ChirugiePhacoréfractive

Refractive Surgery at Bellevue Ophthalmology Clinics

Vision correction at Bellevue clinics is achieved through refractive surgery, a procedure aimed at addressing vision issues such as hyperopia, myopia, presbyopia, and astigmatism. This intervention utilizes medical tools such as lasers and intraocular lenses (IOLs) to restore the eye to a state of unimpaired refraction.

Definitions

Refraction: Ocular refraction refers to the process by which light passes through different structures of the eye and is focused on the retina, where visual images are formed. The human eye comprises several parts, including the cornea, lens, and vitreous humor, all of which play a role in the refraction process. Any anomaly in these components is considered a refractive problem if it affects vision.

Phacorefractive surgery: Replacement of a crystalline lens with an intraocular lens that optimizes a patient's vision and reduces dependence on glasses or contact lenses.

Femtosecond laser: A laser guided by imaging is used in patients undergoing refractive surgery. It enables the precise, micron-level execution of certain stages of the operation, which were traditionally performed manually with blades and forceps. This laser technology optimizes postoperative refractive outcomes. Moreover, it allows for the creation of specific incisions that would not be achievable with conventional surgical techniques, such as incisions within the cornea. This avoids cutting corneal nerves, primarily located on the corneal surface, thereby reducing the risks of postoperative dry eye.

Intraocular Lenses

Intraocular lenses come in various categories, offering diverse features such as astigmatism correction when provided in a toric version. At Bellevue Clinic, the selection process for these specialized lenses involves comprehensive examinations, including optical and ultrasound tests. These steps aim to determine the patient's compatibility with a specific lens type, obtain precise measurements for lens power, and accurately anticipate postoperative results.

Intraocular Lenses

Phacorefractive Surgery and Astigmatism Correction

Scientific studies emphasize the importance of reducing astigmatism—a curvature problem of the cornea—to enhance distance vision quality and diminish undesirable effects such as halos or other postoperative dysphotopsias. In the context of phacorefractive surgery, various preoperative measures, such as the precise implantation of toric intraocular lenses, along with markings and intrastromal corneal incisions (astigmatic keratotomies – AK), all contribute to optimizing visual acuity in individuals with astigmatism.

This approach reduces the need for adjustments, thereby avoiding a second surgical intervention and minimizing operative risks.

The Femtosecond Laser: Leading-edge Practices in Ophthalmic Surgery

Since 2014, Bellevue Clinic has had a femtosecond laser to enhance the precision of its interventions. This technology, not yet available in the public health network in Quebec, plays a crucial role in modernizing surgical practices. It optimizes patient vision by offering higher levels of safety, precision, and predictability than traditional surgery.

Medical Expertise at Bellevue

Engaging in various research projects, our highly specialized ophthalmologists are actively involved in a continuous improvement process. They disseminate postoperative results through publications in scientific journals and contribute to conferences at national and international levels. Our team strives to refine surgical techniques to provide patients with solutions that enhance their vision and quality of life.

Our modern facilities, advanced equipment, and experienced staff ensure efficient, safe, professional, and personalized care.

References

Hayashi K, Yoshida M, Igarashi C, Hirata A., Effect of Refractive Astigmatism on All-Distance Visual Acuity in Eyes With a Trifocal Intraocular Lens., Am J Ophthalmol. 2021 Jan;221:279-286.

Barnett BP., FOCUSED (Femtosecond Optimized Continuous Uncorrected Sight with EDOF and Diffractive Multifocal IOLs) - A Review., Curr Opin Ophthalmol. 2021 Jan;32(1):3-12.

Gibbons A, Ali TK, Waren DP, Donaldson KE., Causes and correction of dissatisfaction after implantation of presbyopia-correcting intraocular lenses., Clin Ophthalmol. 2016 Oct 11;10:1965-1970.

Niels E de Vries 1, Carroll A B Webers, Wouter R H Touwslager, Noel J C Bauer, John de Brabander, Tos T Berendschot, Rudy M M A Nuijts, Dissatisfaction after implantation of multifocal intraocular lenses, J Cataract Refract Surg, 2011 May;37(5):859-65.doi: 10.1016/j.jcrs.2010.11.032. Epub 2011 Mar 11.

Lim CW, Somani S, Chiu HH, Maini R, Tam ES., Astigmatic Outcomes of Single, Non-Paired Intrastromal Limbal Relaxing Incisions During Femtosecond Laser-Assisted Cataract Surgery Based on a Custom Nomogram., Clin Ophthalmol. 2020 Apr 22;14:1059-1070.

Wortz G, Gupta PK, Goernert P, Hartley C, Wortz B, Chiu J, Jaber N.Outcomes of Femtosecond Laser Arcuate Incisions in the Treatment of Low Corneal Astigmatism., Clin Ophthalmol. 2020 Aug 7;14:2229-2236.

Rückl T, Dexl AK, Bachernegg A, Reischl V, Riha W, Ruckhofer J, Binder PS, Grabner G., Femtosecond laser-assisted intrastromal arcuate keratotomy to reduce corneal astigmatism., J Cataract Refract Surg. 2013 Apr;39(4):528-38.

Yang LWY, Mehta JS, Liu YC.,Corneal neuromediator profiles following laser refractive surgery., Neural Regen Res. 2021 Nov;16(11):2177-2183.

The American Academy of Ophthalmology 202-2021 BCSC Basic and Clinical Science Course, Chapter 8: Optimizing Refractive Outcomes of CataractSurgery, https://www.aao.org/education/bcscsnippetdetail.aspx?id=96862731-6e53-4678-b67e-5a9a8e80f91c.

Burkhard Dick, Tim Schultz, Laser-assisted marking for toric intraocular lens alignment, J Cataract Refrac Surg 2016; 42:7–10.

Gills Jp, Van der Karr M, Cherchio M., Combined toric intraocular lens implantation and relaxing incisions to reduce high preexisting astigmatism., J Cataract Refract Surg. 2002 Sep;28(9):1585-8.

Masayuki Ouchi, Shigeru Kinoshita, AcrySof IQ toric IOL implantation combined with limbal relaxing incision during cataract surgery for eyes with astigmatism >2.50 D, J Refract Surg 2011 Sep;27(9):643-7.