Ultrasound Sonography of Eyes
Ultrasound sonography is one of the oldest investigative tools used in the medical field. They also commonly go by the name ‘Video X-ray’ as it has a similar display as X-rays with black and white shadows. It is one of the most convenient tools that helps to visualize various layers of the eyeball in the form of echoes with black and white color.
What Is Ultrasound Sonography Of The Eye?
What Are the Indications of A-Scan (Amplitude Scan)?
The thought of an A-scan may trigger distress in someone as they may think of the transducers touching their naked eye. But as A-scan is done only after the eyes get anesthetized with anesthetic drops, patients feel minimal discomfort. A-scan gives information regarding the following features:
- Length of the eye
- Intraocular lens power
- Lens thickness
- Anterior chamber depth
By studying the characteristics of spikes generated during an A-scan, it helps plan cataract surgeries by giving estimates of correct lens implant and location of placement. It can also determine any internal tumor structures.
The concept of ultrasonography of the eye may horrify someone as they may think of the probe in the eyeball. This depends on what type of scan and what technique the examiner is using to conduct the test. The tear film is enough for effective acoustic transmission of ultrasound waves from the transducer to the eye. However, in some instances, like in ocular trauma or non-compliant patients, transducers can be placed over the eyelids with coupling jelly. It helps to glide the ultrasound probe or the transducer against the eyelid or the cornea.
What Are the Limitations of Ultrasonography of the Eye?
Although ultrasound sonography of the eye is an easy and convenient investigation, it has a few limitations. Some of them are as follows:
- Issues with patient compliance may cause corneal injuries post-procedure due to lack of sensation in the anesthetized eye
- May miss minute retinal detachments and small hemorrhages
- Ocular injuries or globe rupture may be further hampered
- Subjective examiner interpretation may result in an error
Ultrasound sonography of the eyes is a widely used tool to detect pathological eye conditions. There are two types of eye ultrasound, A-scan and B-scan. These two different types of ultrasound investigations have unique components and unique determinants to interpret the report. Eye ultrasonography is used not only as a diagnostic tool but also for monitoring post-operative patients.