眼科學(Opthalmology)

Corneal dystrophies are diverse bilateral genetic and non-inflammatory diseases limited to the cornea. Clinically, it is categorized into three groups; superficial corneal dystrophy, corneal stromal dystrophy, and posterior corneal dystrophy which are further subcategorized into other classes. Macular corneal dystrophy (MCD) is a subcategory of corneal stromal dystrophies. Mutation in carbohydrate (N-acetylglucosamine6-O) sulfotransferase 6 (CHST6) gene is usually responsible for MCD. However, all MCD cases can be explained by mutations in CHST6 coding region, deletion or replacement in the upstream region, or mutations in splice sites resulting in loss of splicing signal.

RP is a disease with a variety of disorders. Some patients show symptoms of vision loss during childhood while some others live without any symptoms. Most cases present classical symptoms of difficulties with adapting to darkness and night blindness (niatalopia) in oldage and loss of vision in early adolescence. Following the disease progression, they lose their distant peripheral vision, tunnel vision, and finally central vision which usually occurs at the age of sixty. The reduction of ROD and CONE is similar in other types. Sometimes the decrease in CONE is greater than that in ROD which is then called cone-rod degeneration, a form of RP in which the loss of vision and defects in color vision are the predominant initial symptoms.

Cornealdystrophies are a group of 1diverse bilateral geneticand non-inflammatory diseases limited to the cornea. 2. Clinically,it is categorized into three groups; , superficialcorneal dystrophy, corneal stromal dystrophy, and posterior corneal dystrophy,which are further subcategorized into other classes.3.Macular corneal dystrophy (MCD) is a subcategory of corneal stromal dystrophies.dystrophy.Mutation in carbohydrate (N-acetylglucosamine6-4acetylglucosamine6-O) sulfotransferase 6 (CHST6) gene is usually responsible for MCD. However, all MCD cases can5cannot be explainedby mutations in the CHST6 coding region, deletion or /replacementin the upstream region, or mutations in splice sites resulting in loss of splicingsignalloss.

RP is adisease witha variety ofthat causes various disorders. Somepatients show symptoms of loss of vision loss duringchildhoodwhile some, whereas others live withoutdo not showany symptoms. until middle age.6Most casespatientspresent classicalwith classicsymptomsof difficulties with, such as difficulty in adapting to darkness and night blindness (niatalopia7 nyctalopia) in oldage andold age as wellas loss of vision in early adolescence. Following theWithdisease progression, they lose their distant peripheral vision, develop 8tunnel vision, and finally lose their central vision,which usually occurs at the agearound 60 years of sixty.age.The reduction of RODin rod and CONE cone issimilar in other types. Sometimes, the decrease in CONEconesis greater than that in RODrods, which is thencalled cone-rodconeroddegeneration, a form of RP in which the loss of vision and defects in colorvision are the predominant initial symptoms.

Cornealdystrophies are a group of 1diverse bilateral geneticand non-inflammatory diseases limited to the cornea. 2. Clinically,itthese diseases isare categorized into three groups; , namely superficial corneal dystrophy, cornealstromal dystrophy, and posterior corneal dystrophy, which these groups 4are further subcategorized into other classes.3. OneMacular cornealdystrophy (MCD) is a subcategory ofcorneal stromal dystrophies.dystrophy is macular corneal dystrophy (MCD),. which is characterizedby bilateral cloudy regions within a hazy stroma, eventually leading to severe visual impairment5. Mutation in the carbohydrate (N-acetylglucosamine6-acetylglucosamine6-6O) sulfotransferase 6 (CHST6) gene is typicallyusuallyresponsible for MCD. However, it is also caused byother factors, and all MCD cases of MCD cancannot7be explained by mutations in the CHST6 coding region, deletion or /replacementin the upstream region, or mutations in splice sites resultingthat result inloss of splicingsignalloss.

Retinitis pigmentosa (RP) is a disease with a variety ofthat causes various disorders. Some patients show symptoms of loss of visionloss duringchildhoodwhile some, whereas others live withoutdo not showany symptoms. until middle age.8Most casespatientspresent classicalwith classicsymptomsof difficulties with, such asnight blindness (nyctalopia) and9 difficulty in adaptingto darkness and night blindness (niatalopia nyctalopia)in oldage andold age as well asand10 loss of vision in early adolescence. Following theWith advanced disease progression, theypatientslose their distant peripheral vision, develop 11tunnel vision, and finally lose their central vision,which usually occurs at the agearound 60 years of sixty.12age.The reduction of RODin rod and CONE cone photoreceptors is similar amongin othertypes. of RP disorders.14 Sometimes,the decrease in CONEcones13 is greaterthan that in RODrods,which is then called cone-rodcone-rod15degeneration, a form of RP in which the lossof vision and defects in color vision are the predominant initial symptoms.