F02. WW 258. The recent advent of next generation sequencing has greatly facilitated the diagnostic. 24-5). 01, A50. While these terms may seem very similar, Frady says, the “code first” terminology represents an instructional note while “in diseases classified elsewhere” is actually a part of the code title itself. Diabetic retinopathy occurs due to damage to the blood vessels in the retina, and it is a major health problem in recent years that progresses slowly without recognizable symptoms. 83 Acinetobacter baumannii as the cause of diseases classified elsewhere. 9 unspecified 332 parkinson's disease 332. H35. 01, A50. endocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. Patients were classified as having a retinal comorbidity if they had two visits with the same code. This warm, moist habitat can provide a suitable environment for the growth of bacteria, viruses, and other. 71)Retinal vein occlusion represents the second leading cause of retinal vascular disorders, with a uniform sex distribution worldwide. 72 should only be used for claims with a date of service on or before September 30, 2015. The peculiar distribution of mitochondria in cells of retinal layers is necessary to assure the appropriate energy supply for the transmission of the light signal. 72 is one of thousands of ICD-9-CM codes. endocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. H59-H59 Intraoperative and postprocedural complications and disorders of eye and adnexa, not elsewhere classified. The second code is for wandering, Z91. H53-H54 Visual disturbances and blindness. autoimmune disease (systemic). 43, A52. . H33 - Retinal detachments and breaks. Log in Join. 43, A52. Contents 1 H00H59 Diseases of the eye and adnexa o 1. 811 Nonproliferative sickle-cell retinopathy, right eye. In this review, we wish to. 42888, 0. ICD 9 Code: 250. H36. 5. 10 (H49-H52) Disorders of ocular muscles, binocular movement, accommodation and refraction. Former Caption. 1) D13. 9 became effective on October 1, 2023. symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. Purely Excluded Conditions. H32 Chorioretinal disorders in diseases classified elsewhere . 01, A50. 9. the sudden appearance of floaters. Arthropathy assoc w metabolic disorder; Arthropathy associated with respiratory disorder; Arthropathy due to a metabolic disorder;Dementia in other diseases classified elsewhere, unspecified severity, with agitation. 71) The billing and coding information in this article is dependent on the coverage indications, limitations and/or medical necessity described in the associated LCD L34760 Scanning Computerized Ophthalmic Diagnostic Imaging (SCODI). Other disorders of optic nerve, not elsewhere classified, bilateral H47. A key issue in the diagnosis of retinal disease is the duration of symptoms, which can be acute, chronic, or acute presentations of chronic disease. Scientific Reports (2023) Diabetic retinopathy (DR) is a common complication of diabetes mellitus and is a major cause of vision loss in middle-aged and elderly. 50 - H44. Diseases of the retina may lead to visual impairment, visual field loss, and more complex disorders such as metamorphopsia (distorted vision) and clouding. H34 - Retinal vascular occlusions. 9 became effective on October 1, 2023. The majority of syndromic IRDs are. ; Short description: Dem in other diseases classd elswhr, moderate, with anxietyRetinal neurodegeneration is predominantly reported as the apoptosis or impaired function of the photoreceptors. Access to this feature is available in the following products: Find-A-Code Essentials. 0) Diabetic retinopathy; H40-H42 Glaucoma (H40. 813-681-1122;. Unspecified retinal disorder. Date H28 first reported (cataract and other disorders of lens in diseases classified elsewhere) 131171: Source of report of H28 (cataract and other disorders of lens in diseases classified elsewhere) 131172: Date H30 first reported (chorioretinal inflammation) 131173: Source of report of H30 (chorioretinal inflammation) 131174 Code Tree. 43, A52. Image of fundus showing scatter laser surgery for diabetic retinopathy. The Alzheimer’s Association reports that six in 10 people (60 percent) with dementia will wander at some point. (H35. 0-) diabetic retinopathy (E08. H35 - Other retinal disorders. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024. F02. Corneal diseases. 43, A52. Add Thaslassemia proliferative retinopathy . A wide range of conditions can cause problems with your retina, such as: a direct injury to retinal tissue, such as a retinal tear. Chorioretinal disorders in diseases classified elsewhere [retinitis] H33. 71)Dementia in other diseases classified elsewhere, severe, with mood disturbance. H46-H47 Disorders of optic nerve and visual path. The retina is a thin. 822 Vitreomacular adhesion, left eye. 1 (H60-H62) Diseases of external ear. Neovascularization is a protective mechanism that many tissues throughout the body have in response to injury. 71)Chorioretinal disorders in diseases classified elsewhere: H33. -)Cleveland Clinic Cole Eye Institute's vitreoretinal team is internationally recognized for its expertise in diagnosing and treating the full range of retina disorders, including age-related macular degeneration, diabetic retinopathy and retinal detachments. 812 Acute on chronic graft-versus-host disease 279. Read more on this blog and contact Florida Eye for treatment. The common theme between IRDs is that individuals develop visual impairment as a result of dysfunction or degeneration of the retina, a highly specialised tissue at the back of the eye which enables vision through the conversion of light energy into neuronal. Retinal diseases can profoundly affect your vision, impacting your daily life. Diseases of the nervous system. H30 - Chorioretinal inflammation. when coding chorioretinal disorders in diseases classified elsewhere, you first code the underlying disease—for example, congenital. You may need to try looking with each eye alone to notice these. In this case the vitreous gel can tug on the retina causing it to tear. Types. F02. The above description is abbreviated. 0 may differ. . Defects in the side vision. 81 - other international versions of ICD-10 H35. Disease. -], and Dementia Unspecified/NOS [F03. 43, A52. The retina, a layer of cells sensitive to light, plays an. ; Short description: Dem in other diseases classd elswhr, mild, with mood disturbICD 10 code for Other specified bacterial agents as the cause of diseases classified elsewhere. For such conditions, the ICD-10-CM has a. Objective: To evaluate the accuracy and feasibility of the auto-detection of 15 retinal disorders with artificial intelligence (AI)-assisted optical coherence tomography (OCT) in community screening. H33-H36 Disorders of the choroid and retina H40-H42 Glaucoma H43-H44 Disorders of vitreous body and globe H46-H47 Disorders of optic nerve and visual pathways H49-H52 Disorders of ocular muscles, binocular movement, accommodation. Get free rules, notes, crosswalks, synonyms, history for ICD-10 code F54. 00* Nonproliferative diabetic retinopathy [NPDR] # H36. F02. underlying disease, such as: amyloidosis (. Unspecified hereditary retinal dystrophy - Hemorrhagic detachment of retinal pigment epithelium, unspecified eye H35. The 2024 edition of ICD-10-CM G32. Solutions available. Cleveland Clinic Cole Eye Institute's vitreoretinal team is internationally recognized for its expertise in diagnosing and treating the full range of retina disorders, including age-related macular degeneration, diabetic retinopathy and retinal detachments. ICD-10-CM Diagnosis Code E85. -) H35. 43, A52. 2023 - New Code 2024 Billable/Specific Code Manifestation Code. View full. Wandering is one of the most dangerous symptoms for patients with dementia. Note: Use an external cause code following the code for the eye condition, if applicable, to identify the cause of the eye condition. Effective visualization of the features of the convolution layers is possible. H00-H59 - Diseases of the eye and adnexa. H31 - Other disorders of choroid. In order to better identify retinal diseases, this paper proposes a new attention mechanism, which can better improve the accuracy of retinal disease recognition. Electroretinography. 71)endocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. . 526 codes were added to the 2024 ICD-10-CM code set, effective October 1, 2023. 82 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. For claims with a date of service on or after October 1, 2015, use an. 9 became effective on October 1, 2023. 01, A50. 8 (Other retinal disorders in diseases classified elsewhere) group, you’ll need to know whether the retinopathy is. Subsequently, the image captured with a digital camera is encoded as a. -], In diseases classified elsewhere [F02. 9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. 2023 - New Code 2024 Billable/Specific Code Manifestation Code. A4 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. 3-, A51. 71)Blurry vision is one of the most common symptoms of retinal vascular disease. WW 274. 0 Background retinopathy and retinal vascular changes. It provides the sharp, central vision needed for reading, driving and seeing fine detail. The retina is among the most metabolically active tissues with high-energy demands. The code title indicates that it is a. Other disorders of eye and adnexa in diseases classified elsewhere. Chorioretinal disorders in diseases classified elsewhere: H33. 01, A50. 71)Q85. G90 Disorders of autonomic nervous system. Blurred or distorted (straight lines look wavy) vision. Download a retinal diseases guide from Cleveland Clinic featuring information on retina disorders such as age-related macular degeneration, diabetic retinopathy as well as other rare conditions plus diagnostic tools, medical treatment and surgery. Accurate and early diagnosis. To choose the correct code from the novel H36. The 2024 edition of ICD-10-CM M53. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. The 2024 edition of ICD-10-CM H35. This is the American ICD-10-CM version of H35. 3-, A51. They constructed a multi class classifier using three linear SVM, and then classified NORMAL and AMD, NORMAL and DME, AMD and DME. 01, A50. 8. G23 Other degenerative diseases of basal ganglia. 19 Unspecified purulent endophthalmitis, right eye - Other endophthalmitis H44. This was the first year ICD-10-CM was implemented into the HIPAA code set. 00 – H34. Type 2 Excludes Help. 43, A52. 01, A50. Diseases of the retina are common and numerous, with causes ranging over inherited, inflammatory, vascular, infectious, neoplastic, traumatic, toxic, and idiopathic etiologies. It is also associated with higher rates of cognitive decline in late life and higher risk of dementia [ 13, 14 ]. H32 - Chorioretinal disorders in diseases classified elsewhere. Many cases of retinal neovascularization are accompanied by the loss of tiny blood vessels elsewhere in the retina, and blocking VEGF inhibits or prevents the re-growth of these vessels. 320. 9: Retinal vascular occlusions: H35. nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit (S05. 81 Graft-versus-host disease (not billable, use one of the below codes) D89. 3-, A51. Nevertheless, an eye may be afflicted with several diseases if proper care is not. 3110 - H35. 001 - H44. Retinal disorders in diseases classified elsewhere Billable Code H36 is a valid billable ICD-10 diagnosis code for Retinal disorders in diseases classified. 89 Other retinal disorders in diseases classified elsewhere NEW CODE. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. Toggle navigation. An excess amount of reactive oxygen species (ROS) can lead to functional and morphological impairments in retinal pigment. Diabetic Retinopathy (DR) DR and DME are considered the leading cause of blindness worldwide, and lead to significant visual morbidity [2,4]. H28 Cataract in diseases classified elsewhere. 37 Central sleep apnea in conditions classified elsewhere. The 2024 edition of ICD-10-CM I43 became effective on October 1, 2023. Profile of retinal diseases in adult patients attending two major eye clinics in Kinshasa, the Democratic Republic of Congo. F02. The term encompasses a heterogenous group of diseases that are characterized by altered biomechanics of. Applicable To. Over 80 forms of syndromic IRDs have been described. 71) FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. 89 Other retinal disorders in diseases classified elsewhere . Symptoms. 43, A52. 12 (H55-H59) Other disorders of eye and adnexa. Contents 1 H00H59 Diseases of the eye and adnexa o 1. 1. Albert J. . Retinitis pigmentosa (RP) is a group of progressive retinal dystrophies affecting about 1 in 3000 individuals [1,2]. H32. One of the leading causes of these impairments is inherited retinal diseases (IRDs) which has a prevalence of 1 in 2000–3000 [2,3]. Retinal disorders in diseases classified elsewhere Billable Code H36 is a valid billable ICD-10 diagnosis code for Retinal disorders in diseases classified elsewhere . . 3-, A51. ICD-10. Quick search helps you quickly navigate to a particular category. Inherited retinal dystrophies (IRD) are a highly heterogeneous group of rare diseases with a molecular diagnostic rate of >50%. This is the American ICD-10-CM version of G99. 001 - H33. FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. 73906] R²: 0. The series is written and illustrated by medical experts and offers select titles in large print, Spanish and Chinese. Many phenotypic features appear shared between the different IRDs that can make their clinical classification challenging although application of molecular diagnostic tools and testing can be applied to provide greater. 3-, A51. Image of fundus showing scatter laser surgery for diabetic retinopathy. 8 Other specified retinal disorders . 43, A52. . 0 to 0. Date H28 first reported (cataract and other disorders of lens in diseases classified elsewhere) 131171: Source of report of H28 (cataract and other disorders of lens in diseases classified elsewhere) 131172: Date H30 first reported (chorioretinal inflammation) 131173: Source of report of H30 (chorioretinal inflammation) 131174Code Tree. 04898 Incremental AUROC (full-covars): -0. 1 Anemia in chronic kidney disease. G73. ; Short description: Dem in oth dis classd elswhr, unsp sev,. ICD 10 code for Other cerebrovascular disorders in diseases classified elsewhere. endocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. 52-Disorders of visual pathways in (due to). Various mutations of genes involved in the function or structure of the outer retinal elements have been identified as the causative factors for these IRDs. ICD 10 code for Arthropathies in other specified diseases classified elsewhere, unspecified site. 2%), followed by disorders of the eyelid, lacrimal system and orbit (11. H33 - Retinal detachments and breaks. ICD-10 Code Type: Diagnosis. 8 other cerebral degeneration 331. The most frequent retinal diseases, such as diabetic retinopathy, age-related macular degeneration and posterior uveitis, are underlined by oxidative stress or aging-induced retinal inflammation, which contributes to vision impairing or loss. H55-H57. 3-, A51. 4), low. 8: Retinal detachments and breaks: H34. 1. 3-, A51. underlying disease, such as: lipid storage disorders (. Retinitis. ICD-10-CM Diagnosis Code H35. 43, A52. 2 H60-H99 - Diseases of the ear and mastoid process. The retina (from Latin: rete "net"; pl. 9: Other retinal disorders: H36: Retinal disorders in diseases classified. You would only see the “code first” note if you look up the code in the tabular list and review the instructional notes, whereas you. Diabetic retinopathy (DR) is a microvascular complication of diabetes and the most common cause of acquired vision loss in adults worldwide. changes in vision. A30. 1 Dataset. Retinal detachment. Choroidal involvement can also occur. 24-5). N50. 2 H00-H06 Disorders of eyelid, lacrimal system and orbit. Further, microRNA is known to play a biased and remarkable role in driving the M1 phenotype in the mixed microglia/macrophage population in retinal diseases, for example, upregulation of miR-155 [48,49]. Those ICD terms containing “classified elsewhere” were treated as obsolete terms in ICDO. 8 OTHER SPECIFIED DISORDERS INVOLVING THE IMMUNE MECHANISM, NOT ELSEWHERE CLASSIFIED D89. Indeed, the presence of ocular features may mirror disease activity elsewhere. H30-H36 - Disorders of choroid and retina. B4 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Reported Trait: TTE retinal disorders in diseases classified elsewhere — AUROC: 0. endocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. Updated Tabular. 1), ) 3. 89 to ICD-9-CM. 1. Unspecified retinal disorder Show additional info Hide additional info. 7* Meningitis in other bacterial diseases classified elsewhere; 320. Diabetic retinopathy ( [ˌrɛtnˈɑpəθi]), also known as diabetic eye disease, is when damage occurs to the retina due to diabetes. 28, 29 Retinal arteriolar occlusion may occur, and multiple cotton-wool spots may be seen (Fig. 3-, A51. 43, A52. 8 Anemia in other chronic diseases classified elsewhere. Extrapyramidal and movement disorders in diseases classified elsewhere: G300: Alzheimer's disease with early onset: G301: Alzheimer's disease with late onset: G308: Other Alzheimer's disease: G309: Alzheimer's disease, unspecified: G3101: Pick's disease: G3109: Other frontotemporal dementia: G311: Senile degeneration of brain, not. 3-, A51. Retinal disorders in diseases classified elsewhere Table of Contents 1. H30-H36 - Disorders of choroid and retina. A 'billable code' is detailed enough to be used to specify a. endocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. 5 Lepromatous leprosy. 01, A50. ICD-10-CM Official Guidelines for Coding and Reporting FY 2021 – UPDATED January 1, 2021 (October 1, 2020 - September 30, 2021) Narrative changes appear in bold textAutonomic neuropathy in diseases classified elsewhere. D63. The most common cause of hospitalisations for diseases of the eye and adnexa were disorders of the lens (62. 3-, A51. 3-, E09. 71 ) Disorders of choroid and retina ( H30-H36 )F51 - Sleep disorders not due to a substance or known physiological condition; F52 - Sexual dysfunction not due to a substance or known physiological condition; F53 - Mental and behavioral disorders associated with the puerperium, not elsewhere classified; F54 - Psychological and behavioral factors associated with disorders or diseases. H40-H42 Glaucoma. F02. WW 285. , Furthermore, Korean citizens tend to seek medical attention related to retinal disorders in Korea, because the country is known to have well-trained retinal specialists and several hospitals have well-equipped facilities for the treatment of retinal diseases. Search All ICD-10 Toggle Dropdown. Major neurocognitive disorder in other diseases classified elsewhere NOS; severe F02. 3-, A51. Common. 01, A50. ICD-10 Code range (H30-H36), Disorders of choroid and retina contains ICD-10 codes for Chorioretinal inflammation, Other disorders of choroid, Chorioretinal disorders in diseases classified elsewhere, Retinal detachments and breaks, Retinal vascular. The study design and methods aredescribed in detail elsewhere. 2. 71)Inherited retinal disease (IRD) is a major cause of bilateral visual decline and blindness worldwide. Convert to ICD-9. E02 Subclinical iodine-deficiency hypothyroi. “Cold” laser to treat central serous retinopathy and other retinal disorders. 2A2. 0 Definitions Manual. The 2024 edition of ICD-10-CM H35. H31. endocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. 5. Code first underlying disease, such as: lipid storage disorders (E75. 119 Unspecified retinal detachment with retinal break, right eye - Cyst of ora serrata, unspecified eye H33. WW 272. 1 Tuberculoid leprosy. 8 for Other retinal disorders in diseases classified elsewhere is a medical classification as listed by WHO under the range - Diseases of the eye and adnexa . B96. -) Excludes1: arteriosclerotic retinopathy (H35. The more retinal disorders among elderly population could be another possible cause for higher prevalence of retinal disorders in BRS relative to BGS. 81 became effective on October 1, 2023. Pattern of dark spots and star-shaped blotches (deposits with bone spicule appearance) that develop from the periphery to the center of the retina. A30. 01, A50. This is the American ICD-10-CM version of I43 - other international versions of ICD-10 I43 may differ. Dementia in other diseases classified elsewhere, unspecified severity, with mood disturbance. Dementia in other diseases classified elsewhere, unspecified severity, with anxiety. 43, A52. H32 is a valid billable ICD-10 diagnosis code for Chorioretinal disorders in diseases classified elsewhere . 82 became effective on October 1, 2023. -] The severity of the dementia is now an integral part of the diagnosis code assignment, with identification. The major players operating in the Macular Degeneration (AMD) and Other Retinal Diseases Drugs market are Novartis AG, F Hoffmann-La Roche, GlaxoSmithKline Pharmaceuticals Ltd. 3-, A51. Retinal detachment. Retinal characteristics isolating and protecting the sensitive neuro-retina from the rest of the ocular tissues challenge drug delivery and promote research and development toward new horizons. H35 Other retinal disorders. 71) H30-H36 Disorders of choroid and retina. 71)ICD 10 code for Systemic disorders of connective tissue in other diseases classified elsewhere. It contains a lot of nerve cells that perceive light. 71)These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. ICD-10-CM H36. Major neurocognitive disorder in other diseases classified elsewhere; Type 1 Excludes. ICD-10-CM Code for Other retinal disorders in diseases classified elsewhere H36. 89 is a new 2024 ICD-10-CM code that became effective on October 1, 2023. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation. Approximately 200 genes are associated with these syndromes. 8 ICD-10 code H36. ICD-10-CM Coding Rules. E85. These may include: Seeing floating specks or cobwebs. vision loss, from retinal or any other disease. H36. Retinal disorders can be categorized in various ways and the way in which they have been described in this review, which is summarized in Figure 1, is certainly not the only way to partition them. H32 Chorioretinal disorders in diseases classified elsewhere H33. Respiratory disorders in diseases classified elsewhere (J99) J98. Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism Type 2 Excludes. Yu-Feng Yao. 3 -, A51. E35 Disorders of endocrine glands in diseases classified elsewhere . Predicted Trait: Reported Trait: Retinal disorders in diseases classified elsewhere (time-to-event) Mapped Trait(s) retinopathy (EFO_0003839) : Additional Trait Informationendocrine, nutritional and metabolic diseases (E00-E88) injury (trauma) of eye and orbit ; injury, poisoning and certain other consequences of external causes ; neoplasms ; symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. Endocrine, Nutritional, and Metabolic Diseases Retinal disorders in diseases classified elsewhere ICD-10-CM H36. 2023 - New Code 2024 Billable/Specific Code Manifestation Code. 9. The code with “in diseases. e. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. "In diseases classified elsewhere" codes are never permitted to be used as first listed or principle diagnosis codes. symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. Over 80 forms of syndromic IRDs. Be sure to code this behavior if documented in the medical record. For example, wound repair in the skin involves the formation of new blood vessels to compensate for those that have been damaged. H00-H59 - Diseases of the eye and adnexa. F02. signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) syphilis related eye disorders (A50. 1 - Neoplasm of uncertain. What Causes Inherited Retinal Diseases? An IRD is a genetic disorder– a change, or variant, in one or more genes that contribute to proper retinal function. It is surrounded by an extension of the membranes that surround the brain.