INTRODUCTION
Multiple mechanisms contribute to the progressive loss of transparency of the lens. The lens epithelium is believed to undergo age-related changes, particularly a decrease in lens epithelial cell density and an aberrant differentiation of lens fiber cells. Although the epithelium of cataractous lenses experiences a low rate of apoptotic death, which is unlikely to cause a significant decrease in cell density, the accumulation of small scale epithelial losses may consequently result in an alteration of lens fiber formation and homeostasis, ultimately leading to loss of lens transparency. Furthermore, as the lens ages, a reduction in the rate at which water and, perhaps, water-soluble low-molecular weight metabolites can enter the cells of the lens nucleus via the epithelium and cortex occurs with a subsequent decrease in the rate of transport of water, nutrients, and antioxidants.
- In the US: At least 300,000-400,000 new visually disabling cataracts occur annually in the US, with complications of modern surgical techniques resulting in at least 7000 irreversibly blind eyes.
- In the Framingham Eye Study from 1973-1975, senile cataract was seen in 15.5% of the 2477 patients examined. The overall rates of senile cataract in general and of its 3 main types — nuclear, cortical, and posterior subcapsular — rapidly increased with age, so that for the oldest age group, 75 years and older, nuclear, cortical, and posterior subcapsular cataracts were found in 65.5%, 27.7%, and 19.7% of the study population, respectively. Nuclear opacities were the most commonly seen lens change.
- Internationally: Senile cataract continues to be the main cause of visual impairment and blindness in the world. At least 5-10 million new visually disabling cataracts occur yearly, with modern surgical techniques resulting in 100,000-200,000 irreversibly blind eyes. Published data estimate that 1.2% of the entire population of Africa is blind, with cataract causing 36% of this blindness. In a survey conducted in 3 districts in the Punjab plains, the overall rates of occurrence of senile cataract was 15.3% among 1269 persons examined who were aged 30 years and older and 4.3% for all ages. This increased markedly to 67% for ages 70 years and older. An analysis of blind registration forms in the west of Scotland showed senile cataract as 1 of the 4 leading causes of blindness.
Mortality/Morbidity
Most morbidity associated with senile cataracts occurs postoperatively and is discussed in further detail later. Failure to treat a developing cataract surgically may lead to devastating consequences such as lens swelling and intumescence, secondary glaucoma, and, eventually, blindness.
While the risk of dying as a result of cataract extraction is almost negligible, studies have shown an increased risk of mortality in patients who underwent surgery. In a comparison of 167 patients aged 50 years or older who underwent cataract extraction at the New England Medical Center in a period of 1 year to 824 patients who elected 1 of 6 other surgical procedures, it was found that the former had almost twice the mortality of the latter. Further analysis showed no significant correlation between diabetes and increased mortality. In a similar 5-year mortality analysis, patients with cataracts who were younger than 75 years had significantly higher age-specific rates of mortality than would be expected from US life tables.
These data imply an association between senile cataracts and increased mortality. Meddings et al suggest that senile cataract may be a marker of generalized tissue aging. Hirsch and Schwartz who proposed the concept that senile cataracts reflect systemic phenomena rather than only a localized ocular disease share this view.
Race:
Although race has been suggested as a possible risk factor for senile cataract, scarce literature exists to prove this theory. However, it has been observed that unoperated cataracts account for a higher percentage of blindness among blacks compared to whites.
Sex:
Studies on the prevalence of senile cataract between males and females have yielded contrasting results.
- In the Framingham Eye Study from 1973-75, females had a higher prevalence than males in both lens changes (63 to 54.1%) and senile cataract (17.1 to 13.2%).
- Sperduto and Hiller noted that each of the 3 types of senile lens opacities was found more often in women than in men. In a separate investigation by Nishikori and Yamomoto, the male-to-female ratio was 1:8 with a female predominance in patients older than 65 years who were operated on for senile cataract.
- In a hospital-based, case-control study of senile cataract conducted in Japan, it was observed that an increased risk of cataract was found in males who were presently spending 7 hours or more outdoors and in females with 4 or fewer remaining teeth. However, in another analysis by Martinez et al, no sexual difference was noted in the prevalence of senile cataract.
Age:
Age is an important risk factor for senile cataract. As a person ages, the chance of developing a senile cataract increases. In the Framingham Eye Study from 1973-1975, the number of total and new cases of senile cataract rose dramatically from 23.0 cases per 100,000 and 3.5 cases per 100,000, respectively, in persons aged 45-64 years to 492.2 cases per 100,000 and 40.8 cases per 100,000 in persons aged 85 years and older.
CLINICAL
History:
Careful history taking is essential in determining the progression and functional impairment in vision resulting from the cataract and in identifying other possible causes for the lens opacity. A patient with senile cataract often presents with a history of gradual progressive deterioration and disturbance in vision. Such visual aberrations are varied depending on the type of cataract present in the patient.
Decreased visual acuity
Decreased visual acuity is the most common complaint of patients with senile cataract. The cataract is considered clinically relevant if visual acuity is affected significantly. Furthermore, different types of cataracts produce different effects on visual acuity. For example, a mild degree of posterior subcapsular cataract can produce a severe reduction in visual acuity with near acuity affected more than distance vision, presumably as a result of accommodative miosis. However, nuclear sclerotic cataracts often are associated with decreased distance acuity and good near vision. A cortical cataract generally is not clinically relevant until late in its progression when cortical spokes compromise the visual axis. However, instances exist when a solitary cortical spoke occasionally results in significant involvement of the visual axis.
Glare
Increased glare is another common complaint of patients with senile cataracts. This complaint may include an entire spectrum from a decrease in contrast sensitivity in brightly lit environments or disabling glare during the day to glare with oncoming headlights at night. Such visual disturbances are prominent particularly with posterior subcapsular cataracts and, to a lesser degree, with cortical cataracts. It is associated less frequently with nuclear sclerosis. Many patients may tolerate moderate levels of glare without much difficulty, and, as such, glare by itself does not require surgical management.
Myopic shift
The progression of cataracts may frequently increase the diopteric power of the lens resulting in a mild-to-moderate degree of myopia or myopic shift. Consequently, presbyopic patients report an increase in their near vision and less need for reading glasses as they experience the so-called second sight. However, such occurrence is temporary, and, as the optical quality of the lens deteriorates, the second sight is eventually lost. Typically, myopic shift and second sight are not seen in cortical and posterior subcapsular cataracts. Furthermore, asymmetric development of the lens-induced myopia may result in significant symptomatic anisometropia that may require surgical management.
Monocular diplopia
At times, the nuclear changes are concentrated in the inner layers of the lens, resulting in a refractile area in the center of the lens, which often is seen best within the red reflex by retinoscopy or direct ophthalmoscopy. Such a phenomenon may lead to monocular diplopia that is not corrected with spectacles, prisms, or contact lenses.
Physical:
After a thorough history is taken, careful physical examination must be performed. The entire body habitus is checked for abnormalities that may point out systemic illnesses that affect the eye and cataract development.
• A complete ocular examination must be performed beginning with visual acuity for both near and far distances. When the patient complains of glare, visual acuity should be tested in a brightly lit room. Contrast sensitivity also must be checked, especially if the history points to a possible problem.
• Examination of the ocular adnexa and intraocular structures may provide clues to the patient's disease and eventual visual prognosis.
o A very important test is the swinging flashlight test which detects for a Marcus Gunn pupil or a relative afferent pupillary defect (RAPD) indicative of optic nerve lesions or diffuse macular involvement. A patient with RAPD and a cataract is expected to have a very guarded visual prognosis after cataract extraction.
o A patient with long-standing ptosis since childhood may have occlusion amblyopia, which may account more for the decreased visual acuity rather than the cataract. Similarly, checking for problems in ocular motility at all directions of gaze is important to rule out any other causes for the patient's visual symptoms.
• Slit lamp examination should not only concentrate on evaluating the lens opacity but the other ocular structures as well (eg, conjunctiva, cornea, iris, anterior chamber).
o Corneal thickness and the presence of corneal opacities such as corneal guttata must be checked carefully.
o Appearance of the lens must be noted meticulously before and after pupillary dilation.
o The visual significance of oil droplet nuclear cataracts and small posterior subcapsular cataracts is evaluated best with a normal-sized pupil to determine if the visual axis is obscured. However, exfoliation syndrome is appreciated with the pupil dilated, revealing exfoliative material on the anterior lens capsule.
o After dilation, nuclear size and brunescence as indicators of cataract density can be determined prior to phacoemulsification surgery. The lens position and integrity of the zonular fibers also should be checked because lens subluxation may indicate previous eye trauma, metabolic disorders, or hypermature cataracts.
• The importance of direct and indirect ophthalmoscopy in evaluating the integrity of the posterior pole must be underscored. Optic nerve and retinal problems may account for the visual disturbance experienced by the patient. Furthermore, the prognosis after lens extraction is affected significantly by detection of pathologies in the posterior pole preoperatively (eg, macular edema, age-related macular degeneration).
Causes: Numerous studies have been conducted to identify risk factors for development of senile cataracts. Various culprits have been implicated including environmental conditions, systemic diseases, diet, and age.
West and Valmadrid stated that age-related cataract is a multifactorial disease with different risk factors associated to the different cataract types. In addition, they stated that cortical and posterior subcapsular cataracts were related closely to environmental stresses, such as ultraviolet (UV) exposure, diabetes, and drug ingestion. However, nuclear cataracts seem to have a correlation with smoking. Alcohol has been associated with all cataract types.
A similar analysis was completed by Miglior et al. They found that cortical cataracts were associated with the presence of diabetes for more than 5 years and increased serum potassium and sodium levels. A history of surgery under general anesthesia and the use of sedative drugs were associated with reduced risks of senile cortical cataracts. Posterior subcapsular cataracts were associated with steroid use and diabetes, while nuclear cataracts had significant correlations with calcitonin and milk intake. Mixed cataracts were linked with a history of surgery under general anesthesia.
• Systemic diseases and senile cataract
o Senile cataracts have been associated with a lot of systemic illnesses, to include the following: cholelithiasis, allergy, pneumonia, coronary disease and heart insufficiency, hypotension, hypertension, mental retardation, and diabetes.
o Systemic hypertension was found to significantly increase the risk for posterior subcapsular cataracts. In a related study by Jahn et al, hypertriglyceridemia, hyperglycemia, and obesity was found to favor the formation of posterior subcapsular cataracts at an early age.
o A possible pathway for the role of hypertension and glaucoma in senile cataract formation was proposed with induced changes in the protein conformational structures in the lens capsules, subsequently causing alterations in membrane transport and permeability of ions, and, finally, increasing intraocular pressure resulting in the exacerbation of cataract formation.
• UV light and senile cataract
o The association of UV light and development of senile cataract has generated much interest. One hypothesis implies that senile cataracts, particularly cortical opacities, may be the result of thermal damage to the lens.
o An animal model by Al-Ghadyan and Cotlier documented an increase in the temperature of the posterior chamber and lens of rabbits after exposure to sunlight due to an ambient temperature effect through the cornea and to increased body temperature.
o In related studies, people living in areas with greater UV exposure were more likely to develop senile cataracts and to develop them earlier than people residing in places with less UV exposure.
• Other risk factors
o Significant associations with senile cataract were noted with increasing age, female sex, social class, and myopia. Consistent evidence from the study of West and Valmadrid suggested that the prevalence of all cataract types was lower among those with higher education. Workers exposed to infrared radiation also were found to have a higher incidence of senile cataract development.
o Although myopia has been implicated as a risk factor, it was shown that persons with myopia who had worn eyeglasses for at least 20 years underwent cataract extraction at a significantly older age than emmetropes, implying a protective effect of the eyeglasses to solar UV radiation.
o The role of nutritional deficiencies in senile cataract has not been proven or established. However, a high intake of the 18-carbon polyunsaturated fatty acids linoleic acid and linolenic acid reportedly may result in an increased risk of developing age-related nuclear opacity.
DIFFERENTIAL
Cataract, Traumatic . Other Problems to be Considered: Aside from being age-related and due to trauma, cataract formation in adult patients also may be due to chronic uveitis, chronic steroid use, or to posterior pole pathologies (eg, intraocular tumor, long-standing retinal detachment).
WORKUP
Lab Studies:
• Diagnosis of senile cataract is made basically after a thorough history and physical examination are performed. Laboratory tests are requested as part of the preoperative screening process to detect coexisting diseases (eg, diabetes mellitus, hypertension, cardiac anomalies). Recent studies have shown that thrombocytopenia may lead to increased perioperative bleeding and, as such, should be properly detected and managed before surgery.
Imaging Studies:
• Ocular imaging studies (eg, ultrasound, CT scan, MRI) are requested when a posterior pole pathology is suspected and an adequate view of the back of the eye is obscured by the dense cataract. This is helpful in planning out the surgical management and providing a more guarded postoperative prognosis for the visual recovery of the patient.
Other Tests:
• Other special tests can be performed when coexisting ocular diseases are suspected, especially in identifying preoperative visual loss resulting from them. Aside from the routine visual acuity testing, testing for brightness acuity and contrast sensitivity and confrontation visual field testing can be performed to assess visual function. Patients with a history of glaucoma, optic nerve disease, or retinal abnormality should undergo an automated visual field test to document the degree of preoperative field loss.
• In patients suspected of having a macular problem, the following tests may be performed to evaluate macular function: Maddox rod test, photostress recovery test, blue-light entoptoscopy, Purkinje entoptic phenomenon, and visual-evoked response and electroretinography (VER-ERG).
o In patients with dense cataracts that preclude adequate visualization of the fundus, a Maddox rod test can be used to grossly evaluate macular function with detection of a large scotoma, represented as a loss of the red line, a sign suggestive of a macular pathology.
o While the photostress recovery test is a semiquantitative estimate of macular function, both blue-light entoptoscopy and Purkinje entoptic phenomenon are subjective means of evaluating macular integrity. The most objective method of measuring macular function is VER-ERG.
• Several measurements should be taken preoperatively, particularly in an anticipated cataract extraction with intraocular lens (IOL) implantation.
o Careful refraction must be performed on both eyes in planning the IOL to be implanted. The power of the IOL on the operated eye must be compatible with the refractive error of the fellow eye to avoid complications (eg, postoperative anisometropia).
o An accurate biometry also should be performed to calculate for the IOL power to be used.
o Corneal integrity, specifically the endothelial layer, must be assessed very well through pachymetry and specular microscopy to predict postoperative corneal morbidities (eg, corneal edema, corneal decompensation) and to weigh the risks versus the benefits of performing cataract extraction.
Histologic Findings: Nuclear cataracts are characterized by homogeneity of the lens nucleus with loss of cellular laminations, while cortical cataracts typically manifest with hydropic swelling of the lens fibers with globules of eosinophilic material (morgagnian globules) seen in slitlike spaces between lens fibers. Finally, a posterior subcapsular cataract is associated with posterior migration of the lens epithelial cells in the posterior subcapsular area, with aberrant enlargement of the epithelial cells (Wedl or bladder cells).
Costello et al examined senile cataracts using electron microscopy to highlight differences in the cellular architecture of the various forms of age-related lens changes. Comparisons were made between a typical nuclear cataract with a central opacity and a transparent rim, and a more advanced or mature, completely opaque nuclear cataract. The former was described as having no obvious cell disruption, cellular debris, or changes that could readily account for the central opacity. The fiber cells had intact uniformly stained cytoplasms with well-defined plasma membrane borders and gap junctions. The mature cataract exhibited various types of cell disruption in the perimeter but not in the core of the nucleus in the form of globules, vacuoles, multilamellar membranes, and clusters of highly undulating membranes.
Staging: Clinical staging of senile cataract is based largely on the visual acuity of the patient. A patient who cannot read better than 20/200 on the visual acuity chart is said to have a mature cataract. If the patient can distinguish letters at lines better than 20/200, then the cataract is described as being immature. An incipient cataract is found in a patient who can still read at 20/20 but possesses a lens opacity as confirmed by slit lamp examination
TREATMENT
Medical Care: No time-tested and proven medical treatment exists to delay, prevent, or reverse the development of senile cataracts. Aldose reductase inhibitors, which are believed to inhibit the conversion of glucose to sorbitol, have shown promising results in preventing sugar cataracts in animals. Other anticataract medications being investigated include sorbitol-lowering agents, aspirin, glutathione-raising agents, and antioxidant vitamins C and E.
Surgical Care: The definitive management for senile cataract is lens extraction. Over the years, various surgical techniques have evolved from the ancient method of couching to the present-day technique of phacoemulsification. Almost parallel is the evolution of the IOLs being used, which vary in ocular location, material, and manner of implantation. Depending on the integrity of the posterior lens capsule, the 2 main types of lens surgery are the intracapsular cataract extraction (ICCE) and the extracapsular cataract extraction (ECCE). Below is a general description of the 3 commonly used surgical procedures in cataract extraction namely ICCE, standard ECCE, and phacoemulsification. Reading books on cataract surgeries for more in-depth discussion of the topic, particularly with regard to technique and procedure is recommended.
• Intracapsular cataract extraction
o Prior to the onset of more modern microsurgical instruments and better IOL, ICCE was the preferred method for cataract removal. It involves extraction of the entire lens, including the posterior capsule. In performing this technique, there is no need to worry about subsequent development and management of capsular opacity. The technique can be performed with less sophisticated equipment and in areas where operating microscopes and irrigating systems are not available.
o However, a number of disadvantages and postoperative complications accompany ICCE. The larger limbal incision, often 160-180°, is associated with the following risks: delayed healing, delayed visual rehabilitation, significant against-the-rule astigmatism, iris incarceration, postoperative wound leaks, and vitreous incarceration. Corneal edema is a common intraoperative and immediate postoperative complication.
o Furthermore, endothelial cell loss is greater in ICCE than in ECCE. The same is true about the incidence of postoperative cystoid macular edema (CME) and retinal detachment. The broken integrity of the vitreous can lead to postoperative complications even after a seemingly uneventful operation. Finally, because the posterior capsule is not intact, the IOL to be implanted must either be placed in the anterior chamber or sutured to the posterior chamber. Both techniques are more difficult to perform than simply placing an IOL in the capsular bag and are associated with postoperative complications, the most notorious of which is pseudophakic bullous keratopathy.
o Although the myriad of postoperative complications has led to the decline in popularity and use of ICCE, it still can be used in cases where zonular integrity is impaired severely to allow successful lens removal and IOL implantation in ECCE. Furthermore, ICCE can be performed in remote areas where more sophisticated equipment is not available.
o ICCE is contraindicated absolutely in children and young adults with cataracts and cases with traumatic capsular rupture. Relative contraindications include high myopia, Marfan syndrome, morgagnian cataracts, and vitreous presenting in the anterior chamber.
• Extracapsular cataract extraction
o In contrast to ICCE, ECCE involves the removal of the lens nucleus through an opening in the anterior capsule with retention of the integrity of the posterior capsule. ECCE possesses a number of advantages over ICCE most of which are related to an intact posterior capsule, as follows:
A smaller incision is required in ECCE and, as such, less trauma to the corneal endothelium is expected.
Short and long-term complications of vitreous adherence to the cornea, iris, and incision is minimized or eliminated.
A better anatomic placement of the IOL is achieved with an intact posterior capsule.
An intact posterior capsule also (1) reduces the iris and vitreous mobility that occurs with saccadic movements (eg, endophthalmodonesis), (2) provides a barrier restricting the exchange of some molecules between the aqueous and vitreous, and (3) reduces the incidence of CME, retinal detachment, and corneal edema.
Conversely, an intact capsule prevents bacteria and other microorganisms inadvertently introduced into the anterior chamber during surgery from gaining access to the posterior vitreous cavity and causing endophthalmitis.
Secondary IOL implantation, filtration surgery, corneal transplantation, and wound repairs are performed more easily with a higher degree of safety with an intact posterior capsule.
o The main requirement for a successful ECCE and posterior capsule IOL implantation is zonular integrity. As such, when zonular support is insufficient or appears suspect to allow a safe removal of the cataract via ECCE, ICCE, or pars plana lensectomy should be considered.
• Standard ECCE and phacoemulsification
o Standard ECCE and phacoemulsification are similar in that extraction of the lens nucleus is performed through an opening in the anterior capsule or anterior capsulotomy. Both techniques also require mechanisms to irrigate and aspirate fluid and cortical material during surgery. Finally, both procedures place the IOL in the posterior capsular bag that is more anatomical than the anteriorly placed IOL.
o Needless to say, significant differences exist between the 2 techniques. Removal of the lens nucleus in ECCE can be performed manually in standard ECCE or with an ultrasonically driven needle to fragment the nucleus of the cataract and aspirate the lens substrate through a needle port in a process termed phacoemulsification.
o The more modern of the 2 techniques, phacoemulsification offers the advantage of using smaller incisions, minimizing complications arising from improper wound closure and affording more rapid wound healing, and faster visual rehabilitation. Furthermore, it uses a relatively closed system during both phacoemulsification and aspiration with better control of intraocular pressure during surgery, providing safeguards against positive vitreous pressure and choroidal hemorrhage. However, more sophisticated machines and instruments are required to perform phacoemulsification.
o Ultimately, the choice of which of the 2 procedures to use in cataract extraction depends on the patient, the type of cataract, the availability of the proper instruments, and the degree at which the surgeon is comfortable and proficient in performing standard ECCE or phacoemulsification.
Consultations: Prior to surgery, a thorough preoperative evaluation must be conducted, which would also include a thorough explanation of the procedure to be performed and its accompanying risks.
• Not all senile cataracts require removal at the time of diagnosis. If vision is not impaired significantly and functionally or if the patient is not prepared medically, psychologically, and financially for surgery, periodic consultations are encouraged to assess progression of the cataract.
• Postoperatively, regular follow-up visits are necessary to monitor visual rehabilitation, as well as to detect and address any immediate and late complications arising from the surgery.
Diet: In relation to the surgery, no established dietary restrictions exist that would affect the course of the operation.
Activity: After surgery, the patient is dissuaded from performing activities that would increase the intraocular pressure, especially after undergoing ICCE or standard ECCE. These activities include lifting heavy loads, chronic vigorous coughing, and straining.
MEDICATION
No drug is available that has been proven to prevent the progression of senile cataracts. Medical therapy is used preoperatively and postoperatively to ensure a successful operation and subsequent visual rehabilitation.
Drug Category: Mydriatics -- Autonomic drugs used to ensure maximal pupillary dilation preoperatively, which is essential for a successful lens extraction. Short-acting mydriatics often are used. Most commonly used mydriatics are phenylephrine hydrochloride and tropicamide.
Drug Category: Corticosteroids -- Help decrease and control inflammatory response following cataract surgery especially in the immediate postoperative period. The most commonly used ophthalmic steroid is prednisolone acetate 1%. Dexamethasone 0.1% ophthalmic solution sometimes is used as an alternative.
Drug Category: Antibiotics -- Broad-spectrum antibiotic ophthalmic solutions often are used prophylactically in immediate postoperative period. A number of topical antibiotics are used depending on surgeon's preference, but, generally, medications are active against both gram-positive and gram-negative organisms.
Drug Category: Nonsteroidal anti-inflammatory ophthalmics -- Used for pain and inflammation associated with cataract surgery.
FOLLOW-UP
Further Inpatient Care:
• Most cataract surgeries are performed on an outpatient basis, especially with the onset of phacoemulsification performed under topical anesthesia. Often, patients are discharged from the clinic as soon as they have recovered from the emotional stress of the procedure. Patients are sent home on topical steroids and antibiotics either separately or in combination. An eye shield is placed on the newly operated eye and removed a few hours after.
Further Outpatient Care:
• On the first postoperative day, visual acuity should be consistent with the refractive state of the eye, the clarity of the cornea and media, and the visual potential of the retina and optic nerve. Mild edema of the eyelid may be evident, as well as some conjunctival injection. The cornea is normally clear with minimal edema and striae. The anterior chamber should be deep with mild cellular reaction. It is important to check whether the posterior capsule is intact and whether the IOL is positioned properly. The red reflex must be strong and clear and the intraocular pressures should be within normal limits. Transient intraocular pressure elevations may be observed and attributed to retained viscoelastic.
• Significant improvement of these initial findings is to be expected in subsequent postoperative evaluation as the ocular inflammation subsides typically within 2 weeks. Topical steroids and antibiotics are tapered accordingly. Refraction is believed to be stable at the sixth to eighth postoperative week at which time corrective lenses can be prescribed. Significant postoperative astigmatism can be addressed by suture removal by the sixth week as guided by keratometry or corneal topography.
In/Out Patient Meds:
• During the postoperative period, the patient is prescribed topical 1% prednisolone acetate, which is applied every hour for the first day, then tapered depending on the inflammatory state of the eye. Recent studies have shown that topical ketorolac tromethamine provides adequate postoperative control of intraocular inflammation without the risk of increased intraocular pressure, which may be associated with steroid use. A broad-spectrum topical antibiotic also is given 4-6 times a day for 1-2 weeks.
Deterrence/Prevention:
• Age is believed to be the most significant risk factor for senile cataract and, as such, it is almost inevitable to develop some degree of lens opacity as one becomes older. No study has established firmly whether avoidance of some of the risk factors for senile cataract (eg, UV exposure, hypercholesterolemia, diabetes mellitus) will lessen the chance of developing a senile cataract.
Complications:
• The following are the major intraoperative complications encountered during cataract surgery:
o Shallow or flat anterior chamber
o Capsular rupture
o Corneal edema
o Suprachoroidal hemorrhage or effusion
o Expulsive choroidal hemorrhage
o Retained lens material
o Vitreous disruption and incarceration into wound
o Iridodialysis
o Retinal light toxicity
• The following are the major immediate postoperative complications encountered during cataract surgery often seen within a few days or weeks after the operation:
o Flat or shallow anterior chamber due to wound leak
o Choroidal detachment
o Pupillary block
o Ciliary block
o Suprachoroidal hemorrhage
o Stromal and epithelial edema
o Hypotony
o Brown-McLean syndrome (peripheral corneal edema with a clear central cornea most frequently seen following ICCE)
o Vitreocorneal adherence and persistent corneal edema
o Delayed choroidal hemorrhage
o Hyphema
o Elevated intraocular pressure (often due to retained viscoelastic)
o Cystoid macular edema
o Retinal detachment
o Acute endophthalmitis
o Uveitis-glaucoma-hyphema (UGH) syndrome
• The following are the major late postoperative complications seen weeks or months after cataract surgery:
o Suture-induced astigmatism
o Pupillary capture
o Decentration and dislocation of the IOL
o Corneal edema and pseudophakic bullous keratopathy
o Chronic uveitis
o Chronic endophthalmitis
o Wrong power of IOL used
• At any stage of the postoperative recovery of the eye, a risk of noninfectious endophthalmitis and infectious endophthalmitis exists. Noninfectious endophthalmitis is believed to be a multifactorial process or an interindividual variable response to a common factor as a hypersensitivity reaction. Treatment may range from the use of topical, transseptal, or oral steroids to the explantation of the intraocular lens. Ultimately, this may lead to infectious endophthalmitis. Of late, a significant increase in the incidence of gram-positive bacteria in bacterial isolates from postoperative eyes suspected of having endophthalmitis has been observed. Furthermore, a significant increase in resistance to ciprofloxacin has occurred. Seemingly, the spectrum of bacteria causing postcataract endophthalmitis is changing partly because of increased resistance to mainstay antibiotics in the treatment of endophthalmitis.
Prognosis:
• In the absence of any other accompanying ocular disease prior to surgery, which would affect significantly the visual outcome such as macular degeneration or optic nerve atrophy, a successful uncomplicated standard ECCE or phacoemulsification carries a very promising visual prognosis of gaining at least 2 lines in the Snellen distance vision chart. The main cause of visual morbidity postoperatively is CME. A major risk factor affecting visual prognosis is the presence of diabetes mellitus and diabetic retinopathy.
Patient Education:
• To date, no established guidelines are available for the prevention of senile cataracts. Education programs are geared toward early detection and surgical intervention when vision is impaired functionally. With the advent of phacoemulsification, patients are advised against delaying lens extraction to the point when the cataract is hard and mature and the likelihood of postoperative complications increases.
• For excellent patient education resources, visit eMedicine's Eye and Vision Center. Also, see eMedicine's patient education article Cataracts.
MISCELLANEOUS
Medical/Legal Pitfalls:
• Tasked with the pivotal role of restoring vision to a functionally impaired patient, the cataract surgeon must now also confront issues that may ultimately jeopardize the medical practice, for example, malpractice litigation, administrative sanctions in the form of expulsion from participation in third-part reimbursement plans, revocation or cancellation of hospital privileges, and, ultimately, limitation or loss of the license to practice. In addition, cut-throat competition coupled with profound changes in the eye care delivery system makes it necessary for the surgeon to be aware of the legal intricacies affecting increased productivity and income creation. The onset of office setting phacoemulsification under topical anesthesia performed in less than 30 minutes ironically has turned the art of cataract surgery into an industry. Remaining productive, creative, and fairly paid is both a concern and a challenge to the modern-day cataract surgeon. As such, the surgeon must be well informed of what is and what is not legal, to thrive and remain in business. Rabin grouped the current legal concerns of the ophthalmologist into 3 categories: (1) conventional malpractice liability, (2) surveillance for regulatory compliance, and (3) practice productivity and income creation.
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