By Dr. David Folden, MD | Twin Cities Eye Consultants
Most patients preparing for cataract surgery focus on choosing the right intraocular lens (IOL). That’s understandable—and important. However, even the best lens can only perform as well as the surgical technique used to place it. One of the most critical yet lesser-known steps in that technique is the capsulotomy.
What Is a Capsulotomy in Cataract Surgery?
Your natural lens is enclosed within a thin, transparent membrane called the lens capsule. During cataract surgery, your surgeon creates a small, circular opening in the front portion of this capsule. This opening allows the surgeon to remove the cloudy natural lens and insert a new artificial intraocular lens (IOL).
When performed manually, this step is referred to as a capsulorrhexis. When created using a femtosecond laser, it is called a capsulotomy. Laser-created capsulotomies are highly precise, with the ability to be centered and sized to within fractions of a millimeter using computer-guided automation.
The size and shape of this capsule opening are critical because they influence how the IOL sits within the eye—not just immediately after surgery, but for the rest of the patient’s life. A capsulotomy is not simply a technical step; it is a key surgical decision that can affect long-term visual outcomes.
Why Does Capsulotomy Size Matter?
The final position of the IOL inside the eye is referred to as the Effective Lens Position (ELP). Surgeons attempt to predict ELP preoperatively using IOL calculation formulas, as even small deviations can impact visual outcomes.
Capsulotomy size appears to play a direct role in influencing ELP. This relationship has been a major focus of my research. As principal investigator of a recent prospective, randomized clinical trial, I studied how capsulotomy size affects the ELP. This study compared two precisely controlled capsulotomy diameters—4.6 mm and 5.6 mm—using femtosecond laser technology to ensure consistency.
I presented these findings at the 2026 American Society of Cataract and Refractive Surgery (ASCRS) annual meeting in Washington, DC, where the study was awarded Best Paper of Session (BPOS).
Overall, the results demonstrated that a larger capsulotomy was associated with the IOL sitting approximately 59 microns further back in the eye compared to a smaller capsulotomy. While modest, this difference becomes more meaningful when considering individual patient anatomy—particularly the thickness of the patient’s natural lens.
How Natural Lens Thickness Changes the Equation
One of the most important findings from our research is that capsulotomy size does not affect all eyes in the same way. The thickness of a patient’s natural lens prior to surgery appears to significantly influence how capsulotomy size impacts IOL position.
In patients with thinner natural lenses (less than 5.0 mm), a larger capsulotomy resulted in the IOL sitting further back in the eye—by approximately 120 microns—compared to a smaller capsulotomy. This degree of shift can result in a hyperopic (farsighted) outcome relative to what traditional IOL formulas would have predicted.
In contrast, patients with thicker natural lenses (greater than 5.0 mm) demonstrated the opposite effect. A larger capsulotomy resulted in the IOL shifting forward by approximately 120 microns, leading to a myopic (nearsighted) tendency compared to predicted outcomes.
The key takeaway is that capsulotomy size appears to be a meaningful variable that can influence effective lens position—particularly when considered in the context of preoperative lens thickness.
It is important to note that this study included 40 eyes (20 per group). While the sample size is relatively small and further studies are needed to improve statistical significance, the directional pattern is consistent. The same capsulotomy size can produce opposite effects depending on patient-specific anatomy, suggesting that a “one-size-fits-all” approach may not be optimal in the context of traditional IOL formulas that surgeons rely on.
What This Could Mean for Surgical Planning
Even small shifts in IOL position can meaningfully affect visual outcomes, especially for patients seeking reduced dependence on glasses after surgery. When the actual ELP differs from what is predicted by traditional formulas, the refractive outcome may not align with expectations.
This applies across all types of IOLs, including monofocal lenses (toric and non-toric), extended depth of focus (EDOF) lenses such as the PureSee (Johnson & Johnson) and Vivity (Alcon), and multifocal lenses such as PanOptix Pro (Alcon), Odyssey (Johnson & Johnson), and enVista Envy (Bausch + Lomb).
Our research points toward a potential solution: capsulotomy nomograms. These would function as personalized surgical guides, helping surgeons select an optimal capsulotomy size based on individual patient characteristics. Such nomograms could complement existing IOL formulas and enhance predictive accuracy. Further research is ongoing to validate and refine this approach.
Does Laser Cataract Surgery Improve Capsulotomy Precision?
Femtosecond laser-assisted cataract surgery introduces a high level of precision into this step of the procedure. Using advanced imaging and computer guidance, the laser can create a capsulotomy that is consistently round, accurately sized, and precisely centered on the natural lens.
This level of reproducibility is difficult to achieve with manual techniques alone. With laser-guided precision, however, capsulotomy size can become a controlled and reliable variable in surgical planning.
In addition to improving consistency, precise capsulotomy architecture may help optimize IOL centration, reduce tilt, and contribute to more predictable refractive outcomes.
At Twin Cities Eye Consultants, we are actively engaged in research aimed at improving visual outcomes following cataract surgery. Our approach emphasizes individualized surgical planning, incorporating advanced technology and patient-specific factors to optimize results across our 11 Twin Cities locations.
What to Look for When Choosing a Cataract Surgeon
High-quality cataract surgery goes beyond technical skill. It requires ongoing engagement with clinical research, a commitment to innovation, and a focus on continually improving patient outcomes.
I’ve performed more than 20,000 cataract, lens exchange, and other refractive surgeries. I completed my surgical training at the University of Minnesota, where I was honored with the Harry Plotke Award for clinical excellence and the Harry Friedman Research Award. I was the first resident surgeon to explore and utilize advanced technology IOLs at the University of Minnesota, including both toric and multifocal IOL technologies during residency training.
I remain an active member of ASCRS and have published research in peer-reviewed journals including the Journal of Cataract and Refractive Surgery, Clinical Ophthalmology, and the American Journal of Ophthalmology. As a practice, Twin Cities Eye Consultants has performed more than 150,000 cataract surgeries, making it one of the most experienced surgical programs in Minnesota.
When selecting a surgeon, it is important to consider experience, specialization, and a demonstrated commitment to staying current with evolving surgical techniques and clinical evidence.
Your Vision After Surgery Starts Here
Most patients rely on their surgeon to manage the technical aspects of cataract surgery—and that trust is well placed. However, understanding the factors that influence surgical outcomes may help you make a more informed decision about your care.
If you are considering cataract surgery and would like to speak with our team at Twin Cities Eye Consultants, we are currently accepting consultations throughout the Twin Cities. Call us at 612-999-2020 or contact our team to request an appointment.
Note: The research findings referenced in this article are based on a presentation by Dr. David Folden, MD, at ASCRS. These results reflect early directional trends, and additional studies are ongoing to further validate clinical significance.
