At its core, an Interventional Mindset prioritizes patient satisfaction and quality of vision, which can translate to enriching the overall quality of life. Having this philosophy at the forefront of treatment dictates that surgeons expand their scope by branching across subspecialty and disease categories, from cataract to refractive to glaucoma to dry eye.
Dr. Paul Singh, a cataract/refractive surgeon and glaucoma specialist embodies this ideology. He explains his thought process on the use of presbyopia-correcting intraocular lenses (IOLs) in conjunction with microinvasive glaucoma surgery (MIGS) to offer glaucoma patients possibly more spectacle independence.
Interventional Mindset is an educational series that gives eye physicians the needed knowledge, edge, and confidence in mastering new technology to grow their practices and provide the highest level of patient care. Our focus is to reduce frustrations associated with adopting new technology by building confidence in your skills to drive transformation.
Browse through our videos on a variety of topics within cataract and refractive surgery, glaucoma, and ocular surface disease to learn practical insights into adopting a variety of new surgical techniques and technology.
MIGS has changed the game
With the new emphasis on performing MIGS and cataract surgery simultaneously, patients are receiving glaucoma intervention, with the goal of halting the progression while they are in the mild stage and still have healthy fields and retinal ganglion cells (RGCs).
Subsequently, this proactive treatment approach allows for the use of advanced vision-correcting IOLs. The advantages of receiving a presbyopia-correcting IOL at the time of MIGS are twofold; it reduces both the burden of eye drops and spectacle dependency.
Previously, with glaucoma patients who were drop-dependent, dry eye prevented the implantation of a multifocal IOL due to the risk of glare and halos. Now, with the ability to potentially eliminate some or all drops, a pre-perimetric patient with a healthy central 10 degrees may prove an excellent candidate for one of the latest generations of presbyopia-correcting IOLs.
Patient selection is paramount
As with any procedure, proper patient selection is the key to success. When deciding whether a glaucoma patient—who has expressed a desire to be spectacle independent—is a good candidate for a presbyopia-correcting IOL, the first step is to do a thorough assessment, taking into consideration the ocular surface, the size of the angle alpha, degree of glaucoma, and so on. For example, for a patient with an alpha angle of 0.7, the risk of glare and halos is too high to consider a multifocal lens.
The basis for patient selection:
- History
- Disease severity at the time of surgery
- Potential risk for progression
- Personality
To determine if and which lens is appropriate, Dr. Singh emphasizes the importance of revisiting the patient’s history, fully assessing their disease severity at the time of surgery, and then judging the potential risk for progression.
Dr. Singh emphasized that by using central 10-2 visual field (VF) testing more routinely, clinicians can potentially diagnose glaucoma earlier, detect progression sooner, and thereby minimize the risk of underestimating or overestimating the extent of the glaucomatous visual field damage throughout all stages of glaucoma.
He sees personality as the final consideration and suggests surgeons evaluate how concerned the particular patient is with experiencing even minor glare and halo.
Advanced technology IOLs (ATIOLs)
In recent years, intraocular lenses have seen significant advancements, making it easier to match an appropriate IOL with the aforementioned patient criteria.
The most commonly used lenses include:
- Basic monofocal for cataract symptoms and potentially distance vision.
- Toric for the reduction of astigmatism and enhancement of distance vision.
- Accommodating (e.g., Crystalens/Trulign), which flexes based on ciliary muscle contraction to focus light to manage distance, intermediate, and near vision.
- Extended depth of focus (EDOF), such as Clareon Vivity, TECNIS Symfony OptiBlue, and TECNIS Synergy, to improve vision at near, intermediate, and distant ranges while limiting halos and glare.
- Trifocal (e.g., Clareon PanOptix), which splits light into three focal points to provide an increased range of vision.
With trifocal lenses, like Clareon PanOptix (Alcon), contrast and light scattering can technically be lower than with a monofocal lens. In addition, the new iterations of multifocals allow more light to enter the eye. Extended depth of field (EDOF) lenses can assist with distance intermediate while maintaining relatively high contrast sensitivity. Meanwhile, accommodating lenses, like the Crystalens (Bausch + Lomb), still have their place and can best benefit certain patients.
Patient selection for ATIOLs
For Dr. Singh, deciding whether to implant a multifocal, accommodating, or toric lens, depends on the risk factors. For example, as glaucoma in itself is a risk factor for success with a multifocal lens, Dr. Singh might not move forward on a patient with uncontrolled moderate glaucoma who would still be drop-dependent after surgery.
However, for a stable primary open-angle glaucoma (POAG) individual with a satisfactory 10-2 VF test and relatively healthy RGC layer, he would offer the opportunity for improved vision through a multifocal lens.
Glaucoma and cataract specialist Nathan Radcliffe, MD, stated, in his practice, he has never experienced a patient who was unhappy with a multifocal IOL who wouldn’t have had similar complaints about a monofocal IOL due to preexisting foveal loss from glaucoma.
Toric lenses as a starting point
For surgeons entering the premium IOL realm who are still hesitant, Dr. Singh suggests starting with toric lenses. Loss of contrast sensitivity is one of the earliest findings in glaucoma patients. The latest toric lenses have the capacity to maximize the light.
Currently, there are available lenses with toric powers as low as 1.25 to correct against the rule astigmatism of 0.75, allowing for vision correction while simultaneously boosting the quality of the light entering the eye.
Refractive surgery in the case of missed targets
If the target is missed with a multifocal lens, the surgeon has the option to perform laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), or another refractive procedure to reach the desired goal. Dr. Singh stated that he, personally, is comfortable performing a PRK enhancement on patients who have mild glaucoma and are stable, as their risk can be relatively low.
As a last resort, though not ideal, a lens exchange is also an option for patients who are not pleased with their surgical results.
Closing thoughts
Dr. Singh stressed that with an interventional mindset, whether it's drug delivery, laser trabeculoplasty, or MIGS procedures, the focus should be on simplifying compliance while enhancing the patient’s satisfaction by improving daily quality of life.
Providing the potential for spectacle independence through a presbyopia-correcting IOL is one way to do this. Fortunately, with MIGS procedures becoming more controlled post-operatively, outcomes are becoming easier to measure and more predictable. Dr. Singh prognosticates this will apply to the predictability of lens outcomes as well.
In closing, with ever-advancing lens technology, surgeons have the opportunity to offer qualifying glaucoma patients the option of possibly becoming spectacle-free, further enhancing their overall wellbeing, which is the ultimate goal of having this mindset.
