Subtenon Injection Research Articles

Safety and pharmacodynamics of suprachoroidal injection of triamcinolone acetonide as a controlled ocular drug release model

Suprachoroidal injection is an emerging technique for drug delivery to the posterior segment, which is hard to reach by non-invasive approaches. However, the injection technique varies and the associated ocular safety is not well understood. In addition, it is not clear if drug formulation is a major factor in optimizing pharmacodynamics using this technique. The current study was designed to compare the suprachoroidal injection of different drug formulations and to characterize the safety and pharmacodynamics of triamcinolone acetonide (TA) delivered by this technique. Both indocyanine green (ICG) solution and TA suspension, at 50μL, 100μL, and 150μL, were suprachoroidally injected and intraocular pressure (IOP) tonometry, fundus photography, and electroretinography were performed over multiple time points up to eight weeks. After 50μL TA (Kenalog-40) suprachoroidal injection, 4–5 animals at 7 time points were sacrificed for aqueous, vitreous, retina, and plasma collections. TA was quantitated using ultra-performance liquid chromatography tandem mass spectrometry. For comparative efficacy study, 50μL (2mg) suprachoroidal TA versus 20mg subtenon TA were performed 4weeks before induction of experimental uveitis with 10ng of intravitreal lipopolysaccharide. After suprachoroidal injection, IOP had an acute elevation, higher volume caused higher IOP (p<0.0001). Equivalent volume of ICG solution led to a significantly smaller IOP elevation than after TA suprachoroidal injection. This finding suggests better distribution of ICG solution than TA suspension in the suprachoroidal space. Following a 50μL suprachoroidal injection, peak TA concentration in the aqueous was below 1ng/mL. In contrast, the posterior vitreous and retina had 1912ng/mL and 400,369ng/mL TA, respectively. Maximum TA in plasma was 11.6ng/mL. Drug exposure to the posterior retina was 523,910 times more than that to the aqueous and 29,516 times more than systemic TA exposure. In the treatment of lipopolysaccharide-induced uveitis, compared with 20mg subtenon injection, suprachoroidal 2mg TA demonstrated much better efficacy with significantly less aqueous humor cells and lower vitreous opacity scores (p<0.05). Histology showed much less vitreous inflammation in the suprachoroidal injection group (p<0.0001). It seems that a 50μL suprachoroidal injection of TA was well tolerated in rabbit eyes and demonstrated excellent penetration into the posterior retina, providing better therapeutic effect than subtenon 20mg TA.

Hypersensitivity to sub-Tenon's topotecan in fibrin adhesive in patients with retinoblastoma

Sub-Tenon's space delivery of topotecan in a fibrin sealant was used as an adjunct to laser therapy for small retinoblastoma tumors in 25 children (77 injections). We report serious hypersensitivity reactions in 2 children on their third sub-Tenon's injection of topotecan in fibrin sealant. One child subsequently had topotecan in an autologous blood clot with no allergic reaction. Although allergic reaction to topotecan has been reported in the literature, fibrin glue reactions are more common and are likely due to aprotinin hypersensitivity.

Optical coherence tomographic reflectivity of cystoid spaces is related to recurrent diabetic macular edema after triamcinolone.

To determine the association between reflectivity levels in foveal cystoid spaces on optical coherence tomography images and the course of the logarithm of the minimum angle of resolution (logMAR) after triamcinolone acetonide treatment for diabetic macular edema. We retrospectively reviewed 58 consecutive eyes treated with an intravitreal or sub-Tenon's injection of triamcinolone acetonide for diabetic macular edema. The foveal cystoid spaces within central 1 mm were circumscribed, followed by measurement of optical coherence tomography reflectivity. The correlation between the reflectivity and visual outcome was investigated. The optical coherence tomography reflectivity levels in foveal cystoid spaces increased at 1 month after treatment, but not at 3 months or 6 months. The preoperative reflectivity levels were correlated negatively with logMAR changes from 1 month to 6 months and from 3 months to 6 months but not with logMAR at individual time points compared with the preoperative logMAR. The changes in foveal thickness from 1 month to 6 months were correlated negatively with the baseline reflectivity and positively with logMAR changes from 1 month to 6 months and from 3 months to 6 months. Lower optical coherence tomography reflectivity in foveal cystoid spaces was associated with the rebound in macular thickening and visual deterioration after triamcinolone acetonide treatment for diabetic macular edema.

Stem Cell Ophthalmology Treatment Study (SCOTS) for retinal and optic nerve diseases: a case report of improvement in relapsing auto-immune optic neuropathy.

We present the results from a patient with relapsing optic neuropathy treated within the Stem Cell Ophthalmology Treatment Study (SCOTS). SCOTS is an Institutional Review Board approved clinical trial and has become the largest ophthalmology stem cell study registered at the National Institutes of Health to date (www.clinicaltrials.gov Identifier NCT 01920867). SCOTS utilizes autologous bone marrow-derived stem cells (BMSCs) for treatment of retinal and optic nerve diseases. Pre-treatment and post-treatment comprehensive eye exams of a 54 year old female patient were performed both at the Florida Study Center, USA and at The Eye Center of Columbus, USA. As a consequence of a relapsing optic neuritis, the patient's previously normal visual acuity decreased to between 20/350 and 20/400 in the right eye and to 20/70 in the left eye. Significant visual field loss developed bilaterally. The patient underwent a right eye vitrectomy with injection of BMSCs into the optic nerve of the right eyeand retrobulbar, subtenon and intravitreal injection of BMSCs in the left eye. At 15 months after SCOTS treatment, the patient's visual acuity had improved to 20/150 in the right eye and 20/20 in the left eye. Bilateral visual fields improved markedly. Both macular thickness and fast retinal nerve fiber layer thickness were maximally improved at 3 and 6 months after SCOTS treatment. The patient also reduced her mycophenylate dose from 1,500 mg per day to 500 mg per day and required no steroid pulse therapy during the 15-month follow up.

Sub-Tenon Injections of Triamcinolone Acetonide Had Limited Effect on Cystoid Macular Edema Secondary to Nanoparticle Albumin-Bound-Paclitaxel (Abraxane).

Purpose. To report the first case of cystoid macular edema (CME) induced by nanoparticle albumin-bound- (nab-) paclitaxel treated with sub-Tenon injections of triamcinolone acetonide (STTA) with detailed long-term follow-up. Case. A 39-year-old Japanese woman with breast cancer presents with decreased vision in both eyes while receiving nab-paclitaxel. Two STTA treatments were administered for persistent CME in her right eye. Central retinal thickness (CRT) of the treated eye decreased after the first STTA, but there was no change after the second STTA. CRT of the other eye and bilateral visual acuity (VA) showed no change after each treatment. However, this patient experienced gradual recovery of visual function after nab-paclitaxel treatment was completed, 3 months after the second STTA. Improvements in VA and CRT did not overlap in time. Moreover, there was a big improvement time lag in VA between the eyes. Conclusion. Cessation of nab-paclitaxel could lead to resolution of CME more than STTA, although STTA had some effect. Since nab-paclitaxel has been recently approved for treating more types of malignancies, the number of the patients with this CME is expected to increase in the near future. Patients and physicians should understand this side effect and prepare for other treatment options.

Effect of Posterior Subtenon Triamcinolone Injection during Vitrectomy for Idiopathic Epiretinal Membrane

Purpose: To evaluate the effect of posterior sub-Tenon triamcinolone acetonide injection combined with vitrectomy for idiopathic epiretinal membrane (ERM). Methods: This study included 40 eyes of 40 patients who underwent vitrectomy and membrane peeling for idiopathic ERM. Triamcinolone acetonide (40 mg) was injected into the posterior sub-Tenon space following vitrectomy in 20 eyes of the injected group. The other 20 eyes that did not receive the injection were selected as the control group to match preoperative visual acuity and central macular thickness with the injected group. Preand postoperative best-corrected visual acuity, central macular thickness, intraocular pressure, and complications were compared between the 2 groups. Results: The average visual acuity in the injected group improved from 0.56 ± 0.23 (log MAR) at baseline to 0.52 ± 0.36 at 1 month, 0.44 ± 0.39 at 3 months, and 0.38 ± 0.41 at 6 months postoperatively. Central macular thickness decreased from 456.2 ± 86.2 to 399.0 ± 60.1 at 1 month, 377.1 ± 71.5 at 3 months, and 353.1 ± 57.4 at 6 months postoperatively. In the control group, average visual acuity improved from 0.56 ± 0.23 at baseline to 0.53 ± 0.25 at 1 month, 0.41 ± 0.20 at 3 months, and 0.37 ± 0.24 at 6 months postoperatively. Central macular thickness decreased from 456.4 ± 74.8 to 394.9 ± 63.5 at 1 month, 377.2 ± 56.8 at 3 months, and 358.0 ± 57.2 at 6 months postoperatively. Significant differences in visual acuity and central macular thickness were not observed between the 2 groups before surgery and during the follow-up period. Intraocular pressure and complications were similar. Conclusions: Posterior sub-Tenon injection of triamcinolone acetonide combined with vitrectomy for idiopathic epiretinal membrane did not affect postoperative anatomical and functional outcomes. J Korean Ophthalmol Soc 2015;56(8):1236-1241

Uveal effusion associated with an IgM lambda subtype monoclonal gammopathy

Case reportA 68-year-old man was referred to the hospital with progressive decreased vision in the right eye over the past year. A moderate cataract and annular choroidal thickening were found. The diagnosis of uveal effusion was confirmed by ultrasound and fluorescein and indocyanine green angiography. Laboratory studies showed an IgM lambda subtype monoclonal gammopathy of undetermined significance. The patient underwent cataract surgery, and a sub-Tenon's triamcinolone injection with a satisfactory short-term outcome. ConclusionThis association has not been previously reported, and it shows that IgM lambda subtype monoclonal gammopathy of undetermined significance should be added to the list of disorders associated with uveal effusion.

Bilateral inferior oblique muscle paresis after posterior subtenon injection of triamcinolone acetonide

Posterior subtenon injections of steroidal drugs are commonly used to treat various chorioretinal inflammatory diseases. Subsequent strabismus is rare, but it is associated with severe visual disturbance when present. We report a case of simultaneous bilateral inferior oblique muscle paresis in a 60-year-old man who developed it after receiving intravitreal injections of bevacizumab and posterior subtenon injections of triamcinolone acetonide for the treatment of diabetic macular edema. The patient complained of excessive pain during the injections, which were performed at the 6 o'clock position in both eyes. According to the literature, inferior oblique muscle paresis after posterior subtenon injections is rare. This complication may be prevented by proper selection of the injection site and paying attention to any unusual patient complaints during the procedure.

Purtscher-like Retinopathy Associated with Systemic Lupus Erythematosus

Purpose: To report on clinical manifestations of Purtscher-like retinopathy (PLR) associated with systemic lupus erythematosus (SLE) and visual outcomes.Methods: We performed a retrospective cohort study of 11 patients (21 affected eyes) with PLR in SLE.Results: All patients were treated with systemic corticosteroids ± immunosuppressive agents. Ocular therapy included intravitreal injections with bevacizumab in 18/21 eyes and posterior sub-Tenon injections with triamcinolone acetonide 13/21 eyes. Panretinal photocoagulation (PRP) was performed in 19/21 eyes and pars plana vitrectomy was required in 5/21 eyes. Visual improvement was found at follow-up of 3 and 6 months (p = 0.05). Poor visual outcome was associated with presence of neovascularizations at onset (p = 0.009), development of vitreous hemorrhage during PRP (p = 0.015), and active status of SLE after onset of PLR (p = 0.029).Conclusions: PLR might manifest as a devastating complication of SLE. We recommend treating any systemic activity of SLE and starting an early ocular treatment.

Sub-tenon Anaesthesia versus Intracameral Anaesthesia in Patients Undergoing Cataract Extraction: A Comparative Study of the Level of Pain, Visual Perception and Anxiety

Background: Phacoemulsification is a modern method of cataract extraction. Sub-tenon anaesthesia used to be the preferred anaesthetic technique for this procedure before intracameral anaesthesia gained its popularity in recent years. Nevertheless, many surgeons still believe that sub-tenon anaesthesia is better than topical anaesthesia. This study aimed to evaluate and compare the experiences of patients who were treated for cataract by phacoemulsification surgery using either sub-tenon or intracameral anaesthesia. Methods: Cross-sectional study conducted at Universiti Kebangsaan Malaysia Medical Centre, Kuala Lumpur, Malaysia. Participants were asked to complete a questionnaire within 1-2 hours following surgery. The questionnaires were designed to gather information on the patient’s level of anxiety, visual perception and amount of pain experienced during cataract surgery. Results: A total of 62 patients were included in the study. Thirty-one patients received anaesthesia by sub-tenon injection, whereas another 31 patients received anaesthesia by intracameral injection. There were no significant differences in the level of pain experienced by the two groups of patients during instillation of anaesthesia and during surgery (p=0.205 and p=0.592, respectively). There were also no significant differences in terms of visual perception and anxiety levels during surgery between the two groups (p=0.178 and p=0.731, respectively). Conclusion: Intracameral anaesthesia obviates the need for an injection during cataract surgery and is as comfortable for patients as sub-tenon anaesthesia in terms of visual perception, level of pain, and anxiety.

532 laser photocoagulation combined with posterior sub-Tenon injection of triamcinolone acetonide in treatment of diffused diabetic macular edema

532 laser photocoagulation combined with posterior sub-Tenon injection of triamcinolone acetonide in treatment of diffused diabetic macular edema

Effects of sub-Tenon’s anaesthesia on ocular hemodynamics

ObjectiveTo research the effects of sub-Tenon’s anaesthesia (STA) on ocular hemodynamics in patients with cataract using colour Doppler imaging (CDI). DesignProspective clinical study. ParticipantsThirty-four eyes of 34 patients with age-related cataract. MethodsPeak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI) values of the ophthalmic artery (OA), central retinal artery, and central retinal vein were measured by CDI before and immediately after performing sub-Tenon block using 2 mL of 2% lidocaine with adrenaline (1:200 000). ResultsBoth PSV and EDV values were significantly decreased after sub-Tenon injection in all the studied vessels of the patients. However, no important changes were observed in the RI values of the vessels. ConclusionsSTA markedly reduced ocular blood flow. The reduction may be more acceptable compared with other retrobulbar block methods. Sub-Tenon block should be performed carefully to senile patients with cataract with vascular occlusive disorder.

Cystoid Macular Edema from Cancer-Associated Retinopathy

This article reviews the diagnosis and management of a patient with cancer-associated retinopathy (CAR) secondary to small cell lung cancer who developed a rare presentation of CAR, cystoid macular edema (CME). CAR is a rare cause of unexplained, often rapid, visual acuity and visual field loss. A 67-year-old man with a recent history of photopsias and simultaneous dimming of vision presented to our clinic. Four months before, he had been diagnosed with small cell lung cancer. Retinal examination was normal, but the visual field was severely constricted. He was referred for an electroretinogram and an evaluation by a retina specialist because of a strong suspicion of CAR, which was confirmed. Despite a lack of strong clinical evidence for the treatment of CAR, and no clinical recommendations for CME found in CAR, our patient's CME was initially treated with diclofenac QID and, subsequently, a sub-tenon injection of triamcinolone. Since his diagnosis of CME, he has been chronically managed with diclofenac QID to treat his edema, with relatively stable visual acuity. His visual fields remain highly constricted. CAR is a rare form of painless bilateral vision loss in patients with a history of cancer. Our patient developed CME from his CAR, and was treated with diclofenac and sub-tenon injections of triamcinolone. Despite potential options for treatment, none have demonstrated much efficacy, and the visual prognosis is typically poor.

Viral Retinitis following Intraocular or Periocular Corticosteroid Administration: A Case Series and Comprehensive Review of the Literature

Purpose: To describe viral retinitis following intravitreal and periocular corticosteroid administration.Methods: Retrospective case series and comprehensive literature review.Results: We analyzed 5 unreported and 25 previously published cases of viral retinitis following local corticosteroid administration. Causes of retinitis included 23 CMV (76.7%), 5 HSV (16.7%), and 1 each VZV and unspecified (3.3%). Two of 22 tested patients (9.1%) were HIV positive. Twenty-one of 30 (70.0%) cases followed one or more intravitreal injections of triamcinolone acetonide (TA), 4 (13.3%) after one or more posterior sub-Tenon injections of TA, 3 (10.0%) after placement of a 0.59-mg fluocinolone acetonide implant (Retisert), and 1 (3.3%) each after an anterior subconjunctival injection of TA (together with IVTA), an anterior chamber injection, and an anterior sub-Tenon injection. Mean time from most recent corticosteroid administration to development of retinitis was 4.2 months (median 3.8; range 0.25–13.0). Twelve patients (40.0%) had type II diabetes mellitus. Treatments used included systemic antiviral agents (26/30, 86.7%), intravitreal antiviral injections (20/30, 66.7%), and ganciclovir intravitreal implants (4/30, 13.3%).Conclusions: Viral retinitis may develop or reactivate following intraocular or periocular corticosteroid administration. Average time to development of retinitis was 4 months, and CMV was the most frequently observed agent. Diabetes was a frequent co-morbidity and several patients with uveitis who developed retinitis were also receiving systemic immunosuppressive therapy.

In Vivo Intraocular Distribution and Safety of Periocular Nanoparticle Carboplatin for Treatment of Advanced Retinoblastoma in Humans

To study the intraocular distribution and safety of polymethylmethacrylate nanoparticles loaded with carboplatin after posterior subtenon injection in humans. Prospective, interventional, comparative case series. Six patients (mean age: 26.83 ± 7.5 years), scheduled to undergo planned uniocular enucleation in aninstitutional setting, were randomly divided into 3 groups. Each group received a 10mg/mL posterior subtenon injection of nanoparticle carboplatin in the eye to be enucleated. Two eyes were enucleated 6, 24 and 72 hours post injection. Intravenous blood was collected during enucleation. The concentration of carboplatin reaching various intraocular tissues was determined by inductively coupled plasma atomic emission spectroscopy. The drug toxicity in the ocular tissues was assessed by histopathology and high-resolution transmission electron microscopy. The highest level of carboplatin was detected in retinas (8.33 ± 1.69mg/g), up to 24 hours post treatment. The intravitreal concentration continued to increase gradually until 72 hours (3.46 ± 0.26mg/g). The choroids and lenses showed very low levels of carboplatin after 6 hours, with negligible amounts at 72 hours. No signs of tissue damage were observed on histopathology or electron microscopy. Intravenous concentration of carboplatin was undetectable in all patients. Results may indicate an increased facilitated trans-scleral transport of nanoparticle carboplatin, with a sustained-release behavior but without any associated short-term ocular or systemic side effects in humans. The very high concentrations achieved in vitreous and retina after a single posterior subtenon injection may be clinically useful for adjunctive treatment of advanced intraocular retinoblastoma with vitreous seeds. However, further studies are needed to assess long-term toxicity andclinical efficacy.

Randomized controlled trial to evaluate intraocular pressure following sub-Tenon's local anesthesia for cataract surgery: With and without hyaluronidase added to anesthetic solution.

Aim:To evaluate effect on intraocular pressure (IOP) during sub-Tenon's local anesthesia (LA) during cataract surgery with 4 ml of anesthetic injected without and with addition of hyluronidase to anesthetic solution.Materials and Methods:This randomized controlled study included 65 eyes of 65 patients undergoing phacoemulsification and lens implant for cataract. The patients were randomized to a standardized procedure of administration of 4 ml of sub-Tenon's LA without and with addition of 15 IU/ml hylaluronidase to 2% lidocaine (control group and intervention group respectively). IOP measurements were carried out immediately prior to and at 2, 5, and 10 and 15 min after sub-Tenon's injection using a hand held tonometer (Tonopen).Results:All patients achieved satisfactory akinesia and complete analgesia during surgery. The mean age of patients in control group was 59.56 ± 14.3 years, and 61.77 ± 11.91 years in intervention group (P = 0.507). The mean preinjection and 15 min IOP was 19.16 ± 4.39 and 20.21 ± 5.49 mm Hg, respectively in control group (P = 0.220); and 19.81 ± 3.8 and 19.68 ± 5.19 mmHg respectively in intervention group (P = 0.911). No statistical difference from baseline was detected between preinjection and at 2, 5, 10, and 15 min after injection in control (P = 0.124, 0.310, 0.804, 0.220, respectively) and intervention group (P = 0.367, 0.879, 0.765, 0.911 respectively).Conclusion:No significant rise in IOP occurs following injection of sub-Tenon's LA, when up to 4 ml of anesthetic is injected. The addition of hyaluronidase to 2% lignocaine has no beneficial lowering effect on IOP in sub-Tenon's LA. Hence, the practice of addition of this agent may not be necessary during cataract surgery.

Intravitreal versus subtenon injection of triamcinolone acetonide for diabetic macular edema

ObjectiveThe aim of this study was to compare the results of intravitreal injection with subtenon injection of triamcinolone in diabetic macular edema (DME).BackgroundTriamcinolone injection for DME.Patents and methodsThe study is a prospective randomized clinical trial including 80 eyes of patients with DME. Patients were divided into two groups: group I and group II. Group I (73.1% men and 26.9% women; mean age 55.7 ± 7.2 years) included 40 eyes that received 4 mg of intravitreal triamcinolone acetonide injection. Group II (65.5% men and 34.5% women; mean age 55.8 ± 7.9 years) comprised 40 eyes that received 40 mg of subtenon triamcinolone acetonide injection. The patients were followed up after 1 week and 1, 3, and 6 months later to assess best-corrected visual acuity, intraocular pressure, and macular thickness. Fluorescein angiography and optical coherence tomography were used to evaluate the improvement.ResultsThere was a statistically significant difference between the studied groups at 1 week and 1 month (P < 0.05) and no significant difference at 3 and 6 months (P > 0.05) as regards their post-treatment outcome for visual acuity, and there was no statistically significant difference between the studied groups at 1 and 6 months (P > 0.05) as regards their post-treatment outcome for macular thickness.ConclusionBoth intravitreal and subtenon triamcinolone injections cause a significant increase in visual acuity; the effect is early and more pronounced in the intravitreal group but subtenon injection is safer.

Efusión uveal asociada a gammapatía monoclonal de significado indeterminado tipo IgM lambda

Case reportA 68-year-old man was referred to the hospital with progressive decreased vision in the right eye over the past year. A moderate cataract and annular choroidal thickening were found. The diagnosis of uveal effusion was confirmed by ultrasound and fluorescein and indocyanine green angiography. Laboratory studies showed an IgM lambda subtype monoclonal gammopathy of undetermined significance. The patient underwent cataract surgery, and a sub-Tenon's triamcinolone injection with a satisfactory short-term outcome. ConclusionThis association has not been previously reported, and it shows that IgM lambda subtype monoclonal gammopathy of undetermined significance should be added to the list of disorders associated with uveal effusion.

Intraoperative Sub-Tenon Injection Increases Optic Nerve Length Transection During Enucleation

To determine the effect of sub-Tenon injection on the length of optic nerve resected during enucleation. Case-control laboratory study on 22 orbits of 11 unpreserved, fresh-frozen human cadavers. Each cadaver underwent a conventional enucleation technique on one side and an otherwise identical technique on the contralateral side that included sub-Tenon injection of 2.5 ml normal saline in each oblique quadrant. Resected optic nerve lengths were measured and compared using Student t tests. The mean optic nerve length was 15.2 mm (range, 5.0-21.0 mm) in the sub-Tenon injection group and 11.3 mm (range, 5.0-19.0 mm) in control group (p = 0.015). Sub-Tenon injection during enucleation allows for significantly longer optic nerve resection lengths in unpreserved, fresh-frozen human cadavers.

Subtenon injection of natural leukocyte interferon α-2a in diabetic macular edema: a case report

BackgroundTo report the effect of subtenon injections of natural leukocyte interferon α-2a (IFNα) on best corrected visual acuity (BCVA) and central macular thickness (CMT) in a patient with diabetic macular edema (DME).Case presentationA 66-year-old man affected by DME, with glycated hemoglobin (HbA1c) at 6.9%, refractory to laser grid treatment and intravitreal injections of triamcinolone, was selected to receive a cycle of three subtenon injections/week of IFNα (1×106 IU/ml). BCVA and CMT, using spectral domain ocular coherence tomography (SD-OCT), were evaluated preoperatively and at 1 week, 1 month, 4 months, and 1 year postoperatively. BCVA and CMT were significantly improved at 1 week after the three injections (20/200 vs. 20/40 and 498 μm vs. 237 μm, respectively). BCVA remained stable during the 1-year follow-up. CMT was slightly increased, but was still lower than the baseline value (215 μm, 255 μm, and 299 μm during the follow-up visits). No adverse events were recorded, with the exception of mild subconjunctival hemorrhage at the injection site.ConclusionsIFNα, with its immunomodulatory, anti-proliferative and anti-angiogenic actions, was effective in improving BCVA and reducing CMT in refractory DME. Further randomized controlled studies are required to assess the effect of IFNα alone or in combination with other therapies for DME treatment.