Comparison of the efficacy and safety of different methods of posterior subtenon injection.
OBJECTIVE
To compare the safety and efficacy of different methods of posterior subtenon (PST) injection of corticosteroids in the treatment of cystoid macular edema secondary to intermediate uveitis.


METHODS
Prospective comparative randomized interventional study.


METHODS
A total number of 30 eyes with cystoid macular edema secondary to intermediate uveitis were examined.


METHODS
Patients were randomized into 3 treatment groups of 10 eyes each. Each group received PST injection of triamcinolone acetonide 0.5 mL (20 mg) by one of three methods: cannula method (group 1), Smith and Nozik method (group 2), or orbital floor injection method (group 3). Patients underwent Snellen's and ETDRS visual acuity (VA) testing, clinical evaluation, optical coherence tomography (OCT), and fundus fluorescein angiography (FFA) at baseline and follow-up visits.


METHODS
Changes in Snellen and ETDRS VA, OCT retinal thickness and assessments of safety were recorded in follow-up visits.


RESULTS
Postintervention patients were followed up at the 1st, 2nd, 6th, and 12th weeks. Statistically significant (p = .00) improvement in VA was present in group1 from 0.25 +/- 0.08 (mean +/- standard deviation) to 0.75 +/- 0.24, in group 2 from 0.29 +/- 0.12 to 0.78 +/- 0.23, and in group 3 from 0.24 +/- 0.10 to 0.72 +/- 0.27. Statistically significant decrease in OCT central macular thickness (43.97% in group 1, 32.46% in group 2, and 29.75% in group 3) was noted at 12 weeks. However, the difference between individual groups at each visit did not reach statistical significance. Steroid-induced rise in intraocular pressure was observed in all the three groups with no statistical difference between individual groups.


CONCLUSIONS
The different methods of PST injection are equally efficacious in terms of improving visual acuity. However, the cannula method achieves the greatest quantitative reduction in macular thickness. As the cannula method is as efficacious as Smith and Nozik method it may be a preferable method to deliver posterior subtenon injection of corticosteroids.
Venkatesh
Pradeep
P
Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. venkyprao@yahoo.com
Kumar
Chandra Shekhar
CS
Abbas
Zahir
Z
Garg
Satpal
S
D002404:Catheterization; D003238:Connective Tissue; D005123:Eye; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D005938:Glucocorticoids / Q000008:administration & dosage*; D006801:Humans; D007267:Injections / Q000009:adverse effects* / Q000379:methods*; D007429:Intraocular Pressure / Q000187:drug effects; D008266:Macula Lutea / Q000187:drug effects / Q000473:pathology; D008269:Macular Edema / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D009915:Orbit; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014222:Triamcinolone Acetonide / Q000008:administration & dosage*; D015867:Uveitis, Intermediate / Q000150:complications; D014792:Visual Acuity / Q000187:drug effects
D005938:Glucocorticoids; D014222:Triamcinolone Acetonide