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Peng Xi Feng
Ophthalmology
About me
Shenzhen Longgang Central Hospital, Ophthalmology Deputy Chief Physician.
Proficient in diseases
Familiar with the diagnosis of various common eye diseases such as cataracts, glaucoma, eye trauma, and ocular surface diseases, skilled in eye fluorescein angiography, electrophysiology, eye A/B ultrasound and other examinations.
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What is the difference between refractive error and nearsightedness?
Myopia is a type of refractive error, which refers to the condition where, when the eye is not adjusting, parallel light rays after passing through the refractive action of the eye, do not form a clear image on the retina, but rather image in front of or behind the retina. This includes hyperopia, myopia, and astigmatism. When parallel light rays image in front of the retina after passing through the eye's refractive action, it is called myopia.
The main cause of myopia formation
Myopia is primarily caused by the focusing system of the eyeball focusing parallel light rays in front of the retina when our eyes are in a relaxed adjustment state. The far point of a myopic eye is at a certain point in front of the eye. The occurrence of myopia is influenced by a combination of factors including genetics and environment, and the incidence is still being explored. Based on the refractive components, myopia can be classified into refractive myopia and axial myopia. According to the degree of myopia, it can be classified into mild myopia (below 300 degrees), moderate myopia (300 to 600 degrees), and high myopia (above 600 degrees). The clinical manifestations of myopia include blurry distance vision but good near vision, often with fluctuating distance vision where squinting is needed to see clearly at a distance.
Cataracts are a condition of the eye.
Cataracts are degenerative changes causing a decline in optical quality, which are due to the decreased transparency or color change of a structure in the eye called the lens. The pathogenesis of cataracts is quite complex, resulting from the long-term combined effects of various internal and external factors on the lens. The lens is situated in the fluid environment of the eye, and any factor impacting this environment, such as aging, genetics, metabolic abnormalities, trauma, radiation, poisoning, localized nutritional disorders, as well as certain systemic metabolic or immune diseases, can directly or indirectly damage the tissue structure of the lens, interfere with its normal metabolism, and cause the lens to become opaque.
What department should I go to for cataracts?
The department for cataract consultations is ophthalmology. Various factors such as aging, genetics, local nutritional disorders, immune and metabolic abnormalities, trauma, poisoning, radiation, etc., can cause metabolic disturbances in the lens, leading to the denaturation of lens proteins and resulting in opacity, known as cataracts. At this time, light is obstructed by the cloudy lens and cannot be projected onto the retina, causing blurred vision. This condition is commonly seen in individuals over forty years old, and the incidence increases with age. The disease can also be divided into congenital cataracts and acquired cataracts.
What are the symptoms of a glaucoma attack?
Typical acute angle-closure glaucoma has several different clinical stages, divided into the preclinical stage, prodromal stage, acute attack stage, intermittent stage, chronic stage, and absolute stage. The acute attack stage is mainly characterized by severe headache, eye pain, photophobia, tearing, and significant deterioration of vision, often reduced to counting fingers or hand motion, and may be accompanied by systemic symptoms such as nausea and vomiting. Physical signs include eyelid edema, mixed congestion, corneal epithelial edema, and the appearance of small droplets under the slit lamp. Patients may complain of rainbow vision, which primarily occurs due to the large number of small vesicles in the swollen corneal epithelium and the spaces between epithelial cells.
The main symptoms of cataracts
The main symptoms of cataracts include: First, a decline in vision, which is the most obvious and significant symptom of cataracts. Second, a decrease in contrast sensitivity, particularly noticeable at high spatial frequencies in cataract patients. Third, changes in refractive power. Nuclear cataracts lead to increased lens power due to an increase in the lens and refractive index, causing nuclear myopia. Fourth, monocular diplopia or polyopia due to uneven refractive power across different parts of the lens, similar to the effect of a prism, resulting in monocular diplopia or polyopia. Fifth, glare. Sixth, changes in color perception. Seventh, varying degrees of visual field defects.
Cataract is what?
All sorts of reasons, such as aging, genetics, local nutritional disorders, immune and metabolic abnormalities, trauma, poisoning, radiation, etc., can cause metabolic disorders in the lens, leading to the denaturation of the lens proteins and resulting in opacity known as cataract. At this point, the light is obstructed by the opaque lens and cannot be projected onto the retina, causing blurred vision. It is commonly seen in people over the age of forty, and the incidence increases with age. This disease can be divided into congenital cataracts and acquired cataracts. Congenital cataracts are also known as developmental cataracts, and there are six types of acquired cataracts.
How is trachoma transmitted?
Trachoma is somewhat contagious. When it is confirmed as trachoma, the eyelids and the conjunctiva of the eyes will carry the bacterium due to Chlamydia infection. When patients touch their eyes with their hands, their fingers or palms are already carrying the bacteria, including Chlamydia. Therefore, when they come into contact with others, cross-infection can occur. Prevention of trachoma primarily involves avoiding contact infection, improving environmental hygiene, enhancing the sanitary management of service industries such as hotels, swimming pools, and barber shops, and developing good hygiene habits, including avoiding rubbing the eyes with hands.
Causes of Retinal Detachment
Retinal detachment can be categorized into three main types: rhegmatogenous, tractional, and exudative. Rhegmatogenous retinal detachment is commonly seen in the elderly, highly myopic individuals, those having undergone trauma to the eye leading to the absence of the natural lens or having artificial lens implants, and those with a history of retinal detachment or a family history of the condition, which are risk factors. Tractional retinal detachment is caused by proliferative membranes pulling on the retina. It is observed in conditions like diabetic retinopathy, central retinal vein occlusion, and other ischemic retinal diseases leading to neovascular membranes, or due to proliferative scarring from penetrating eye injuries. Exudative retinal detachment typically occurs in conditions such as Coat’s disease, uveitis, and malignant hypertension.
Does conjunctivitis require injections?
Conjunctivitis generally does not require injections. Treatment is based on the cause, primarily with local medication, and systemic medication is used only when necessary. During the acute phase, avoid bandaging the affected eye. First, using eye drops is the most basic way to administer treatment for conjunctivitis. Second, apply eye ointment, preferably before going to sleep. Third, rinse the conjunctival sac. Fourth, for severe conjunctivitis, such as gonococcal conjunctivitis, in addition to local treatment, systemic antibiotics are also necessary.