Cataract consists of the progressive opacification of the crystalline lens, which is normally transparent, due to degenerative phenomena that affect the proteins that make it up. The onset of cataract occurs more frequently after the age of 65. It can also affect younger patients, especially if it is related to secondary factors such as the use of particular drugs, diabetes, trauma, eye inflammation, X-ray exposure, UVB, and medical conditions (iatrogenic) such as surgical interventions, etc. There is also congenital cataract, which is present since birth, essentially due to chromosomal alterations, metabolic diseases (e.g. galactosemia), intrauterine infections such as rubella or other maternal illnesses occurring during pregnancy. The opacification process may affect all the components of the crystalline, depending on whether the interests of more or less central areas and interfere with the vision differently. The evolution of cataracts is progressive and unstoppable. If you do not intervene promptly, you will reach full opacity (total cataracts) resulting in blindness.
Symptoms Of Cataracts
Cataract does not cause burning, tearing, blushing in the eyes, but blurred vision and yellowing, glare, monocular split vision, the vision of light around an object, myopia or hypermetropia, and visual acuity fluctuations.
Causes Of Cataracts
The development of cataracts is due to a degenerative process of crystalline proteins. There are several factors that progress the onset of age: smoking, eye trauma, UVB exposure, diabetes, corticosteroid intake, and environmental, toxic, nutritional, and genetic factors.
How To Care For Cataracts?
Cataract therapy is essentially surgical and involves the removal of the opaque crystalline by replacing it with an artificial crystalline lens (IOL = Intra Ocular Lens).
Cataract surgery has undergone remarkable technological evolution over the years. The introduction of the laser to Femto Laser has literally revolutionized this surgery: thanks to this, the main phases of surgery are programmed by the surgeon to the computer and performed by the laser in seconds without the use of scalpels and clamps. All the steps are monitored in real time through Optical Consistency Tomography (OCT), which performs a three-dimensional control of the structures to operate, guiding the laser action. Not all eyes are compatible with this technique, only the ophthalmologist, through specific examinations, can evaluate and establish the most suitable operative method.
When Do Cataracts Start?
It usually occurs when the visual decline interferes with the normal daily activities of the patient. This decision must always be taken by the eye doctor in agreement with the patient in order to obtain the maximum benefit. There are also pathological conditions of the eye that require urgent intervention to avoid worse complications (diabetic retinopathy, senile macular degeneration, phagogenetic uveitis, high risk of acute glaucoma). Today, it is no longer necessary to wait for cataracts to mature before surgery that may lead to more difficulties and complications. The natural course of the untreated disease leads to the development of hyper mature cataracts (or morgagnian cataracts) with a high risk of ocular inflammation (anaphylactic uveitis) and increased ocular pressure (secondary phagogenetic or phacolytic glaucoma) with irreversible damage.
What To Expect After Cataract Surgery
In the absence of ocular concomitant illnesses (corneal opacity, glaucoma, retinal and optic nerve damage), in most cases, a brilliant functional recovery is achieved in very short times. At the end of the convalescence, there may be prescribed lenses to optimize vision by distance or reading. In case of pre-existing astigmatism, correction can be programmed during the operating session, although this is not always easily obtainable.
In minority of cases, although surgery is technically successful, optimum visual recovery may be less than expected because damage to the retina and optic nerve from other ocular pathologies (such as senile macular degeneration, glaucoma, diabetic retinopathy, etc.) may limit functional success.
Intervention Techniques
Cataract extraction surgery is perfectly standardized and safe and is carried out all over the world with the same technique as the phacoemulsification of cataracts followed by the secondary implant of an intraocular artificial lens.
The phacoemulsification that uses ultrasound is a standardized and safe technique. It consists of the removal of cataracts by the use of ultrasound that allows to crush the hard core of the lens and extract it through a small corneal incision of 2.8 mm or even less. Always through the same incision, they extract the remaining softest areas of the crystalline, leaving intact the capsule that contained the old crystalline. It is through the same incision that the new artificial crystalline lens (IOL) will be implanted by an injection system, allowing the new generation IOLs, being very soft, to be bent and inserted through small apertures (we have now reached 1.8 mm).
It is, therefore, a mini-invasive technique that significantly reduces recovery and healing times, and in some cases, does not require suture points allowing the use of topical anesthesia.
Artificial Crystalline Lenses. The IOL (intraocular lens) is inserted to replace the natural one, now opaque and removed by the surgeon. These lenses are made of unalterable plastic materials that last longer than human life and can, therefore, be implanted even in very young patients. There are two different types of IOL, rigid or soft, although the only ones used are the latter, which allow them to be bent and injected into the eye through micro incisions. At present, multifocal lenses (MIOLs) are also available, which allow good vision both at a distance and in close proximity, almost completely removing the use of glasses. These lenses, however, require a careful selection of the patient as they are not tolerated by all subjects.
Complications Of Cataract Surgery
Cataract surgery does not escape the general rule that there is no risk-free surgery. It is therefore not possible to guarantee the success of the operation beforehand but globally, the various complications generally have a very low incidence, of less than 1%. The cataract operation in the eyes that had glaucoma, retina, or corneal interventions increases the difficulty and is more susceptible to inaccuracies and complications. Complexity also increases in the case of pre-existing ocular pathologies (corneal problems, high myopia, glaucoma) and also due to some systemic diseases (diabetes, coagulation disorders, and others) and the administration of certain drugs. Complications are distinguished in preoperative, intraoperative, and postoperative classes and in turn, can be serious and less serious.
Serious preoperative complications are extremely rare and mainly related to anesthesia with injections; that consists of:
- perforation of the eyeball with anesthetic injection
- damage to the optic nerve
Less serious preoperative complications:
- eyelid and/or periocular and/or retrobulbar hemorrhage
- damage to the muscles of the eye
Severe intraoperative complications (extremely rare):
- choroidal intraoperative hemorrhage: in exceptional cases, it can be very severe and lead to loss of vision, even loss of the affected eye
Less serious intraoperative complications:
- rear capsule breakage (the crystalline casing) without the falling of the cataract material inside the eye: rare
- capsule rupture with the material loss in the vitreous chamber: rare, the loss of crystalline parts may require a second intervention (vitrectomy) for their removal
- vitreous loss and/or ablation of a part of it
- retinal detachment: very rare; may require one or more interventions for its reattachment
- incomplete crystalline extraction; normally does not have negative effects and the micro-fragment is ejected from the eye without perception but may in rare cases cause eye inflammation (uveitis); is a result of the lack of recovery of a micro-fragment of the crystalline since the micro-fragment may have concealed behind anatomical elements such as the iris, that is delicate, and which could be damaged by the extractor; in such a case, if there is any nuisance, it is necessary to perform subsequent surgery to remove the micro-fragment/s
- incorrect positioning of the artificial crystalline lens (vertical, horizontal, tilting)
- removal of a small fragment of the iris
- in case of insertion failure, the patient will be forced to use a particularly high optical correction with glasses or contact lenses; in some cases, with another intervention, still, insertion of the artificial crystalline lens (secondary insertion of IOL)
- total cataract extraction (ICCE), i.e. also with its casing; therefore lacking support for positioning the artificial crystalline lens in the casing; the artificial crystalline lens can be placed in another location during the same operation or with a subsequent operation; this type of complication is more common in total or complicated cataracts
Among the postoperative complications, some are controllable with medical therapies; others may be permanent or require subsequent surgery (corneal transplantation, retinal detachment, removal of remaining cataract material, repositioning/replacement/addition of artificial crystalline lens, and removal/addition of suture points).
Serious postoperative complications:
- infection: it is very rare; can be curable with medical therapy; sometimes one or more interventions can be helpful for proper diagnosis and therapy; in particularly severe cases, the infection may result in anatomical and functional loss of the eye
Less severe postoperative complications:
- corneal disturbances (temporary or persistent blur) may, in severe cases, require corneal transplantation due to aphakic/pseudophakic (ABK/PBK) keratopathy, i.e. persistent corneal obstruction due to endothelial failure during cataract surgery
- central retinal edema (macular region) that may temporarily or permanently reduce visual acuity (cystoid macular edema or Irvine-Gass syndrome)
- retinal burn due to the illumination of the operating microscope
- retinal hemorrhage
- worsening of existing retinal damage (breaks, macular holes, degenerations)
- scarring due to insufficient waterproofing (corneal incision)
- reduction or zeroing of the space between the iris and cornea (absence of front chamber)
- prolapse of the iris within the corneal tunnel
- partial fall of the upper eyelid (ptosis)
- muscle deficit of the eye
- eye or eyebrow hematoma (conjunctival or ocular hemorrhage)
- perception of flying flies (eye floaters), already occurred before surgery but not perceptible by the patient due to low vision caused by the cataract
- increased sensitivity to light, usually temporary
- double vision (diplopia)
- inflammation of the eye
- increased intraocular (hypertensive) pressure, often transient
- glaucoma
- deformation of the cornea (astigmatism)
- displacement of the artificial crystalline lens (decentralization of the IOL)
- calculation error of crystalline power: requires the use of stronger postoperative eyeglasses and/or different from the calculation derived from pre-operative examinations; may require replacement of the crystalline or other refractive action to correct the residual defect; this complication is much more frequent in myopia, amblyopia, and all eyes where interventions on the cornea have been performed
- occasionally weeks, months, and even a few years after the surgery, it may be necessary to change, reposition or remove the artificial crystalline lens
Cataract Intervention
- Surgery is the only alternative to solving the problem of cataracts.
- After cataract removal, an artificial crystalline lens is normally implanted.
- During the years following surgery, the opacification of the posterior capsule (casing of the crystalline lens) may be responsible for a new decrease in vision.
- Failure to properly perform postoperative care, medication, and controls may compromise the course and the success of the intervention.
- It is not advisable to do any strenuous activities or rub the eye in the first few days after the operation.
- Visual recovery after surgery also depends on the general pre-existing conditions of the eye.
- After the cataract surgery, corrective lenses may be needed.
- In very rare cases, one of the complications of surgery may be an eye infection.
