➤ Some important tests like B-scan, Color Fundus, OCT, and its Reporting are discussed here.
👉B-Scan-:::⊙Brightness-Scan⊙
➤ The structures behind the lens are better visualized by the B-Scan ultra-biomicroscopy at 10 to 12 Mhz frequency.
➤ A normal B-scan Report shows hypoechoic(Black shadows) normal vitreous, optic nerve, optic disc, and hyper-echoic(White shadows) normal retina, choroid, and sclera.
➤ The B-scan uses ultrasound waves to produce echoes upon striking the interface between acoustically different structures.
➤ Mainly used in eyes having media opacities like corneal opacities, dense cataracts, dense vitreous hemorrhage to check the status of the retina, choroid, sclera, sclera, and other orbital structures.
➤ Along with A-Scan, it shows low to moderate or moderate to high spikes which confirms the evidence of abnormalities.
👉B-Scan-Reporting Formats:::⊙
(I). Normal Case👀
2. Observe the RNFL Thickness map and RNFL Deviation Map
3. Observe numbers are similar to the database.
6. The last part here is a 3.4 mm ring of RNFL and you have to check this part to make sure about the segmentation.
RNFL- Profile-Check::👆
(a). This is the B-Scan Ultrasonography of the Right eye(R.E) or Left eye(L.E).
(b). The anterior chamber(AC) is well visualized.
(c). It does not show any evidence of low-level echoes.
(d). The Lens is in a normal position.
(e). Echogenic Strands show that there is no evidence of vitreous hemorrhage or Retinal Detachment(RD), and Choroidal detachment.
(f). The optic nerve is well visualized.
(g). There is no evidence of foreign body(FB).
(h). The diagnosis shows
(II). Abnormal Case👀
(a). This is the B-Scan Ultrasonography of the Right eye(R.E) or Left eye(L.E).
(b). The anterior chamber(AC) is well visualized.
(c). It does not show any evidence of low-level echoes.
(d). The Lens is in a normal position or displaced or dislocated from the original position.
(e). Echogenic Strands moving with the movement of eye noted in the vitreous chamber of the Right eye(R.E) or Left eye(L.E) as shown below.👇
NOTE:-🙋
➤ The echogenic vitreous shows...
(1). Hemophthalmia- Bleeding into the vitreous or Vitreous Haemorrhage
(2). Degenerative changes
(3). Acute Vitritis
(4). Chronic Vitritis
(5). Pyogenic Vitreous like endophthalmitis, panophthalmitis
(6). Vitreous Haze( Chronic intermediate uveitis )
(7). Proliferative VitreoRetinopathy
(8). Asteroid Hyalosis
(9). Emulsified Silicone Oil
(10). Synchysis Scintillans
(11). Ocular trauma
(12). Choroidal Melanoma
(13). Retinoblastoma
(14). Foreign Body(FB)
(f). The optic nerve is well visualized or not well visualized.
(g). There is no evidence of foreign body(FB) or evidence of foreign body(FB).
(h). The probable diagnosis maybe .....
NOTE:-🙋
- Whatever an optometrist or an ophthalmic assistant(OA) diagnoses provisionally but final diagnosis is done by the ophthalmologist.
👉Color Funduscopy:::⊙
➤ Direct ophthalmoscope, Indirect ophthalmoscope, and color fundus photography are used to diagnose the Color fundus of the eye.
➤ Such as evaluation of the vascular integrity of the retina and choroid vessels, the integrity of the blood ocular barrier, Normal physiology of the retina and choroidal circulation, as well as disease process affecting the macula.
👉Color Fundus Photo Reporting Formats:⊙
1. This is the Color fundus photography of the Right eye(R.E) / Light eye(L.E).
2. It is showing that the media is hazy or clear.
3. The size of the disc is _________________.
4. The Shape of the disc is _______________.
5. The Color Reflex of the Fundal glow is _____________.
6. The Thickness of Neuro-Retinal-Rim(NRR) is Following [I>S>N>T-Rule].
7. The Cup to disc Ratio(CD-Ratio) is _______.
8. The Macula and Foveolar reflex(FR+) is_______.
9. The Blood Vessel Arrangement:-
- is it tortuosity?
- is it irregularities?
- is there any small hemorrhages or bleeding of vessels?
- is there any changes in the vessel wall?
- is there any presence of Aneurism?
- is there any Neovascularization or Proliferation?
10. Exudates:-Soft or Hard Exudates and their place of location
- The place of location may be Nasal or Temporal or near to macula or near to optic disc.
- _________ Exudates located near to _________.
11. Hemorhhages - Place or Location
- It can be present anywhere so mention the exact location.
- like Sphincter hemorrhage.
- Pinpoint hemorrhage or Dot and Blot hemorrhages.
- Flame-shaped hemorrhage
12. The probable diagnosis of this Fundus examination is____________.
13. The diagnosis is confirmed by the eye specialist doctor with their signature remark.
👉Ocular Coherence Tomography(OCT):::⊙
➤ OCT is a non-invasive diagnostic imaging technique and provides cross-sectional histopathology of the different layers of the retina.
➤ It uses lightwave and displays different layers of the retina by different color coding(Red, Red-yellow, Bluish-Black).
➤ OCT representation can be color scale, grayscale, and inverted scale.
➤ The best OCT Scan Signal quality or strength should also take into consideration.
➤ For example:
- In CIRRUS OCT:- Good signal consider > 6
- In RTVUE(OPTOVUE):- Good signal consider > 30
➤ There are different types of OCT and the purpose of usage is also different. During reporting, it should be mentioned in the reporting Format.
- Various OCT instruments are available such as HEIDELBERG, NADIK, OPTOVUE, TOPCON, ZEISS.
- The different generation OCT are TD-OCT and SD-OCT.
👉OCT Report Analysis:⊙
➤ Which generation OCT should be checked first.
A. Macular Thickness-Analysis
- There should be Four questions(4) always kept in mind before reporting of OCT-analysis.
1. How does the vitreoretinal(VR) interface appear?
2. What is the shape of the Foveal contour?
3. Is inner retinal architecture altered?
4. Outer RPE layer disrupted or not?
- The diagnosis is done based on above basic results.
B. RNFL and ONH-Analysis
[a].TD-OCT:👉
➤ In time-domain OCT 3.4mm diameter circle with 256 A-Scan in the circle(speed:400A-scan/sec, R-10 microns) is applied.
1. RNFL:-
- The Thickness measurement data of retinal nerve fiber(RNFL) shown in the OCT-Report print starts from Temporal to superior, superior to nasal, nasal to inferior, and back to temporal. ( Starting from temporal and ending in temporal )
2. ONH-Analysis:-
- The optic nerve head scan is composed of six-linear scans in a spoke pattern separated by 30-degree intervals centered on the ONH.
[b].SD-OCT-RNFL and ONH Optic disc-ANALYSIS:👉
1. First check the signal quality and report.
- If the numbers are similar to the database, it will be in gray but if it is away it will be in yellow or red.
4. Yellow means it is found in five percent(5%) of the population only and red means it is found in one percent of the population.
- The machine algorithm determines the termination of Bruch's membrane as the disc edge.
- Then locate the center of the area and draw a circle of 3.4mm and starts to calculate the thickness of the retinal nerve fiber layer(RNFL) along with this surface.
5. Check the extracted horizontal tomogram and vertical tomogram:- it helps incorrectly estimate the amount of neuroretinal rim(NRR) form Minimum Bruch's membrane origin(BMO) and Minimum rim area(MRA).
➤ The profile from the 2 eyes is very similar or not, symmetric or not.
➤ Check the double hump appearance of the nerve fiber layer. It is more in the Superior and inferior parts.
➤ Then check the ISNT rule:- is it followed or not.
USEFUL-LINK👇
