In a recent study published in the Journal of Clinical Medicine, researchers investigated whether the rise in new glaucoma surgeries has affected the baseline features of glaucoma patients.
Give me some background first.
Minimally-invasive glaucoma surgery (MIGS) is often used to describe new surgical approaches to lower intraocular pressure (IOP) that have the following characteristics:
- An ab-interno approach
- Minimal manipulation of the target tissue
- Efficacy in lowering IOP
- Safety from serious complications
- Short learning curve for the surgeon
- Short recovery time for patients
Comparatively, minimally-invasive bleb surgery (MIBS) represents an autonomous subfield of MIGS that shares the following characteristics:
- Creation of a conjunctival filtration bleb with traditional surgery
- Safer surgical profile
Now, talk about the study.
Researchers conducted a retrospective study that evaluated the baseline features of patients receiving glaucoma surgery for the first time in 2011 and 2021.
The following data was collected:
- IOP
- Visual field (VF) parameters
- Stage of disease
- Type of surgery
Who was included in the study?
The analysis included 455 patients comprised of:
- Group A
- 230 eyes that received glaucoma surgery in 2011
- 117 males
- 113 females
- Group B
- 225 eyes that received glaucoma surgery in 2021
- 128 males
- 97 females
What were the inclusion criteria?
The inclusion criteria were as follows:
- Aged 18+
- Uncontrolled glaucoma with an IOP >21 mmHg
- Progressive glaucomatous damage at the VF
- Confirmed on three consecutive examinations
Findings?
When considering baseline features, Group A:
- Was older than Group B
- 72.7 ± 10.7 and 70 ± 12.4 years; p = 0.02, respectively
- Showed a significantly more advanced VF mean defect
- −16.4 ± 8.8 and −13.8 ± 8.7 dB; p < 0.01, respectively
- Showed a higher IOP
- 25.9 ± 6.6 and 24.9 ± 7.8 mmHg; p = 0.02, respectively
Tell me more.
Overall, severe VF damage at the time of surgery was more frequent in Group A (74.3%) than in Group B (60.8%) (p < 0.01)
Further:
- The overall number of traditional glaucoma surgeries was 211 in 2011, reducing to 94 a decade later, with similar severe preoperative VF defects
- MIBS represented 58% of all surgeries in 2021
Limitations?
The authors noted that this study was retrospective, which may have caused selection bias due to incomplete data. Additionally, all currently available MIGS were not considered for inclusion in this research.
Lastly, bias may have occurred due to the extensive use of Mini Shunt—an FDA approved (in 2003) method originally developed by Optonol Ltd and known to be the preferred method used by the surgeons who performed the glaucoma procedures in the study.
What this means: Per the authors, this may have created bias as to what is occurring (ie: a decline in use) to filtration surgery.
Expert opinion?
The researchers stated that baseline feature changes may have been due to, “the diffusion of new procedures, especially MIBS, which allowed for treating patients at an earlier stage, reserving traditional procedures for advanced cases.”
Take home.
Based on this research patients receiving glaucoma surgery for the first time:
- Are of younger age
- Have a lower IOP
- Diagnosed with a less severe disease
- Are increasingly treated with MIBS procedures