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ORIGINAL ARTICLE
Year : 2017  |  Volume : 4  |  Issue : 2  |  Page : 46-48

A study on evaluation of bevacizumab in the management of diabetic retinopathy


1 Department of Clinical Pharmacology, Batterjee Medical College, North Obhur, Jeddah 21442, Kingdom of Saudi Arabia
2 Department of Ophthalmologist, Prakash Eye Hospital, Sainagar, India
3 Pharm D Intern, Raghavendra Institute of Pharmaceutical Education and Research, Ananthapuramu, Andhra Pradesh, India
4 Department of Quality and Development, Batterjee Medical College, North Obhur, P.O. 6231, Jeddah 21442, Kingdom of Saudi Arabia

Date of Web Publication17-Nov-2017

Correspondence Address:
Mohammad Jaffar Sadiq
Department of Clinical Pharmacology, Batterjee Medical College, North Obhur, P.O. 6231, Jeddah 21442
Kingdom of Saudi Arabia
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/erj.erj_6_17

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  Abstract 


Aims: The study stands to evaluate the usage of bevacizumab against diabetic retinal neovascularisation. Materials and Methods: The outcome measures of study include the determination of visual acuity and retinal cum macular thickness after bevacizumab administration. Twenty diabetic retinopathy patients were screened for bevacizumab administration and given either one or two doses of bevacizumab. Patient's visual acuity and optical tomography's results were analyzed to determine the vision, retinal, and macular thickness. Statistical Analysis Used: The numeric results were passed through analysis of variance, employing “Student's t-test” as posttest for statistically determining the numeric outcomes. Results: Within 1 month of bevacizumab administration visual acuity (distant vision, near vision, and pinhole vision) was improved to logarithm of the minimum angle of resolution (MAR) 0.63 ± 0.07 from 0.87 ± 0.12 of distant vision. Pinhole vision was improved to log MAR 0.37 ± 0.06 from 0.478 ± 0.07 and near vision was improve to log MAR 0.477 ± 0.071 from 0.528 ± 0.069, and retinal thickness was decreased to 336 ± 17.35 μm from 429 ± 30.20 μm. Mean macular thickness was improved to 363.75 ± 24.54 μm from 452.37 ± 30.99 μm. Conclusion: Hence, the off-label use of bevacizumab for the said treatment may be proven beneficial.

Keywords: Bevacizumab, macular thickness, retinal thickness, visual acuity


How to cite this article:
Sadiq MJ, Zaki AA, Rao BP, Vaasanthi P, Thriveni K, Prasad P S, Rudra J T, Imran F. A study on evaluation of bevacizumab in the management of diabetic retinopathy. Egypt Retina J 2017;4:46-8

How to cite this URL:
Sadiq MJ, Zaki AA, Rao BP, Vaasanthi P, Thriveni K, Prasad P S, Rudra J T, Imran F. A study on evaluation of bevacizumab in the management of diabetic retinopathy. Egypt Retina J [serial online] 2017 [cited 2017 Dec 11];4:46-8. Available from: http://www.egyptretinaj.com/text.asp?2017/4/2/46/218588




  Introduction Top


Diabetes in long-term may affect organs such as kidney, heart, brain, and eye and produce secondary complications such as retinopathy, nephropathy, ketoacidosis, and organ dysfunction.[1]

Diabetic retinopathy is a microvascular complication that affects the retina and becoming one of the leading causes of the blindness and accounts for almost 5% of total blind people of the world among the age group of 20–60 years. As on date, approximately 93 million people are identified to be suffering with diabetic retinopathy out of which, 17% were identified to be suffering with proliferative retinopathy, 21 million people were with diabetic macular edema, 28 million people were with vision-threatening diabetic retinopathy.[2] In Asian countries like India, the most common reason of blindness is improper correcting of the vision, and related issues as add on to the blindness, India may double the number of diabetic cases by 2025 which may increase the risk of retinal complications further.[1],[3]

Bevacizumab is a vascular endothelial growth factor A (VEGF-A) inhibitor and plays a significant role in inhibition of the growth of blood vessels.[4] Its off-label application in the treatment of diabetic retinopathy is very high. Hence, the present study was designed to study the efficacy of the bevacizumab in the management of diabetic retinopathy.


  Materials and Methods Top


It is a prospective, observational, and unicenter study which was carried out for 6 months at a ophthalmic hospital of a town in Andhra Pradesh, and the study was approved by the Institutional Review Board with number RIPER/IRB/2014/03.

A total of 20 diabetic retinopathy participants aged above 40 years suffering from diabetic maculopathy, retinopathy, and intended to be administered with bevacizumab were included in the study, of which 16 participants responded very well during both sessions, i.e., baseline study and follow-up, where as four participants were considered follow-up failures. Participants with other complications were excluded from the study.

Participants who were previously given other treatments such as panretinal photocoagulation and grid laser therapy were also included in the study. All the patients were administered with intravitreal bevacizumab at a dose of 1.25 or 2.5 mg basing upon the requirement by the ophthalmologist. Both baseline data and follow-up data of the patients were collected basing upon the guidance of the ophthalmologist. Outcome measures included in the study were visual acuity, retinal thickness, and mean macular thickness. Retinal thickness and macular thickness was identified using optical coherence tomography. Visual acuity was analyzed using Snellen chart.

The obtained numeric results were put to the test through analysis of variance, and the results are represented in mean ± standard error of mean with their relative probabilities expressed as P*, unpaired t-test (Student's t-test) was employed to study as post t-test for the results of different parameters. The difference was considered statistically significant if the P* value is lower than or equals to 0.05.


  Results Top


Of 20 patients, seven patients had laser therapy before intravitreal bevacizumab administration (35%) and remaining was only administered with bevacizumab. All patients were diagnosed with diabetic retinopathy using optical coherence tomography, and the results were expressed as the baseline values [Table 1].
Table 1: Details of the patients (n=20)

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Within 1 month of intravitreal bevacizumab administration visual acuity (distant vision, near vision, and pinhole vision) was measured again and the improvement was expressed through decrease in logarithm of the minimum angle of resolution (MAR) values to 0.63 ± 0.07 from 0.87 ± 0.12 of distant vision (P = 0.1401). Pinhole vision was improved to log MAR 0.37 ± 0.06 from 0.478 ± 0.07 (P = 0.2956) and near vision was improve to log MAR 0.477 ± 0.071 from 0.528 ± 0.069 (P = 0.6149) [Table 2].
Table 2: Values of logarithm of the minimum angle of resolution before and after the treatment

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Optical coherence tomography results were available for only 16 cases as four participants were considered as follow-up failures. One month after the bevacizumab administration mean retinal thickness was reduced to 336 ± 17.35 μm from 429 ± 30.20 μm (P < 0.05*). Mean macular thickness was improved to 363.75 ± 24.54 μm from 452.37 ± 30.99 μm (P < 0.05*). The distant vision was much improved in comparison to near vision (P > 0.05*). As bevacizumab is an anti-VEGF agent, it markedly decreases the proliferation of newer blood vessels which shall be considered beneficial outcome in case of diabetic retinopathy. Study also identifies that the retinal thickness and macular thickness was decreased by significant level (P < 0.05*) and the results are expressed below [Table 3].
Table 3: Values of retinal and macular thickness before and after the treatment

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  Discussion Top


Blindness remains a serious health problem in many developing countries. It is estimated that there are 38 million people who have visual impairment and are at risk of becoming blind though the exact number of people who are at the brink of becoming blind are not known. The prevalence of blindness in developing countries is 10–40 times higher than in developed countries and three-fourth of the world's blindness is either preventable or curable.[5]

Excess proliferation of newer blood vessels may cause vision threatening in diabetic retinopathy. The process of proliferation passes through the involvement of many chemical mediators including cytokines and VEGF plays an important role as one among them.[6] There are several cases reported related to the use of anti-VEGF agents (bevacizumab) in the management of retinal neovascularisation in participants suffering with diabetic retinopathy with beneficial outcomes. These anti-VEGF agents came on to the screen recently, and have been used for the management of ocular neovascularisation worldwide.[6]

Visual acuity (distant vision, near vision, and pinhole vision) was expressed as log MAR values and optical coherence tomography was performed to analyze retinal and macular thickness; vision was corrected to the possible extent and the mean retinal and macular thickness was decreased after the bevacizumab administration which may be attributed to the decreased angiogenesis after the administration of bevacizumab (P = 0.013* for retinal thickness and P = 0.031* for macular thickness).

A phase II randomized clinical trial was performed and the outcomes were reported as beneficial in the favor of usage of bevacizumab in the treatment of diabetes-related macular disorders,[7] which coinsides with the outcome of the current study. It is not a contradicting explanation but geographically differences have not altered any result outcomes.

In an independent study, which was carried out by Arevalo et al. with the multiple administration of bevacizumab through intravitreal route using avastin a branded preparation of bevacizumab has resulted in reducing the macular thickness and proliferative diabetic retinopathy and the results parallels with the findings of the current study.[8] Where the bevacizumab was administered only once. The difference in the frequency of drug administration is independent decision of the ophthalmologist which may be changed depending upon the decision making needs.

An internet-based safety assessment of bevacizumab has revealed that there is most number of adverse reactions reported in the participants worldwide with the incidence rate (ratio) of less than one. This shall be further explained as that there are adverse drug reactions noticed after the administration of bevacizumab but at less incidence rates.[9]

Hence, the results obtained in the current study and the comparison with other such studies at geographically different regions has proved that the off-label use of bevacizumab in the treatment of retinal disorders in diabetic patients may be considered beneficial with least adverse events.


  Conclusion Top


The study concludes that the usage of Bevacizumab may be acceptable in the management of Diabetic Retinopathy, where a thorough research like a systemic review or a meta analysis of the titled study may provide concrete solid evidence in the justification of usage of Bevacizumab in the management of Diabetic Retinopathy.

Acknowledgment

All the authors are especially thankful to all the people who are directly or indirectly involved in the study till the successful completion.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Sadiq MJ, Bheemachari, Kumar S, Vigneshwaran E, Balaji K. A study on antidiabetic potency of mixture of powders of dried fruits of Eucalyptus globules and rhizomes of Curcuma zedoaria. RJPBCS 2011;2:326-32.  Back to cited text no. 1
    
2.
Simó R, Hernández C. Intravitreous anti-VEGF for diabetic retinopathy: Hopes and fears for a new therapeutic strategy. Diabetologia 2008;51:1574-80.  Back to cited text no. 2
    
3.
Rohilla A, Kumar R, Rohilla S, Kushnoor A. Diabetic retinopathy: Origin and complications. Eur J Exp Biol 2012;2:88-94.  Back to cited text no. 3
    
4.
Sajida S, Jaffar SM, Balaji K, Narayana G. A possible case of complete loss of vision after intra ocular administration of bevacizumab: Case report. Indian J Pharm Pract 2013;6:82-3.  Back to cited text no. 4
    
5.
Tabbara KF. Blindness in the eastern Mediterranean countries. Br J Ophthalmol 2001;85:771-5.  Back to cited text no. 5
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6.
Arevalo JF, Wu L, Sanchez JG, Maia M, Saravia MJ, Fernandez CF, et al. Intravitreal bevacizumab (avastin) for proliferative diabetic retinopathy: 6-months follow-up. Eye (Lond) 2009;23:117-23.  Back to cited text no. 6
[PUBMED]    
7.
Scott IU. A phase II randomised clinical trial of intravitreal bevacizumab for diabetic macular edema. Ophthalmology 2007;114:1860-7.  Back to cited text no. 7
    
8.
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;114:743-50.  Back to cited text no. 8
[PUBMED]    
9.
Fung AE, Rosenfeld PJ, Reichel E. The International Intravitreal Bevacizumab Safety Survey: Using the internet to assess drug safety worldwide. Br J Ophthalmol 2006;90:1344-9.  Back to cited text no. 9
[PUBMED]    



 
 
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  [Table 1], [Table 2], [Table 3]



 

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