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Risk factors such as UVB exposure and smoking can be addressed. Although no means of preventing cataracts has been scientifically proven, wearing sunglasses that counteract ultraviolet light may slow their development. While adequate intake of antioxidants (such as vitamins A, C, and E) has been thought to protect against the risk of cataracts, clinical trials have shown no benefit from supplements; though evidence is mixed, but weakly positive, for a potential protective effect of the nutrients lutein and zeaxanthin. Statin use is somewhat associated with a lower risk of nuclear sclerotic cataracts.
Most people with the disease need laser repairs to the retina, and about 60 per cent need further surgery.
N-Acetylcarnosine drops have been investigated as a medical treatment for cataracts. The drops are believed to work by reducing oxidation and glycation damage in the lens, particularly reducing crystallin crosslinking. Some benefit has been shown in small manufacturer sponsored randomized controlled trials but further independent corroboration is still required.
Femtosecond laser mode-locking, used during cataract surgery, was originally used to cut accurate and predictable flaps in LASIK surgery, and has been introduced to cataract surgery. The incision at the junction of the sclera and cornea and the hole in capsule during capsulorhexis, traditionally made with a handheld blade, needle, and forceps, are dependent on skill and experience of the surgeon. Sophisticated three-dimensional images of the eyes can be used to guide lasers to make these incisions. can also then break up the cataract as in phacoemulsification.
Stem cells have been used in a clinical trial for lens regeneration in twelve children under the age of two with cataracts present at birth. The children were followed for six months, so it is unknown what the long-term results will be, and it is unknown if this procedure would work in adults.
In general, the younger the child, the greater the urgency in removing the cataract, because of the risk of amblyopia. For optimal visual development in newborns and young infants, a visually significant unilateral congenital cataract should be detected and removed before age 6 weeks, and visually significant bilateral congenital cataracts should be removed before age 10 weeks.
Some congenital cataracts are too small to affect vision, therefore no surgery or treatment will be done. If they are superficial and small, an ophthalmologist will continue to monitor them throughout a patient's life. Commonly, a patient with small congenital cataracts that do not affect vision will eventually be affected later in life; generally this will take decades to occur.
Irvine–Gass syndrome, pseudophakic cystoid macular edema or postcataract CME is one of the most common causes of visual loss after cataract surgery. The syndrome is named in honor of S. Rodman Irvine and J. Donald M. Gass.
The incidence is more common in older types of cataract surgery, where postcataract CME could occur in 20–60% of patients, but with modern cataract surgery, incidence of Irvine–Gass syndrome have reduced significantly.
Replacement of the lens as treatment for cataract can cause pseudophakic macular edema. (‘pseudophakia’ means ‘replacement lens’) this could occur as the surgery involved sometimes irritates the retina (and other parts of the eye) causing the capillaries in the retina to dilate and leak fluid into the retina. This is less common today with modern lens replacement techniques
Cryotherapy (freezing) or laser photocoagulation are occasionally used alone to wall off a small area of retinal detachment so that the detachment does not spread.
Patients usually do not require treatment due to benign nature of the disease. In case cataract develops patients generally do well with cataract surgery.
Risk factors for retinal detachment include severe myopia, retinal tears, trauma, family history, as well as complications from cataract surgery.
Retinal detachment can be mitigated in some cases when the warning signs are caught early. The most effective means of prevention and risk reduction is through education of the initial signs, and encouragement for people to seek ophthalmic medical attention if they have symptoms suggestive of a posterior vitreous detachment. Early examination allows detection of retinal tears which can be treated with laser or cryotherapy. This reduces the risk of retinal detachment in those who have tears from around 1:3 to 1:20. For this reason, the governing bodies in some sports require regular eye examination.
Trauma-related cases of retinal detachment can occur in high-impact sports or in high speed sports. Although some recommend avoiding activities that increase pressure in the eye, including diving and skydiving, there is little evidence to support this recommendation, especially in the general population. Nevertheless, ophthalmologists generally advise people with high degrees of myopia to try to avoid exposure to activities that have the potential for trauma, increase pressure on or within the eye itself, or include rapid acceleration and deceleration, such as bungee jumping or roller coaster rides.
Intraocular pressure spikes occur during any activity accompanied by the Valsalva maneuver, including weightlifting. An epidemiological study suggests that heavy manual lifting at work may be associated with increased risk of rhegmatogenous retinal detachment, but this relationship is not strong. In this study, obesity also appeared to increase the risk of retinal detachment. A high Body Mass Index (BMI) and elevated blood pressure have been identified as a risk factor in non-myopic individuals.
Genetic factors promoting local inflammation and photoreceptor degeneration may also be involved in the development of the disease.
Other risk factors include the following:
- Glaucoma
- AIDS
- Cataract surgery
- Diabetic retinopathy
- Eclampsia
- Family history of retinal detachment
- Homocysteinuria
- Malignant hypertension
- Metastatic cancer, which spreads to the eye (eye cancer)
- Retinoblastoma
- Severe myopia
- Smoking and passive smoking
- Stickler syndrome
- Von Hippel-Lindau disease
Colobomas of the iris may be treated in a number of ways. A simple cosmetic solution is a specialized cosmetic contact lens with an artificial pupil aperture. Surgical repair of the iris defect is also possible. Surgeons can close the defect by stitching in some cases. More recently artificial iris prosthetic devices such as the Human Optics artificial iris have been used successfully by specialist surgeons. This device cannot be used if the natural lens is in place and is not suitable for children. Suture repair is a better option where the lens is still present.
Vision can be improved with glasses, contact lenses or even laser eye surgery but may be limited if the retina is affected or there is amblyopia.
While surgeries do exist to correct for severe cases of floaters, there are currently no medications (including eye drops) that can correct for this vitreous deterioration. Floaters are often caused by the normal aging process and will usually disappear as the brain learns to ignore them. Looking up/down and left/right will cause the floaters to leave the direct field of vision as the vitreous humour swirls around due to the sudden movement. If floaters significantly increase in numbers and/or severely affect vision, then one of the below surgeries may be necessary.
Currently, insufficient evidence is available to compare the safety and efficacy of surgical vitrectomy with laser vitreolysis for the treatment of floaters. A 2017 Cochrane Review did not find any relevant studies that compared the two treatments.
Aggressive marketing campaigns are currently promoting the use of laser vitreolysis for the treatment of floaters. No strong evidence currently exists for the treatment of floaters with laser vitreolysis. Currently, the strongest available evidence comparing these two treatment modalities are retrospective case series.
It has been suggested that the disease follows a x-linked pattern of inheritance though studies done on this particular disease are few.
Galactosemic infants present clinical symptoms just days after the onset of a galactose diet. They include difficulty feeding, diarrhea, lethargy, hypotonia, jaundice, cataract, and hepatomegaly (enlarged liver). If not treated immediately, and many times even with treatment, severe mental retardation, verbal dyspraxia (difficulty), motor abnormalities, and reproductive complications may ensue. The most effective treatment for many of the initial symptoms is complete removal of galactose from the diet. Breast milk and cow's milk should be replaced with soy alternatives. Infant formula based on casein hydrolysates and dextrin maltose as a carbohydrate source can also be used for initial management, but are still high in galactose. The reason for long-term complications despite a discontinuation of the galactose diet is vaguely understood. However, it has been suggested that endogenous (internal) production of galactose may be the cause.
The treatment for galactosemic cataract is no different from general galactosemia treatment. In fact, galactosemic cataract is one of the few symptoms that is actually reversible. Infants should be immediately removed from a galactose diet when symptoms present, and the cataract should disappear and visibility should return to normal. Aldose reductase inhibitors, such as sorbinil, have also proven promising in preventing and reversing galactosemic cataracts. AR inhibitors hinder aldose reductase from synthesizing galactitol in the lens, and thus restricts the osmotic swelling of the lens fibers. Other AR inhibitors include the acetic acid compounds zopolrestat, tolrestat, alrestatin, and epalrestat. Many of these compounds have not been successful in clinical trials due to adverse pharmokinetic properties, inadequate efficacy and efficiency, and toxic side effects. Testing on such drug-treatments continues in order to determine potential long-term complications, and for a more detailed mechanism of how AR inhibitors prevent and reverse the galactosemic cataract.
In 2005, steroids were investigated for the treatment of macular edema due to retinal blood vessel blockage such as CRVO and BRVO.
Laser vitreolysis is a possible treatment option for the removal of vitreous strands and opacities (floaters). In this procedure an ophthalmic laser (usually a yttrium aluminium garnet (YAG) laser) applies a series of nanosecond pulses of low-energy laser light to evaporate the vitreous opacities and to sever the vitreous strands. During this process, the laser energy evaporates the collagen and hyaluronin molecules to form a gas. (It is important to note that the laser energy applied during vitreolysis treatment does not simply break the floater into smaller pieces. Instead, the laser energy converts the floater material to a gas, which is then absorbed into the eye.) The end result is that the floater is removed and/or reduced to a size that no longer impedes vision.
Vitreolysis is an outpatient procedure, which is much less invasive to the eye than a vitrectomy. Side effects may include cataract and intraocular pressure (IOP) spike. It offers a very good degree of patient satisfaction. It can also delay or obviate surgery.
The technique of using YAG lasers to treat vitreous strands and opacities dates to the 1980s, when professors Aron Rosa (Paris, France) and Franz Fankhauser (Berne, Switzerland), pioneers in the use of YAG lasers, both published on their success with vitreolysis.
In a Dutch study by Cees van der Windt, MD, and colleagues, 100 eyes, with PVD-related floaters persisting for more than nine months, were treated with YAG laser vitreolysis ("n" = 65) or pars plana vitrectomy ("n" = 35). After all eyes were treated, both the YAG and vitrectomy groups reported an improvement in vision at 85% and 90% respectively. Furthermore, over a follow-up period of eight years, no complications were observed among YAG-treated patients. These findings support those of two small-scale 1990s studies conducted by Tsai, et al., and Toczolowski, et al.. In both studies, a near 100% rate of floater removal was achieved with vitreolysis, and no intra- or post-operative complications occurred in any patient.
The number of floaters treated during a treatment session depends on the type of floater(s) and the laser energy required to treat the floater(s) (that is, to convert the floater material into a gas). During treatment, the ophthalmologist will monitor the level of laser energy used for each shot, as well as the total amount of energy delivered to the eye. In order to ensure safe, effective treatment with minimal patient discomfort, if these energy levels fall outside a predetermined range then any remaining floaters will need to be treated in a subsequent treatment session.
Every eye is different and there are a number of variables that affect the outcome of treatment. Some floaters, for example, are located too close to the retina and cannot be safely treated. The majority of patients will need to undergo two or three treatment sessions in order to achieve a satisfactory result.
When performed with a YAG laser designed specifically for vitreolysis, reported side effects and complications associated with vitreolysis are rare. However, YAG lasers have traditionally been designed for use in the anterior portion of the eye, i.e. posterior capsulotomy and iridotomy treatments. As a result, they often provide a limited view of the vitreous, which can make it difficult to identify the targeted floaters and membranes. They also carry a high risk of damage to surrounding ocular tissue. Accordingly, vitreolysis is not widely practised, being performed by very few specialists. One of them, John Karickhoff, has performed the procedure more than 1,400 times and claims a 90 percent success rate. However, the MedicineNet web site states that "there is no evidence that this [laser treatment] is effective. The use of a laser also poses significant risks to the vision in what is otherwise a healthy eye." A YAG laser optimized for use in the posterior segment, in addition to use in the anterior segment, is recommended for vitreolysis. In order to visualize the floater and target accordingly, the laser's light source must be positioned in the same optical axis as the ophthalmologist's visual axis. Most conventional YAG lasers, in contrast, use a lower angle of illuminating light. Whilst these lasers are well-suited to use in the anterior part of the eye, they are ill-equipped for use in the vitreous chamber, and thereby make it difficult for the ophthalmologist to visualize (and treat) the floater(s).
Fuchs heterochromic iridocyclitis (FHI) is a chronic unilateral uveitis appearing with the triad of heterochromia, predisposition to cataract and glaucoma, and keratitic precipitates on the posterior corneal surface. Patients are often asymptomatic and the disease is often discovered through investigation of the cause of the heterochromia or cataract. Neovascularisation (growth of new abnormal vessels) is possible and any eye surgery, such as cataract surgery, can cause bleeding from the fragile vessels in the atrophic iris causing accumulation of blood in anterior chamber of the eye, also known as hyphema.
In general, approximately one-third of congenital cataracts are a component of a more extensive syndrome or disease (e.g., cataract resulting from congenital rubella syndrome), one-third occur as an isolated inherited trait, and one-third result from undetermined causes. Metabolic diseases tend to be more commonly associated with bilateral cataracts.
Wagner's syndrome has for a long time been considered a synonym for Stickler's syndrome. However, since the gene that is responsible for Wagner disease (and Erosive Vitreoretinopathie) is known (2005), the confusion has ended. For Wagner disease is the Versican gene (VCAN) located at 5q14.3 is responsible.
For Stickler there are 4 genes are known to cause this syndrome: COL2A1 (75% of Stickler cases), COL11A1 (also Marshall syndrome), COL11A2 (non-ocular Stickler) and COL9A1 (recessive Stickler).
The gene involved helps regulate how the body makes collagen, a sort of chemical glue that holds tissues together in many parts of the body. This particular collagen gene only becomes active in the jelly-like material that fills the eyeball; in Wagner's disease this "vitreous" jelly grabs too tightly to the already weak retina and pulls it away.
Macular edema sometimes occurs for a few days or weeks after cataract surgery, but most such cases can be successfully treated with NSAID or cortisone eye drops. Prophylactic use of Nonsteroidal anti-inflammatory drugs has been reported to reduce the risk of macular edema to some extent.
In 2010 the US FDA approved the use of Lucentis intravitreal injections for macular edema.
Iluvien, a sustained release intravitreal implant developed by Alimera Sciences, has been approved in Austria, Portugal and the U.K. for the treatment of vision impairment associated with chronic diabetic macular edema (DME) considered insufficiently responsive to available therapies. Additional EU country approvals are anticipated.
In 2013 Lucentis by intravitreal injection was approved by the National Institute for Health and Care Excellence in the UK for the treatment of macular edema caused by diabetes and/or retinal vein occlusion.
On July 29, 2014, Eylea (aflibercept), an intravitreal injection produced by Regeneron Pharmaceuticals Inc., was approved to treat DME in the United States.
Zonular cataract and nystagmus, also referred as Nystagmus with congenital zonular cataract is a rare congenital disease associated with Nystagmus and zonular cataract of the eye.
In veterinary practice, nuclear sclerosis is a consistent finding in dogs greater than six years old. Nuclear sclerosis appears as a bilateral bluish-grey haziness at the nucleus, or center of the lens, caused by an increase in the refractive index of that part of the lens due to its increased density. It is often confused with cataracts. The condition is differentiated from a cataract by its appearance and by shining a penlight into the eye. With nuclear sclerosis, a reflection from the tapetum will be seen, while a cataract will block reflection.
There is no treatment for this condition currently.
In general, strabismus can be approached and treated with a variety of procedures. Depending on the individual case, treatment options include:
- Correction of refractive errors by glasses
- Prism therapy (if tolerated, to manage diplopia)
- Patching (mainly to manage amblyopia in children and diplopia in adults)
- Botulinum toxin injection
- Surgical correction
Surgical correction of the hypertropia is desired to achieve binocularity, manage diplopia and/or correct the cosmetic defect. Steps to achieve the same depend on mechanism of the hypertropia and identification of the offending muscles causing the misalignment. Various surgical procedures have been described and should be offered after careful examination of eyes, including a detailed orthoptic examination focussing on the disturbances in ocular motility and visual status. Specialty fellowship trained pediatric ophthalmologists and strabismus surgeons are best equipped to deal with these complex procedures.
Non-surgical treatments of FCED may be used to treat symptoms of early disease. Medical management includes topical hypertonic saline, the use of a hairdryer to dehydrate the precorneal tear film, and therapeutic soft contact lenses. Hypertonic saline draws water out of the cornea through osmosis. When using a hairdryer, the patient is instructed to hold it at an arm's length or directed across the face on a cold setting, to dry out the epithelial blisters. This can be done two or three times a day. Definitive treatment, however, (especially with increased corneal edema) is surgical in the form of corneal transplantation. The most common types of surgery for FCED are Descemet's stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK), which account for over half of corneal transplants in the United States.
More speculative future directions in the treatment of FED include in-vitro expansion of human corneal endothelial cells for transplantation, artificial corneas (keratoprosthesis) and genetic modification. Surgery where the central diseased endothelium is stripped off but not replaced with donor tissue, with subsequent Rho-Associated Kinase (ROCK) inhibition of endothelial cell division may offer a viable medical treatment.
A greater understanding of FED pathophysiology may assist in the future with the development of treatments to prevent progression of disease. Although much progress has been made in the research and treatment of FED, many questions remain to be answered. The exact causes of illness, the prediction of disease progression and delivery of an accurate prognosis, methods of prevention and effective nonsurgical treatment are all the subject of inquiries that necessitate an answer.
Increased attention must be given to research that can address the most basic questions of how the disease develops: what are the biomolecular pathways implicated in disease, and what genetic or environmental factors contribute to its progression? In addition to shaping our understanding of FED, identification of these factors would be essential for the prevention and management of this condition.
Intraoperative floppy iris syndrome (IFIS) is a complication that may occur during cataract extraction in certain patients. This syndrome is characterized by a flaccid iris which billows in response to ordinary intraocular fluid currents, a propensity for this floppy iris to prolapse towards the area of cataract extraction during surgery, and progressive intraoperative pupil constriction despite standard procedures to prevent this.
IFIS has been associated with tamsulosin (e.g., Flomax), a medication widely prescribed for urinary symptoms associated with benign prostatic hyperplasia (BPH). Tamsulosin is a selective alpha blocker that works by relaxing the bladder and prostatic smooth muscle. As such, it also relaxes the iris dilator muscle by binding to its postsynaptic nerve endings. Even if a patient has only taken tamsulosin once in their life, that dose is enough to cause IFIS during cataract extraction indefinitely. Various alpha-blockers are associated with IFIS, but tamsulosin has a stronger association than the others.
A joint statement of two ophthalmologic societies states that "the other major class of drugs to treat BPH — 5-alpha reductase inhibitors — do not appear to cause IFIS to any significant degree." 5-ARIs include finasteride, a medication typically used as first line therapy for BPH and androgenic alopecia. The medication is also associated with cataract formation.
IFIS may also be associated with other causes of small pupil like synechiae, pseudoexfoliation and other medications (used for conditions such as glaucoma, diabetes and high blood pressure). IFIS does not usually cause significant changes in postoperative outcomes. Patients may experience more pain, a longer recovery period, and less improvement in visual acuity than a patient with an uncomplicated cataract removal.
The severity of the condition is not linked to the duration of tamsulosin intake.
Distorted vision is a symptom with several different possible causes.
Although advancement has been slow to come during the decades of research dedicated to the galactosemic cataract, some notable additions have been made. In 2006, Michael L. Mulhern and colleagues further investigated the effects of the osmotic swelling on galactosemic cataract development. Experiments were based on systematic observation of rats fed a 50% galactose diet. According to Mulhern, 7 to 9 days after the onset of the galactose diet, lenses appeared hydrated and highly vacuolated. Lens fibers became liquefied after nine days of the diet, and nuclear cataract formation appeared after 15 days of the diet.
The experiment concluded that
Apoptosis in lens epithelial cells (LEC) is linked to cataract formation. Essentially, the study suggested that the mechanism outlined by Friedenwald and Kinoshita, which centers on osmotic swelling of the lens fibers, is just the beginning in a cascade of events that causes and progresses the galactosemic cataract. Mulhern determined that osmotic swelling is actually a cataractogenic stressor that leads to LEC apoptosis. This is because osmotic swelling of lens fibers considerably strains LEC endoplasmic reticula. As the endoplasmic reticulum is the principal site of protein synthesis, stressors on the ER can cause proteins to become misfolded. The subsequent accumulation of misfolded proteins in the ER activates the unfolded protein response (UPR) in LECs. In agreement, it was later observed on galactosemic yeast models, the activation of UPR upon galactose treatment. UPR initiates apoptosis, or cell death, by various mechanisms, one of which is the release of reactive oxygen species (ROS). Thus, according to recent findings, osmotic swelling, UPR, oxidative damage, and the resultant LEC apoptosis all play key roles in the onset and progression of the galactosemic cataract. Other studies claim that the oxidative damage in LECs is less a result of the release of ROS and more because of the competition between aldose reductase and glutathione reductase for nicotinamide adenine dinucleotide phosphate (NADPH). Aldose reductase requires NADPH for the reduction of galactose to galactitol, while glutathione reductase utilizes NADPH to reduce glutathione disulfide (GSSG) to its sulfhydryl form, GSH. GSH is an important cellular antioxidant. Therefore, what exactly the key roles are for these cataractogenic factors is not yet fully understood or agreed upon by researchers.