New findings published in Heliyon detail positive six-month postoperative data supporting the use of the Smaller-Incision New-Generation Implantable Miniature Telescope (SING IMT; Samsara Vision) among late-stage age-related macular degeneration (AMD) patients.
First thing’s first: a rundown on the SING IMT.
SING IMT is a prosthetic device intended for monocular implantation to improve vision in patients aged 55+ diagnosed with bilateral central scotomas associated with late-stage AMD.
- As a preloaded device for insertion, it is implanted during cataract surgery using the Tsert SI pre-loading delivery system with a corneal incision range of 6.5 mm to 7.5 mm.
How it works: During the procedure, images seen in “straight-ahead” vision are magnified 2.7x and projected into healthy, undamaged areas of the macula located in the back of the eye.
- The purpose of this: To reduce the impact of the typical central vision “blind spot” found in AMD patients.
Watch a video of this process here.
And how long does the procedure take?
Around 25 minutes, according to the company
Where that number comes from: This is based on findings reported during the development of the SING IMT, in which the entire duration of the outpatient procedure with the injector system dropped from around 60 minutes in routine procedures.
Has the FDA cleared this device yet?
While the SING IMT already received the CE mark in the European Union in 2020, it is not yet approved in the United States.
- Samsara has stated it is working with the FDA to “determine the timeline and pathway” to bring the device to the U.S. market.
- And take note: The SING IMT is actually an advanced version of the original IMT, which the FDA approved in 2010.
What’s the difference between the two versions?
The SING IMT includes a smaller corneal wound as well as the potential for increased device safety, implantation ease, and a faster recovery period for patients.
See here for specifics on the IMT.
Now let’s get to this new research.
To start, investigators in this retrospective cohort study reviewed the medical records of 35 patients (mean age: 77.4 years) who were implanted with the SING IMT at two clinical sites in Italy.
- See here for patient inclusion and exclusion criteria.
What was the protocol following this procedure?
Following device implantation, participants received:
- Topical medications (antibiotic and anti-inflammatory eye drops) for one month
- Mydriatic and cycloplegic agents (for at least two weeks)
- Hypertonic medications (for two weeks) in the case of corneal edema
Plus: Starting six weeks postop, patients participated in a rehabilitation program for visual outcomes consisting of eight sessions every two to three weeks.
And what was measured?
Evaluated up to 6 months following surgery, outcomes included:
- Best-corrected distance visual acuity (BCDVA)
- Distance-corrected near visual acuity (DCNVA)
- Intraocular pressure (IOP)
- Anterior chamber depth (ACD)
- Corneal endothelial cell density (CED)
- Adverse events
Next: the findings.
To note: Investigators gathered patients’ baseline and postop outcomes using electronic medical records (EMRs) consisting of their follow-up visits at day 1, month 1, month 3, and month 6.
At the six-month postop mark:
- 97.1%, 68.6%, and 51.4% of implanted eyes achieved at least 1-, 2-, and 3-line gains in BCDVA, respectively
- Mean standard deviation (SD) change in BCDVA from baseline: -0.29± 0.142
- 97.1% of participants could read at near distance (compared to 28.6% at baseline)
- DCNVA significantly improved by ~3 lines
How did IOP and ACD fare?
No “clinically meaningful” changes were noted from baseline—although the mean (SD) change from baseline in corneal ECD was -280.7 (315.9) cells/mm2 (-11.4%).
And at the three- and six-month follow-up visits, no new complications arose.
Any adverse events?
Yes … although most (such as corneal edema among 22% of patients) were resolved by the six-month mark following topical medications.
Other device-related events—iris damage and pigment deposits, for example—continued beyond this point, “indicating an acceptable safety profile” for the SING IMT's implantation.
Sounds promising … so how does this data compare to previous?
As we previously covered, safety and efficacy outcomes from the first and largest single-surgeon case series on the device (a retrospective, non-comparative, and single-center three-month study) observed:
- Significantly higher CDVA than the fellow eye (P<0.0001 for both) by months 1 and 3.
- See more findings.
And for more data, take a gander at all recent research conducted on the SING IMT.
Noted. And any limitations?
A few … including the study’s retrospective design and smaller number of patients.
One other mention: The study authors also noted that “the effect on the visual outcomes of the cataract surgery alone has not been compared with SING IMT implantation.”
- Check out the complete list.
So what are the final takeaways from this study?
Based on the data, the authors stated that their analysis “reaffirmed the prior evidence” on the safety and efficacy of the SING IMT implantation—including the "substantial enhancement” in distance visual acuity and “significant improvement” in DCNVA, among other findings.
While investigators will continue monitoring the patients’ vision, the authors stated:
- "This six-month review highlights the potential of SING IMT to restore meaningful vision to individuals blinded by AMD, while preserving long-term corneal health with its innovative design.”
And any future data to keep in mind?
The prosthetic device is currently under clinical investigation in the multicenter CONCERTO trial (NCT05438732)
This 12-month study has enrolled an estimated 125 participants diagnosed with moderate-severe central vision loss due to late-stage AMD who underwent the SING IMT implantation.
- See here for more details.
Take note: The study is expected to conclude in December 2025.