.99%. Thus, the prevalence of OCT changes was higher in patients with higher HbA1c values (P value < 0.0001) [Table 1].
Table 1 Correlation of mean HbA1c with fundus and OCT findings

Click here to view

The personal history of the patients revealed that 20 (18.7%) patients had positive history of smoking, whereas alcohol intake was present in 16 (15.0%) patients. Of the 20 cases having positive history of smoking, fundus changes were present in six patients, that is, 30%, and OCT changes were present in 12 cases, that is, 60%. Out of the 16 cases having positive history of alcohol intake, fundus changes were present in six cases, that is, 37.5%, and OCT changes were present in 14 cases, that is, 87.5%. Hence, we can conclude that smoking and alcohol consumption were not found to be related to either the fundus changes or the mean macular thickness as illustrated by OCT (P values 0.15 and 0.20, respectively).

On fundus examination, 74 (37%) showed various grades of DR, whereas there was no DR in 126 eyes (63.0%) [[Table 2]; [Figure 1] and [Figure 2]]. Clinically, significant macular edema was seen in 28 eyes (13.8%).
Table 2 Clinical classification of eyes with diabetic retinopathy

Click here to view
Figure 1 Fundus photograph and OCT macular scan of a patient with no diabetic retinopathy

Click here to view
Figure 2 Fundus photograph and OCT macular scan of a patient with normal fundus. OCT shows decreased parafoveal and perifoveal thicknesses in right eye and decreased foveal thickness in left eye

Click here to view

Various OCT changes seen in our patients have been summarized in [Table 3]. OCT showed findings such as microaneurysms, hard exudates, hemorrhage, cotton wool spots, and increased or decreased foveal and peripheral (perifoveal and parafoveal) ring thicknesses. Changes in zonal macular thickness were the most common feature of OCT changes in DR [[Figure 3] and [Figure 4]]. Of the two, decreased thickness was as common as increased foveal thickness. These OCT changes have no relation with duration of diabetes (P value = 0.34).
Table 3 Distribution of OCT changes in diabetes

Click here to view
Figure 3 Fundus photograph shows absence of diabetic retinopathy. OCT macular scan shows decreased parafoveal and perifoveal thicknesses in right eye, and increased (superior outer quadrant) and decreased perifoveal thickness (remaining outer quadrant) in left eye

Click here to view
Figure 4 Fundus photograph and OCT macular scan of a patient with severe NPDR with CSME. It shows microaneurysms, hard exudates, hemorrhages, cotton wool spots, and dull foveal reflex. OCT macular scan shows above lesions as hyperreflective areas in outer retina, CSME as cystoid spaces and increased macular thickness (pink and yellow color)

Click here to view

In eyes with normal OCT (N = 55; 27.50%), fundus was found to be normal in 51 eyes (92.73%), whereas four eyes (7.27%) had fundus changes/retinopathy. On the contrary, out of 126 eyes with normal fundus, 75 eyes (59.52%) were having abnormal OCT, whereas normal OCT was seen in 51 eyes (40.48%) [Table 4]. Thus, the OCT showed changes in eyes in the absence of clinically apparent fundus changes (37.50%) as compared to the clinical examination of fundus, which showed changes in eyes with normal OCT (2.00%), which was highly statistically significant (P < 0.0001).
Table 4 Correlation between fundus and OCT findings

Click here to view

The eyes with clinical retinopathy had a thicker fovea than those with normal fundi (P < 0.001). In the same way, average parafoveal and perifoveal thickness were significantly more in eyes with fundus changes compared to those with normal fundi (P = 0.000) [Table 5].
Table 5 Correlation of macular thickness with fundus findings

Click here to view

  Discussion Top

OCT can perform high-resolution, cross-sectional imaging of the retina. A major advantage of OCT is that patients find it very comfortable because it is noncontact and the measurement time is very short. Our study compares the OCT and fundus examination for the detection of DR and describes the changes in zonal macular thickness.

The prevalence of DR has been shown to increase with age, even after adjustment for duration of diabetes.[14] Similarly, prevalence also increases with longer duration of diabetes (P < 0.0001).[15],[16],[17]

No correlation was found between the OCT changes and either the increasing age of the patient or the duration of diabetes in our study (P = 0.27 and 0.17, respectively). This is similar to the studies by Sng et al.[18] and Rodrigues et al.[19] However, increasing age has been noted to have inverse relation with macular thickness in some studies,[15] whereas others have not observed this relationship.[20],[21],[22]

We observed that patients with OCT changes had greater mean values of blood sugars, that is, FBS (P = 0.001), PPBS (P = 0.029), and HbA1c (P = 0.000) compared to those with normal OCT. This is similar to the previous studies that reported increased macular thickness with higher HbA1c levels.[23],[24] On the contrary, Lonneville et al.[25] have demonstrated that macular thickness decreases with poor metabolic control in diabetic patients with or without clinically detectable DR as high sugar cause apoptosis of ganglion cells, inner nuclear, and inner plexiform layers leading to early neurodegeneration leading to thinning of the retinal layers.

The most common lesion detected on SD-OCT was hard exudates (29.00%) followed by hemorrhages (24.50%), microaneurysms (11.00%), and cotton wool spots (3.50%) in that order. Similar findings were noted in the study conducted by Gella et al.[26] But the most common findings on OCT noted in our study was decreased parafoveal and perifoveal thickness (36.50%) followed by increased parafoveal and perifoveal thickness (32.50%). We observed more patients with decreased parafoveal thickness than increased thickness, which is similar to the observations reported by Asefzadeh et al.,[27] Biallosterski et al.,[28] Nilsson et al.,[29] and Verma et al.[30] The contradictory results, that is, increased macular thickness, were shown in some studies such as Schaudig et al.,[31] Lattanzio et al.,[32] Sugimoto et al.,[33] and Fritsche et al.[34]Recent evidence suggests that the selective thinning of inner retinal layers is due to the early neurodegenerative component in patients with minimal DR[35] and thicker macula is due to microvascular abnormalities.[36],[37] The OCT can thus be successfully utilized for objective monitoring of the macular thickness before and after therapy in patients with DR.

We thus found that OCT can be used for preclinical evaluation and follow-up of DR patients. The OCT changes may even precede the development of fundus changes. Early changes in macular thickness in particular can be found in diabetic patients without retinopathy.[36] These changes may be related to both neuronal and vascular abnormalities that occur in the early stage of diabetic retinas.[38] We also suggest that if there is abnormal macular thickening or thinning on OCT, the patient should be followed up more closely.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

The Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 1997;20:1183-97.  Back to cited text no. 1
Moss SE, Klein R, Klein BE. The 14-year incidence of visual loss in a diabetic population. Ophthalmology 1998;105:998-1003.  Back to cited text no. 2
World Health Organization. Definition, diagnosis and classification of diabetes mellitus and its complications: Report of a WHO Consultation. Part 1: Diagnosis and classification of diabetes mellitus. Geneva: World Health Organ; 1999.  Back to cited text no. 3
Williams R, Airey M, Baxter H, Forrester J, Kennedy-Martin T, Girach A. Epidemiology of diabetic retinopathy and macular oedema: A systematic review. Eye (Lond) 2004;18:963-83.  Back to cited text no. 4
Resnikoff S, Pascolini D, Etyáala D, Kocur I, Pararajasegaram R, Pokharel GP et al. Global data on visual impairment in the year2002. Bull World Health Organ 2004;82:844-51.  Back to cited text no. 5
Singh R, Ramasamy K, Abraham C, Gupta V, Gupta A. Diabetic retinopathy: An update. Indian J Ophthalmol 2008;56:179-88.  Back to cited text no. 6
[PUBMED]  [Full text]  
Klein R, Klein BE, Moss SE, Davis MD, De Mets DL. The Wisconsin epidemiologic study of diabetic retinopathy. II. Prevalence and risk of diabetic retinopathy when age at diagnose is 30 or less years. Arch Ophthalmol 1984;102:520-32.  Back to cited text no. 7
Hee MR, Izatt JA, Swanson EA, Huang D, Schuman JS, Lin CP et al. Optical coherence tomography of the human retina. Arch Ophthalmol 1995;113:325-32.  Back to cited text no. 8
Huang D, Swanson EA, Lin CP, Schuman JS, Stinson WG, Chang W et al. Optical coherence tomography. Science 1991;254:1178-81.  Back to cited text no. 9
Fercher F, Drexler W, Hitzenberger CK, Lasser T. Optical coherence tomography-principles and applications. Rep Prog Phys 2003;66:239-303.  Back to cited text no. 10
Puliafito CA, Hee MR, Lin CP, Reichel E, Schuman JS, Duker JS et al. Imaging of macular diseases with optical coherence tomography (OCT). Ophthalmology 1995;102:217-29.  Back to cited text no. 11
Cabrera Fernández D, Salinas HM, Puliafito CA. Automated detection of retinal layer structures on optical coherence tomography images. Opt Express 2005;13:10200-16.  Back to cited text no. 12
Ozdek SC, Erdinc MA, Gurelik G, Aydin B, Bahçeci U, Hasanreisoğlu B. Optical coherence tomographic assessment of diabetic macular edema. Comparison with fluorescein angiographic and clinical findings. Ophthalmologica 2005;219:86-92.  Back to cited text no. 13
Naliboff BD, Rosenthal M. Effects of age on complications in adult-onset diabetes. J Am Geriatr Soc 1989;37:838-42.  Back to cited text no. 14
Rema M, Premkumar S, Anitha B, Deepa R, Pradeepa R, Mohan V. Prevalence of diabetic retinopathy in urban India: The Chennai Urban Rural Epidemiology Study (CURES) eye study, I. Invest Ophthalmol Vis Sci 2005;46:2328-33.  Back to cited text no. 15
Dandona L, Dandona R, Naduvilath TJ, McCarty CA, Rao GN. Population based assessment of diabetic retinopathy in an urban population in southern India. Br J Ophthal 1999;83:937-40.  Back to cited text no. 16
Rema M, Shanthirani CS, Deepa R, Pradeepa R, Mohan V. Prevalence of diabetic retinopathy in a selected South Indian population—The Chennai Urban Population Study (CUPS). Diabetes Res Clin Pract 2000;50:S252.  Back to cited text no. 17
Sng CCA, Cheung CY, Man RE, Wong W, Lavanya R, Mitchell P et al. Influence of diabetes on macular thickness measured using optical coherence tomography: The Singapore Indian Eye Study. Eye 2012;26:690-8.  Back to cited text no. 18
Rodrigues EB, Urias MG, Penha FM, Badaró E, Novais E, Meirelles R et al. Diabetes induces changes in neuroretina before retinal vessels: A spectral-domain optical coherence tomography study. Int J Retina Vitreous 2015;1:4.  Back to cited text no. 19
Eriksson U, Alm A. Macular thickness decreases with age in normal eyes. A study on the macular thickness map protocol in the Stratus OCT. Br J Ophthalmol 2008;93:1448-52.  Back to cited text no. 20
Chan A, Duker JS, Ko TH, Fujimoto JG, Schuman JS. Normal macular thickness measurements in healthy eyes using Stratus optical coherence tomography. Arch Ophthalmol 2006;124:193-8.  Back to cited text no. 21
Massin P, Erginay A, Haouchine B, Mehidi AB, Paques M, Gaudric A. Retinal thickness in healthy and diabetic subjects measured using optical coherence tomography mapping software. Eur J Ophthalmol 2002;12:102-8.  Back to cited text no. 22
Yeung L, Sun CC, Ku WC, Chuang LH, Chen CH, Huang BY et al. Associations between chronic glycosylated haemoglobin (HbA1c) level and macular volume in diabetes patients without macular oedema. Acta Ophthalmol 2010;88:753-8.  Back to cited text no. 23
Chou TH, Wu PC, Kuo JZ, Lai CH, Kuo CN. Relationship of diabetic macular oedema with glycosylated haemoglobin. Eye 2009;23:1360-3.  Back to cited text no. 24
Lonneville YH, Ozdek SC, Onol M, Yetkin I, Gürelik G, Hasanreisoğlu B. The effect of blood glucose regulation on retinal nerve fiber layer thickness in diabetic patients. Ophthalmologica 2003;217:347-50.  Back to cited text no. 25
Gella L, Raman R, Rani PK, Sharma T. Spectral domain optical coherence tomography characteristics in diabetic retinopathy. Oman J Ophthalmol 2014;7:126-9.  Back to cited text no. 26
[PUBMED]  [Full text]  
Asefzadeh B, Fisch BM, Parenteau CE, Cavallerano AA. Macular thickness and systemic markers for diabetes in individuals with no or mild diabetic retinopathy. Clin Experiment Ophthalmol 2008;36:455-63.  Back to cited text no. 27
Biallosterski C, van Velthoven M, Michels R, Schlingemann RO, DeVries JH, Verbraak FD. Decreased optical coherence tomography-measured pericentral retinal thickness in patients with diabetes mellitus type 1 with minimal diabetic retinopathy. Br J Ophthalmol 2007;91:1135-8.  Back to cited text no. 28
Nilsson M, von Wendt G, Wanger P, Martin L. Early detection of macular changes in patients with diabetes using Rarebit Fovea Test and optical coherence tomography. Br J Ophthalmol 2007;91:1596-8.  Back to cited text no. 29
Verma A, Rani P, Raman R, Laxmi G, Gupta M, Sahu C. Is neuronal dysfunction an early sign of diabetic retinopathy? Microperimetry and SD-OCT study in individuals with diabetes, but no diabetic retinopathy. Eye 2009;23:1824-30.  Back to cited text no. 30
Schaudig UH, Glaefke C, Scholz F, Richard G. Optical coherence tomography for retinal thickness measurement in diabetic patients without clinically significant macular edema. Ophthal Surg Lasers Imag 2000;31:182-6.  Back to cited text no. 31
Lattanzio R, Brancato R, Pierro L, Bandello F, Iaccher B, Fiore T et al. Macular thickness measured by optical coherence tomography in diabetic patients. Eur J Ophthalmol 2002;12:482-7.  Back to cited text no. 32
Sugimoto M, Sasoh M, Ido M, Wakitani Y, Takahashi C, Uji Y. Detection of early diabetic change with optical coherence tomography in type 2 diabetes mellitus patients without retinopathy. Ophthalmologica 2005; 219:379-85.  Back to cited text no. 33
Fritsche P, Van der Heijde R, Suttorp-Schulten M, Polak BC. Retinal thickness analysis (RTA): An objective method to assess and quantify the retinal thickness in healthy controls and in diabetics without diabetic retinopathy. Retina 2002;22:768-71.  Back to cited text no. 34
Van Dijk HW, Kok PH, Garvin M, Sonka M, Devries JH, Michels RP et al. Selective loss of inner retinal layer thickness in type I diabetic patients with minimal diabetic retinopathy. Invest Ophthalmol Vis Sci 2009;50:3404-9.  Back to cited text no. 35
Oshitari T, Hanawa K, Adachi-Usami E. Changes of macular and RNFL thicknesses measured by Stratus OCT in patients with early stage diabetes. Eye 2009;23:884-9.  Back to cited text no. 36
Vujosevic S, Muraca A, Alkabes M, Villani E, Cavarzeran F, Rossetti L et al. Early microvascular and neural changes in patients with type 1 and type 2 diabetes mellitus without clinical signs of diabetic retinopathy. Retina 2017. doi: 10.1097/IAE.0000000000001990. PubMed PMID: 29206758. [Epub ahead of print].  Back to cited text no. 37
Oshitari T, Hanawa K, Adachi-Usami E. Changes of macular and RNFL thicknesses measured by Stratus OCT in patients with early stage diabetes. Eye 2009;23:884-9.  Back to cited text no. 38


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5]


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
Subjects and Methods
Article Figures
Article Tables

 Article Access Statistics
    PDF Downloaded382    
    Comments [Add]    

Recommend this journal