Effect of Posterior Subtenon Triamcinolone Acetonide Injection on Diabetic Macular Edema Refractory to Intravitreal Bevacizumab Injection

INCIDENCE OF STEROID-RELATED OCULAR HYPERTENSION AND CATARACT FORMATION AFTER SUB-TENON TRIAMCINOLONE IN NONUVEITIC PEDIATRIC PATIENTS

PURPOSE

To describe intraocular pressure changes after injection of sub-Tenon triamcinolone during examination under anesthesia for pediatric patients.

METHODS

Multicenter, retrospective case series of pediatric patients who received sub-Tenon triamcinolone from three tertiary care ophthalmic services between November 2018 and October 2023.

RESULTS

Of 392 patients identified, 59 eyes (10.5%) of 41 patients were included. Laser was administered in 95.1% of the cases. Sub-Tenon triamcinolone dose ranged from 4 to 20 mg. The most common diagnosis was retinopathy of prematurity (43.9%). Two eyes (3.4%) of two patients (4.9%) were mild steroid responders. One eye (1.7%) of 1 patient (2.4%) was a moderate responder. There were no high steroid responders, and all eyes with steroid response showed a return of intraocular pressure to normal range at next visit without needing any intraocular pressure-lowering medications. No patients were diagnosed with glaucoma or required glaucoma surgery. Only 1 eye (1.7%) developed trace posterior subcapsular cataract, whereas no optic disk cupping or inflammation were noted.

CONCLUSION

Sub-Tenon triamcinolone injection is commonly used to prevent inflammation at the time of retinal photocoagulation treatment in pediatric patients. It has a favorable safety profile in relation to intraocular pressure elevation and cataract formation. There was no requirement for intraocular pressure-lowering medications or surgical interventions.

Switching to subtenon triamcinolone acetonide does not jeopardize the functional and anatomic outcomes of dexamethasone implant treated eyes with diabetic macular edema

BACKGROUND

Intraocular dexamethasone implant (DEXi) is an efficient treatment for diabetic macular edema (DME). However, it may be unavailable or contraindicated. Triamcinolone acetonide is another corticosteroid that has proved to be safe and effective in treating macular edema complicating various diseases including diabetes. The purpose of this study is to evaluate the outcomes of a switch from DEXi to subtenon triamcinolone acetonide (STTA) and back, in eyes with DME.

METHODS

Retrospective study. DME eyes that had been treated with DEXi and switched to STTA between October 2018 and February 2019 (stock shortage of DEXi) were included. The functional and anatomical outcomes of the switch and switch-back were studied.

RESULTS

26 eyes of 17 patients (mean age 67.1 ± 8.2 years) were considered. The mean baseline visual acuity (VA) was 0.35 ± 0.17 decimals remaining stable after DEXi, STTA and switch-back to DEXi. The mean central macular thickness (CMT) was 492.7 ± 32.8 µm initially, decreasing to 294.3 ± 133.4 µm after DEXi, 369.9 ± 182.3 µm after STTA and 297.6 ± 72.0 µm after switching back to DEXi (all p < 0.05 versus baseline). Compared to baseline, the CMT reduction was numerically better after DEXi and switching back to DEXi than after STTA (mean reduction: -200.4 µm, -167.7 µm, and -95.08 µm respectively, p = 0.13). Intraocular pressure was comparable after DEXi and STTA.

CONCLUSION

DEXi is the steroid of choice in DME. However, STTA can be a cost-effective alternative when DEXi is unavailable or contraindicated. This study suggests that STTA may be used in the context of a step therapy in DME.

Persistent diabetic macular edema: Definition, incidence, biomarkers, and treatment methods

Intravitreal antivascular endothelial growth factor (anti-VEGF) treatment has drastically improved the visual and anatomical outcomes in patients with diabetic macular edema (DME); however, success is not always guaranteed, and a proportion of these eyes demonstrate persistent DME (pDME) despite intensive treatment. While standardized criteria to define these treatment-resistant eyes have not yet been established, many studies refer to eyes with no clinical response or an unsatisfactory partial response as having pDME. A patient is considered to have pDME if the retinal thickness improves less than 10-25% after 6 months of treatment. A range of treatment options have been recommended for eyes with pDME, including switching anti-VEGF agents, using corticosteroids and/or antioxidant drugs in adjunct with anti-VEGF therapy, and vitrectomy. In addition, multimodal imaging of DME eyes may be advantageous in predicting the responsiveness to treatment; this is beneficial when initiating alternative therapies. We explore the literature on persistent DME regarding its defining criteria, incidence, the baseline biological markers that may be useful in anticipating the response to treatment, and the available treatment options.

Optimizing treatment for diabetic macular edema during cataract surgery

Diabetic macular edema (DME) causes visual impairment in diabetic retinopathy (DR). Diabetes mellitus is a global epidemic and diabetic individuals are at risk of developing DR. Approximately 1 in 10 diabetic patients suffers from DME, which is the commonest cause of vision-threatening DR at primary-care screening. Furthermore, diabetes predisposes to a higher frequency and a younger onset of cataract, which further threatens vision in DME patients. Although cataract extraction is an effective cure, vision may still deteriorate following cataract surgery due to DME progression or recurrence, of which the risks are significantly higher than for patients without concurrent or previous history of DME at the time of operation. The management of pre-existing DME with visually significant cataract is a clinical conundrum. Deferring cataract surgery until DME is adequately treated is not ideal because of prolonged visual impairment and maturation of cataract jeopardizing surgical safety and monitoring of DR. On the other hand, the progression or recurrence of DME following prompt cataract surgery is a profound disappointment for patients and ophthalmic surgeons who had high expectations for postoperative visual improvement. Prescription of perioperative anti-inflammatory eye drops is effective in lowering the risk of new-onset DME after cataract surgery. However, management of concurrent DME at the time of cataract surgery is much more challenging because DME is unlikely to resolve spontaneously even with the aid of anti-inflammatory non-steroidal or steroid eye drops. A number of clinical trials using intravitreal injection of corticosteroids and anti-vascular endothelial growth factor (anti-VEGF) as first-line therapy have demonstrated safety and efficacy to treat DME. These drugs have also been administered perioperatively for the prevention of DME worsening in patients undergoing cataract surgery. This article reviews the scientific evidence to guide ophthalmologists on the efficacy and safety of various therapies for managing patients with DME who are particularly vulnerable to cataract surgery-induced inflammation, which disintegrates the blood-retinal barrier and egression of fluid in macular edema.

Optical Coherence Tomography Reflectivity in Foveal Cysts: A Novel Biomarker for Early-Response Prediction of Diabetic Macular Edema Treated with Dexamethasone

This study investigated spectral-domain optical coherence tomography (OCT) biomarkers to predict short-term anatomical improvement for diabetic macular edema (DME) after dexamethasone (DEX) injection in intravitreal anti-vascular endothelial growth factor (anti-VEGF) non-responders. This retrospective comparative study included 31 eyes of 31 patients with DME unresponsive to anti-VEGF, divided into better and lesser responder groups. OCT prior to DEX injection was used to evaluate the morphological features including optical density (ODN) and optical density ratio (ODR) of the outer nuclear layer (ONL) cysts. Correlations between baseline OCT parameters and mean central macular thickness (CMT) changes at 1 month were analyzed. There were no between-group differences in age, sex, number of previous anti-VEGF injections, duration of diabetes, or HbA1c level. However, ODN and ODR values in ONL cysts were lower in the better responder group (p = 0.020 and p < 0.001, respectively). ODN and ODR showed negative correlations with CMT changes (R = −0.546, p = 0.002 and R = −0.436, p = 0.014, respectively). Higher OCT reflectivity in the foveal cystoid space was associated with a lesser decrease in CMT after DEX injection in anti-VEGF non-responders, suggesting the usefulness of this parameter in predicting short-term CMT responses after DEX injection.

Choroidal Structural Changes of Posterior Subtenon Triamcinolone Acetonide Injection in Eyes with Refractory Diabetic Macular Edema

Purpose

To access the choroidal structural changes of posterior subtenon triamcinolone acetonide (PSTA) injection in eyes with refractory diabetic macular edema (DME).

Methods

Patients with refractory DME were enrolled and followed for 4 weeks after switching to PSTA injection. All patients underwent spectral-domain optical coherence tomography with enhanced depth imaging, and the choroidal images were binarized into the luminal area and total choroidal area. Subfoveal choroidal thickness (SFCT) and choroidal vascularity index (CVI) were evaluated before and after switching treatments.

Results

After switching to PSTA treatment, the final best-corrected visual acuity and central subfield thickness in eyes with refractory DME were significantly improved compared to the baseline values (P=0.002 and P < 0.001, respectively). Both the SFCT and CVI decreased during the follow-up period, and significant decreases were observed at 4-week follow-up (P < 0.001 and P=0.012, respectively). The linear regression analysis showed a significant correlation between the baseline SFCT and the final visual outcomes (P=0.047).

Conclusions

The alterations of SFCT and CVI in this study suggest that the choroidal vasculature is involved in the pathogenesis of refractory DME and could be affected by PSTA treatment. SFCT rather than CVI may be a prognostic biomarker for eyes with refractory DME.

Corticosteroids in ophthalmology: drug delivery innovations, pharmacology, clinical applications, and future perspectives

Corticosteroids remain the mainstay of the treatment for various ocular conditions affecting the ocular surface, anterior and posterior segments of the eye due to their anti-inflammatory, anti-oedematous, and anti-neovascularization properties. Prednisolone, prednisolone acetate, dexamethasone, triamcinolone acetonide, fluocinolone acetonide, and loteprednol etabonate are amongst the most widely used ophthalmic corticosteroids. Corticosteroids differ in their activity and potency in the eye due to their inherent pharmacological and pharmaceutical differences. Different routes and regimens are available for ocular administration of corticosteroids. Conventional topical application to the eye is the route of choice when targeting diseases affecting the ocular surface and anterior segment, while periocular, intravitreal, and suprachoroidal injections can be potentially effective for posterior segment diseases. Corticosteroid-induced intraocular pressure elevation and cataract formation remain the most significant local risks following topical as well as systemic corticosteroid administration. Invasive drug administration via intracameral, subconjunctival, and intravitreal injection can enhance ocular bioavailability and minimize dose and dosing frequency of administration, yet may exacerbate ocular side effects of corticosteroids. This review provides a critical appraisal of the ophthalmic uses of corticosteroid, routes of administration, drug delivery fundamentals and novel ocular implantable steroid delivery systems, factors influencing side effects, and future perspectives for ocular corticosteroid therapy.

The effects of intravitreal triamcinolone acetonide in diabetic macular edema refractory to anti-VEGF treatment

PURPOSE

To investigate the efficacy and safety of primary intravitreal triamcinolone acetonide (IVTA) in eyes affected by diabetic macular edema (DME) refractory to anti-vascular endothelial growth factor (VEGF) therapy.

STUDY DESIGN

Retrospective observational study METHODS: The medical records of patients who attended our clinic from March 2013 to September 2018 with refractory macular were reviewed. We included the patients who were injected at least one IVTA and completed 6 months of observation. Best-corrected Snellen visual acuity (VA), central macular thickness (CMT), intraocular pressure (IOP), and adverse events (AEs) were examined at baseline and at 1 month, 2 months, 3 months, and 6 months.

RESULTS

Sixty-four eyes of 54 subjects were included. The mean VA was improved significantly at all time points compared to pre-treatment (P < 0.0001), with the greatest mean improvement at 1 month (0.3 logMAR). The reduction in mean CMT was also significant at all follow-up examinations compared to baseline (P < 0.0001), with the greatest decrease at 1 month (113.68 ± 53.78 μm). A poorer VA before injection was a factor that influenced visual gain 1 month post treatment (0.247 logMAR units/unit increase in baseline VA, P = 0.006). The most common AE associated with IVTA treatment was elevated IOP (11 eyes), observed significantly more often after IVTA injections containing a preservative (25.8%) than after those that were preservative-free (9.1%) (P = 0.033).

CONCLUSION

IVTA injection can be an alternative steroid treatment for DME refractory to anti-VEGF therapy.

Characteristics of diabetic macular edema patients refractory to anti-VEGF treatments and a dexamethasone implant

Purpose

To determine the characteristics of diabetic macular edema (DME) patients refractory to intravitreal bevacizumab (IVB) treatments and an additional dexamethasone implant.

Methods

We classified 119 DME patients according to whether or not they are responsive to 3 consecutive monthly anti-VEGF treatments and/or an additional dexamethasone implant. We compared their concentrations of IL (interleukin)-1β, IL-8, IL-10, IL-17, placental growth factor (PlGF), and vascular endothelial growth factor (VEGF) in the aqueous humor as well as their optical coherence tomography (OCT) findings, and baseline characteristics. We used logistic regression analyses to identify preoperative factors related to refractoriness to treatments.

Results

Of 119 treatment-naïve DME patients, 50 (42.02%) patients showed responsiveness [central subfield thickness (CST) < 300μm] after 3 IVBs, and 59 (49.58%) patients showed responsiveness after an additional dexamethasone implant, but 10 (8.40%) patients showed CST 300 ≥ μm even after both treatments. Refractory DME patients showed significantly higher number of hyperreflective foci (HF) in the OCT and higher average level of aqueous IL-1β at baseline (p<0.001 and p = 0.042, respectively). In the logistic regression analysis, higher number of HF in the OCT was associated with the refractoriness to both treatments (odds ratio [OR]: 7.03, p = 0.007)

Conclusions

Higher number of HF in the OCT at the initial visit was associated with poor responses to IVBs and an additional dexamethasone implant.

Pharmacology of Corticosteroids for Diabetic Macular Edema

Purpose

Corticosteroids remain the mainstay of treatment for inflammatory diseases almost 80 years after their first clinical use. Topical ophthalmic formulations of corticosteroids have been available to treat disease of the anterior segment of the eye, but the approval of corticosteroids to treat vitreoretinal diseases, including vein occlusion, diabetic macular edema, and uveitis, has occurred only recently. Although most diseases respond to corticosteroid therapy, some patients are resistant to this therapy and side effects, including cataract and elevated intraocular pressure, can limit their use. The purpose of this review is to detail the basic science of corticosteroids focusing on differences in potency, drug delivery, pharmacokinetics, and gene activation, and how these differences affect safety and efficacy in the treatment of diabetic macular edema.

Methods

A review was conducted of basic science and pharmacology of the corticosteroids used to treat diabetic macular edema.

Results

Clinically available corticosteroids not only have differing potency and pharmacokinetics, but also activate different genes in different target tissues. These differences are associated with distinct efficacy, pharmacokinetic, and safety profiles. It is important to understand these differences in selecting corticosteroids to treat diabetic macular edema.

Conclusions

Recent advances in our understanding of the basic science of corticosteroids can explain clinical differences in these agents regarding efficacy and safety. Importantly, this understanding should allow the future discovery of additional novel corticosteroids to treat diabetic macular edema.

Treatment outcomes and predicting factors for diabetic macular edema treated with ranibizumab - One-year real-life results in Taiwan

PURPOSE

To report the one-year outcomes of diabetic macular edema (DME) treated with ranibizumab under a real-life setting in Taiwan, and to identify the prognostic factors.

METHODS

Between July 2013 and January 2015, 119 eyes receiving intravitreal ranibizumab for DME were retrospectively recruited. Best-corrected visual acuity (BCVA) and central foveal thickness (CFT) measured with optical coherence tomography were collected at baseline and at Month 3, 6, and 12. Linear regression was used to identify the predicting factors for changes in BCVA and CFT at Month 12.

RESULTS

The average number of ranibizumab given within one year was 4.36 ± 1.87. The BCVA (logMAR) improved from 0.74 ± 0.30 at baseline to 0.64 ± 0.37 at Month 12 (p = 0.002). A better improvement in BCVA at Month 3 was significantly correlated with a better visual improvement at Month 12 (p < 0.001). The existence of subretinal fluid at baseline (p = 0.02) and a greater reduction in CFT at Month 3 (p < 0.001) were both correlated with a greater reduction in CFT at Month 12. Previous subtenon injection of triamcinolone acetonide was associated with fewer additional IVR after Month 3 (odds ratio = 0.35, 95% CI = 0.14-0.89).

CONCLUSION

Compared with existing prospective studies, the one-year real-life data in Taiwan showed fewer ranibizumab injections for DME and a less prominent yet still significant visual improvement. Both visual and anatomical improvements at Month 3 were correlated with the level of improvements at Month 12. Previous subtenon steroid injection might reduce the need of additional ranibizumab injections.

Changes in aqueous concentrations of various cytokines after intravitreal bevacizumab and subtenon triamcinolone injection for diabetic macular edema

PURPOSE

The purpose of this study was to compare the changes in the aqueous cytokine levels after intravitreal bevacizumab with those after combined intravitreal bevacizumab and subtenon triamcinolone injection in diabetic macular edema (DME).

METHODS

This study examined 24 eyes of 23 patients with DME. Each patient with DME received randomly either an intravitreal injection of bevacizumab (IVBe) or IVBe with a subtenon triamcinolone injection (IVBe + STTA). Best corrected visual acuity and foveal thickness were evaluated and aqueous samples were obtained before and 4 weeks after the injection. The aqueous concentrations of interleukin (IL)-6, IL-8, interferon-induced protein (IP)-10, monocyte chemotactic protein (MCP)-1, platelet-derived growth factor (PDGF)-AA, and vascular endothelial growth factor (VEGF) were measured using a multiplex bead assay.

RESULTS

After the injection, the foveal thickness decreased more in the IVBe + STTA group than in the IVBe group (P = 0.042). The MCP-1, PDGF-AA, and VEGF levels decreased significantly in the IVBe + STTA group (p = 0.013, p = 0.004 and p = 0.018 respectively), but only the VEGF level decreased in the IVBe group (p = 0.001). IL-8 was significantly increased in the IVBe + STTA group (p = 0.003) but the changes in the VEGF levels were smaller than in the IVBe group (p = 0.025).

CONCLUSION

Intravitreal bevacizumab and subtenon triamcinolone injection reduces the VEGF, MCP-1 and PDGF-AA levels and increases the IL-8 level in the plural cytokine profiles of patients with DME, which might explain the limited therapeutic effect of combination therapy.