Cataract

There are many kinds of intraocular lenses that can be implanted to replace the cataract and they fall into two basic categories: Multifocal or Monofocal.

Intraocular Multifocal Lens

A lens which allows focused vision for far and near distances, and usually offers better quality overall vision and freedom from corrective eyeglasses. However, there are a few eye diseases that hinder its use. The doctor will advise the patient if that is the case. Sadalla Amin Ghanem Eye Hospital works with the world’s most modern lenses but this does not mean that vision will be 100% after every cataract surgery and for any distance. All lenses implanted by our surgeons are imported and flexible.

Kinds of Intraocular Multifocal Lenses:

Nowadays there are several intraocular multifocal lens models that give different quality of vision and different distance of focus. Patients’ satisfaction index with multifocal lenses is greater than 90% (ninety percent) and varies depending on the kind of lens chosen. However, no lens guarantees perfect vision, even after a very well performed surgery by your doctor.

Multifocal Echelette

This lens allows better vision for far distance, with less occurrence of halos around light sources at night than other multifocal lenses. It usually provides excellent vision on the computer (intermediate vision) and good near vision. Eighty percent (80%) of the patients have no need to wear glasses for near vision, however, in some situations there might be a need for glasses. To reduce the chance of needing glasses for near vision the surgeon can leave a small myopia in one or both eyes. This technique allows good vision for far distance and improves near vision. The patient must tell his doctor the category of his driver’s license. If the driver’s license is “C”, “D”, or “E” (truck driver) far vision will have priority.

Multifocal Trifocal

This lens promotes good quality vision for far, intermediate and near distances. Halos around light sources at night might occur more than with the Multifocal Echelette. These night time vision disturbances usually diminish during the first 6 (six) to 12 (twelve) months after surgery. About 5% (five percent) of the patients might need glasses in some or several situations. Multifocal Echelette and Multifocal Trifocal are the most modern lenses available at this time.

Multifocal Total Diffractive +3,25 or +4,00

This is an excellent lens but has, basically, two distances of focus: far and near. Therefore, intermediate vision is worse than with the previous mentioned lenses. Night time halos, as described with Multifocal Trifocal lenses, might happen.

Multifocal Partial Diffractive +2,50

This is a lens that offers good focused vision for far and intermediate distances, but the chance of needing glasses for near vision is greater than with the previous mentioned lenses. Even then, patient satisfaction is very high. The chance of needing glasses with this lens is much lower than with  Monofocal lenses.

Important Information: To achieve good vision after a surgical procedure with a multifocal implant, the post-operative  refractive error in the eyes must be null or very small. If the result is a refractive error that affects the patient’s vision, the patient might need to undergo a free of charge Excimer Laser surgical procedure, unless there is a medical reason for not having it done. This procedure takes place in about 5% (five percent) of the patients. The best possible vision is attained only after cataract surgery has been performed in both eyes, except when the surgery on both eyes is not recommended by the surgeon. Similar to what happens when a person starts wearing multifocal glasses, an adaptation time period is needed to reach the full benefits of the intraocular multifocal lenses. This might  take from 1 (one) to 6 (six) months. Although the satisfaction index with multifocal lenses is very high, it is possible that a patient might be not satisfied with the result. There is treatment for the great majority of cases of dissatisfaction with multifocal lenses. Although rare (less than 1%), it is possible that a person will not adapt with the multifocal lens implanted (intense halos around lights at night, intense light sensitivity, or blurred vision that does not improve with corrective lenses, etc.) and there might be a need to exchange it for a monofocal lens. If this is the case, the patient will need to wear glasses again for some or all situations. Such lens exchange is paid for by a health plan most of the time. If a health plan does not pay, the patient will  be responsible for it (the cost is much less than the first surgery with multifocal lens).

Intraocular Monofocal Lens: 

Aspheric Hydrophobic Monofocal

This is the best monofocal lens available. As with all monofocal lenses, this lens has one distance of focus (far or near). Therefore, a lens with focus better for near vision is implanted in one eye, and in the other eye a lens with focus better for far vision, with some exceptions. This is known as balanced vision or monovision. The overall vision will depend on the adaptation to monovision, the refractive error present after the surgery on both eyes, and the patient’s visual needs. The probability of needing glasses is considerable higher than with multifocal lenses. Many patients will be comfortable without glasses for far and near vision, but about 20% (twenty percent) will need glasses for far, and 50% (fifty percent)  for near distance. Some patients might need multifocal eyeglasses.

Aspheric Hydrophilic Monofocal or Simple Monofocal

This is a lens similar to a Hydrophobic Monofocal Lens but it requires a wider incision (micro cut) to be implanted. For this reason the refractive error after the surgery might be a little stronger, and the need for glasses might be higher.

Spherical Monofocal

This is the simplest lens available. It might not give the same quality of vision achieved by the previously described lenses and it might result in more halos and glare at night because it does not correct spherical aberration (optical aberration that decreases the quality of vision a little). However, this lens usually allows  good vision for the majority of patients. The need to wear glasses increases with this lens. The biometry (exam that calculates the intraocular lens power) performed to implant a Spherical Monofocal Lens is the conventional biometry, and is less foreseeable than the exam performed to implant other kind of lenses. An exam with the Verion equipment is not done before a surgery with Spherical Monofocal Lens. This exam is designed to help the surgical plan to increase the precision to correct refractive errors.

Toric Lens:

This lens corrects astigmatism (refractive error that can cause visual distortion). A toric lens can be a Multifocal Echlette, Trifocal, Total Diffractive, or Spherical Hydrophobic Monofocal.

Phacoemulsification

A modern technique where the cataract is broken into tiny pieces and removed by an incision smaller than 3 mm and a flexible silicone intraocular lens is implanted. This technique is more natural and less aggressive to the eye, thus the technique of choice more than 98% of the time. Vision recovery after cataract surgery is usually quick allowing the patient to return to work after a few days.

Extracapsular

This is an older surgery technique. An incision of approximately 180 degrees is made on the eye to remove the whole lens with the cataract. Next, an intraocular lens of metylmetacrylate (a rigid plastic) is implanted in the eye. This technique is rarely used, reserved only for very old hard cataracts.

Laser

Sadalla Amin Ghanem Eye Hospital has the equipment necessary to perform laser cataract surgery. For more information, talk to your eye surgeon.

After any cataract surgery the occurrence of posterior capsule opacification is possible, and the result is vision impairment. This usually happens months or years after the surgery and is easily corrected with a Yag Laser. Such laser application (which is not a surgery) is needed in about 30% (thirty percent) of the patients. The application is quick and safe. The patient goes home right after the laser procedure, without activity restictions other than driving home from the hospital because his pupil will be dilated.

Modernness and technology are also present during the performance of your cataract surgery. Sadalla Amin Ghanem Eye Hospital provides a safe and satisfactory experience during cataract surgical treatment for its patients.

Surgical Microscopes OPMI Lumera and Leica M822: these German surgical microscopes are tools that make possible  detailed observations of the ocular structures during the surgery.

CENTURION® Vision System and CONSTELLATION® Vison System: these types of equipment are used during the cataract surgery, meeting many of the surgeon`s needs, such as phacoemulsification (cataract surgery). This is advanced technology, manufactured in the USA, that improves each step of the procedure, offering greater agility and safety. The equipment adapts automatically to the changes in the eye condition during the surgery promoting better control of the intraocular pressure and better synchronizing between the velocity of the ocular globe irrigation and the lens suction. Through its Xenon lighting system the CONSTELLATION® allows better visibility of the ocular tissues.

Femtosecond laser FEMTO LDV Z8™: this equipment performs the laser lens fragmentation and also the incisions needed to implant the intraocular lens. For more information, talk to your eye surgeon.

One of the most modern and advanced equipment for evaluation of the optical system, OPD Scan III is a single workstation with multiple features. It measures objective refraction, and the measured refractive error can be used as a reference when prescribing corrective lenses such as glasses and contact lenses. Corneal curvature, measurement and the anterior segment shape (topography and tomography) can be used as a reference when selecting the base curve of contact lenses or refractive power of intraocular lenses. It evaluates areas of the anterior segment for better selection of phakic intraocular lenses for cataract surgery. Accurately evaluates corneal power with one of more accurate existing topographers, with 33 rings of blue light. It also enables to evaluate individually ocular astigmatism: corneal, internal and total. The size of the pupil of the patient’s eye, as well as measuring the diameter and center may be used as a reference for selecting multifocal intraocular lenses. Wavefront aberrations can be used, for example, to quantify the components of irregular astigmatism or simulated views showing how the visual acuity optotypes are seen by the patient with vision correction. Allows separate evaluation of corneal aberrations, internal and total, as well as corneal asphericity. Accurate evaluation of the actual position of toric intraocular lenses, enabling better rotational control. Therefore, this technology allows accurate and detailed examination of the cornea and the entire optical system, providing the physician greater accuracy in the diagnosis and treatment of each case, as well as facilitating the planning of refractive and cataract surgery. Equipament: OPD -SCAN III (Japan).

It is an exam indicated for patients with low visual acuity whom will undergo cataract surgery. It evaluates the visual potential before surgery and it must be performed after pupil dilation. Equipament: Macular Acuity Potential.

The optical biometry examination is performed at Sadalla Amin Ghanem Eye Hospital using the most advanced equipment today, IOL Master® 700. This device, manufactured by Zeiss in Germany, increases the accuracy of calculating the intraocular lens for cataract surgery, using optical interferometry associated with optical coherence tomography (OCT) to optimize refractive outcomes. It is possible to verify the axial length of the eye, the anterior chamber depth, corneal diameter and also the central keratometry. This equipment greatly reduces the chance of unexpected results in diopters after surgery. Equipament: IOL Master® 700 (Germany).

Ultrasonic Biometry is usually performed when cataract is very advanced and it is not possible to measure by optical biometry. Equipament: Ocuscan RxP (USA).

Also known as specular microscopy, it is a photograph taken through the Specular Microscope CEM-530 and enables the visualization of endothelial cells, the innermost layer of the cornea. It is a computerized exam, with no contact, that estimates the cell density, size and shape of these cells, and the presence of deposits, showing the vitality of the endothelium. The specular microscope that we have enables the evaluation of the corneal center, 8 paracentral points and 6 peripheral points. Equipament: Specular Microscope CEM-530 (Japan).

More information: This exam can be requested in the presence or suspicion of corneal degenerative diseases and as a preoperative exam for cataract, glaucoma, corneal transplant and refractive surgery, to assist the surgeon assess surgical risk.

Generates an image of a virtual sagittal cut of the cornea. It is possible to measure the thickness of different locations of the cornea with precision in few microns (thousandths of a millimeter). Corneal scars and degenerations are located accurately and when interpreting the image, the surgeon can plan with more safety the appropriate treatment. In a patient who has previously undergone a corneal surgery, OCT allows the surgeon to view the Lasik flap and residual stromal (the remaining cornea under the flap) or measure the exact depth of intracorneal rings inserted in keratoconus patients. Equipament: 3D OCT-2000 FA PLUS (USA) and Cirrus 5000 HD-OCT (USA).

More information: OCT may be required before or after the following surgeries: LASIK, PTK, implant of intracorneal ring, lamellar keratoplasty (DALK, DSEK, DMEK), penetrating keratoplasty. It also helps in surgical planning for the treatment of corneal opacities.

The VERION® Image Guided System is a high-tech device that allows the surgeon to customize cataract surgery according to each patient, enabling a safer and more accurate surgery. The VERION® Image Guided System, including the VERION® Reference Unit and the VERION® Digital Marker, was developed to assist in: Improving clinical efficiency; Increasing the accuracy of toric and multifocal lenses; Optimizing refractive outcomes; Minimizing data transcription errors.

The VERION® Reference Unit performs the main eye measurements for patient diagnosis, such as keratometry dynamics, position and diameter of the corneal limbus, white-to-white horizontal distance, pupillometry, corneal reflex position, eccentricity of the visual axis, among others. These measures will guide the surgical procedure, allowing better planning for the surgeon. Next, the VERION® Reference Unit generates a digital high resolution image of the patient’s eye as a reference, capturing reference points of the episcleral and limbal vessels, and iris. This “eye fingerprint” is used to: Record and track the eye during the surgical procedure; Provide a visual reference of all incisions, capsulotomy and lens positioning.

Data generated by the VERION® Reference Unit is sent to the VERION® Digital Marker, which with its advanced image processing features, allows instant access in real time to reference points overlaid digitally, to increase the accuracy in each step of cataract surgery, enabling better alignment and positioning of the intraocular lens (IOL).

Computerized topographers measure millions of points on about 95% of the corneal surface. Most of them are based on the principles of Placido disk, which uses the cornea as a reflective mirror, projecting a series of rings on it. These rings are captured, analyzed and codified into colors, generating curvature maps. We use in our hospital the high definition topographer E300, by Medmont.

More information: Computed topography is an excellent tool to confirm the diagnosis of keratoconus, in the evaluation of patients eligible for laser treatment, or in intraocular lens implants, even when the characteristic signs are still not observed. The position of the apex and the progression of the disease can be seen when analyzing the colored maps.

It is requested when the doctor can’t see the fundus due to opacities of the cornea, lens or vitreous, or when he or she needs a view from the back of the eyeball. It also assists in the diagnosis of tumors, vitreous hemorrhage, intraocular foreign bodies, retinal displacement and phthisis bulbi. It is a semiologic method of great importance, always indicated when there is a need to evaluate the internal conditions of the eyeball and orbit. In this exam, a probe emits ultrasound waves (sounds with frequencies higher than the upper audible limit of human hearing) that reflect echoes when in contact with the ocular structure of the patient. The exam can be performed by module A, which is the unidimensional acoustic representation in which the echoes are represented as vertical oscillations. Or by module B, where the acoustic representation is two dimensional, allowing the panoramic vision of the eye and orbit and analysis of shapes and structures. Equipament: Ultra Scan Imaging System.