Intraocular Pressure after Intravitreal Injection of Dexamethasone Implant for Macular Edema Resulting from Retinal Vein Occlusion

A narrative review on the association of high intraocular pressure and glaucoma in patients with retinal vein occlusion

BACKGROUND AND OBJECTIVE

Retinal vein occlusion (RVO) is a major cause of vision loss and elevated intraocular pressure (IOP), high ocular perfusion pressure, and glaucoma are known ophthalmic risk factors for RVO. The aim of this paper is to provide the update on the association and management of high IOP/glaucoma and RVO.

METHODS

A literature review was performed in PubMed and Medline until May 2022 utilizing specific keywords and cross-matched reference lists.

KEY CONTENT AND FINDINGS

The association of RVO with high IOP/glaucoma may be attributed to retinal ganglion cell loss due to retinal ischemia in high IOP and glaucoma. As new modalities showed, decreased optic disc perfusion, reduced density of blood vessels in the optic nerve head of glaucoma patients, changes in the peripapillary microvascular parameters, and decreased retinal nerve fiber layer (RNFL) thickness of the optic nerve head of eyes with RVO suggest a common pathway between RVO and glaucoma. Literature suggests the close follow up for glaucoma development among patients with non-arteriovenous (AV) crossing (optic cup or optic nerve sited) RVO in fellow eye and management of elevated IOP among RVO cases treated with anti-vascular endothelial growth factor (VEGF) antibodies/corticosteroids and those with preexisting primary open angle glaucoma (POAG).

CONCLUSIONS

Determining potential patient responses to treatment and considering therapeutic options are challenging among patients with RVO and glaucoma. However, IOP lowering managements in preventing IOP spikes in patients with preexisting glaucoma and early treatment of macular edema in eyes with RVO is recommended.

Phaco-non-penetrating deep sclerectomy in ocular hypertension secondary to dexamethasone intravitreal implant

PURPOSE

To evaluate the characteristics and progression of patients treated with a 0.7mg dexamethasone intravitreal implant (Ozurdex^®) and required glaucoma filtering surgery (phaco-non-penetrating deep sclerectomy) to control ocular hypertension (OHT).

METHODS

A retrospective observational study including patients treated with Ozurdex^® in a tertiary-care university hospital from May 2011 to April 2016.

RESULTS

In five years of follow-up, 1.10% (4/363) of patients treated with 0.7mg dexamethasone intravitreal implant required phaco-non-penetrating deep sclerectomy (PNPDS) to control OHT refractory to topical treatment. All four patients started or increased previous antihypertensive topical treatment since the first dexamethasone intravitreal implant. Three or more dexamethasone intravitreal implants were injected in the four cases before intraocular pressure (IOP) became uncontrolled and PNPDS was performed. All four patients have a successfully controlled IOP without treatment after PNPDS. Two patients required additional treatment with dexamethasone intravitreal implants after PNPDS, maintaining IOP under control without treatment.

CONCLUSIONS

To the best of our knowledge, this is the first study describing the successful results of PNPDS in OHT secondary to dexamethasone intravitreal implant. All four patients have achieved controlled IOP without treatment. Re-treatment with dexamethasone intravitreal implant in those patients who underwent PNPDS is also possible, and IOP remains controlled.

SAFETY OF INTRAVITREAL DEXAMETHASONE IMPLANT (OZURDEX): The SAFODEX study. Incidence and Risk Factors of Ocular Hypertension

PURPOSE

To analyze the incidence, risk factors, and time course of intraocular pressure elevation after intravitreal dexamethasone implant (Ozurdex).

METHODS

The medical charts of 421 consecutive eyes (361 patients) receiving one or more Ozurdex implant between October 2010 and February 2015 were reviewed retrospectively. Ocular hypertension was defined as intraocular pressure of at least 25 mmHg or an increase of at least 10 mmHg from baseline. The main indications for treatment were retinal vein occlusion (34%), diabetic macular edema (30%), postsurgical macular edema (17%), uveitis (14%), and other etiologies (5%).

RESULTS

Among 1,000 intravitreal injections, ocular hypertension was recorded for 28.5% of injected eyes over a mean follow-up period of 16.8 months (3-55). Intraocular pressure-lowering medication was required for 31% of eyes. Only three eyes with preexisting glaucoma required filtering surgery to manage postinjection intraocular pressure elevation. Early retreatment between the third and fourth month does not increase the risk of intraocular pressure elevation. Younger age, male sex, Type 1 diabetes, preexisting glaucoma treated with dual or triple therapy, and a history of retinal vein occlusion or uveitis were significant risk factors for ocular hypertension after dexamethasone implant injection (P < 0.05 for all the above).

CONCLUSION

Episodes of ocular hypertension after Ozurdex implant were generally transient and successfully managed with topical treatment. An analysis of the risk factors may help to determine the risk-benefit ratio for individual patients treated with dexamethasone implants.

TOLERANCE OF INTRAVITREAL DEXAMETHASONE IMPLANTS IN PATIENTS WITH OCULAR HYPERTENSION OR OPEN-ANGLE GLAUCOMA

PURPOSE

Evaluate the pressure tolerance of dexamethasone implants in open-angle glaucoma (OAG+) patients and ocular hypertension (OHT+) patients compared with nonglaucomatous and nonhypertensive patients.

METHODS

Retrospective observational 2-center, controlled study including 100 patients treated with intravitreal injections of dexamethasone, divided into 2 groups: Group 1, OAG+/OHT+ (n = 50), and Group 2, OAG-/OHT- (n = 50), matched for age and disease. Intraocular pressure (IOP) and hypotensive treatment were evaluated initially, at 8 days, and every month for 6 months after intravitreal treatment. The primary endpoint was IOP increase greater than 10 mmHg.

RESULTS

Thirty-four percent of glaucomatous patients experienced a transient IOP increase greater than 10 mmHg versus 16% in the OAG-/OHT- group (P = 0.06). Intraocular pressure greater than 25 mmHg was recorded early on Day 8 in 6% of the OAG+ patients versus 2% of the OAG- patients. Fifty-four percent of the glaucoma patients increased their treatment, and hypotensive treatment was initiated in 38% of the OAG- patients (P = 0.1). Filtering surgery was only required in the OAG+/OHT+ group (6% versus 0%), particularly in dual-therapy and triple-therapy patients, who had a higher risk of filtering surgery (P = 0.008).

CONCLUSION

Half of the OAG+ and OHT+ patients needed an add-on treatment, with early onset beginning on Day 8 in 6%. This emphasizes the need for IOP monitoring during treatment, especially for OAG+/OHT+ patients.

Retinal vein occlusion and the use of a dexamethasone intravitreal implant (Ozurdex®) in its treatment

Purpose

To review published data pertaining to the clinical experience with a dexamethasone intravitreal implant (Ozurdex®) with a view to establishing a clinically based therapeutic regime.

Methods

A PubMed search using the MeSH terms “retinal vein occlusion” and either “pathophysiology” or “dexamethasone intravitreal implant” was undertaken for manuscripts published until August 2015. The analysis included studies involving minimally 15 patients under a prospective design or 30 under a retrospective design, a minimal follow up of 6 months, and at least 2 intravitreal Ozurdex® injections per eye.

Results

In the vast majority of eyes, satisfactory outcomes were achieved with retreatment intervals of between 3 and 5 months. Initial evidence indicates a similar efficacy compared to anti-VEGF therapies as a first-line treatment. Safety concerns associated with the long-term and repeated use of Ozurdex® are not borne out by clinical findings: its implantation is not associated with a sustained increase in intraocular pressure (IOP) over time or with the number of applications.

Conclusion

Compared with anti-VEGF therapies, the burden of retreatment is reduced. In patients with chronic macular edema not responsive to repetitive anti-VEGF therapies, the outcome after dexamethasone implant treatment is encouraging. However, these results are achieved at the expense of side effects typically associated with steroids: in up to 20 % of the Ozurdex®-treated patients, an elevation in IOP, which could be medically controlled in the majority of cases, and cataract formation or progression was observed.