Efficacy of adjuvant topical timolol-dorzolamide with intravitreal bevacizumab injection in diabetic macular edema: A contralateral eye study

The effect of combination therapy with intravitreal bevacizumab and topical timolol-dorzolamide eye drops on diabetic macular edema: a double-blind randomized controlled trial

BACKGROUND

The mainstay of treatment in diabetic macular edema (DME) is intravitreal administration of anti-vascular endothelial growth factors (anti-VEGFs). Aqueous depressants may enhance the effects of anti-VEGF agents by prolonging their clearance via aqueous outflow.

PURPOSE

To compare the anatomical and functional outcomes of treatment with intravitreal bevacizumab (IVB) and topical timolol-dorzolamide versus IVB alone.

METHOD

In this randomized placebo-controlled clinical trial, patients with center-involving DME (ci-DME) and best corrected visual acuity (BCVA) of 20/30 or less were enrolled and randomly allocated to two treatment arms. One group received three monthly IVB injections and timolol-dorzolamide eye drops twice a day (IVB + TD group); the other group received three monthly IVB injections and artificial tear drops as placebo (IVB group). Patients underwent ophthalmic evaluations and macular optical coherence tomography scans at baseline and 1 month after the third injection.

RESULT

Forty-six eyes from 46 patients with ci-DME were recruited. There was no intergroup difference regarding age, gender distribution, diabetic retinopathy stage, glycemic indices, BCVA, central macular thickness (CMT), or intraocular pressure at baseline. BCVA was significantly improved in the IVB + TD group (0.46 ± 0.18 to 0.36 ± 0.18 logarithm of the minimum angle of resolution [logMAR], p = 0.002), in contrast to IVB group (0.40 ± 0.17 to 0.35 ± 0.22 logMAR, p = 0.113). Similarly, the IVB + TD group showed a significant reduction in CMT (p < 0.001), unlike the IVB group (p = 0.086); and the CMT change in the former was greater than in the latter (- 0.57 ± 57.67 vs. - 25.52 ± 68.02 μm, p = 0.033).

CONCLUSION

Our findings support the short-term effectiveness of topical timolol-dorzolamide as adjunctive therapy to IVB injections in managing center-involving DME in terms of anatomical and visual outcomes.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05083689 (October 19, 2021).

Topical Dorzolamide as Adjunctive Treatment With Intravitreal Bevacizumab in Bilateral Diabetic Macular Edema

BACKGROUND

 Intravitreal injection of anti-vascular endothelial growth factor (VEGF) agents is accepted as the gold standard treatment for center-involving diabetic macular edema (CI-DME). Adjunctive administration of topical dorzolamide may enhance the therapeutic effects of anti-VEGF agents. In this study, we compared the efficacy of topical dorzolamide plus intravitreal injection of bevacizumab (IVB) versus IVB alone in patients with bilateral DME.

METHODS

This prospective, randomized contralateral eye study was carried out in a tertiary referral ophthalmology center, Al-Zahra Eye Hospital, Zahedan, Iran, between April 2021 and April 2022. This study included 50 eyes of 25 patients with bilateral DME. All eyes received three consecutive monthly injections of IVB. For each patient, one eye was randomized to instill dorzolamide eye drops three times a day as an intervention, and the other received artificial tear drops as a placebo. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) were evaluated before starting treatment and then monthly for the first three months.

RESULTS

Among 25 included patients, the average age was 56.64 ± 7.97 years, and 48% were female. BCVA did not improve significantly in any groups (P > 0.05). No significant difference was observed in terms of BCVA between the intervention and control groups (P > 0.05). The present study showed a decrease in CMT in both study groups (P < 0.05). At month 3, the decrease in mean CMT from baseline was significantly higher in eyes receiving topical dorzolamide compared to the control group (-88.92 ± 82.90 vs. -37.64 ± 86.16 µM, respectively; P = 0.037). IOP decreased significantly only in eyes receiving dorzolamide (P < 0.001).

CONCLUSIONS

The results of the present study indicate that adjunctive administration of topical dorzolamide has a beneficial effect on CMT reduction from baseline, but it did not have an additive effect on BCVA improvement compared to IVB monotherapy.

Prophylactic intraocular pressure lowering measures in anti-vascular endothelial growth factor therapy: A systematic review and meta-analysis

Acute intraocular pressure (IOP) elevation following repeat intravitreal anti-vascular endothelial growth factor (VEGF) injections (IVI) may pose a risk to the integrity of the retinal nerve fiber (RNFL). This meta-analysis investigates the role of IOP-lowering interventions such as an anterior chamber paracentesis (ACP) and IOP-lowering medications on the IOP in patients undergoing IVIs. MEDLINE, EMBASE, and the Cochrane Library were searched up to February, 2021. Studies investigating IOP-lowering interventions in patients undergoing IVI versus controls were included. The primary outcome was the IOP in the short- and long-term post-IVI. Secondary outcomes were changes in the RNFL thickness and best corrected visual acuity (BCVA). ACP at time of anti-VEGF injection significantly lowered IOP immediately post anti-VEGF (WMD: -27.98 mm Hg, P < 0.001). Patients in the ACP group also had significantly thicker RNFL compared to control (WMD: 2.07 um, P < 0.00001) at median follow-up of 16.5 months. IOP-lowering medications (on the day of injection or in the long-term) significantly reduced IOP up to 30 minutes after injection (WMD: -3.31 mm Hg, P = 0.003). This effect was statistically significant between the 2 arms up to 1 month follow-up. There was no difference in BCVA in intervention versus controls. ACP reduces immediate IOP spikes post-IVI and preserves the RNFL in the short- and longterms IOP-lowering medications also reduce IOP spike, with limited data on RNFL thickness.

Efficacy of topical dorzolamide 2% in diabetic cystoid macular edema

AIM

To study the effect of topical dorzolamide 2% on macular thickness reduction in diabetic cystoid macular edema (CME).

METHODS

This was a prospective, non-randomized, open study including eyes with diabetic macular edema (DME). All eyes received topical dorzolamide 2% three times daily for one month. Changes in best-corrected visual acuity (BCVA), and central macular thickness (CMT) by optical coherence tomography) were evaluated at 1wk, 1, and 3mo post-treatment.

RESULTS

Ninety-three eyes (84 patients) were included. Mean±SD (logMAR) BCVA improved significantly from 1.08±0.26 pretreatment to 0.66±0.24 at 1mo and 0.87±0.26 at 3mo post-treatment (P<0.001 both). The mean±SD CMT was significantly reduced from 535.27±97.4 µm at baseline to 357.43±125.8 µm at 1mo and 376.23±114.5 µm at 3mo post-treatment (P<0.001 both). No significant ocular or systemic side effects were recorded.

CONCLUSION

Topical dorzolamide 2% results in significant improvement of mean BCVA and reduction of mean CMT at 3mo post-treatment. It can be used as an effective, affordable, and safe therapy for treatment of non-refractory diabetic CME.

Anti-VEGF-Resistant Retinal Diseases: A Review of the Latest Treatment Options

Anti-vascular endothelial growth factor (anti-VEGF) therapy currently plays a central role in the treatment of numerous retinal diseases, most notably exudative age-related macular degeneration (eAMD), diabetic retinopathy and retinal vein occlusions. While offering significant functional and anatomic benefits in most patients, there exists a subset of 15–40% of eyes that fail to respond or only partially respond. For these cases, various treatment options have been explored with a range of outcomes. These options include steroid injections, laser treatment (both thermal therapy for retinal vascular diseases and photodynamic therapy for eAMD), abbreviated anti-VEGF treatment intervals, switching anti-VEGF agents and topical medications. In this article, we review the effectiveness of these treatment options along with a discussion of the current research into future directions for anti-VEGF-resistant eyes.

Initial Ten Years of Experience with the Intravitreal Dexamethasone Implant: A Retrospective Chart Review

Purpose

To evaluate the initial ten years of results from the intravitreal dexamethasone implant (DEX) in patients treated for retinal vein occlusion (RVO), diabetic macular edema (DME) or uveitis.

Methods

Retrospective chart review of patients receiving DEX since its FDA approval. Best-corrected visual acuity (BCVA), central macular thickness (CMT) on optical coherence tomography, intraocular pressure and cataract status were collected. Baseline data were collected from the initial DEX and post-treatment data at the visit at least four weeks after the last DEX.

Results

In total, 315 eyes received 1216 DEX over 63.9±4.6 weeks. In the branch RVO (n=90), central RVO (n=59) and DME (n=62) cohorts, BCVA improved significantly (p<0.05). The uveitis (n=154) cohort did not have a significant change in BCVA, 0.62±0.04 to 0.61±0.04 logMAR (p=0.34). Younger patients, vitrectomized eyes, and eyes without a history of glaucoma were associated with significantly better BCVA outcomes in the uveitis cohort (p<0.05). Overall, CMT decreased significantly from 376.6±6.8 to 322.7±5.0 µm (p<0.05). Intraocular pressure increased significantly (p<0.001) and the percentage of patients requiring anti-glaucoma medications increased from 33.0% to 67.6%. Of phakic eyes, 58.8% (n=63) had cataract progression or underwent surgery with those who underwent surgery experiencing a significant improvement in BCVA (p<0.05).

Conclusion

Repeated DEX over extended follow-up offers significant anatomic benefits to all cohorts. Visual benefits are only seen in RVO, DME and select uveitis demographics.