Скачать или смотреть NEET PG-Lasers In Ophthalmology-Ophthalmology

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In this we will be learning most important lasers in ophthalmology from exam point of view.
The questions they as in exam from lasers will be of 4 kinds.
Name of the laser
Their wavelength
Type of tissue interaction
Their applications(where its used)
Ophthalmology Is the first department to use laser energy in patient treatment.
Important Laser tissue interactions:
We will study three important types of tissue interactions of laser.
1.Photocoagulation (two types of lasers),
2.photoablation (excimer laser using argon floride used in refractive surgeries),
3.photodisruption (2 lasers)
Wherever wavelength is given, it is very important to memorise the wavelengths, as they have been asked many times in exams.
And the name of the laser+ wavelength and the application( where they are used).
We will study each one in detail in the coming slides(we will learn 5 different lasers with three different principles)
Principle of Photocoagulation: Laser is absorbed by the tissue & is converted to heat, raising the temperature.
It destroys the tissue either by necrotising the tissue, or by destroying the tissue, vaporizing, coagulation.
So, The laser light is primarily absorbed by Melanin in Retinal Pigment Epithelium, Choroid and Hemoglobin.
So, when the photocoagulation of retina is done, the neuro sensory layer of retina is not much destroyed because the absorption is primarily by the retinal pigment epithelium.
Retinal laser photocoagulation is a minimally invasive procedure used to seal or destroy leaking blood vessels in the retina that lead to serious retinal conditions such as diabetic retinopathy and macular edema. This procedure can also seal retinal tears and destroy abnormal tissue found in the back of the eye
Three principles to reduce the IOP in Open angle glaucoma is
Drugs – to force drain the aqueous humour by trabecular meshwork
If drugs doesn’t work go for ALT.
If ALT doesn’t work go for trabeculectomy.
Refractive surgery is done to get rid of glasses.
Argon fluoride of 193nm wavelength is used for refractive surgeries/ lasik (important question)
Capsulotomy – When you have cataract surgery, your ophthalmologist removes your eye's cloudy lens. They replace it with a clear, artificial intraocular lens (IOL). The IOL is held in place in the eye’s natural lens capsule. Weeks, months or years later, this capsule can become cloudy or wrinkled, causing blurry vision. This is called a posterior capsule opacification (PCO). It’s also sometimes called a "secondary cataract" or "scar tissue." With posterior capsulotomy, a laser Nd YAG laser (1064 nm) is used to make an opening in the cloudy capsule. This allows light to pass through again for clear vision.
When there is increase in the intra ocular pressure in the eye due to blockage in the aqueous humor flow because of the closed angle in the angle closure glaucoma, Nd yag laser (1064 nm) is used for laser iridotomy.
It creates small holes in the iris for the aqueous humor to flow and there by decreasing IOP.
The laser automates the circular internal incision made during cataract lens removal (capsulorehexis), in other words a circular incision which is very difficult to do it manually….Femto second laser(1053nm) is used in flacs to get that perfect circular incision.

On the whole we learnt five important lasers with three different techniques.