Modifiable Intraocular Lens Technologies
Mohamed Salah Aldeen Mohamed Noor;
Abstract
The evolution of catarct surgery started since 500 BC and it is an ongoing process up till now. The procedure first documented was known as Couching. It was done by displacing the lens into the vitreous cavity. In 1880 a newer procedure was introduced known as Intracapsular Cataract Extraction (ICCE). It was done by removing the whole lens through a large corneal incision.
Later on the Extracapsular Cataract Extraction (ECCE) was developed. It was done by opening the anterior aspect of the lens capsule to remove the lens nucleus and Irrigation/Aspiration was used to remove the lens cortex. It was done through a large corneal incision which caused a significant postoperative Astigmatism.
The development of phacoemulsification was a great achievement. The procedure was first described in 1967. It was done by using ultrasonic waves to liquefy the cataractous lens and remove it without damaging the surrounding structures. In some developing countries, where the phacoemulsification is not available, an alternate procedure called Manual Small Incision Cataract Surgery (SICS) was developed. It is a sutureless non phaco surgery where the lens nucleus is removed through a scleral tunnel, self sealed incision inducing less postoperative Astigmatism.
Recently, the Femtosecond Laser was applied in cataract surgery. It was used to create the corneal incisions, capsulotomy, lens fragmentations and astigmatic relaxing incisions.
The evolution of cataract surgery has gone hand in hand with the evolution of Intraocular Lenses (IOLs). The first IOL was developed by Sir Harold Ridley. It was made of Polymethyl methacrylate (PMMA). PMMA was an inert material, so it was suitable for manufacturing IOLs. However, it has the disadvantage of being nonfoldable. It can’t be implanted through the small corneal incision of the phaco suergery. Thus, foldable materials were developed for manufacturing IOLs. These foldable materials included silicone, hydrophilic acrylic, hydrophobic acrylic and collamer IOLs.
Also, many IOL designs were developed to achieve the best IOL performance and the least complications. IOL haptics may be plate haptics or open-loop style. Also, the haptic may be made of different material from the optic, in multipiece IOLs, or from the same material of the optic, in monobloc IOLs. The IOL may contain angulated or planar haptics. As regarding the IOL optic; IOLs may contain different shape and edge designs. Also, the optic geometry is different in IOls for certain indications such as toric, aspheric, or multifocal IOLs. There are special types of IOLs that are designed for certain indications such as IOLs for insufficient capsular support, phakic IOLs, accommodating IOls and IOLs for aniridia.
Eye surgeons have long needed a solution to a commonly occurring problem, which are the residual refractive errors following cataract surgery. Thus, several IOLs were developed so that their power could be adjusted postoperatively. They are known as modifiable IOLs.
The Light-adjustable IOL is one of these modifiable IOLs. It contains phaoreactive components that react to ultraviolet (UV) waves of a certain wave length allowing changing the IOL shape and power. Another kind of modifiable IOls is the multicomponent IOL. It has a base lens component implanted in the lens capsular bag and a front lens component that can be changed several times allowing change of the IOL power with minor surgical procedure.
In the mechanical modifiable IOL the outer
Later on the Extracapsular Cataract Extraction (ECCE) was developed. It was done by opening the anterior aspect of the lens capsule to remove the lens nucleus and Irrigation/Aspiration was used to remove the lens cortex. It was done through a large corneal incision which caused a significant postoperative Astigmatism.
The development of phacoemulsification was a great achievement. The procedure was first described in 1967. It was done by using ultrasonic waves to liquefy the cataractous lens and remove it without damaging the surrounding structures. In some developing countries, where the phacoemulsification is not available, an alternate procedure called Manual Small Incision Cataract Surgery (SICS) was developed. It is a sutureless non phaco surgery where the lens nucleus is removed through a scleral tunnel, self sealed incision inducing less postoperative Astigmatism.
Recently, the Femtosecond Laser was applied in cataract surgery. It was used to create the corneal incisions, capsulotomy, lens fragmentations and astigmatic relaxing incisions.
The evolution of cataract surgery has gone hand in hand with the evolution of Intraocular Lenses (IOLs). The first IOL was developed by Sir Harold Ridley. It was made of Polymethyl methacrylate (PMMA). PMMA was an inert material, so it was suitable for manufacturing IOLs. However, it has the disadvantage of being nonfoldable. It can’t be implanted through the small corneal incision of the phaco suergery. Thus, foldable materials were developed for manufacturing IOLs. These foldable materials included silicone, hydrophilic acrylic, hydrophobic acrylic and collamer IOLs.
Also, many IOL designs were developed to achieve the best IOL performance and the least complications. IOL haptics may be plate haptics or open-loop style. Also, the haptic may be made of different material from the optic, in multipiece IOLs, or from the same material of the optic, in monobloc IOLs. The IOL may contain angulated or planar haptics. As regarding the IOL optic; IOLs may contain different shape and edge designs. Also, the optic geometry is different in IOls for certain indications such as toric, aspheric, or multifocal IOLs. There are special types of IOLs that are designed for certain indications such as IOLs for insufficient capsular support, phakic IOLs, accommodating IOls and IOLs for aniridia.
Eye surgeons have long needed a solution to a commonly occurring problem, which are the residual refractive errors following cataract surgery. Thus, several IOLs were developed so that their power could be adjusted postoperatively. They are known as modifiable IOLs.
The Light-adjustable IOL is one of these modifiable IOLs. It contains phaoreactive components that react to ultraviolet (UV) waves of a certain wave length allowing changing the IOL shape and power. Another kind of modifiable IOls is the multicomponent IOL. It has a base lens component implanted in the lens capsular bag and a front lens component that can be changed several times allowing change of the IOL power with minor surgical procedure.
In the mechanical modifiable IOL the outer
Other data
| Title | Modifiable Intraocular Lens Technologies | Other Titles | تكنولوجيا العدسات داخل العين القابلة للتعديل | Authors | Mohamed Salah Aldeen Mohamed Noor | Issue Date | 2017 |
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