Cataract surgery is one of the most common procedures performed worldwide. It is also one of the oldest. The current word cataract, which means both an opacity of the lens and a torrent of water, comes from the Greek word υπόχυσις (kataráktēs) meaning the fall of water.
The Latins called it suffusio, an extravasation and coagulation of humors behind the iris; and the Arabas, white water. The old Egyptian name for the lens is not yet known and the medical literature does not let us conclude that old Egyptians were able to diagnose cataracts.
The only possible reference to cataract is the ch.t disease mentioned in the Ebers Papyrus about 1525 B.C. Ebbel translated the ch.t disease as cataract -Ebbel, 1937-. However, other distinguished linguistists interpreted it as a discharge or accumulation of water in the eyes, Hirschberg, 1899; Deines et al., 1958; Andersen, 1997.
According to Ebers Papyrus, the old Egyptians tried to treat cases of ch.t disease by eye ointments and magic spells. It is hardly believable that such remedies had any effect on the cataract, since the extraction of the lens is the only effective measure
Alongside advancements in cataract surgical techniques have been improvements in intraocular lens replacement technology. Cataract surgery may be considered among the most successful treatments in all of medicine.
When a cataract becomes visually significant, cataract surgery is the only established method of treatment. The definition of “visually significant” has evolved over time, to its current meaning of a visual acuity of 20/40 or worse.
The earliest known method of treating a cataract is couching, which dates back to the fifth century BC. The word “couching” comes from the French verb “coucher,” which means “to put to bed.” Couching was typically performed on mature cataracts.
The oldest documented case of cataract throughout history was reported in a famous and small statue from the 5th dynasty (about 2457-2467 B.C.) contained in the Egyptian Museum in Cairo, Egypt. This statue, discovered in 1860 in Saqqāra, dates from the Old Kingdom and represents a male figure, the priest reader Ka-āper, also called Cheikh el-Beled.
The cataract was not removed from the eye. Instead, the mature cataract was purposefully dislodged out of the visual axis with a needle. The cataract remained in the eye but was no longer blocking light, producing instantaneous improvement in vision.
Indeed, in the very immediate postoperative period, couching was considered a success, but the retained cataractous lens and the lack of aseptic technique soon had deleterious effects on the eye, often resulting in blindness shortly after the procedure. Unfortunately, couching is still in practice in some developing countries.
Sir Harold Ridley implanted the first IOL on February 8, 1950. Charlie Kelman’s US Patent for phacoemulsification was filed July 25, 1967. Following the introduction of these foundational elements of modern cataract surgery, myriad incremental innovations have brought about what is surely the fastest, safest, and most effective surgical procedure in the world today.
These innovations include reducing the size and therefore the morbidity related to incisions, increasing the efficiency of lens extraction by optimizing the energy required to break up and evacuate the lens, and improving the accuracy of intraocular lens power calculations to refine postoperative refractive outcomes.
The development of adjunctive tools and tricks to alleviate the negative impact of preexisting risk factors such as a small pupil or a weakened zonule has improved the safety of surgery, while the introduction of the femtosecond laser has created a new opportunity for innovation and precision in the treatment of astigmatism.
All of these advances have combined to make a big “wow” for our patients. Clinical research has also produced important advances in our knowledge of cataract surgery. One of the most significant findings of recent studies of minimally invasive glaucoma surgery is confirmation of the substantial reduction of intraocular pressure in patients with mild to moderate glaucoma from cataract surgery alone.
Investigational device exemption randomized clinical trials of both the CyPass and the Hydrus demonstrated a remarkable concordance in terms of the proportions of subject eyes in the control groups with unmedicated mean diurnal IOP reductions greater than or equal to 20% from baseline (57.8% compared with 58.0%) and the reductions in the control groups in unmedicated mean diurnal IOP from baseline (both -5.3 mmHg).
These clinically significant reductions in IOP in glaucoma patients having cataract surgery alone have now been demonstrated by randomized, controlled clinical trials which provide the highest standard of evidence for this phenomenon.
Nevertheless, challenges remain to provoke the imagination of scientists and entrepreneurs as global demographics predict an increasing demand for cataract surgery. For example, cystoid macular edema, or Irvine-Gass Syndrome, remains the most common complication associated with routine cataract surgery and can occur in patients with or without risk factors, such as diabetes or pre-existing macular disease.
While topical anti-inflammatory agents are considered prophylactic in the perioperative period, the use of intravitreal anti-VEGF agents as treatment has garnered support. This unpredictable and potentially sight-threatening complication deserves attention.
Another example of an unpredictable complication, capsule contraction syndrome, is related to fibrous metaplasia of lens epithelial cells similar to the pathogenesis of posterior capsular opacification and usually occurs within the first 3 months following surgery.
Changes in refraction may occur due to axial displacement or tilting of the IOL due to the capsular contraction. Capsule contraction syndrome “has occurred in eyes with and without risk factors after the implantation of every IOL type (PMMA, silicone and acrylic).”
Identified risk factors include small capsulorhexis diameter, postoperative inflammation, pseudoexfoliation syndrome, uveitis, retinitis pigmentosa, history of retinal surgery, myotonic dystrophy and diabetes.
Treatment of capsular contraction syndrome has relied primarily on Nd:YAG laser relaxing anterior capsulotomies to eliminate constriction. Radial capsulotomies “can significantly enlarge the anterior capsule opening” but “the IOL can remain decentered and folded within the capsular bag, especially in case of shrinkage or thick fibrous anterior membrane. ”
Femtosecond laser capsulotomies have advantages in terms of precision, and, despite difficulty cutting thickened capsular tissue, are “easier and safer than previous techniques.
The lesson of IOL development is that innovation is not for the weak of heart. Early phaco, just as much as early IOLs, did damage many eyes. Nevertheless, perseverance had great rewards, and it will no doubt continue to do so as we invent the next generation of cataract surgery innovations. Early phaco, just as much as early IOLs, did damage many eyes. Nevertheless, perseverance had great rewards.