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June 29, 2022


The most important ophthalmology research updates, delivered directly to you.
 

In this week's issue
  • HORIZON 5-year results for Hydrus microstent safety and efficacy reveals significantly less need for glaucoma medications or additional surgery.
  • Ranibizumab port delivery system is likely a more expensive alternative to ranibizumab or aflibercept depending on the frequency of injections.
  • Topical latanoprostene bunod enhances retinal vessel density in patients with ocular hypertension or open-angle glaucoma. 

Big things on the HORIZON: 5-year results of the HORIZON trial

Ophthalmology

A microstent only 8mm long may lead to profound changes in the quality of life for glaucoma patients. The HORIZON study was a prospective, multicenter, single-masked, randomized controlled clinical trial where researchers investigated the Hydrus Microstent in patients with primary open-angle glaucoma (POAG) undergoing either cataract surgery alone or cataract surgery combined with Hydrus. There were no safety issues identified with Hydrus (measured by adverse events as well as endothelial cell loss). Patients who received Hydrus were more likely to have intraocular pressures (IOPs) <18mmHg (49.5% in Hydrus group vs. 33.8% cataract surgery alone; p = 0.003) and needed less glaucoma medications at five years. Of note, only 2.4% of Hydrus patients had additional incisional glaucoma surgery (compared to 6.2% in the cataract only group, p = 0.027). In addition, 66% of patients that received Hydrus were medication free at five years (compared to 46% in the cataract only group). This study proved the safety and efficacy of the Hydrus stent in POAG patients undergoing cataract surgery, but did not study this intervention in patients with other comorbidities.

Cost of novel anti-VEGF port delivery system vs. intravitreal injections

JAMA Ophthalmology

Is newer better and cheaper? It depends. Long acting anti-VEGF is the holy grail of treating many retinal diseases. Approved by the Food and Drug Administration in 2022, a novel port delivery system (PDS) promises to reduce anti-VEGF injection frequency for those with neovascular AMD. The PDS functions as a reservoir that allows ranibizumab, an anti-VEGF monoclonal antibody, to diffuse into the vitreous. Phase 3 clinical trials have shown that 98% of patients remained stable with 6-month intervals between PDS refills. This model found that the mean one-year cost of ranibizumab PDS therapy was $21,016. When comparing monthly injections to PDS therapy, ranibizumab cost $1,943 more (p = 0.34), aflibercept cost $5,702 more (p = 0.04), bevacizumab cost $16,732 less (P < 0.001). Bimonthly aflibercept cost $7,658 less (p = 0.006). From this analysis, ranibizumab PDS with one refill would cost more than ranibizumab or aflibercept intravitreal injections if less than 10 or 11 injections were needed in the first year. Beyond one-year, intravitreal injections would be cheaper if less than 4.4 and 3.8 injections were needed per six-month PDS refill for ranibizumab and aflibercept, respectively. Finally, bevacizumab cost less than ranibizumab PDS across all scenarios. Physician services, testing, and procedures such as more in office visits to monitor did not significantly affect cost but rather cost of the drug is what largely drove overall costs.  Costs and potential safety issues of endophthalmitis after PDS implantation may lead to hesitancy in uptake. 

Effect of latanoprostene bunod or timolol on retinal vessel density

American Journal of Ophthalmology

Drop it down low for better flow! Glaucomatous change has been associated with decreased macular and retinal vessel density (VD) on optical coherence tomography angiography (OCTA). While we know that latanoprostene bunod (latanoprost + nitric oxide) and timolol are both effective topical treatments to lower intraocular pressure (IOP) in patients with both ocular hypertension (OH) and open angle glaucoma (OAG), it is unclear how they affect the retinal vasculature and blood flow. This randomized, crossover clinical trial investigated the macular and peripapillary VD via OCTA in 50 eyes (10 healthy, 26 OH, and 14 OAG eyes) that were treated with latanoprostene bunod and timolol with a two week washout period between the two treatments. There was no significant change in IOP or VD in healthy patients with either treatment, however a decrease in VD of -0.56% [95% CI: -1.08%-0.03%] was noted in the nasal inferior peripapillary sector in patients with OH and OAG following treatment with timolol compared to baseline. Additionally, treatment with latanoprostene bunod demonstrated a significant increase in both macular and peripapillary VD of 0.76% [95% CI: 0.20%-1.33%] and 0.86% [95% CI: 0.05%-1.66%] respectively in patients with OH and OAG compared to baseline. While these initial results are promising and suggest latanoprostene bunod’s ability to both lower IOP and increase retinal VD, future studies should incorporate larger sample sizes, parallel study design, and equivalent dosing schedules.

Pediatrics

Rate of pediatric secondary visual axis opacification based on intraocular lens (IOL) type

Ophthalmology

Does IOL type matter in pediatric cataract surgery? A recent study found 3 piece IOLs  were much less likely to form visually significant posterior capsule opacification (PCO), which are caused by inflammatory fibrinous membranes or remnant lens epithelial cells after cataract surgery and can limit visual acuity. With higher incidence in children than in adults, this condition is a major challenge in the treatment of pediatric cataracts. This study assessed the time course of PCO formation after primary implantation of single-piece acrylic, 3-piece acrylic, or bag-in-lens IOLs. A bag-in-lens technique refers to when the surgeon makes a posterior lens capsule rhexus and places an IOL directly into the posterior capsule, directly anterior to the vitreous. This technique has been associated with lower rates of visually significant opacification. In this single-surgeon retrospective analysis, 95 children (135 eyes) aged 1 to 14 years who underwent cataract surgery with primary IOL implantation between 2000 and 2020 were evaluated. There were 13 cases of PCO at a median of 10 months after surgery. As compared to 3-piece acrylic IOLs, the adjusted hazard ratio was 32.8 (95% CI 3.3–327) for 1-piece acrylic IOLs and 19.6 (CI 1.22–316) for bag-in-lens IOLs. This study showed that 3-piece acrylic IOLs had the lowest rate of PCO, however, the results were confounded by how the patient’s age and comorbidities affected which type of IOL placement the surgeon chose.

Lens Landmarks
When a storm is brewing inside of the vitreous, how do you get to the destination safely? Before the 1995 EVS study, there was no clear consensus on how to utilize vitrectomy and IV antibiotics for patients with post-op endophthalmitis. Therefore, the EVS study sought to define a treatment protocol for these scary cases. In the study, 420 patients with clinical evidence of endophthalmitis within 6 weeks after cataract surgery or secondary intraocular lens implantation were randomly assigned to four groups with combinations of pars plana vitrectomy PPV or no PPV, and treatment with or without systemic antibiotics.

Key Points:
  • Systemic antibiotics may not be necessary and increase cost, length of stay, and toxic side effects.
  • Routine PPV is not necessary for patients with better than light perception (LP) vision at presentation.
  • PPV is beneficial for patients presenting with LP or worse vision, leading to better visual outcomes and reduced adverse outcomes
Overall, EVS established an LP cutoff for routine PPV in post-op endophthalmitis. If a patient can see HM, you can wave them goodbye instead of taking them to the OR.

Question of the Week
A 3 year-old boy has been diagnosed with retinoblastoma by an ophthalmologist. Sonography and MRI reveal a large tumor burden occupying >50% of the globe. The ophthalmologist recommends a procedure in which the extraocular muscles are cut at their insertion on the globe, before the optic nerve is cut and the globe is removed, as is illustrated below. 
What is this procedure called?

A. Exenteration
B. Evisceration 
C. Enucleation
D. None of the above


 
Keep scrolling for answer or click here
 

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Quiz Answer: C
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