Benha Medical Journal

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 35  |  Issue : 1  |  Page : 13--19

Comparison between the effects of intravitreal and posterior subtenon injection of triamcinolone acetonide for treatment of diabetic macular edema


Mohamed A Soliman1, Ayman A Hamed1, Tarek Nehad1, Islam M. Abdelhakim Ali Metawee2,  
1 Department of Ophthalmology, Faculty of Medicine, Benha University, Benha, Egypt
2 Faculty of Medicine, Mansoura University, Mansoura, Egypt

Correspondence Address:
Islam M. Abdelhakim Ali Metawee
6th Floor Horya Building, Elshonaa Street, Belqas, Dakahliya, 35632
Egypt

Abstract

Aims Comparing the effect of intravitreal versus posterior subtenon injection of triamcinolone acetonide in treatment of diabetic macular edema. Settings and Design The study was conducted at Ophthalmology Department, Benha University Hospital in the period from march 2016 till september 2016. Material and methods This is prospective randomized longitudinal interventional comparative study including 30 eyes of patients with DME. Patients were divided into two groups. Group I included 15 eyes that received 4 mg of intravitreal triamcinolone acetonide injection. Group II comprised 15 eyes that received 40 mg of subtenon triamcinolone acetonide injection. Patients will be examined in the first post-injection day, then at 1st, 4th, 12th week interval after injection. At each visit full ophthalmological examination will be done . Central Macular Thickness (CMT) measurement with optical coherence tomography (at the 4th and 12th week). Statistical analysis Statistical Package of Social Sciences version 20 was used. P value of less than or equal (0.05) was considered statistically significant. Results There was no significant difference at 1 and 3 months (P > 0.05) as regards their post-treatment outcome for visual acuity and macular thickness. There was statistically significant difference in IOP change after 1 and 3 months after injection between the two groups, the change of IOP in the intravitreal injection group was greater than that of the posterior subtenon injection group. Conclusions Subtenon triamcinolone acetonide achieves results comparable to intravitreal injection as regards the reduction in CMT and the improvement in VA . However, Subtenon triamcinolone acetonide is safer.



How to cite this article:
Soliman MA, Hamed AA, Nehad T, Metawee IA. Comparison between the effects of intravitreal and posterior subtenon injection of triamcinolone acetonide for treatment of diabetic macular edema.Benha Med J 2018;35:13-19


How to cite this URL:
Soliman MA, Hamed AA, Nehad T, Metawee IA. Comparison between the effects of intravitreal and posterior subtenon injection of triamcinolone acetonide for treatment of diabetic macular edema. Benha Med J [serial online] 2018 [cited 2018 Jun 19 ];35:13-19
Available from: http://www.bmfj.eg.net/text.asp?2018/35/1/13/226424


Full Text



 Introduction



Diabetic retinopathy remains a major threat to sight in the developed world. Furthermore, it is increasing as a major cause of blindness in other parts of the world, especially in developing countries [1].

Diabetic macular edema (DME) is a general term defined as retinal thickening within two disc diameters of the foveal center; it can be either focal or diffuse in distribution [2].

Many studies including the Early Treatment Diabetic Retinopathy Study have demonstrated that macular photocoagulation is effective for the treatment of macular edema but does not usually restore vision loss occurring before treatment. Laser photocoagulation, however, only has a moderate effect in preventing further visual loss in about 50% of patients [3],[4],[5].

Among alternative treatments, triamcinolone acetonide (TA) has been reported to be effective against cases of DME when administered either by the intravitreal route [6],[7] or by the posterior subtenon route [8],[9]. In the present study, we prospectively compared the efficacy and safety of both treatment modalities, intravitreal TA treatment and posterior subtenon TA treatment, in the management of DME.

 Patients and methods



We carried out a prospective, randomized, longitudinal, interventional comparative study that included 30 eyes of 20 patients with diffuse DME, who attended the retina clinic at the Ophthalmology Department, Benha University Hospital, in the period between March 2016 and September 2016.

Inclusion criteria for the present study were as follows

Diffuse DME as defined in Early Treatment Diabetic Retinopathy Study.Retinal thickness in the central macular area (central 1 mm subfield) >300 μm by optical coherence tomography (OCT).Best corrected visual acuity (BCVA) of up to 0.5 or worse by Snellen’s charts.

Patients were excluded if they met any of the following criteria:Patients with other pathologies affecting the macula or vision.Patients with optic disc diseases with special concern to glaucoma or ocular hypertension [intraocular pressure (IOP) is 21 mmHg or more by Goldman’s tonometer].Patients who have undergone intraocular surgery or macular grid laser photocoagulation within 3 months before the injection.

Complete assessment was carried out as follows:Personal history taking:Age.Medical history.Past surgical history.Examination data: Complete ophthalmological examinationBCVA by Snellen’s charts.Anterior segment assessment by Topcon slit-lamp biomicroscopy.IOP measurement by Goldman’s applanation tonometer.Fundus examination by slit-lamp biomicroscopy using a Volk 90 diopter lens (Volk Optical Inc., 7893 Enterprise Drive Mentor, OH, USA).Retinal periphery was examined by indirect ophthalmoscopy using Volk 20 diopter lens. Investigations:Fundus fluorescein angiography.OCT.

Patients were classified into two groups, each composed of 15 eyes:

Group I underwent a single intravitreal injection of 4-mg TA.

Group II underwent a single subtenon injection of 40-mg TA.

Technique and performance of triamcinolone acetonide injection

All injections were administered in the operating rooms under complete aseptic conditions. After obtaining an informed written consent, the conjunctiva was anesthetized using benoxinate hydrochloride 0.4% drops.

Standard sterilization by povidone – iodine 10% – lid swabbing and instillation of Betadine 5% in the conjunctival sac were performed and the patient was draped.

Intravitreal triamcinolone acetonide

Four mg of TA (Kenacort-A; Bristol-Myers Squibb Company New York, Cairo, Egypt) was aspirated into an insulin syringe using a 23-G needle. The needle was then replaced by a 27-G needle for the injection.

The lower temporal bulbar conjunctiva was then exposed, and a caliper was used to mark 4 mm from the limbus. The needle was inserted at the mark towards the center of the globe till its hub. After injection, the needle was retracted. Antibiotic eye drops were subscribed for 1 week.

Subtenon triamcinolone acetonide

Overall 40 mg of triamcinolone acetonide (Kenacort-A; Bristol-Myers Squibb Company New York) was aspirated into an insulin syringe using a 23-G needle. The needle was then replaced by a subtenon injection cannula.

The superior temporal bulbar conjunctiva was then exposed, and a caliper was used to mark 8 mm from the limbus. A small buttonhole in the conjunctiva and tenon capsule was created at the mark using Wesscot scissors to access the subtenon space. Blood vessels were avoided. The cannula was passed into the subtenon space, and the drug was injected. Antibiotic eye drops were subscribed for 1 week.

Statistical analysis

Data were managed using Statistical Package of Social Sciences (version 20 for Microsoft Window; SPSS Inc., Chicago, Illinois, USA). Statistical significance tests were used, and a P-value of less than or equal 0.05 was considered statistically significant (at 95% level of confidence).

 Results



A total of thirty eyes with CSME were included in this study. All patients were Egyptians. Their pretreatment BCVA ranged from 0.05 to 0.50. The duration of diabetes mellitus ranged from 8 to 20 years. The central macular thickness (CMT) of the patients ranged from 303 to 786 μm. Their pretreatment IOP ranged from 13 to 19 mmHg. The eyes were randomly divided into two groups, each of 15 eyes. The first group underwent intravitreal injection of triamcinolone acetonide (IVTA), and the second group underwent posterior subtenon triamcinolone acetonide injection (STTA). All patients were followed-up for a period of 3 months.

Demographic study

Intravitreal injection of triamcinolone acetonide – group I

This group included 15 eyes of 10 patients. Their ages ranged between 50 and 71 years (mean+SD: 57.9+7.2). There were seven (46.67%) males and eight (53.33%) females ([Table 1]).{Table 1}

Posterior subtenon triamcinolone acetonide injection – group II

This group included 15 eyes of 10 patients. Their ages ranged between 55 and 64 years (mean+SD: 59.4+2.8). There were six (40.00%) males and nine (60.00%) females ([Table 1]).

Ocular study

Intravitreal injection of triamcinolone acetonide and subtenon triamcinolone acetonide injection with regard to visual acuity

[Table 2] shows statistically insignificant differences between the groups with regard to visual acuity (VA) using independent sample t-test, with a P-value of more than 0.05 NS over the follow-up period.{Table 2}

One month after injection, the mean VA in the IVTA group was 0.38 with three lines improvement from baseline, and the mean VA in the STTA group was 0.46, gaining an improvement of three lines from baseline (P=0.242).

Three months after injection, the IVTA group visual acuity was 0.31, while the STTA group visual acuity was 0.45 (P=0.083).

Intravitreal injection of triamcinolone acetonide and subtenon triamcinolone acetonide injection with regard to central macular thickness

[Table 3] shows no statistically significant difference between groups with regard to CMT, using independent sample t-test, with a P-value more than 0.05 NS. In the first month after injection, the difference was 151.4 μm in the IVTA group and 107.94 μm in the STTA group (=0.723).{Table 3}

Three months later, the difference was 163.2 μm in the IVTA group and 97.4 μm in the STTA group (P=0.324).

Intravitreal injection of triamcinolone acetonide and subtenon triamcinolone acetonide injection with regard to intraocular pressure

[Table 4] shows statistically significant differences between groups with regard to IOP over the follow-up period, using independent sample t-test, with a P-value less than 0.05 (significant).{Table 4}

One month after injection, there was a rise of 0–93 mmHg from baseline IOP in the STTA group, whereas in the IVTA group there was rise of 4.87 mmHg, with three eyes complicated by glaucoma (P=0.004).

Three months after injection, the difference in IOP from mean baseline values was 1.27 and 0.93 mmHg in the IVTA and STTA groups, respectively (P=0.017).

Complication

The rate of occurrence of complications showed that the IVTA group had three cases (three eyes) of glaucoma and three cases (three eyes) of progression of pre-existing cataract.

The STTA group had two cases (two eyes) of progression of pre-existing cataract. The number of patients suffering from drop in VA from baseline at the end of the follow-up period was higher in the STTA group (three eyes) than in the IVTA group (one eye) ([Figure 1] and [Figure 2]).{Figure 1}{Figure 2}

 Discussion



TA, which is a corticosteroid suspension, was demonstrated to reduce the breakdown of the blood–retinal barrier after intravitreal application [10] and was used to treat macular edema by means of anti-inflammatory, antiangiogenic, and blood–retinal barrier stabilizing effects.

In our study, we included 30 eyes with clinically significant macular edema divided into two groups of 15 eyes each. The first group was treated with IVTA, whereas the second group was treated with STTA.

This study demonstrates that intravitreal or posterior subtenon injection has a beneficial effect in reducing diabetic macular edema. The two groups did not show any significant difference in visual acuity or mean CMT thickness improvement after injection at the end of the follow-up period.

Visual acuity

In this study, the mean VA before injection was worse in the IVTA group (0.19) than in the STTA group (0.25), but this showed no statistical difference between both groups.

The improvement in visual acuity in the intravitreal group from baseline was statistically significant after 1 and 3 months. In addition, in the subtenon group, the improvement was statistically significant over the entire follow-up period.

Both groups showed no statistical difference in VA over the follow-up periods. This is in agreement with studies of Bakri and Kaiser [11] and Cellini et al. [12] that found both IVTA and STTA improved VA.

Central macular thickness

The change in mean CMT from baseline after intravitreal injection was statistically significant after 1 and 3 months. These results are similar to previous studies. Martidis et al. [13] reported that CMT decreased by 55 and 57.5% at 1 and 3 months after intravitreal triamcinolone injection, respectively.

The change in mean CMT from baseline after posterior subtenon injection was statistically significant after 1 and 3 months.

However, there was no statistical significance in the change in mean CMT between the two groups over the follow-up period after 1 month and 3 months, and this is in agreement with results from Choi et al. [14] and Luo et al. [15] who reported that both IVTA and STTA improve CMT, and subtenon triamcinolone injection is an alternative to intravitreal triamcinolone injection for DME.

Intraocular pressure

There was a statistically significant difference in IOP change after injection between the two groups at 1 and 3 months; the change in IOP in the intravitreal injection group was greater than that in the posterior subtenon injection group. This is in agreement with results of Choi and colleagues and Cellini and colleagues.

In the study by Choi et al. [14] there was a statistically significant difference in IOP after 3 months from baseline levels in the IVT group (P=0.072), but it was insignificant in the STTA group (P=0.292); there was also a statistically significant difference between the two groups after 3 months of follow-up (P=0.026) and posterior subtenon injection of TA had a comparable effect with intravitreal triamcinolone injection and showed a lower risk of elevated IOP.

In the study by Cellini et al. [12] there was also a statistically significant difference in IOP between the two groups after 1 (P<0.026) and 3 months (P<0.030), with the IVT group having high values.

Complications

The rate of complications was higher in the IVTA group:Cataract 20% (progression of pre-existing cataract).Secondary glaucoma 20%.

However, in the STTA group, only cataract was noticed in 13% of the patients.

Other complications such as endophthalmitis and retinal detachment were also reported following intravitreal injection in other studies, but none of these complications occurred in our study.

 Conclusion



TA is a long-acting steroid that is used for the treatment of DME whether by intravitreal or subtenon injection.

Subtenon TA achieves clinical results comparable with IVTA with regard to the reduction in CMT and improvement in VA.

Subtenon TA carries a lower rate of intraocular complications than IVTA injection and does not appear to affect the IOP.

Therefore, posterior subtenon injection of TA may be a good option for the treatment of diffuse DME, especially when corticosteroids are preferred over antivascular endothelial growth factor (anti-VEGF) in patients with cerebrovascular and cardiac thromboembolic problems.

In addition, posterior subtenon injection may offer a safe alternative route for corticosteroid delivery in conjunction with intravitreal anti-VEGF in patients with high values of CMT who respond poorly to anti-VEGF alone.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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