types of Optometry Practices & the Role of OCTMark Braddon14.09.20227 min. read
Various types of optometry practices have always played a crucial role in diagnosing many eye diseases and promptly referring to a retinal expert. According to Essilor International research, poor vision is the most common disability in the world today. The good news is that 90% of vision loss cases are treatable or preventable if discovered in their early stages.
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However, by performing only traditional types of optometry practices, such as anterior and posterior segment examinations, optometrists may miss the complete picture of a patient’s eyes. That is why optometry specialists are embracing a new technique: optical coherence tomography (OCT) examination.Optometry OCT practice helps go beyond standard eye examination procedure by better visualizing the eye’s structures and providing an additional quantitative assessment.
In this article, I will discuss the most important types of optometry practices and emphasize the role of OCT scan interpretation in optometry.
Types of optometry practices
When performing a full optometric examination, the optometrist should not only assess the visual acuity with an eye chart but also check their eye health. The types of optometry practices and tools are now very diverse and depend on the application field and the qualification level. Nowadays, there are a few eye examination techniques, although they may vary from country to country, that help diagnose a patient more accurately and improve follow-up care.
Ophthalmoscope eye examination
Ophthalmoscopy plays a crucial role in detecting the conditions of the retina, blood vessels, and optic disc. This is a basic eye examination procedure that optometrists usually perform to evaluate many diseases, such as diabetic retinopathy or retinal vein occlusion.
During the direct ophthalmoscopy, the optometrist shines a light into the patient’s eyes to see the inside. Binocular indirect ophthalmoscopy also involves shining a light into the patient’s eyes, however, it allows eye care specialists to take a better look at the retina and its parts that are difficult to see with other eye examination techniques. The indirect ophthalmoscopy is usually combined with pupil dilation and another optometry practice called scleral depression.
Slit lamp optometric examination
A slit lamp consists of a microscope, light source, and frame on which a patient lies their head. This regular eye examination procedure lets an optometrist focus on the eye by working with the light: expand or narrow it, increase brightness, and filter with colors. Sometimes the procedure also includes putting a few dye drops in a patient’s eye to examine some of its parts.
Slit lamp examination is pain-free and allows an optometrist to view the sclera, iris, or cornea to detect diseases related to allergies, autoimmune disorders, gout, or even melanoma. Such eye examination procedure also allows to view the retina of the eye to detect the pathological signs of diabetes. Optometrists usually use a slit lamp along with an ophthalmoscope examination.
Refraction eye examination procedure
One more type of types of optometry practices is a refraction test, usually performed to detect if a patient needs glasses or contact lenses. This test made with a phoropter is quick and painless. During the optometric examination, the optometrist adjusts the power of the lenses by moving or turning them back and forth until a patient can clearly see the letters on the chart.
An optimal value of 20/20 is considered ideal vision, while a deviation means a refractive error. This may indicate that when light passes through the lens of the patient’s eye, it is not refracted properly. An optometrist can detect astigmatism, myopia, presbyopia, and a refractive eye problem during a refraction test. This, in turn, helps detect macular degeneration, retinal vein occlusion, retinitis pigmentosa, and retinal detachment.
Sometimes the optometrist may decide that the normal refraction is insufficient or inaccurate due to error. During refraction, the patient may unconsciously focus, affecting the test result and showing nearsightedness or farsightedness.
Then the optometrist performs cycloplegic refraction using cycloplegic eye drops. This eye examination procedure paralyzes the muscles that focus the eye to determine the refractive error. Сycloplegic refraction exam is especially useful for children, patients with pre-presbyopia, and LASIK patients.
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Autorefraction is an eye examination procedure performed using a special autorefractor device, also called an optometer. This exam automates the estimation of refraction and determines its error. Usually, the indications for the procedure are myopia, farsightedness, astigmatism, presbyopia, and prescription of glasses and contact lenses.
Retinoscopy optometric examination
Among different types of optometry practices usually performed to detect farsighted, nearsighted, or astigmatism, and the need for glasses is retinoscopy. This procedure is pain-free and quick. Using a retinoscope, the optometrist projects a beam of light into the patient’s eye. This light moves along a horizontal and vertical trajectory, reflecting off the back of the eye. The eye care practitioner observes the movement of light with the help of lenses they place in front of the eye. Then the optometrist changes the lens’s power and tracks the reflection’s direction and pattern. This test is performed to find a possible anomaly.
Role of optometry OCT practice
The types of optometry eye examination techniques described above are fundamental for any diagnosis. However, adopting modern optometry OCT practice systems already complements clinical practice perfectly and has the prospect of widespread distribution among optometrists worldwide.
Knowing that the prevalence of some eye conditions, such as Myopia or Dry AMD, has increased with the pandemic, specialists need to implement modern methods and eye examination techniques in their clinical practice. Current optical coherence tomography devices allow optometrists to perform consistent analysis and furthermore have special software and a database for storing patient information. Compared to other retinal examination methods, such as fundus photography, OCT scan interpretation enhances patient care by improving the quality of diagnosis.
High-quality information provided
Modern optometry OCT diagnostics allow optometrists to quickly obtain a huge amount of information about the patient’s eye. Built-in software collects images and compares results to normative databases. This allows optometrists to easily track patient progress or regression and generate reports that ophthalmologists or surgeons may need for follow-up treatment.
For example, suppose a patient has a disorder with the optic nerve, macula, or vascular system. In that case, the optometrist can send data to the ophthalmologist promptly, highlight important aspects of the patient’s condition, and provide abnormal OCT scan results for additional clarity.
No missed pathologies
Optometry OCT practice provides higher diagnostic standards, ensuring fewer pathologies or pathological signs are missed. OCT scan interpretation helps detect early vision-threatening eye conditions. For example, the system can detect AMD in the early stages, which is crucial for preventing vision loss due to subretinal fibrosis. With optometry OCT practice, the thickness of the retina over the macula and posterior pole can be analyzed to detect retinal edema or atrophy. Optometrists can also confirm diabetic macular edema (DME) and decide on further treatment based on the results of its examination. In addition, OCT perfectly visualizes the retinal pigment epithelium (RPE) and choroid.
More patients served with comfort
By better visualization of the eye structures, optometrists provide each patient with an individual approach. This level of service ensures comfort for patients and trust for a specialist. Optometry OCT practice allows optometrists to avoid routine work and devote more time and energy to patients. More importantly, the OCT scan interpretation helps establish contact, allowing patients to understand the examination and treatment plan.
Impact of AI on optometry OCT practice
OCT scanning allows optometrists to accumulate large amounts of patient data. However, a large amount of information can be difficult and time-consuming to process, even for experienced specialists. The collaboration of optometry OCT practice and artificial intelligence (AI) gives optometrists a unique opportunity to analyze a large amount of data and make better clinical decisions. Here are 4 key benefits of AI which completely transform the OCT scan interpretation process for optometrists:
- Gaining confidence. 16.3% of interviewed eye care practitioners still avoid using OCT in their daily practice because of the lack of confidence in their interpretation skills. However, with AI, this problem will be solved.
- Fast examination. Implementing AI-powered management systems in daily clinical practice reduces the time optometrists have to spend on non-pathological scans.
- Clear diagnosis. 59% of specialists acknowledge that they have to interpret controversial scans around 1-3 times a week. AI helps optometrists with controversial and abnormal OCT scans, so they don’t need to guess the diagnosis.
- High diagnostic standards. 30,5% of interviewed ECPs admit they are unsure how often they miss pathologies. When working with OCT, AI systems ensure no minor, early, rare pathologies are missed.
OCT scanning allows specialists to easily, quickly, and safely obtain many images, producing a lot of data. As AI aims to work with large volumes of data, more and more AI models are being created to help optometrists.
Altris AI has developed an artificial intelligence platform to assist ECPs during their optometric examination and already plays a significant role in diagnosing and treating eye diseases using optometry OCT techniques. We have trained an AI algorithm on 5 million OCT scans collected in 11 ophthalmic clinics with a 91% accuracy. Watch a short video to see how to detect pathological signs with Altris AI:
Future of optometry oct practices
The integration of OCT into the clinical practice of optometrists is beneficial and shows great promise. However, to gain the most accurate diagnosis, the interpretation of scans should be carried out in cooperation with other optometry eye examination tools. Optical coherence tomography implemented with other eye examination techniques, including gonioscopy or slit lamp biomicroscopy, boosts diagnostic performance and provides valuable data.
Optometry oct practices are becoming routine for providing improved examination and patient care. This technology can also improve the confidence of eye care specialists. Detecting many pathologies using optical coherence tomography has an immediate practical benefit. Due to its high resolution, it defines and identifies early pathological signs before patients even notice any symptoms.
Top 11 Optometry & Ophthalmology Mobile Apps for Eye Care SpecialistsMaria Znamenska15.08.202210 min. read
Today, there are hundreds of ophthalmology mobile apps available to both experienced eye care specialists and beginners. Some of them assist in learning and practice as clinical tools, and some of them are educational apps for opticians. Some mobile applications are basically a database of useful materials, ophthalmic atlases, so to say.
FDA approved AI that detects 70 retina pathologies
In this post, I will focus on educational ophthalmology and optometry apps and highlight their main features and functions.
Altris Education OCT
Altris Education OCT is a unique free ophthalmology mobile app that contains millions of OCT scans labeled by a team of retina experts. More than 9000 eye care specialists have already joined the application.
The app is interactive, which means that eye care specialists can highlight pathological signs on the scan 1 by 1 to learn about their location. The database of OCT scans is updated every day with a new labeled OCT scan, so users can gather their library right within the app.
Watch a short video and learn how to interpret scans with Altris Education OCT ophthalmology mobile app:
Interactive eye atlas
The home page of the Altris Education OCT ophthalmology mobile app consists of 4 sections:
- In the Feed section, users will find millions of OCT scans of the retina to practice and improve their skills.
- In the Folders sections, there are 41 folders with various hereditary diseases, pathologies, and pathological signs. If an eye care specialist uploads the app for a specific reason, for example, to learn how to detect Epiretinal Fibrosis, he/she can easily find a folder with needed scans and work on them.
- In the News section, users can find recent news from the OCT world and current researches.
- In the Community section, a user can create a post and discuss curious cases with their colleagues.
A team of Altirs Education OCT has the aim to build a real community of ophthalmologists and optometrists worldwide who share their passion for learning. Most eye care specialists often face difficulty while interpreting OCT scans in their everyday clinical practice. We created a community where each app user can discuss problematic scans or ask OCT-related questions ( what OCT equipment to choose?).
Moreover, the Altris team will engage experienced OCT experts in the forums to give a professional assessment of the scans.
In addition, the Altris ophthalmology mobile app allows its users to like, comment and share OCT scans, as well as save them in a personal library.
In Altis ophthalmology mobile app, each pathological sign is highlighted with a different color so eye care specialists can easily learn how to interpret OCT scans. Each scan contains two tabs: pathologies and diagnosis, so users are able to highlight the pathologies in the first place and then guess the diagnosis. To check himself/herself, a user switches to the diagnosis tab and finds out the name of the disease. What is more, he/she can zoom in on OCT scans to view pathological signs in detail.
FDA approved AI that detects 70 retina pathologies
Altris ophthalmology mobile app not only provides its users with a huge database of educational materials. It also engages eye care specialists to invite friends, gain budges and upgrade their level. To reach the next level, there are tasks like “Search your first scan” or “Learn 5 scans in detail”. When a user level up, he/she gets access to new folders with pathological scans.
Another great feature of the app is that it constantly sends its users an unfamiliar OCT scan, so they can explore something new on a daily basis. The basic functionality of the app is completely free. However, ophthalmologists and optometrists can also become Pro users of Altris Education OCT and unlock more scans and app features for $4 monthly or $25 annually.
Please upload this FREE app if you are interested:
Being on the market since 2010, Eye Handbook is well known and loved by many ophthalmologists and optometrists. Eye Handbook is used worldwide for both diagnosis and treatment, as the app provides eye care professionals with tools for acuity testing, children’s target fixation, or color vision testing. Now let’s take a closer look at the app’s functionality.
The overview of diseases in the mobile ophthalmology app begins with the Eye Atlas tab, which is a database of various pathologies arranged in alphabetical order. The description of each disease is accompanied by fundus photos, OCT images, or fluorescein angiography. Users can sort pathologies by category choosing, for example, retinal diseases, glaucoma, or oculoplastics.
Moreover, with the Eye Handbook ophthalmology mobile app, users can view videos of ophthalmic surgeries, such as posterior polar cataract surgery, and many more. Users are also able to sort videos by most relevant or ranked. In addition to videos, the application provides ophthalmologists and optometrists with access to audio materials, flash cards, and slides.
The Eye Handbook mobile ophthalmology app has a forum with topics open for discussion. Users can become a part of the community, add their posts, choose the appropriate category and invite like-minded eye care specialists to discuss the latest news in the field of ophthalmology.
The Eye Handbook is a very useful application not only for ophthalmologists but also for optometrists. Not to mention a bunch of study materials, the application has collected a large number of vision tests such as Amsler grids, duo-chrome test, OKN drum, and a lot more.
The ophthalmology mobile app contains a variety of calculators, like the Glaucoma risk calculator, which eye care specialists can use in their clinical practice right from their smartphones. Eye Handbook gathered even coding, like ICD-10 or CPT. In the app, they are also able to find detailed information about ophthalmic meds, check the EHB manual, and get access to a constantly updating news feed.
Eye Emergency Manual
Eye Emergency Manual mobile ophthalmology app is a great emergency aid because it quickly provides basic information about eye diseases. The application has several features, which I will explain in more detail below.
This mobile ophthalmology app provides structured and detailed information about many eye traumas and treatments. Users can find fundus photos, photographs of real people’s eyes, or scans of each trauma and read about their initial treatment. In some cases, the developers even created Eye Trauma Communication Checklists to help eye care specialists come to a medical conclusion many times faster.
The Eye Emergency Manual app also contains a database of acute red eye or eyelid cases. All the information is presented clearly and plainly.
Each pathology overview can be saved so the app users can later explore their favorite pages or favorite glossary terms. The app also provides eye care professionals with the ability to search for a needed term, pathology, or assessment.
One of the unique features of the Eye Emergency Manual app is a variety of checklists, both for a certain pathology or a patient in general. In the app, users can find a comprehensive list of questions to ask their patients, which is useful both for ophthalmologists and optometrists. Eye Manual also contains pediatric assessment and injured patient assessment.
What is more, the app developers created a diagnostic tree that is aimed to help users by suggesting diagnoses. After answering a few questions, the app showcases a few diseases and suggests reading about them in the eye atlas.
One of the main differences between the OCTaVIA mobile ophthalmology app and other apps is the fact that it isn’t free. Some other apps for opticians, which I mention in this article, have a paid subscription, but OCTaVIA itself costs $5.99 yearly. However, it is interesting to explore how this price is justified.
This ophthalmology app contains a constantly updated database of diseases from A to Z. Needless to mention that the application covers only retinal pathologies and provides information about retinal diseases, from Chorioretinal scars to VMT (Vitreo-Macular Traction).
One of the advantages of the OCTaVIA mobile ophthalmology app is that for each pathology it provides two views — fundus photo and OCT scan. They may be colored or not, but each fundus photo and OCT scan contains markers, which are explained in the text. What is curious, there are always a few useful links, so users can discover more trustworthy information about the disease.
Atlas of Ophthalmology Onjoph
The Atlas of Ophthalmology Onjoph app offers a clinical picture for almost all eye diagnoses. It includes more than 6,000 pathologies, from glaucoma to macular degeneration, and even includes such rare diseases as Stargardt syndrome. The image database is constantly being expanded and updated to include other eye diseases.
Using the search function, eye care specialists can find specific clinical pictures and display them in lists based on diagnoses, ICD-10 code, or keywords. In the Atlas of Ophthalmology Onjoph, users will also find:
- accompanying diagnosis;
- code according to ICD-10;
- brief comment.
Atlas users can also change the font size, save essential images, or forward images by email.
The mobile ophthalmology app has a clear structure for all images. All pathological cases are arranged according to eye regions (conjunctiva, cornea, retina, lens, etc.). Within the eye area, the images are listed according to the type of disease (degeneration, inflammation, tumors, etc.).
The mobile application also allows its users to save their favorite articles in the Favorites folder, but this feature is paid and has two types of subscription:
- $3.99 for a Silver plan
- $29.99 for a Gold plan
Other ophthalmology & optometry apps tools worth mentioning
In case an eye care specialist needs a topic-oriented mobile ophthalmology app, they may check Ophthalmology Guide. Its users are allowed to choose the desired topic and find out the key characteristics of pathologies. In addition, they can also find several fundus photos, scans, and pathology charts.
Unfortunately, I can’t say that the Ophthalmology Guide app is user-friendly. It contains a few bugs and lacks some additional options, like eye atlases or lectures.
However, the app is promising thanks to the clear categorization of topics, it can be very convenient for ophthalmologists and optometrists to quickly find specific information about examination and management of the pathology.
Easy Ophthalmology Atlas
Easy Ophthalmology Atlas is one of those ophthalmology and optometry apps that are also worth mentioning. It is an offline color atlas of the most common eye diseases. The app contains 13 chapters, where users can find clinical features, diagnosis, and treatment management for different pathologies.
Easy Ophthalmology Atlas lacks quite a lot of features compared to other ophthalmologist tools on the list.
However, this mobile ophthalmology app has the potential to replace the heavy paper versions of the ophthalmology guides if the information is updated regularly in it.
Ophthalmology & Optometry Guide
Another representative of ophthalmology and optometry apps was created to assist students in learning the clinical signs, symptoms, and complications of different pathologies. It provides users with basic knowledge of eye diseases and pathologies, their causes, and treatment.
Ophthalmology & Optometry Guide has up to 18 sections, each stands for a specific eye region (conjunctiva, cornea, retina, optic nerve, pupil, etc.). Each section explains the importance of eye region examination and highlights various abnormalities.
I would recommend this ophthalmology mobile app for beginners or students of the 1st course because it contains a lot of general information that can be useful for those who have just started their careers. However, in the long run, the app lacks media content, real-life examples, and other important features.
Ophthalmology Atlas is a database for ophthalmologists and optometrists, showcasing up to 12 areas of eye diseases from A to Z.
Here users can find diseases of the cornea, lens, retina, and 9 more. The app is a digital variant of a paper atlas with a bunch of real photos and a lot of complicated cases, which is great for beginners.
The Clinical Ophthalmology mobile app has a very simple interface and a list of 20 pathologies to read about. Although the application has only one feature and lacks media content, the team has provided users with the ability to share content.
3D Atlas of Ophthalmology
The app is a collection of various 3D photos and videos, mostly created by Dr. John Davis. One of the distinctive features of the app is that to watch media content users will need to wear Red-Blue 3D glasses or VR Headset.
Will Ophthalmology Mobile Apps Replace Webinars and Conferences?
According to our research on OCT education, 36% of optometrists and ophthalmologists around the world choose webinars to study OCT interpretation. 36% prefer conferences as the source of new information, 18% choose atlases, and only 11% of eye care specialists trust ophthalmology mobile apps.
On the one hand, mobile ophthalmology app cannot replace atlases, webinars, internships, and clinical practice. On the other hand, interactive mobile application contribute to the assimilation of information much better than printed materials and have unlimited data storage capacity. Another of their advantages is that users can learn on the go for little money, while internships and clinical practice takes much time and can be expensive.
Summing up, any ophthalmologist and optometrist who has worked at least a little with OCT knows that practical skills are more important than theory. That is why our team believes that ophthalmology mobile apps will inevitably become an additional effective tool for learning OCT interpretation.
OCT Interpretation & Eye Examination: How AI can Solve 4 main ProblemsMaria Znamenska10 July 20225 min. read
OCT imaging system is a highly informative non-invasive method of retinal examination, and because of its resolution, it is called histology or microscopy. Usually, thinking of the benefits of OCT eye examination and OCT interpretation, eye care specialists talk about three key points: high scanning speed, non-invasiveness, and the absence of contact.
FDA approved AI that detects 70+ retina pathologies
How do eye care specialists learn the interpretation of OCT?
However, learning OCT interpretation is challenging. It takes time and money to master OCT interpretation skills and become a professional. Most often, ophthalmologists and optometrists choose one of the following methods of education when it comes to OCT scan interpretation, according to our survey.
- Webinars. They have become popular with the Covid epidemic. Now there are plenty of various educational webinars where less experienced eye care specialists can obtain useful knowledge.
- Conferences. Unfortunately, travel restrictions made it impossible to travel much, but before the pandemic, eye care specialists could learn by visiting various conferences.
- Atlases are still quite popular, but unfortunately, it is impossible to update information in them often.
- Mobile apps are a new educational tool that is gaining popularity among eye care specialists.
Because OCT interpretation education requires a lot of resources from eye care specialists, ophthalmologists and optometrists may lack the experience that they need so much to feel 100% confident with OCT eye examination.
Poor knowledge of OCT interpretation results in problems
At Altris Education OCT, we decided to talk to optometrists and ophthalmologists who use our application about the most common problems with OCT eye examinations. That is what we’ve learned, receiving 1034 answers from eye care specialists from all over the world. There are 4 main problems connected with OCT:
No interpretation of OCT
This problem with OCT interpretation can be hidden, but it turns out that 16, 3 % of eye care specialists avoid offering OCT eye examinations to their clients because they are not sure about their interpretation skills.
OCT eye examination takes time and practice to master before an eye care specialist will be able to perform a high-quality OCT examination fast. Some eye care specialists can spend up to 40 minutes on OCT, which will result negatively on the quality of the service of the clinic or individual optometry. On average, eye care specialists spend 10 minutes on 1 OCT eye examination.
Minor, early, rare pathologies missed.
Another common problem in OCT scan interpretation is missing minor, early, rare pathologies on OCT scans. It turns out that 20,2% of eye care specialists miss them 1-3 times a week, while 4,4% miss them even more frequently: 3-5 times a week. What is most surprising is how often eye care specialists are not aware of their ignorance at all. 30,5% of ophthalmologists and optometrists admit that they have no idea if they miss any minor, early or rare pathologies at all.
If an eye care specialist misses early signs of glaucoma, it can lead to irreversible blindness.
FDA approved AI that detects 70+ retina pathologies
Why is that so important? Missing pathologies at their early stage can have serious negative consequences for patients. For instance, missing glaucoma, which is irreversible, can lead to blindness. Missing rare and minor pathologies can result in inadequate follow-up and treatment of a patient, which can make the situation worse. Accurate interpretation of OCT scans and diagnosis is the main condition of positive patient outcomes.
It turned out that a majority of eye care specialists come across controversial scans they don’t know how to interpret. It is difficult to determine the right diagnosis on such scans and additional time is needed to interpret them.
In the majority of cases ( 99% to be precise) eye care specialists consult their colleagues when they come across a scan they do not know how to interpret. They can ask their colleagues personally, in groups on Social Media or create special chats in messengers.
How Altris AI solves most problems of OCT interpretation
With Altris AI, a standalone SaaS for the decision-making support of ophthalmologists and optometrists, all these problems will be solved. Altris AI provides:
- Fast differentiation between pathological and non-pathological scans
- Identification of minor, early, and rare pathologies
- Second opinion when working with the interpretation of OCT scans
- Confidence when coming across controversial OCT scans
Our web platform is capable of accurate b-scans severity differentiation. After OCT scans are uploaded inside the system, the AI model assesses them ( up to 512 b-scans) and differentiates between normal scans and scans with moderate and severe pathology.
The most helpful module of our platform is called Classification/Segmentation. Inside this module, an eye care specialist can analyze any OCT scan on the absence/presence of more than 70 retina pathologies and pathological signs. It excludes the possibility of missing some rare pathologies.
The system is already available for a free trial to anyone who wants to try to solve the main OCT scan interpretation pain points.
OCT Examination vs Fundus Photo: Which Method to ChooseMaria Znamenska26 July 20229 min. read
Before talking about the difference between OCT Examination and fundus photography (FP), we need to note that modern technologies, such as FP and optical coherence tomography imaging, have a positive effect on the daily practice of ophthalmologists and optometrists, facilitate early diagnosis and allow better management of eye disorders. Currently, special attention is paid to these two methods and their ability to provide a comprehensive description of the morphology and function of the retina.
FDA approved AI that detects 70+ retina pathologies
At first glance, both methods have great potential for effective screening of retinal abnormalities. However, OCT images of the retina provide an improved diagnosis of many diseases, and the role of FP as the gold standard is losing popularity. In this post, we will look at the critical limitations of fundus photography and explore why the OCT imaging system is gaining credibility among ophthalmologists and optometrists worldwide.
What are the benefits and limitations of fundus photography?
To expand on the topic of fundus photography vs OCT, we need to talk about the benefits and limitations of FP. Being widely available, the fundus imaging system is vital for visualization of retinal and optic nerve conditions. Fundus photography is easy to use and cost-effective, contributing to its rapid spread over the past few years. However, this method also has a few disadvantages which make it less effective than OCT examination. Let’s take a closer look at the benefits and limitations of fundus imaging systems.
The benefits of the fundus photo
Fundus photography is a quick and simple non-invasive technique that allows eye care specialists to visualize the retina and provide the accurate diagnosis. FP shows the landmarks of the eye. In addition, fundus photo provides an early and accurate diagnosis, which is highly important for timely treatment and improved therapy.
Fundus photography helps ophthalmologists and optometrists not only identify retinal abnormalities and pathologies but also to monitor the progression of eye diseases. In this way, any eye care specialist can develop an effective treatment plan for different people with different eye types.
The limitations of the fundus photo
Despite all the benefits of the fundus photo, this technology also has some disadvantages. FP allows eye care specialists to examine the retina by looking at it from above. They may see an uneven retinal surface or curvature. However, FP does not allow observing the microscopic changes inside the retina which correspond to early stages of the disease. It, therefore, can be obtained with OCT image interpretation.
Taking about fundus photography vs OCT, the key disadvantage of FP compared to optical coherence tomography imaging is its lower resolution. Thus, the pathology size detected in the fundus photography is larger. The FP is unable to detect the invisible pathologies on different retinal layers, which usually present at the stage when the patient does not even have any complaints. In fact, the fundus imaging system sees what the human eye can see. With this technology, an ophthalmologist or optometrist detects only pathologies that are visible to human eyes.
What are the main principles of OCT examination?
OCT examination has revolutionized retinal research, allowing doctors to review the pathophysiology of many diseases. But what is the main difference between OCT and fundus photography? FP is the process of photographing the back of the eye using a specialized camera consisting of a microscope attached to a camera with a flash. In contrast, optical coherence tomography imaging estimates the depth at which a particular backscatter occurred by measuring its flight time.
The reflection of light allows determining exactly from what retinal layer the signal is coming. As we know that it takes more time for the light to return from deeper layers. The physical principle of OCT examination is similar to ultrasound. The only difference is that the OCT does not use acoustic waves but near-infrared optical wavelength radiation.
Modern OCT examination allows doctors to get images with a reasonably high resolution, ranging from 1 to 10 μm. In fact, optical coherence tomography is also called an optical retinal biopsy. The architecture of the retinal structure in the images is very close to the histological structure of the retina. Histologically, the retina consists of 10 layers, but OCT technology allows anyone to assess the retina itself and the structures surrounding it. The modern classification has 18 zones (layers), which can be estimated and described using this technology.
How does the OCT examination boost your working process?
Modern equipment allows patients to undergo both OCT and fundus photography quite comfortably – without dilation of the pupil and through a non-contact method of research. But optical coherence tomography imaging has many advantages that make this method the most progressive, leaving all competitors behind.
OCT imaging system is a highly informative method of retinal examination, and because of its resolution, it is called histology or microscopy. With this technology, ophthalmologists see what could only be seen under a microscope without OCT.
Usually, thinking of the benefits of OCT, eye care specialists talk about three key points:
- High scanning speed
However, experienced ophthalmologists and optometrists know these are not the only advantages. Let’s discuss how OCT image interpretation helps examine the layers of the retina and determine the causes of eye diseases.
Determining pathologies at early stages
Many diseases at the early stages are almost invisible to even an experienced optometrist or ophthalmologist. Most retinal abnormalities progress with age and develop slowly and gradually, so diagnosing them is pretty difficult. However, modern OCT image interpretation allows physicians to detect the warning signs of the disease, classify hundreds of pathologies, and re-monitor images to track the progression of pathologies.
Moreover, OCT image interpretation helps ophthalmologists understand the pathophysiology of retinal diseases, for example, how macular holes arose. This discovery showed doctors that they often misdiagnosed fluid location in the retina. Modern OCT examination help determine the location of abnormal new blood vessels, which is especially important when working with patients suffering from wet AMD.
FDA approved AI that detects 70+ retina pathologies
OCT imaging allows eye care specialists to measure the retina’s thickness and the magnitude of the pathological process in μm. It is advantageous for the diseases that cause fluid accumulation, such as retinal vein occlusion (RVO) and diabetic macular edema (DME).
Fundus photography does not provide such an opportunity because the supervision of the dynamics is unavailable in FP. Because OCT imaging allows the retina to be examined in layers, any eye care specialist can detect changes in the structure of the eye that will never be able to be tracked by the FP.
In addition, creating a map of the total thickness of the retina or its layers is crucial for monitoring patients with glaucoma, for example. The retinal nerve fiber thickness in such patients becomes thinner as the disease progresses so it is vital to monitor it.
Determining the severity of eye disease
Well-made retinal images allow to determine the severity and stage of the disease, compare images after examination with documented results, and track disease progression. Moreover, obtaining clear images of the retina helps different eye care specialists who monitor the same patient to choose the most accurate diagnosis.
Providing high patient tolerance
Needless to say that patient cooperation is highly important while performing any type of diagnosis. If a patient moves during the procedure, the quality of the image may deteriorate significantly. However, with modern optical coherence tomography principles, the acquisition time is shorter which results in fewer motion-related artifacts.
OCT uses completely safe laser light, avoiding all the side effects or risks. Moreover, with its scanning speed, the process becomes comfortable and effortless both for the ophthalmologist/optometrist and the patient.
Disadvantages of OCT examination
Despite the high-quality information provided with optical coherence tomography imaging, the technology also has a few limitations. As OCT uses light waves, some images can contain media opacities. Thus, the OCT scan can be limited by staging a hemorrhage in the vitreous body, a dense cataract, or clouding of the cornea.
Current use of OCT examination
Although standard fundus imaging is widely used, more and more eye care specialists are switching to modern OCT systems that provide more detailed information about various retinal abnormalities.
Today, the commercially available and clinical standard of choice for most specialists is SD-OCT (spectral-domain OCT) systems, which provide volumetric images of the human retina with a lateral resolution of better than 20 μm. Current SD-OCT devices use retinal images to re-trace the same image area during several subsequent examinations to monitor treatment progress.
The ophthalmological practice also uses SS-OCT (swept-source OCT) systems, which provide access to a large number of parameters of the eye, which is important for measurements through dense cataracts. SS-OCT supports high image speed and a large scanning depth range compared to SD-OCT. However, the cost of SS-OCT devices is much higher than their counterparts, so these systems have not yet gained widespread clinical implementation. Assuming that the cost of lasers will decrease, it is likely that SS-OCT will eventually also replace SD-OCT in most daily clinical practice.
In general, the modern OCT devices available today, whether SS-OCT or SD-OCT, are multimodal, which means that ophthalmologists can quickly and easily acquire an incredible amount of information. In addition to image acquisition, modern OCT imagin systems are equipped with special software. It collects retinal images and compares the results to regulatory databases. This allows doctors to make better patient treatment decisions.
The future of retinal imaging with OCT examination
Coming back to the topic of fundus photography vs OCT, these two methods are pretty difficult to compare because these are completely different technologies. OCT and FP carry different information and can sometimes even complement each other. After many years of using the fundus imaging system, this method has been perfected, the quality of cameras has increased, and it has become possible to take pictures without dilating the pupil.
For example, FP is a great method for revealing vascular diseases of the eye. However, in most cases, the resolution of OCT is much higher than the resolution of fundus photography. FP will never be able to track invisible changes in the retina structure that OCT can track.
OCT image interpretation makes it possible to examine 18 zones of the retina, which allows ophthalmologists and optometrists to investigate pathologies in the early stages and detect foci of diseases up to 20 μm. That is why both young specialists and experienced professionals should choose OCT to examine the patient’s retina.
The future of OCT examination is definitely connected to technologies.
For instance, mobile apps for ophthalmologists, such as Altris Education OCT, help eye care specialists learn OCT image interpretation on millions of labeled scans.
Altris AI web platform supports ophthalmologists and optometrists in decision-making: the system detects 54 pathologies and 49 pathological signs on OCT providing eye care specialists with a higher level of confidence in diagnostics.
The combination of the knowledge of eye care specialists powered by AI technologies will result in higher diagnostic standards for the industry and better patient outcomes. Imagine how many diseases can be prevented if detected at early stages! Watch a short and useful video about the main features of Altris AI platform: