Amblyopia, otherwise known as lazy eye, is a disorder of the visual system that is characterized by poor or indistinct vision in an eye that is otherwise physically normal, or out of proportion to associated structural abnormalities. It has been estimated to affect 1–5% of the population.
The problem is caused by either no transmission or poor transmission of the visual image to the brain for a sustained period of dysfunction or during early childhood. Amblyopia normally only affects one eye, but it is possible to be amblyopic in both eyes if both are similarly deprived of a good, clear visual image. Detecting the condition in early childhood increases the chance of successful treatment.
While the colloquialism “lazy eye” is frequently used to refer to amblyopia, the term is inaccurate because there is no “laziness” of either the eye or the amblyope involved in the condition.
Amblyopia is a developmental problem in the brain, not an organic problem in the eye (although organic problems can induce amblyopia which persist after the organic problem has resolved). The part of the brain corresponding to the visual system from the affected eye is not stimulated properly, and develops abnormally. This has been confirmed via direct brain examination. David H. Hubel and Torsten Wiesel won the Nobel Prize in Physiology or Medicine in 1981 for their work demonstrating the irreversible damage to ocular dominance columns produced in kittens by sufficient visual deprivation during the so-called “critical period”. The maximum critical period in humans is from birth to two years old.
Symptoms of Amblyopia
Many people with amblyopia, especially those who are only mildly so, are not even aware they have the condition until tested at older ages, since the vision in their stronger eye is normal. However, people who have severe amblyopia may experience associated visual disorders, most notably poor depth perception. Amblyopes may suffer from poor spatial acuity, low sensitivity to contrast and some “higher-level” deficits to vision such as reduced sensitivity to motion. These deficits are usually specific to the amblyopic eye, not the unaffected “fellow” eye. Amblyopes also suffer from problems of binocular vision such as limited stereoscopic depth perception and usually have difficulty seeing the three-dimensional images in hidden stereoscopic displays such as autostereograms. However perception of depth from monocular cues such as size, perspective, and motion parallax is normal.
Types of Amblyopia
Amblyopia can be caused by deprivation of vision early in life by vision-obstructing disorders such as congenital cataracts, by strabismus (misaligned eyes), or by anisometropia (different degrees of myopia or hyperopia in each eye).
Strabismus, sometimes erroneously also called lazy eye, is a condition in which the eyes are misaligned. Strabismus usually results in normal vision in the preferred sighting (or “fellow”) eye, but may cause abnormal vision in the deviating or strabismic eye due to the discrepancy between the images projecting to the brain from the two eyes. Adult-onset strabismus usually causes double vision (diplopia), since the two eyes are not fixated on the same object. Children’s brains, however, are more neuroplastic, and therefore can more easily adapt by suppressing images from one of the eyes, eliminating the double vision. This plastic response of the brain, however, interrupts the brain’s normal development, resulting in the amblyopia.
Strabismic amblyopia is treated by clarifying the visual image with glasses, and/or encouraging use of the amblyopic eye with an eyepatch over the dominant eye or pharmacologic penalization of it. Penalization usually consists of applying atropine drops to temporarily dilate the pupil, which leads to blurring of vision in the good eye. This helps to prevent the bullying and teasing associated with wearing a patch, although application of the eyedrops is more challenging. The ocular alignment itself may be treated with surgical or non-surgical methods, depending on the type and severity of the strabismus.
Refractive or anisometropic amblyopia
Refractive amblyopia may result from anisometropia (unequal refractive indices between the two eyes). Anisometropia exists when there is a difference in the refraction between the two eyes. The eye which provides the brain with a clearer image (closer to 20/20) typically becomes the dominant eye. The image in the other eye is blurred, which results in abnormal development of one half of the visual system. Refractive amblyopia is usually less severe than strabismic amblyopia and is commonly missed by primary care physicians because of its less dramatic appearance and lack of obvious physical manifestation, such as with strabismus. Frequently, amblyopia is associated with a combination of anisometropia and strabismus.
Pure refractive amblyopia is treated by correcting the refractive error early with prescription lenses and patching or penalizing the good eye.
Meridional amblyopia is a mild condition in which lines are seen less clearly at some orientations than others after full refractive correction. An individual who had an astigmatism at a young age that was not corrected by glasses will later have astigmatism that cannot be optically corrected.
Form-deprivation and occlusion amblyopia
Form-deprivation amblyopia (Amblyopia ex anopsia) results when the ocular media become opaque, such as is the case with cataracts or corneal scarring from forceps injuries during birth. These opacities prevent adequate visual input from reaching the eye, and therefore disrupt development. If not treated in a timely fashion, amblyopia may persist even after the cause of the opacity is removed. Sometimes, drooping of the eyelid (ptosis) or some other problem causes the upper eyelid to physically occlude a child’s vision, which may cause amblyopia quickly. Occlusion amblyopia may be a complication of a hemangioma that blocks some or all of the eye.
Treatment and prognosis for Amblyopia
Treatment of strabismic or anisometropic amblyopia consists of correcting the optical deficit and forcing use of the amblyopic eye, either by patching the good eye, or by instilling topical atropine in the eye with better vision. One should also be wary of over-patching or over-penalizing the good eye when treating for amblyopia, as this can create so-called “reverse amblyopia” in the other eye.
Form deprivation amblyopia is treated by removing the opacity as soon as possible followed by patching or penalizing the good eye to encourage use of the amblyopic eye.
Although the best outcome is achieved if treatment is started before age 5, research has shown that children older than age 10 and some adults can show improvement in the affected eye. Children from 7 to 12 who wore an eye patch and performed near point activities (vision therapy) were four times as likely to show a two line improvement on a standard 11 line eye chart than amblyopic children who did not receive treatment. Adolescents aged 13 to 17 showed improvement as well, albeit in smaller amounts than younger children. (NEI-funded Pediatric Eye Disease Investigator Group, 2005)
Vision therapy programs are at least somewhat effective on adults. To quote Dr. Leonard J. Press, FAAO, FCOVD: “It’s been proven that a motivated adult with strabismus and/or amblyopia who works diligently at vision therapy can obtain meaningful improvement in visual function. As my patients are fond of saying: “I’m not looking for perfection; I’m looking for you to help me make it better”. It’s important that eye doctors don’t make sweeping value judgments for patients. Rather than saying “nothing can be done”, the proper advice would be: “You won’t have as much improvement as you would have had at a younger age; but I’ll refer you to a vision specialist who can help you if you’re motivated.”
Clinical trials and experiments
A recent study, widely reported in the popular press, has suggested that repetitive transcranial magnetic stimulation may temporarily improve contrast sensitivity and spatial resolution in the bad eye of amblyopic adults. These results await verification by other researchers.
Virtual reality computer games where each eye receives different signals of the virtual world that the player’s brain must combine in order to successfully play the game have shown some promise in improving both monocularity in the affected eye as well as binocularity.
In another recent clinical trial conducted in a hospital in China and coordinated with a research program at University of Southern California, 28 of 30 patients being treated for amblyopia showed dramatic gains with some developing 20/20 vision. The treatment involved only the use of basic computer desktop software and vision training exercises.
Homeopathy Treatment for Amblyopia
Keywords: homeopathy, homeopathic, treatment, cure, remedy, remedies, medicine
Homeopathy treats the person as a whole. It means that homeopathic treatment focuses on the patient as a person, as well as his pathological condition. The homeopathic medicines are selected after a full individualizing examination and case-analysis, which includes the medical history of the patient, physical and mental constitution, family history, presenting symptoms, underlying pathology, possible causative factors etc. A miasmatic tendency (predisposition/susceptibility) is also often taken into account for the treatment of chronic conditions. A homeopathy doctor tries to treat more than just the presenting symptoms. The focus is usually on what caused the disease condition? Why ‘this patient’ is sick ‘this way’. The disease diagnosis is important but in homeopathy, the cause of disease is not just probed to the level of bacteria and viruses. Other factors like mental, emotional and physical stress that could predispose a person to illness are also looked for. No a days, even modern medicine also considers a large number of diseases as psychosomatic. The correct homeopathy remedy tries to correct this disease predisposition. The focus is not on curing the disease but to cure the person who is sick, to restore the health. If a disease pathology is not very advanced, homeopathy remedies do give a hope for cure but even in incurable cases, the quality of life can be greatly improved with homeopathic medicines.
The homeopathic remedies (medicines) given below indicate the therapeutic affinity but this is not a complete and definite guide to the homeopathy treatment of this condition. The symptoms listed against each homeopathic remedy may not be directly related to this disease because in homeopathy general symptoms and constitutional indications are also taken into account for selecting a remedy. To study any of the following remedies in more detail, please visit the Materia Medica section at Hpathy.
None of these medicines should be taken without professional advice and guidance.
Homeopathy Remedies for Amblyopia :
Ammc., anag., atro., caps., chin-s., chin., con., crot-h., dros., euph., gels., hyos., ign., merc., nat-m., nux-v., op., phos., ph-ac., puls., ruta., sil., stram.
- ^ “Information from your family doctor. Amblyopia (“lazy eye”) in your child”. American family physician 75 (3): 368. 2007. PMID 17304868.
- ^ Weber, JL; Wood, Joanne (2005). “Amblyopia: Prevalence, Natural History, Functional Effects and Treatment” ([dead link] – Scholar search). Clinical and Experimental Optometry 88 (6): 365–375, https://www.optometrists.asn.au/gui/files/ceo886365.pdf.
- ^ McKee, SP., Levi, DM., Movshon, JA. (2003). “The pattern of visual deficits in amblyopia“. J Vision 3 (5): 380–405. doi:10.1167/3.5.5, https://journalofvision.org/3/5/5/McKee-2003-jov-3-5-5.pdf.
- ^ Jeffrey Cooper & Rachel Cooper. “All About Strabismus“. Optometrists Network. Retrieved on 2008-03-09.
- ^ Hess, R.F., Mansouri, B., Dakin, S.C., & Allen, H.A. (2006). “Integration of local motion is normal in amblyopia”. J Opt Soc Am A Opt Image Sci Vis 23 (5): 986–992. doi:10.1364/JOSAA.23.000986.
- ^ Tyler, C.W. (2004). Binocular Vision In, Duane’s Foundations of Clinical Ophthalmology. Vol. 2, Tasman W., Jaeger E.A. (Eds.), J.B. Lippincott Co.: Philadelphia.
- ^ Levi, D.M. (2006). “Visual processing in amblyopia: human studies”. Strabismus 14 (1): 11–19. doi:10.1080/09273970500536243.
- ^ a b c d Holmes, Repka, Kraker & Clarke (2006). “The treatment of amblyopia”. Strabismus 14 (1): 37–42. doi:10.1080/09273970500536227.
- ^ “Commonly Missed Diagnoses in the Childhood Eye Examination“. American Family Physician (August 15, 2001).
- ^ Angell et al. (1981). “Visual prognosis in patients with ruptures in Descemet’s membrane due to forceps injuries“. Arch Ophthalmol 99 (12): 2137, https://archopht.ama-assn.org/cgi/content/abstract/99/12/2137.
- ^ Amblyopia NEI Health Information
- ^ Pediatric Eye Disease Investigator Group (2005). “Randomized trial of treatment of amblyopia in children aged 7 to 17 years”. Archives of Ophthalmology 123 (April): 437–447. doi:10.1001/archopht.123.4.437. PMID 15824215.
- ^ Treatment of Amblyopia (Lazy Eye)
- ^ Benjamin Thompson, Behzad Mansouri, Lisa Koski, and Robert F. Hess (2008). “Brain Plasticity in the Adult: Modulation of Function in Amblyopia with rTMS“. Current Biology 18: 1067-1071, https://www.current-biology.com/content/article/abstract?uid=PIIS0960982208008087.
- ^ National Public Radio. “Magnetic Pulses To Brain Help ‘Lazy Eye’“.
- ^ BBC News: Video games tackle ‘lazy eye’
- ^ USC College News