A toric intraocular lens for astigmatism is an artificial lens implanted in the eye during cataract surgery or refractive lens exchange and designed to reduce the optical effect of regular corneal astigmatism. These lenses are medically known as toric intraocular lenses. A toric lens does not change the shape of the cornea but aims to optically balance the refractive error in different meridians. In suitable patients, the aim is therefore to reduce blurred vision caused by astigmatism and the need for glasses after surgery. The outcome depends on the nature of the astigmatism, placement of the lens on the correct axis and general eye health. It cannot be said that astigmatism will be completely corrected or that the use of glasses will end in every patient.
What Is a Toric Intraocular Lens?
A toric intraocular lens has different refractive powers in different meridians. It is generally implanted during the same operation to replace the natural lens removed due to cataract. Unlike standard intraocular lenses, it has an additional optical feature designed to reduce regular corneal astigmatism. Its effectiveness depends on the lens being positioned in accordance with the predetermined axis of astigmatism. The lens type is selected by assessing corneal measurements and daily visual needs together. A toric design may be available in monofocal, multifocal or extended depth of focus lenses.
How Does Astigmatism Affect Vision?
Astigmatism occurs when different refractive powers in the cornea or the natural lens of the eye prevent light from focusing at the same point. This may cause blurred, shadowed or distorted vision at near or far distances. Some people may also experience eye strain and headaches. Even when the natural lens is removed during cataract surgery, astigmatism originating from the cornea may persist. A standard intraocular lens may not adequately compensate for this refractive error on its own. In suitable patients, a toric lens may be considered to reduce residual corneal astigmatism.
How Does a Toric Lens Compensate for Astigmatism?
The different optical powers of a toric lens in specific directions help compensate for the effect of regular differences in corneal curvature. This effect is achieved by positioning the lens on the planned axis. The lens does not reshape the cornea or alter its anatomical structure. Instead, it helps light focus more appropriately on the retina. Measurements of the front and back surfaces of the cornea and changes that may be caused by surgery are taken into account during planning. The outcome may vary according to the degree of astigmatism and any accompanying eye conditions.
Types of Toric Intraocular Lenses
Monofocal toric lenses generally support vision at a selected distance while reducing astigmatism. If distance vision is targeted, glasses may be needed for near tasks. Multifocal toric lenses aim to support vision at several distances in addition to correcting astigmatism. Trifocal toric designs have different focal zones for distance, intermediate and near vision. EDOF toric lenses aim to provide a wider range of vision, particularly at distance and intermediate ranges. The appropriate option is determined according to the individual's eye structure and expectations in daily life.
Multifocal and Trifocal Toric Lenses
A trifocal toric lens is designed to support distance, intermediate and near vision while reducing regular astigmatism. Multifocal toric lenses may also aim to reduce the need for glasses at different viewing distances. However, the multifocal optical design of these lenses may cause halos, glare or reduced contrast in some people. These symptoms are associated more with the multifocal design of the lens than with its toric feature. These options must be assessed separately in people with macular disease, advanced glaucoma or marked corneal irregularity. Suitability for a monofocal toric lens does not necessarily mean suitability for a multifocal toric lens.
Who Is Suitable for EDOF Toric Lenses?
EDOF toric lenses aim to provide an extended depth of focus while reducing astigmatism. With these lenses, visual needs at distance and intermediate ranges may be prioritised. Daily activities requiring intermediate vision, such as using a computer, are considered when selecting the lens. Some people may still need glasses for small print at near distances. Effects related to light scatter and night vision may vary according to the design used. Suitability is determined according to visual priorities and a detailed eye examination.
When Are Toric Lenses Used?
Toric lenses are most commonly considered for people who are planning cataract surgery and have regular corneal astigmatism. When the natural lens affected by cataract is removed, an intraocular lens that helps compensate for astigmatism is implanted. Toric options may also be considered during refractive lens exchange in some patients. However, this procedure requires removal of the natural lens and carries risks specific to intraocular surgery. Phakic toric lenses, in which the natural lens is left in place, are a separate procedure. The need for a toric lens is determined by assessing astigmatism measurements and the person's visual needs together.
Who Is Suitable for a Toric Lens?
People with regular corneal astigmatism and consistent measurements may be assessed for a toric lens. This option may be considered for patients who wish to reduce their need for glasses due to astigmatism after cataract surgery. It is important that the ocular surface is healthy and the corneal measurements are repeatable. The ability to position the lens appropriately within the capsular bag must also be assessed. Visual expectations, occupation and priorities for distance or near vision are also considered. Suitability is not determined solely by the degree of astigmatism.
When Is a Toric Lens Not Recommended?
Advanced irregular corneal astigmatism may make it difficult for a toric lens to provide the expected optical effect. Uncontrolled dry eye and corneal surface diseases may reduce the reliability of measurements. Changes in corneal structure must be assessed separately in conditions such as progressive keratoconus. Weakness in the tissues supporting the lens or problems with capsular integrity may affect the position of the lens. A monofocal toric lens is not entirely excluded in a person with retinal disease, but the achievable level of vision may depend on the underlying condition. The suitability of multifocal toric lenses is assessed more carefully in retinal and optic nerve diseases.
Can a Toric Lens Be Used in Keratoconus?
Keratoconus may cause the shape of the cornea to change and irregular astigmatism to develop. The optical effect of a toric lens may be unpredictable in advanced or progressive cases. However, a toric lens may be considered in some people whose condition is stable and who have a regular component of astigmatism in the centre. Corneal topography and tomography must be examined in detail before this decision is made. Changes in the cornea over time and expectations after surgery are assessed together. The presence of keratoconus does not mean that the same lens option will be used for every patient.
Which Measurements Are Taken Before Surgery?
When planning a toric lens, the length of the eye, corneal curvature and the axis of astigmatism are measured. Keratometry, optical biometry, corneal topography and tomography where necessary assist with this assessment. The reliability of the measurements is checked by examining the tear film and ocular surface. If marked dry eye is detected, treatment of this condition may be planned first. A retinal examination and, in patients for whom it is considered necessary, macular imaging may also be performed. Any inconsistencies between measurements must be assessed before the lens selection is finalised.
Why Is Posterior Corneal Astigmatism Important?
Corneal astigmatism is not caused solely by differences in curvature on the front surface of the eye. The back surface of the cornea also contributes to its total refractive power. Assessments based only on the front surface may affect the lens calculation in some people. It is therefore important to consider posterior corneal astigmatism when determining toric lens power. Changes associated with the surgical incision and the position of the lens inside the eye may also be included in the calculation. Personalised planning helps assess the possibility of unexpected residual astigmatism after surgery.
Do Previous Laser Surgeries Affect Lens Selection?
Corneal laser procedures such as LASIK or PRK may change the refractive characteristics of the front surface of the eye. These changes may require more detailed assessment when determining toric lens power and axis. Previous laser surgery alone does not prevent the use of a toric intraocular lens. Corneal topography, consistency of measurements and information about the previous surgery are assessed together. A toric lens may be used in some people with regular astigmatism. If marked optical irregularity is detected, different treatment options may be considered.
Toric Intraocular Lens Surgery
Toric lens surgery involves removing the natural lens of the eye and implanting an appropriate toric lens. The procedure is generally planned under topical or local anaesthesia. The lens affected by cataract is usually broken up and removed using phacoemulsification. A foldable toric lens is then implanted in the capsular bag in suitable patients. The markings on the lens are aligned with the previously calculated axis of astigmatism. The surgical method, duration of the operation and timing of procedures for both eyes may vary according to the individual situation.
Positioning the Lens on the Correct Axis
For a toric lens to reduce astigmatism, it must be positioned inside the eye in accordance with the planned axis. Preoperative measurements and marking methods considered necessary are used to determine the axis. The reference markings on the lens are checked during the procedure. Deviation of the lens from its planned position may reduce its corrective effect. Therefore, the position of the lens is also assessed during postoperative examinations. Although axis accuracy is important, it does not alone guarantee perfect vision.
What Happens If the Toric Lens Rotates?
If a toric lens moves away from the planned axis, its astigmatism-correcting effect may be reduced. This may be noticed as blurred vision or a greater need for glasses than expected. The risk of lens rotation may be associated with the structure of the eye, capsular characteristics and surgical conditions. Normal eye movements alone cannot be said to rotate the lens. If a marked change in axis is detected, the need for repositioning is assessed. The decision to perform an additional procedure is made by considering the expected benefit and the risks of intraocular surgery together.
Side Effects of Toric Lenses
Temporary blurred vision, sensitivity to light and mild discomfort in the eye may occur after surgery. Dry eye may affect image quality during the healing period. Deviation of the lens from its axis or residual astigmatism may result in vision below the expected level. Symptoms such as halos and glare may be more noticeable, particularly with multifocal toric lenses. The occurrence of these symptoms with monofocal toric lenses is not always related to the toric design. The cause of the symptoms must be assessed according to the examination findings.
Risks of Toric Lens Surgery
Toric lens implantation carries surgical risks similar to those of other intraocular operations. Infection, intraocular inflammation, corneal oedema and changes in intraocular pressure may develop. Retinal oedema, retinal tears and retinal detachment are also considered among the possible risks. Lens displacement, rotation or a different residual prescription than expected may require additional intervention. Severe pain, increasing redness and sudden reduction in vision must be assessed without delay. Flashes of light or the sensation of a curtain in the field of vision are also symptoms requiring prompt examination.
Will Glasses Be Needed After Surgery?
The aim of a toric lens is to reduce the effect of corneal astigmatism on the need for glasses. However, it cannot be guaranteed that astigmatism will be completely eliminated or that glasses will never be needed. With monofocal toric lenses, glasses may be required for near tasks. Additional glasses may also be needed in some situations with multifocal or EDOF toric lenses. Residual refractive error, retinal health and daily visual expectations affect the outcome. These possibilities must be assessed before selecting the lens.
Recovery and Postoperative Care
It is important to use the recommended eye drops as directed after surgery. The eye must not be rubbed and should be protected from impact. The timing of returning to swimming pools, dirty water, strenuous exercise and similar activities is determined according to individual recovery. Intraocular pressure, visual acuity and the axis of the toric lens are assessed during follow-up examinations. Fluctuating vision or sensitivity to light may occur during the early period. If unexpected pain, redness or reduced vision develops, the patient should not wait until the scheduled follow-up date.
What Is Done If Astigmatism Persists?
Residual astigmatism after surgery may have different causes. A different effect from the planned lens power, posterior corneal characteristics or lens rotation are assessed. Dryness of the ocular surface may also affect measurements and image quality. If necessary, glasses, ocular surface treatment or additional laser options in suitable patients may be considered. If there is marked lens rotation, repositioning of the lens may also be assessed. The approach is determined according to the source of the astigmatism and the person's visual needs.
Toric Lens Implantation in Izmir
Toric intraocular lens implantation in Izmir is planned by assessing corneal astigmatism and general eye health together. The condition of the cataract, regularity of the astigmatism and retinal findings are important when selecting the lens. Daily visual needs may also be considered during the assessment performed by Assoc. Prof. Berkay Akmaz in Konak. A monofocal toric lens may be suitable for some patients, while trifocal or EDOF toric options may be considered for others. Different treatment methods may be required in patients with an irregular corneal structure. The decision to perform surgery should be made after an examination and personalised measurements.
Toric Lens Surgery Prices
Toric lens surgery prices may vary according to the characteristics of the astigmatism and the optical design of the selected intraocular lens. Monofocal, trifocal or EDOF toric lens options may result in differences in planning. Whether the procedure is performed on one or both eyes also affects the assessment. The necessary measurements, accompanying eye diseases and surgical conditions are also considered. Therefore, it is not appropriate to specify a single fee applicable to everyone without an examination. You can contact us through the website for information about toric intraocular lens options and the assessment process.
