Biometry-2 | Measurement of Axial length | Smart Optometry
37.1 هزار بار بازدید -
5 سال پیش
-
AXIAL LENGTH: Axial length is
AXIAL LENGTH: Axial length is the distance between anterior and posterior pole of eyeball
At birth 17 mm
In adult 24 mm
In myopia more than 24 mm
In hyperopia less than 24 mm
METHODS: There are two methods
A. Ultrasonic
B. Optical
ULTRASONIC METHOD:
i. It contain a 10MHz solid probe with inbuilt fixation
ii. It has to be aligned with optical axis of the eye for accurate measurement
iii. This can be done in two technique :
A. Immersion technique
B. Contact technique
1. IMMERSION TECHNIQUE:
--------Patient lie in supine position looking a fixation at the ceiling
--------A scleral shell is applied to the eye filled with 1% OR 2% Methylcellulose
--------Probe is Immersed in the solution keeping 5-10 mm away from the cornea
--------Probe is gently moved intil properly aligned with optical axis
--------Echo spike will displayed in the monitor.
ECHO SPIKES ARE:-
--- IS = INITIAL SPIKE PRODUCED BY PROBE
--- C1 = ANTERIOR CORNEAL SPIKE
--- C2 = POSTERIOR CORNEAL SPIKE
--- L1 = ANTERIOR LENS SPIKE
--- L2 = POSTERIOR LENS SPIKE
--- R = RETINAL SPIKE
--- S = SCLERAL SPIKE
--- O = ORBITAL SPIKE
2. CONTACT TECHNIQUE:
i. Alternative to immersion technique doesn’t use scleral shell
ii. Probe directly contact with cornea
iii. These can be done in two methods:
1. Hand held
2. Attaching with slit lamp or applanation tonometer
PROCEDURE:
------ Patients seated after applying local anesthetic drop
------ Asked to fixed a target straight with non-testing eye
------ Probe is properly aligned along with visual axis & brought forward to touch the cornea
------ Five spike will be displayed on the screen.
ECHO SPIKES ARE:
--- C = POSTERIOR COrNEAL SPIKE
--- A = ANTERIOR LENS SPIKE
--- P = POSTERIOR LENS SPIKE
--- R = RETINAL SPIKE
--- S = SCLERAL SPIKE
B.. OPTICAL TECHNIQUE:
i. Use partial coherence laser
ii. Biometer measure the time required for infrared light to travel to retina
iii. This technique doesn’t have contact with cornea, so corneal compression
artifacts are eliminated.
FOR DETAILS NOTE;
VISIT OUR WEBSITE: https://www.smartopto.blogspot.com
--------------------------------------------------------------------------------------------------------------------
Binocular Subjective Refraction:
Part-1: Binocular Subjective refraction- Intr...
Part-2: Septum Method - Turville Infinity Bin...
Part -3: Polarization Method - Polarized Targe...
Part -4: Fogging Method - Binocular Subjective...
Part-5: Steps of Binocular Subjective Refract...
Biometry:
Part-1: Introduction Of Biometry | Smart Opto...
Paet-2: Biometry-2 | Measurement of Axial len...
Part-3 Biometry-3 | Measurement of Corneal ...
Optical Coherence Topography:
Full: Optical Coherence Tomography - OCT (F...
Part-1: Optical Coherence Tomography - OCT | ...
Part-2: Optical Coherence Tomography - OCT | ...
Dry Eye:
Part-1: Dry Eye - Introduction and Mechanism ...
Part -2: Dry Eye - Classification and Cause (w...
Part -3: Dry Eye - Clinical Features and Inves...
Part -4: Dry Eye – Treatment (within 4:30 mins...
Part -5: Tear Film Break-up Time Test (Within ...
Part- 6: Schirmer test - Dry Eye within 2:30 min
Full: Dry Eye - Full Tutorial
Myopia
Part-1: Myopia - Introduction and Etiology (w...
Part-2: dvrkegdkxq
Part-3: Myopia - Clinical Picture (within 3:3...
Part -4: Myopia - Ocular examination or Invest...
Part -5: Myopia - Management or Treatment 5/5
At birth 17 mm
In adult 24 mm
In myopia more than 24 mm
In hyperopia less than 24 mm
METHODS: There are two methods
A. Ultrasonic
B. Optical
ULTRASONIC METHOD:
i. It contain a 10MHz solid probe with inbuilt fixation
ii. It has to be aligned with optical axis of the eye for accurate measurement
iii. This can be done in two technique :
A. Immersion technique
B. Contact technique
1. IMMERSION TECHNIQUE:
--------Patient lie in supine position looking a fixation at the ceiling
--------A scleral shell is applied to the eye filled with 1% OR 2% Methylcellulose
--------Probe is Immersed in the solution keeping 5-10 mm away from the cornea
--------Probe is gently moved intil properly aligned with optical axis
--------Echo spike will displayed in the monitor.
ECHO SPIKES ARE:-
--- IS = INITIAL SPIKE PRODUCED BY PROBE
--- C1 = ANTERIOR CORNEAL SPIKE
--- C2 = POSTERIOR CORNEAL SPIKE
--- L1 = ANTERIOR LENS SPIKE
--- L2 = POSTERIOR LENS SPIKE
--- R = RETINAL SPIKE
--- S = SCLERAL SPIKE
--- O = ORBITAL SPIKE
2. CONTACT TECHNIQUE:
i. Alternative to immersion technique doesn’t use scleral shell
ii. Probe directly contact with cornea
iii. These can be done in two methods:
1. Hand held
2. Attaching with slit lamp or applanation tonometer
PROCEDURE:
------ Patients seated after applying local anesthetic drop
------ Asked to fixed a target straight with non-testing eye
------ Probe is properly aligned along with visual axis & brought forward to touch the cornea
------ Five spike will be displayed on the screen.
ECHO SPIKES ARE:
--- C = POSTERIOR COrNEAL SPIKE
--- A = ANTERIOR LENS SPIKE
--- P = POSTERIOR LENS SPIKE
--- R = RETINAL SPIKE
--- S = SCLERAL SPIKE
B.. OPTICAL TECHNIQUE:
i. Use partial coherence laser
ii. Biometer measure the time required for infrared light to travel to retina
iii. This technique doesn’t have contact with cornea, so corneal compression
artifacts are eliminated.
FOR DETAILS NOTE;
VISIT OUR WEBSITE: https://www.smartopto.blogspot.com
--------------------------------------------------------------------------------------------------------------------
Binocular Subjective Refraction:
Part-1: Binocular Subjective refraction- Intr...
Part-2: Septum Method - Turville Infinity Bin...
Part -3: Polarization Method - Polarized Targe...
Part -4: Fogging Method - Binocular Subjective...
Part-5: Steps of Binocular Subjective Refract...
Biometry:
Part-1: Introduction Of Biometry | Smart Opto...
Paet-2: Biometry-2 | Measurement of Axial len...
Part-3 Biometry-3 | Measurement of Corneal ...
Optical Coherence Topography:
Full: Optical Coherence Tomography - OCT (F...
Part-1: Optical Coherence Tomography - OCT | ...
Part-2: Optical Coherence Tomography - OCT | ...
Dry Eye:
Part-1: Dry Eye - Introduction and Mechanism ...
Part -2: Dry Eye - Classification and Cause (w...
Part -3: Dry Eye - Clinical Features and Inves...
Part -4: Dry Eye – Treatment (within 4:30 mins...
Part -5: Tear Film Break-up Time Test (Within ...
Part- 6: Schirmer test - Dry Eye within 2:30 min
Full: Dry Eye - Full Tutorial
Myopia
Part-1: Myopia - Introduction and Etiology (w...
Part-2: dvrkegdkxq
Part-3: Myopia - Clinical Picture (within 3:3...
Part -4: Myopia - Ocular examination or Invest...
Part -5: Myopia - Management or Treatment 5/5
5 سال پیش
در تاریخ 1398/07/26 منتشر شده
است.
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