History
The first record of cataract being surgically treated is from 600 B.C. by Susruta of India.[3] Cataracts were surgically addressed by couching. Basically the surgeon would insert a long instrument posterior to the limbus and push the lens into the vitreous cavity, thus clearing the visual axis of the dense lens. Complication rate was high at that time, but it would change the patient's life by giving him some ambulatory vision and self-dependence. Couching is still performed by some traditional 'healers' in some parts of Africa, the Middle East and few other parts of the world. 33.3% of patients who undergo traditional couching end up with no light perception vision.[4] It is likely that outcomes of couching would have been worse in ancient times when there was no recourse to modern antibiotics for endophthalmitis or treatments for glaucoma. The concept of cataract extraction rather than pushing the lens inside the eye was introduced by Ammar Ibn Ali in Choice of Eye Diseases written in Egypt in the 10th century. Ibn Ali invented the hollow needle and oral suction device, for the purpose of cataract extraction:
"Then I constructed the hollow needle, but I did not operate with it on anybody at all, before I came to Tiberias. There came a man for an operation who told me: Do as you like with me, only I cannot lie on my back. Then I operated on him with the hollow needle and extracted the cataract; and he saw immediately and did not need to lie, but slept as he liked. Only I bandaged his eye for seven days. With this needle nobody preceded me. I have done many operations with it in Egypt.[5]"
As one would expect, this technique would not work on dense cataract and couching remained the widely performed surgery to treat cataract for many decades.[3]
In 1747, a French ophthalmologist, Jacques Daviel, was the first to perform extracapsular cataract extraction through a large corneal incision. Then, he would incise the anterior capsule and express the nucleus. Because of the incomplete removal of the cortex, chronic inflammation with glaucoma and secondary capsular opacification would lead to unsatisfactory outcome. Thus, the procedure was not widely accepted at that time and surgeons tried to remove the lens as a whole with the capsular bag. In 1753, Samuel Sharp was among the first to successfully perform intracapsular cataract extraction (ICCE) through limbal incision using pressure from his thumb.
Lens expression technique was improved over many years by using different approaches. In 1957, Joaquin Barraquer used α-chymotrypsin to dissolve the zonules to facilitate lens removal. However, glaucoma and clogging the trabecular meshwork with zonule fibers remnant was one of the many complications of the technique. Cryoprobe was first introduced in 1961 by Tadeusz Krwawicz to remove the lens by forming iceball and lessen the risk of capsular rupture. ICCE was a very successful operation compared to couching and early ECCE. However, the rate of potentially blinding complications was 5% apart from aphakia related habitation problems.[6]
The gradual introduction of operating microscopes during the 1970s offered better intraocular visibility and ability to safely place multiple corneal sutures. In addition, it had the advantages of leaving the posterior capsule intact which reduced the risk of potentially blinding complications (e.g., vitreous loss or retinal detachment). It also allowed posterior chamber lens implantation.
Phacoemulsification was introduced in 1967 by Dr. Charles Kelman. Since then, there has been significant improvement in fluidics, energy delivery, efficiency and most important, safety of this procedure. Currently, phacoemulsification is the standard of care for cataract extraction in the western world. The major advantage of phacoemulsification is that it reduced the morbidity from cataract surgery by reducing the incision size with subsequent faster recovery and decreased risk of complications including endophthalmitis.
A major advance in cataract surgery was the invention of an intraocular lens that can be implanted to replace the extracted cataractous lens. Casaamata is believed to be the first surgeon to implant an intraocular lens (IOL) in 1795.[7] The idea of IOL implantation was revived by Harold Ridley. Ridley inserted an artificial lens in the form of polymethyl-methacrylate (PMMA) in 1949.[7,8] However, the idea of PMMA IOL did not gain popularity due to miscalculation of the postoperative refraction. The cause of this miscalculation was later discovered to be due to the difference in the refractive index of PMMA material in air vs in fluid inside the eye. Another drawback of the PMMA lenses is that they were rigid and could not be folded which necessitated large corneal incisions to insert such lenses. Subsequent IOLs made of acrylic and silicone, were flexible and could be folded and inserted through a significantly smaller incision.
Expert Rev Ophthalmol. 2013;8(5):447-456. © 2013 Expert Reviews Ltd.
