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Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
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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.
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.
Though there is no treatment for Cone dystrophy, certain supplements may help in delaying the progression of the disease.
The beta-carotenoids, lutein and zeaxanthin, have been evidenced to reduce the risk of developing age related macular degeneration (AMD), and may therefore provide similar benefits to Cone dystrophy sufferers.
Consuming omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) has been correlated with a reduced progression of early AMD, and in conjunction with low glycemic index foods, with reduced progression of advanced AMD, and may therefore delay the progression of cone dystrophy.
There is no cure for retinitis pigmentosa, but the efficacy and safety of various prospective treatments are currently being evaluated. The efficiency of various supplements, such as Vitamin A, DHA, and Lutein, in delaying disease progression remains an unresolved, yet prospective treatment option. Clinical trials investigating optic prosthetic devices, gene therapy mechanisms, and retinal sheet transplantations are active areas of study in the partial restoration of vision in retinitis pigmentosa patients.
Studies have demonstrated the delay of rod photoreceptor degeneration by the daily intake of 15000 IU (equivalent to 4.5 mg) of vitamin A palmitate; thus, stalling disease progression in some patients. Recent investigations have shown that proper vitamin A supplementation can postpone blindness by up to 10 years (by reducing the 10% loss pa to 8.3% pa) in some patients in certain stages of the disease.
The Argus retinal prosthesis became the first approved treatment for the disease in February 2011, and is currently available in Germany, France, Italy, and the UK. Interim results on 30 patients long term trials were published in 2012. The Argus II retinal implant has also received market approval in the US. The device may help adults with RP who have lost the ability to perceive shapes and movement to be more mobile and to perform day-to-day activities. In June 2013, twelve hospitals in the US announced they would soon accept consultation for patients with RP in preparation for the launch of Argus II later that year. The Alpha-IMS is a subretinal implant involving the surgical implantation of a small image-recording chip beneath the optic fovea. Measures of visual improvements from Alpha-IMS studies require the demonstration of the device's safety before proceeding with clinical trials and granting market approval.
The goal of gene therapy studies is to virally supplement retinal cells expressing mutant genes associated with the retinitis pigmentosa phenotype with healthy forms of the gene; thus, allowing the repair and proper functioning of retinal photoreceptor cells in response to the instructions associated with the inserted healthy gene. Clinical trials investigating the insertion of the healthy RPE65 gene in retinas expressing the LCA2 retinitis pigmentosa phenotype measured modest improvements in vision; however, the degradation of retinal photoreceptors continued at the disease-related rate. Likely, gene therapy may preserve remaining healthy retinal cells while failing to repair the earlier accumulation of damage in already diseased photoreceptor cells. Response to gene therapy would theoretically benefit young patients exhibiting the shortest progression of photoreceptor decline; thus, correlating to a higher possibility of cell rescue via the healthy inserted gene.
The progressive nature of and lack of a definitive cure for retinitis pigmentosa contribute to the inevitably discouraging outlook for patients with this disease. While complete blindness is rare, the patient's visual acuity and visual field will continue to decline as initial rod photoreceptor and later cone photoreceptor degradation proceeds. Possible treatments remain in the research and clinical trial stages; however, treatment studies concerning visual restoration in retinitis pigmentosa prove promising for the future.
Studies indicate that children carrying the disease genotype benefit from presymptomatic counseling in order to prepare for the physical and social implications associated with progressive vision loss. While the psychological prognosis can be slightly alleviated with active counseling the physical implications and progression of the disease depend largely on the age of initial symptom manifestation and the rate of photoreceptor degradation, rather than access to prospective treatments. Corrective visual aids and personalized vision therapy provided by Low Vision Specialists may help patients correct slight disturbances in visual acuity and optimize their remaining visual field. Support groups, vision insurance, and lifestyle therapy are additional useful tools for those managing progressive visual decline.
There is no known cure for this syndrome. Patients usually need ophthalmic surgery and may also need dental surgery
Genetic counseling and screening of the mother's relatives is recommended.
Patients usually do not require treatment due to benign nature of the disease. In case cataract develops patients generally do well with cataract surgery.
There is currently no defined treatment to ameliorate the muscle weakness of CPEO. Treatments used to treat other pathologies causing ophthalmoplegia has not been shown to be effective.
Experimental treatment with tetracycline has been used to improve ocular motility in one patient. Coenzyme Q has also been used to treat this condition. However, most neuro-ophthalmologists do not ascribe to any treatment.
Ptosis associated with CPEO may be corrected with surgery to raise the lids, however due to weakness of the orbicularis oculi muscles, care must be taken not to raise the lids in excess causing an inability to close the lids. This results in an exposure keratopathy. Therefore, rarely should lid surgery be performed and only by a neuro-ophthalmologist familiar with the disease.
The most common strabismus finding is large angle exotropia which can be treated by maximal bilateral eye surgery, but due to the progressive nature of the disease, strabismus may recur. Those that have diplopia as a result of asymmetric ophthalmoplegia may be corrected with prisms or with surgery to create a better alignment of the eyes.
Currently there is no effective therapy for dominant optic atrophy, and consequently, these patients are simply monitored for changes in vision by their eye-care professional. Children of patients should be screened regularly for visual changes related to dominant optic atrophy. Research is underway to further characterize the disease so that therapies may be developed.
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.
Treatment is dependent upon diagnosis and the stage at which the diagnosis is secured. For toxic and nutritional optic neuropathies, the most important course is to remove the offending agent if possible and to replace the missing nutritional elements, orally, intramuscularly, or intravenously. If treatment is delayed, the injury may be irreversible. The course of treatment varies with the congenital forms of these neuropathies. There are some drug treatments that have shown modest success, such as Idebenone used to treat LOHN. Often treatment is relegated to lifestyle alterations and accommodations and supportive measures.
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.
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.
There is no known curative treatment presently. Hearing aids and cataract surgery may be of use. Control of seizures, heart failure and treatment of infection is important. Tube feeding may be needed.
Cataract removal can be performed at any stage and no longer requires ripening of the lens. Surgery is usually 'outpatient' and performed using local anesthesia. About 9 of 10 patients can achieve a corrected vision of 20/40 or better after surgery.
Several recent evaluations found that cataract surgery can meet expectations only when significant functional impairment due to cataracts exists before surgery. Visual function estimates such as VF-14 have been found to give more realistic estimates than visual acuity testing alone. In some developed countries, a trend to overuse cataract surgery has been noted, which may lead to disappointing results.
Phacoemulsification is the most widely used cataract surgery in the developed world. This procedure uses ultrasonic energy to emulsify the cataract lens. Phacoemulsification typically comprises six steps:
- Anaesthetic – The eye is numbed with either a subtenon injection around the eye (see: retrobulbar block) or topical anesthetic eye drops. The former also provides paralysis of the eye muscles.
- Corneal incision – Two cuts are made at the margin of the clear cornea to allow insertion of instruments into the eye.
- Capsulorhexis – A needle or small pair of forceps is used to create a circular hole in the capsule in which the lens sits.
- Phacoemulsification – A handheld ultrasonic probe is used to break up and emulsify the lens into liquid using the energy of ultrasound waves. The resulting 'emulsion' is sucked away.
- Irrigation and aspiration – The cortex, which is the soft outer layer of the cataract, is aspirated or sucked away. Fluid removed is continually replaced with a saline solution to prevent collapse of the structure of the anterior chamber (the front part of the eye).
- Lens insertion – A plastic, foldable lens is inserted into the capsular bag that formerly contained the natural lens. Some surgeons also inject an antibiotic into the eye to reduce the risk of infection. The final step is to inject salt water into the corneal wounds to cause the area to swell and seal the incision.
Extracapsular cataract extraction (ECCE) consists of removing the lens manually, but leaving the majority of the capsule intact. The lens is expressed through a 10- to 12-mm incision which is closed with sutures at the end of surgery. ECCE is less frequently performed than phacoemulsification, but can be useful when dealing with very hard cataracts or other situations where emulsification is problematic. Manual small incision cataract surgery (MSICS) has evolved from ECCE. In MSICS, the lens is removed through a self-sealing scleral tunnel wound in the sclera which, ideally, is watertight and does not require suturing. Although "small", the incision is still markedly larger than the portal in phacoemulsion. This surgery is increasingly popular in the developing world where access to phacoemulsification is still limited.
Intracapsular cataract extraction (ICCE) is rarely performed. The lens and surrounding capsule are removed in one piece through a large incision while pressure is applied to the vitreous membrane. The surgery has a high rate of complications.
Most people with the disease need laser repairs to the retina, and about 60 per cent need further surgery.
Treatment is supportive and consists of management of manifestations. User of hearing aids and/or cochlear implant, suitable educational programs can be offered. Periodic surveillance is also important.
Many professionals that are likely to be involved in the treatment of those with Stickler's syndrome, include anesthesiologists, oral and maxillofacial surgeons; craniofacial surgeons; ear, nose, and throat specialists, ophthalmologists, optometrists, audiologists, speech pathologists, physical therapists and rheumatologists.
Treatment is usually unnecessary. In severe cases, surgery with a bilateral levator excision and frontalis brow suspension may be used.
Although treatment may be unnecessary, there may be social implications, especially in young children when venturing from a supportive home environment to a public environment (e.g., starting school). Continued support, including monitoring behavior and educating the child about his or her appearance as seen by others, is encouraged. Gradual or sudden withdrawal from interaction with others is a sign that may or may not be related to such behavior. Studies are being conducted to elucidate these implications.
Early diagnosis allows better planning of therapy in young patients with NF II. In many cases, the hearing loss is present for 10 years before the correct diagnosis is established. Early in the condition, surgery for an acoustic neurinoma can protect facial nerve function in many patients. In selected cases of patients with very small tumors and good bilateral hearing, surgery may offer the possibility of long-term hearing preservation.
Patients with the Wishard phenotype suffer multiple recurrences of the tumour after surgical treatment. In the case of facial nerve palsy, the muscles of the eyelids can lose their mobility, leading to conjunctivitis and corneal injury. "Lidloading" (implantation of small magnets, gold weights, or springs in the lid) can help prevent these complications. Other means of preserving corneal health include tarsorrhaphy, where the eyelids are partially sewn together to narrow the opening of the eye, or the use of punctal plugs, which block the duct that drains tears from the conjunctival sac. All these techniques conserve moisture from the lacrymal glands, which lubricates the cornea and prevents injury. Most patients with NF II develop cataracts, which often require replacement of the lens. Children of affected parents should have a specialist examination every year to detect developing tumors. Learning of sign language is one means of preparation for those that will most probably suffer complete hearing loss.
There are several different surgical techniques for the removal of acoustic neuroma. The choice of approach is determined by size of the tumour, hearing capability, and general clinical condition of the patient.
- The retrosigmoid approach offers some opportunity for the retention of hearing.
- The translabyrinthine approach will sacrifice hearing on that side, but will usually spare the facial nerve. Post-operative cerebrospinal fluid leaks are more common.
- The middle fossa approach is preferred for small tumours, and offers the highest probability of retention of hearing and vestibular function.
- Less invasive endoscopic techniques have been done outside of the United States for some time. Recovery times are reported to be faster. However, this technique is not yet mainstream among surgeons in the US.
Larger tumors can be treated by either the translabyrinthine approach or the retrosigmoid approach, depending upon the experience of the surgical team. With large tumors, the chance of hearing preservation is small with any approach. When hearing is already poor, the translabyrinthine approach may be used for even small tumors. Small, lateralized tumours in patients with good hearing should have the middle fossa approach. When the location of the tumour is more medial a retrosigmoid approach may be better.
Auditory canal decompression is another surgical technique that can prolong usable hearing when a vestibular schwannoma has grown too large to remove without damage to the cochlear nerve. In the IAC (internal auditory canal) decompression, a middle fossa approach is employed to expose the bony roof of the IAC without any attempt to remove the tumor. The bone overlying the acoustic nerve is removed, allowing the tumour to expand upward into the middle cranial fossa. In this way, pressure on the cochlear nerve is relieved, reducing the risk of further hearing loss from direct compression or obstruction of vascular supply to the nerve.
Radiosurgery is a conservative alternative to cranial base or other intracranial surgery. With conformal radiosurgical techniques, therapeutic radiation focused on the tumour, sparing exposure to surrounding normal tissues. Although radiosurgery can seldom completely destroy a tumor, it can often arrest its growth or reduce its size. While radiation is less immediately damaging than conventional surgery, it incurs a higher risk of subsequent malignant change in the irradiated tissues, and this risk in higher in NF2 than in sporadic (non-NF2) lesions.
It has been suggested that the disease follows a x-linked pattern of inheritance though studies done on this particular disease are few.
Lip pits may be surgically removed either for aesthetic reasons or discomfort due to inflammation caused by bacterial infections or chronic saliva excretion, though spontaneous shrinkage of the lip pits has occurred in some rare cases. Chronic inflammation has also been reported to cause squamous-cell carcinoma. It is essential to completely remove the entire lip pit canal, as mucoid cysts can develop if mucous glands are not removed. A possible side effect of removing the lip pits is a loose lip muscle. Other conditions associated with VWS, including CL, CP, congenital heart defects, etc. are surgically corrected or otherwise treated as they would be if they were non-syndromic.
Autoimmune polyendocrine syndrome type 1 treatment is based on the symptoms that are presented by the affected individual, additionally there is:
- Hormone replacement
- Systemic antifungal treatment
- Immunosuppressive treatment