We optimize cataract surgery thanks to the precise study of the crystalline lens
We improve and advance in cataract surgery. A study led by Miranza Madrid confirms that the natural position of the crystalline lens (the eye’s natural lens) before cataract surgery is a determining factor in the final alignment of the intraocular lens (IOL) and, therefore, in the patient’s visual outcomes.
The study provides evidence in a Caucasian population undergoing femtosecond laser-assisted cataract surgery (FLACS), in which a laser emitting extremely brief pulses of light is used, achieving high precision without damaging adjacent tissues.
The research, entitled Tilt and Decentration of the Crystalline Lens and Intraocular Lens After Femtosecond Laser-Assisted Cataract Surgery, was led by Dr. Félix González, Medical Director of Miranza Madrid, and analyzed 125 patients.
“The human crystalline lens is not perfectly aligned with the visual axis, but instead shows a slight tilt and decentration, generally toward the temporal side (toward the temple),” explains Dr. Félix González. “What the study demonstrates is that this initial position largely determines how the intraocular lens will be positioned after surgery, potentially influencing the final visual outcome”, adds the specialist.
A Relevant finding
The study focused exclusively on Caucasian patients who underwent FLACS, a distinguishing feature compared with previous research conducted in Asian populations. “Biometric differences between ethnic groups mean that those results are not entirely extrapolable,” notes the principal investigator. “In addition, the use of the femtosecond laser provides greater surgical precision and reproducibility, strengthening the robustness of the data obtained,” he adds.
Using next-generation anterior segment optical coherence tomography (CASIA2 AS-OCT), researchers measured the tilt and decentration of the crystalline lens before surgery and compared them with the position of the intraocular lens one month after the procedure. OCT is a non-invasive ophthalmic diagnostic test that uses infrared light to create high-resolution cross-sectional images of ocular structures.
The results show that the mean preoperative crystalline lens tilt (5.20°) remained virtually unchanged in the implanted intraocular lens (5.08°), with a slight increase in decentration. This correlation confirms that it is possible to anticipate lens behavior before surgery. “This is especially relevant when we talk about advanced lenses, such as diffractive multifocal lenses, whose performance may be compromised in eyes with significant tilt or decentration,” highlights Dr. Félix González.
Key technology for more precise and safer surgery
The research underscores the importance of technology in modern cataract surgery. “The FLACS technique allows part of the procedure to be performed painlessly and with extreme precision from outside the eye, increasing safety and facilitating more accurate centering of the intraocular lens,” explains the ophthalmologist.
For its part, anterior segment OCT has represented a major advance in the study of the eye’s anterior segment. “These devices make it possible, in just 0.3 seconds, to obtain high-resolution images and precisely analyze the position of the crystalline lens and the intraocular lens using dedicated software,” adds Dr. Félix González, who has collaborated for years in the development of this technology.
Although this technology is well established, its high cost limits its widespread implementation. “Few centers have both a femtosecond laser and advanced anterior segment OCT at the same time, as is the case in our center,” the specialist points out.
Toward increasingly personalized cataract surgery
The study also identified the influence of anatomical factors such as axial eye length and patient age. Longer eyes, typically myopic, show less crystalline lens tilt, while aging and the progressive thickening of the crystalline lens influence its decentration.
“Cataract surgery is refractive surgery,” emphasizes Dr. Félix González. “We not only remove the cataract but also aim to reduce dependence on glasses as much as ocular anatomy and technology allow. Studies like this help us move in that direction.”
According to the doctor, integrating the evaluation of crystalline lens tilt and decentration into the preoperative assessment makes it possible to select the most appropriate intraocular lens for each patient and better manage expectations. “The more objective data we have and the better we understand lens behavior, the greater our ability to personalize surgery,” he states.
Among future lines of research, the Miranza Madrid team plans to analyze how different intraocular lens designs perform according to these parameters and to evaluate their impact on visual quality and patient satisfaction. “As these parameters become integrated into routine clinical practice, it is reasonable to think that they will also be incorporated into lens calculation formulas, further improving refractive accuracy,” concludes Dr. Félix González.
