Cataract

What are cataracts?

What are cataracts?
Presbyopia correction
Intraocular Lenses Types
Glaucoma and Cataract

What are cataracts?

Cataract is the progressive clouding of the natural crystalline lens of our eye. This lens is created during the embryogenesis in the womb. The crystalline Lens and the cornea are the main refractive surfaces of the eye and are responsible for focusing the light on the retina.

With age, the crystalline lens gets thicker due to the gradual and constant deposition of lens fibres on its surface. This hardens the central lens fibres causing changes in the clarity of them and resulting in a characteristic yellowing of the lens (nuclear sclerosis).

Changes in the clarity of the crystalline lens can also occur in the cortex of the lens or at its posterior or anterior capsule. These types of cataracts are called cortical and subcapsular cataracts respectively. Quite often, cataract types can co-exist.

All the above changes cause changes in how the light is refracted through the lens and they cause symptoms such as blurring of the vision, glare, difficulty seeing in low light, frequent changes in the spectacle prescription or seeing some haloes around lights .

With respect to risk factors for developing cataracts, aside from age, other risk factors include the presence of Diabetes, other metabolic diseases, excess tobacco use, use of steroid medications, previous trauma or inflammation of the eye and previous eye operations like vitrectomy.

How is cataract diagnosed and how is it treated?

The diagnosis of cataract is made after a comprehensive eye examination which involves the measurement of visual acuity, refractive error, intraocular pressure (eye pressure) and a full examination of the anterior and posterior segment of the eye on the slit lamp.

Careful pre-operative assessment is crucial in order to achieve the best visual outcome for the patient and this is achieved by obtaining accurate measurements of the eye that aid the selection of the right intraocular lens implant power. At the same time, during the pre-operative assessment, co-existing eye pathologies like Age Related Macular Degeneration (AMD), Diabetic eye Disease and Glaucoma are identified so that the can be treated if needed and also enable the surgeon to counsel the patient on the predicted visual outcome.

Cataracts can only be treated surgically and the surgery involves the removal of the natural crystalline lens that has become cloudy with time (and this is what we call cataract) and the implantation of an intraocular lens implant that is selected based on the preferences of the patient and their visual needs.

When is the right time to have cataract surgery?

Being diagnosed with cataracts does not necessarily mean that cataract surgery is needed. Often, the vision can be corrected with glasses and can remain at a good level for a prolonged period of time.

Cataract surgery is usually advised when the visual symptoms arising from the cataract are affecting the patient’s daily life and activities, there is no other cause for the reduced vision except the presence of cataracts and the symptoms are significant enough to justify the risks associated with having cataract surgery.

Do I need to wear glasses after cataract surgery?

The answer depends on the type of intraocular lens implant that will be used, the choice of which is done after having a pre-operative assessment and an in-depth discussion with the surgeon on the various options and the pros and cons of each option.

Generally speaking, when a standard monofocal lens is used, patients can have excellent unaided distance vision and need reading and/or intermediate glasses. In the Subsection “IOL Types”, you may find a detailed description of all available types of intraocular lenses.

Why choose Dr Siempis?

Dr Siempis has been trained to a high standard in cataract surgery having performed over a thousand cases during his training and fellowships in the United Kingdom and Canada. He is a Consultant Ophthalmologist in one of the largest independent eye service providers in the United Kingdom performing high volume cataract surgery on a regular basis. What is more, he has significant surgical experience in dealing with complex cataract cases such as the ones with unstable crystalline lenses sure to previous trauma or pseudo exfoliation and in cataracts with short or long axial lengths.

Even though cataract surgery is now considered a routine surgery and is indeed one of the most commonly procedures performed on a worldwide basis, its success lies in the careful pre-operative assessment and planning, in the surgical technique as well as the post-operative monitoring for detection of any post-operative complications especially in cases with co-existing eye diseases. Dr Siempis personally examines all of his patients, establishes the needs of every patient and tailors the surgical plan accordingly in order to give to all patients the best possible vision after the surgery.

All patients undergoing cataract surgery have special non invasive scans of the eye (Optical Coherence Tomography) of the macula (central part of the retina) and optic nerve in order to detect any underlying undiagnosed eye pathology and accurate pre-operative biometry of the eye that is done with the Alcon Argos® Swept Source Biometry which is a state of the art optical biometry that incorporates the latest IOL formulas that are necessary to achieve the best possible visual outcome.

Though the practice, there is access to all the latest IOL technologies like aspheric Monofocal IOLs, Toric (astigmatic) Intraocular lenses, Multifocal IOLS and EDOF - Extended Depth of Focus IOLS that come from Alcon, Johnson and Johnson and Bausch & Lomb.

The surgeries take place in the Day Surgery Unit of St Luke’s Hospital in Panorama, Thessaloniki, which is equipped with the latest phacoemulsification machines from Alcon (Centurion®) and surgical microscopes from Zeiss.

Presbyopia correction

The technology behind Introcular Lenses (IOLs) has evolved significantly over the past decade and surgeons are now able to offer more choices to their patients with respect to the correction of astigmatism and presbyopia.

These types of IOLs are called «Premium IOLs». The development of such technology addresses the changes in life expectancy, the increasing use tablets, phones and computers in people across all age groups along with the fact that people are now working longer in their lifetimes than before, wishing clear vision across all distances ideally without glasses.

Dr Siempis offers access to the most well known and trusted IOL platforms. These are described in detail in the next subsections.

A brief summary on the use of multifocal and extended depth of focus lenses is presented below along with a description of the method of "Monovision". Detailed descriptions of each type of IOL are presented in the subsection “IOL types”

Intraocular Lenses of Presbyopia Correction

The use of Multifocal and Extended Depth of Focus (EDOF) Intraocular Lenses (IOLs) can enable patients to have complete or partial spectacle independence following cataract surgery.

These types of IOLs require careful patient selection and a thorough preoperative assessment. The surgeon should explain in detail the advantages and disadvantages of these lenses in order to ensure patient satisfaction.

Any preoperative ocular pathology such as the presence of glaucoma or macular degeneration that could potentially limit the visual outcome or be a relative contraindication of the implantation of such IOLs should be identified prior to the surgery and counsel the patient accordingly. At the same time, it is very important to correct any significant astigmatism with the use of the toric versions of these IOLs.

Following the surgery, there is a 5%-10% chance of additional surgery in the form of laser surgery (top up refractive laser) in order to achieve the best refractive outcome.

Monovision

Monovision is another way of addressing the issue of presbyopia which is the progressive loss of the ability of the eyes to focus on nearby objects. The idea behind mono vision is to correct one eye for distance (the dominant eye) and the fellow eye for near or intermediate.

Some patients already experience Monovision through their contact lens correction and it is also possible to simulate the effect of it prior to cataract surgery with a contact lens trial. Other ways of achieving monovision include the use of refractive corneal surgery (PRK or LASIK) or through cataract surgery by selecting the appropriate power for the IOL for each eye.

Monovision requires careful patient counselling and preoperative assessment and the surgeon should take into consideration the previous refractive status of the eye along with the patient’s need and lifestyle.

Some drawbacks of this method include that there is a partial loss of depth perception due to the imbalance between the two eyes and few patients might be unable to adapt in the difference in the refractive error between the two eyes. Rarely, the patient might experience diplopia in cases of latent squints that decompensate to the change in the refractive status of the eyes

Intraocular Lenses Types

The first intraocular lenses (IOLs) ere launched in the 50s and since then have improved tremendously when it comes to the materials used, their design and their ability to provide more clear vision across a wider range of distances (Extended Depth of Focus and Multifocal - IOLs).

The most commonly used IOLs with respect to the material used are the hydrophobic acrylic IOLs that are foldable and can easily be inserted through a very small incision of 2.2 mm.

Cataract surgery nowadays offers patients the chance to correct fully their refractive error or reduce it as much as possible as the surgeons are able to select the appropriate power for the IOL based on accurate calculations of the dimensions and the shape of the eye. In the next subsections, the main 4 types of IOLs are analysed based on their optical designs and properties.

Monofocal IOLs

This is the most commonly used type of Intraocular lens (IOL). It offers excellent vision at a certain plane of focus, usually distance or near. If a distance target is selected, this means that in most cases, the patient can have good unaided vision for far away (except if there is pre-existing significant astigmatism) but near and intermediate glasses are required.Most IOLs nowadays are aspheric. This means that there are no aberrations of light at the peripheral parts of the IOL optic and this is associated with better vision at nighttime. In selected cases, a near correction can be chosen (for example at 40 cm) and this is useful in patients who wish clear vision for reading close up without the use of reading glasses. In such cases, the trade off is that distance glasses would be needed.Dr Siempis uses monodical IOLs from Alcon (Acrysof IQ® and Clareon®), theTecnis® platform from Johnson and Johnson Vision as well as the EnVista® IOL from Bausch and Lomb.

Monofocal Plus IOLs

Johnson and Johnson Vision has recently launched the Eyhance™ IOL. According to the company and some studies, this IOL is an improved version of the existing Technis IOL monodical platforms due to its special optical design. It offers better vision at a far intermediate distance (for example when using our phone or laptop at 65 cm or further away) without compromising the quality of vision for distance and without any side effects such as haloes or glare.The Enhance™ platform is also available in toric (astigmatic) versions.

Extended Depth of Focus IOLs (EFOF IOLs)

EDOF IOLs are in the middle of the spectrum of available IOLs in between Multifocal and Monofocal IOLs with respect to their ability to offer a degree of close up vision without the use of spectacles while at the same time minimise any symptoms of haloes, glare or reduced contrast sensitivity. One of the most commonly used EDOF IOLs is the Vivity® IOLs from Alcon. This IOL has a specially designed anterior surface that alters the passage of light to the retina thereby allowing better unaided vision at an intermediate distance (for example when using our phone or tablet). The incidence of glare and haloes is reduced compared to Multifocal IOL designs according to published studies. It is worth noting that most patients will need reading glasses for close up vision. Another EDOF IOL is the Symfony® platform from Johnson and Johnson Vision. This type of IOL lengthens the focal point of light due to its specially designed surface and like Vivity® enables the patient to have clear unaided intermediate vision without compromising the quality of distance vision.

Multifocal IOLs

Multifocal IOLs have been used for many years for presbyopia correction in patients undergoing cataract surgery. They allow for unaided vision for near, intermediate and distance making them an attractive choice for patients who want full spectacle independence.Depending on their design and optical properties, they can be subdivided in Bifocals, Trifocals with diffractive design and refractive ones.Some patients might experience symptoms of dysphotopsia with these IOLs like haloes and glare or feel that the contrast is reduced. As a result it is imperative to counsel the patients accordingly and select the right type of patients who would benefit from these IOLs.In the recent years, the use of Trifocal IOLs like the Panoptix® from Alcon has steadily increased. This multifocal IOL has a diffractive design and enables patients to have spectacle free vision across all distances. Diffractive IOLs have a higher risk of causing dysphotopsias when compared to EDOFs and monofocals. Having said that, the majority of patients are happy with them and do not experience any troublesome symptoms. Johnson and Johnson Vision also has a multifocal IOL called Synergy®. This IOL provides continuous range of vision with favourable characteristics when it comes to contrast and incidence of dysphotopsias.

Τoric IOLs

Astigmatism is the refractive status of the eye in which the image is not perfectly focused on the retina primarily due to the shape of the anterior part of the eye (the cornea). This is due to the fact that in some people the cornea is steeper at some meridians than others just like a rugby ball. Occasionally, astigmatism can be due to lenticular changes from the presence of a cataract. Astigmatism can be surgically corrected in younger people through corneal refractive laser procedures. In older ages when cataract formation has usually occurred, the usual approach is that of cataract surgery with an implantation of a specially designed intraocular lens (IOL) called a toric IOL. This can either eliminate or significantly reduced any astigmatic refractive error making it more likely to achieve good unaided vision for distance or near depending on the patient’s preference. . Toric IOLs come in monofocal, Extended Depth of Focus and Multifocal versions. Careful pre-operative assessment and planning is needed from experienced surgeons in order to achieve an optimal refractive outcome.

Glaucoma and Cataract

Glaucoma and cataract often coexist especially in older ages. At the same time, in some patients the presence of cataracts can exacerbate some types of glaucoma.

There are several considerations when treating a patient who has glaucoma and cataract. This special group of patients that is best treated by Glaucoma specialists as they can provide a more comprehensive and tailored treatment plan.

More specifically, it is necessary to make a thorough assessment of the glaucomatous disease and determine the type of glaucoma, the severity of the disease based on the visual fields and OCT, decide if the control of the pre-operative intraocular pressure is satisfactory and also note any clinical signs during the pre-operative assessment that could complicate the surgery. These include the presence of a short axial length, pseudoexfoliation, shallow anterior chamber, small pupil and/or the presence of phacodonesis. At the same time, patients who have very advanced glaucoma are at risk of loss of central vision after the surgery (the “so called snuff out" phenomenon) and for this reason the patient should be counselled accordingly and every effort should be made to minimise the chances of this happening. Finally, the surgeon should advise whether the patient would benefit from combined cataract and glaucoma surgery.

Dr Siempis has developed an expertise in dealing with the aforementioned cases during his fellowships in the UK and Canada and also working as a Consultant Ophthalmologists in the UK.

Having a special interest in Micro-Invasive Glaucoma Surgery (MIGS), he is also able to counsel patients on whether a combined operation is needed and provides access to combined cataract and MIGS operations with the use of the iStent microimplant or the GATT technique. In selected cases, the surgeon might advise that the patient would benefit from combined cataract and filtering surgery such as combined cataract and trabeculectomy surgery or cataract surgery with concurrent Xen Gel Stent implantation or cataract surgery with the insertion of an anti-glaucoma drainage device.

Contact Us

Dr Siempis accepts new consults at his new private practice in the city centre of Thessaloniki that is located at Mitropoleos 110 Street and is equipped with state of the art diagnostic equipment.

He also accepts new patients at St Luke’s Hospital in Panorama.

Please call +30 2313 022 975 to book an appointment.

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