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K. G. Pratinya et al.
Table 19.1 Showing the evolution of the deep learning­based optic disc image analysis
Study Method Sihota etal. [20] Moorelds regression
analysis
Almazrao etal. [21] Deep learning-based
segmentation algorithms
Park etal. [22] Deep learning-based vCDR
estimation
Lee etal. [23] Deep learning-based RNFL
analysis
19.6.1 AI Framework
There are two commonly used approaches in the AI framework for optic disc analysis and glau­coma detection: the one-step and two-step frameworks.
1. One-step framework: A single deep learning model is trained to directly classify optic disc images as normal or glaucomatous in the one­step framework. The model takes the raw input images and performs both feature extraction and classication in a single step. This approach leverages the ability of deep learning algorithms to automatically learn rel­evant features and make predictions from the raw data.
2. Two-step framework: In the two-step frame­work, the optic disc analysis process is divided into two distinct steps: feature extraction and classication.
Step 1: Feature extraction:
• Deep learning models extract features
from the optic disc images, such as optic disc cupping, rim thickness, vessel charac­teristics, or other relevant parameters asso­ciated with glaucoma.
• The feature extraction step aims to capture
informative representations of the optic disc that can be used for subsequent classication.
Step 2: Classication:
• The extracted features are fed into a sepa-
rate classication algorithm or model, such as a support vector machine (SVM) or ran-
dom forest classier, to perform the nal classication task.
• The classier uses the extracted features as input and determines whether the optic disc is normal or shows signs of glaucoma.
While the one-step framework simplies the workow by combining feature extraction and classication into a single model, reducing com­plexity and computational requirements, the two­step framework allows extracting specic features relevant to glaucoma detection. These features can be further analyzed and interpreted by clinicians, and it also provides exibility in selecting different classiers for the classication step; it thus enables the use of various algorithms depending on the specic requirements and char­acteristics of the dataset. The superiority of the two-step process over the one-step process in optic disc analysis for glaucoma detection depends on various factors and the specic con­text of the application [13].
Various studies were done to assess the agree­ment of AI with manual grading [1419].
For example, Shroff et al. [14] studied the agreement of vCDR measured by an ofine AI-integrated smartphone fundus camera with SD-OCT vCDR measurements and manual grad­ing by experts on a stereoscopic fundus camera on 473 eyes from 244 patients. They found that the ofine AI had an excellent agreement and correlation with the SD-OCT and manual grad­ing. MacCormik et al. [18] studied a glaucoma detection algorithm that segments and analyzes color photographs to quantify optic nerve rim consistency around the entire disc at 15-degree intervals. They found that it accurately distin­guished glaucomatous and healthy discs on inter­nal and external validation with an area under the ROC of 99.6% and 91.0%, respectively.
Deep learning algorithms can assist in glau­coma screening and diagnosis by analyzing optic disc photographs. By analyzing the enhanced images and comparing them with a vast database of reference images, the system can highlight potential abnormalities, suggest follow-up tests, or provide risk stratication for glaucoma [13].
19 Optic Disc Photography
231
Future directions: Ongoing research and development in AI and deep learning continue to advance the eld of enhanced optic disc photog­raphy. Efforts are being made to incorporate mul­timodal imaging data, such as combining optic disc photographs with OCT or visual eld data, to improve diagnostic accuracy further. Additionally, integrating AI algorithms into por­table and handheld imaging devices opens up the possibilities for point-of-care screening and remote monitoring [14].
19.7 Conclusion
Optic disc photography has played a pivotal role in the screening and diagnosing glaucoma, con­tributing to the early detection and management of this sight-threatening disease. Technological advancements have revolutionized optic disc image analysis from its historical roots in the early twentieth century to the modern era. AI-powered frameworks have emerged as trans­formative tools for automated segmentation and abnormality detection. These developments have enabled large-scale, low-cost screening, and extended eye care services to remote areas lack­ing access to qualied ophthalmologists. As research in this eld continues, we anticipate fur­ther innovations that will enhance the accuracy and accessibility of glaucoma screening and management, offering a brighter outlook for patients worldwide.
Funding Hyderabad Eye Research Foundation.
Disclosure Nil.
References
1. Panwar N, Huang P, Lee J, etal. Fundus photography in the 21st century—a review of recent technological advances and their implications for worldwide health­care. Telemed J E Health. 2016;22(3):198–208.
2. Yannuzzi LA. The retinal atlas. Elsevier Health Sciences; 2010. p.929.
3. Keeler R, Singh AD, Dua HS.Reecting on reec­tions: Gullstrand’s large reex-free ophthalmoscope. Br J Ophthalmol. 2010;94(7):826–6.
4. Myers J, Fudemberg S, Lee D. Evolution of optic nerve photography for glaucoma screening: a review: evolution of disc photos for screening. Clin Experiment Ophthalmol. 2018;46(2):169–76.
5. Varma R, Steinmann WC, Scott IU. Expert agree­ment in evaluating the optic disc for glaucoma. Ophthalmology. 1992;99(2):215–21.
6. Morgan JE, Sheen NJL, North RV, etal. Digital imag­ing of the optic nerve head: monoscopic and stereo­scopic analysis. Br J Ophthalmol. 2005;89(7):879–84.
7. Parkin B, Shuttleworth G, Costen M, Davison C. A comparison of stereoscopic and monoscopic evaluation of optic disc topography using a digi­tal optic disc stereo camera. Br J Ophthalmol. 2001;85(11):1347–51.
8. Yang J, Qu Y, Zhao J, et al. Stereoscopic vs. mono­scopic photographs on optic disc evaluation and glau­coma diagnosis among general ophthalmologists: a cloud-based real-world multicenter study. Front Med (Lausanne). 2022;9:990611.
9. Varshney T, Parthasarathy DR, Gupta V. Articial intelligence integrated smartphone fundus camera for screening the glaucomatous optic disc. Indian J Ophthalmol. 2021;69(12):3787–9.
10. Das S, Kuht HJ, De Silva I, et al. Feasibility and clinical utility of handheld fundus cameras for retinal imaging. Eye (Lond). 2023;37(2):274–9.
11. Bak E, Choi HJ. Structure-function relationship in glaucoma: optical coherence tomography en face imaging vs. red-free fundus photography. Eye (Lond). 2023;37(14):2969–76.
12. Watanabe T, Hiratsuka Y, Kita Y, et al. Combining optical coherence tomography and fundus photog­raphy to improve glaucoma screening. Diagnostics (Basel). 2022;12(5):1100.
13. Coan L, Williams B, Venkatesh KA, etal. Automatic detection of glaucoma via fundus imaging and arti­cial intelligence: a review. Surv Ophthalmol. 2023;68(1):17–41.
14. Shroff S, Rao DP, Savoy FM, etal. Agreement of a novel articial intelligence software with optical coherence tomography and manual grading of the optic disc in glaucoma. J Glaucoma. 2023;32(4):280–6.
15. Youse S. Clinical applications of articial intel­ligence in glaucoma. J Ophthalmic Vis Res. 2023;18(1):97–112.
16. Mvoulana A, Kachouri R, Akil M.Fully automated method for glaucoma screening using robust optic nerve head detection and unsupervised segmenta­tion based cup-to-disc ratio computation in reti­nal fundus images. Comput Med Imaging Graph. 2019;77:101643.
17. Bajwa MN, Malik MI, Siddiqui SA, et al. Two­stage framework for optic disc localization and glaucoma classication in retinal fundus images using deep learning. BMC Med Inform Decis Mak. 2019;19(1):136.
18. MacCormick IJC, Williams BM, Zheng Y, et al. Accurate, fast, data efcient and interpretable glaucoma diagnosis with automated spatial analy-
232
K. G. Pratinya et al.
sis of the whole cup to disc prole. PLoS One. 2019;14(1):e0209409.
19. Zhao R, Chen X, Liu X, et al. Direct cup-to-disc ratio estimation for glaucoma screening via semi­supervised learning. IEEE J Biomed Health Inform. 2020;24(4):1104–13.
20. Sihota R, Gulati V, Agarwal HC, et al. Variables affecting test-retest variability of Heidelberg retina Tomograph II stereometric parameters. J Glaucoma. 2002;11(4):321–8.
21. Almazroa A, Burman R, Raahemifar K, Lakshminarayanan V. Optic disc and optic cup seg-
mentation methodologies for glaucoma image detec­tion: a survey. J Ophthalmol. 2015;2015:180972.
22. Park K, Kim J, Lee J. Automatic optic nerve head localization and cup-to-disc ratio detection using state-of-the-art deep-learning architectures. Sci Rep. 2020;10(1):5025.
23. Lee T, Jammal AA, Mariottoni EB, Medeiros FA.Predicting glaucoma development with longitu­dinal deep learning predictions from fundus photo­graphs. Am J Ophthalmol. 2021;225:86–94.
OCT inGlaucoma
K.GowriPratinya , AparnaRao , PallaviRay, andBhoomiThakkar
20
20.1 Introduction
Glaucoma is a chronic progressive optic neuropa­thy characterized by optic nerve head changes due to the progressive loss of retinal ganglion cells. Diagnosing this structural damage early is crucial in managing glaucoma. Though it can be clinically assessed by optic nerve head (ONH) and peripapil­lary retinal nerve ber layer (RNFL) examinations, the introduction of optical coherence tomography (OCT) has allowed for supplemental objective and quantitative evaluation of ONH and RNFL changes. OCT is a noninvasive, noncontact technique that uses the differences in the optical properties of tis­sue structures to create an “optical biopsy” thereby providing high- resolution and cross-sectional imaging of the ONH, RNFL, and macula [1].
20.2 Technology
Optical coherence tomography is based on the principle of the Michelson low-coherence inter­ferometry. This imaging technique directs waves
K. G. Pratinya · A. Rao (*) Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India e-mail: kolipaka.pratinya@lvpei.org; aparna@lvpei.org
P. Ray · B. Thakkar Mithu Tulsi Chanrai Campus, L V Prasad Eye Institute, Bhubaneswar, India e-mail: pallavi.ray@lvpei.org;
bhoomi.Thakkar@lvpei.org
to the tissue under examination, where the waves echo off the tissue structure. The reected waves are analyzed, and their delay is measured to doc­ument the depth at which the reection occurred. OCT uses light in the near infrared. The delay of the reected waves cannot be measured directly, so a reference measurement is used. In an inter­ferometer, part of the light is directed to the sam­ple, and another portion is sent to a reference arm with a well-known length. These techniques were adapted into time domain (TD) OCT and evolved into Fourier domain-OCTs.
20.2.1 Time-Domain OCT
The rst commercial TD-OCT was OCT 1 by Carl Zeiss Meditec (Dublin, CA, USA) [2]. The light of a low-coherence source is guided to the interferometer. The input beam is split into the sample and reference beams by a beam splitter. The reference beam travels to a mirror on a trans­lational stage and is reected back. The light reected from the eye is compared with that reected from the reference mirror using a low­coherence interferometry system. The reference mirror is moved mechanically from the beam splitter to estimate the depth of the reection within the tissue. Multiple axial scans are created to construct B-scans. Final 2D or 3D images are created by computer systems in the OCT devices either in grayscale or false colors.
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 T. Das, P. Satgunam (eds.), Ophthalmic Diagnostics, https://doi.org/10.1007/978-981-97-0138-4_20
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20.2.2 Spectral-Domain OCT
Spectral-domain (SD) OCT techniques use Fourier domain transformation [3]. Fourier trans­formation helps transform the signals between two different domains, from the time- or spatial domain to the frequency domain [4]. Using the Fourier transformation, the technology from the original method of TD-OCT, the SD-OCT, was developed. While the TD-OCT encoded the loca­tion of each reection in the time information relating the position of a moving reference mirror to the location of the reection, SD-OCT, instead, acquires all data in a single axial scan through the tissue simultaneously by evaluating the frequency spectrum of the interference between the reected light and a stationary reference mirror. Zeiss Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA), Heidelberg Engineering Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) Optovue RTVue (Optovue Inc., Fremont, CA, USA), and Topcon 3D OCT 2000 (Topcon Medical Systems, Oakland, NJ) use the SD-OCT system.
Advantages of SD-OCT over TD-OCT:
• It uses a xed reference mirror, which acquires 18,000–70,000 A-scans/s compared to the 400A-scans/s TD-OCT acquires. Hence, SD­OCT systems are 200–400 times faster than TD-OCT systems.
• Increased scanning speed results in a higher axial resolution (around 5μm).
• Due to increased scanning speed, the artifacts caused by eye movements are reduced.
20.2.3 Swept-Source OCT
Swept-source OCT is based on the Fourier domain principles. It combines the advantages of TD-OCT and SD-OCT.The light source used in SS-OCT is of a narrow bandwidth, which changes and sweeps the wavelength across a narrow band in time. The variation in frequency with time encodes different echo delay times in the light beams [5]. The light source in the SS-OCT is divided into a spectrum using a swept-source
laser; therefore, unlike SD-OCT, a spectrometer is not required. In SS-OCT, high-speed detectors detect interference signals in time and measure echo delays using Fourier transformation [6].
20.3 Clinical Utility ofOCT inGlaucoma
The use of SD-OCT for glaucoma diagnosis is an increasingly common practice. While progres­sive neuro-retinal rim changes such as thinning and excavation are more specic for glaucoma, the RNFL changes are more sensitive for detect­ing glaucoma. OCT plays a key role in detecting early glaucoma not detected by the perimetric examination.
20.3.1 Glaucoma Diagnosis
Standard automated perimetry is widely used for the diagnosis, staging, and monitoring of glau­coma, but it is only likely to detect functional decits after at least 20–40% of retinal ganglion cells (RGCs) are lost [7, 8]. Additionally, visual eld testing requires patient cooperation and understanding and is often variable [9]. Picking up the early glaucomatous structural damage, such as thinning of the RNFL and inner retinal layers, is fundamental for early diagnosis and prevention of vision loss.
The diagnostic capabilities of SD-OCT depend on the severity/stage of glaucoma; it per­forms better when discriminating healthy from advanced disease rather than early stages of glau­coma [10].
Taking multiple parameters into account, such as peripapillary RNFL, ONH, and macular parameters, OCT is useful for diagnosing early glaucoma (Fig.20.1a–c), staging the severity of glaucoma, and evaluating risk in glaucoma sus­pects [11]. Although using multiple parameters could increase false-positive results, structural damage may be present in one parameter and not the other, and thus it is helpful to have informa­tion from the macula, ONH, and RNFL in glau­coma diagnosis [10].
20 OCT inGlaucoma
235
a
Fig. 20.1 (a) Red-free fundus photograph of the RE showing a disc indicative of glaucoma with inferior nerve ber layer defect. (b) Humphrey visual eld print out of
bc
20.3.2 Glaucoma Progression
To assess the progression of glaucoma with the RNFL thickness obtained by OCT, we need to be aware of a few factors: (a) thinning due to normal aging; (b) the oor effect of this parameter; (c) thinning suggestive of glaucoma progression, both globally and within a sector; and (d) correla­tion of RNFL loss with visual eld loss.
The RNFL undergoes attrition with age in healthy eyes at a mean rate of 0.48μm/year in Cirrus and 0.60 μm/year in Spectralis images. Glaucoma progression, on the other hand, has a faster rate of RNFL thinning, ranging from0.98μm/year for the Cirrus to 2.12μm/ year for the Spectralis images. RNFL measure­ment continues to decrease as glaucoma advances, but does not go to zero, a phenomenon known as the “oor effect.” This is because the architectural support of the Müller cells, astroglia, microglia, and blood vessels do not allow the structure of the RNFL to degenerate completely with the retinal ganglion cell axons. Average RNFL oor values range from 49.2μm for the Spectralis to 57μm for the Cirrus to 64.7μm for the RTVue images. Once the RNFL thickness reaches the oor, pro­gression can still occur but cannot be detected by OCT. Therefore, the clinician should consider using macular OCT and the Humphry Visual Field (HVF, Carl Zeiss, Dublin, CA, USA) to monitor the progression of advanced glaucoma.
Each OCT device provides progression analy­sis, which can be event- or trend-based. The event-
the same eye showing a normal eld. (c) OCT (ONH and RNFL analysis) showing inferior RNFL thinning on devi­ation and clock hour map (red arrow and red circle)
based analysis measures the difference between baseline and follow-up measurements. A decrease of >5 μm in average RNFL thickness indicates glaucoma progression, while a decrease of 7–8μm or more in a sector also suggests progression. The trend-based analysis identies progression by monitoring the slope of RNFL thickness over time. Cirrus provides a glaucoma progression algorithm based on events and trend, comparing the RNFL thickness of individual pixels between baseline and follow-up images. Pixels are coded yellow if there is test–retest variability between a follow-up and baseline image, while red indicates the same change on three consecutive scans. In Spectralis, the system looks for specic patterns in retinal structures to position the retest scan in the same location automatically; RNFL thickness change and trend reports are plotted over time to compare the rate of change. The RTVue system offers a trend-based analysis, which includes side­by-side comparisons of global RNFL thicknesses, six sectorial thickness analyses, and a regression line to determine the slope and standard error. Although progression analysis software can be a great tool, especially in a busy clinic, one should always review the original scans and the sectors, as subtle changes in a small area can be easily missed.
Although SD-OCT has signicantly increased signal-to-noise ratio and decreased motion arti­facts than TD-OCT, both are prone to image arti­facts. These artifacts include speckle noise, segmentation errors (Fig. 20.2a, b), alignment errors, low signal quality, software problems, and
236
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K. G. Pratinya et al.
Fig. 20.2 (a) Ganglion cell analysis showing false thinning over the macular region due to improper segmentation (red arrow). (b) Repeat OCT of the same patient with proper segmentation (red arrow) and normal macular thickness
media opacities, such as reduced corneal clarity or cataracts. Fixational eye movements, such as ocular tremors, drift, and microsaccades, can fur­ther reduce image quality.
While SD-OCT devices still require a trained imaging technician to minimize artifacts, it is comparatively less operator dependent than TD-OCT devices. Clinicians should be cautious in interpreting these OCT ndings and avoid overtreating people with false-positive results.
20.4 New Advances
inGlaucomaOCT
20.4.1 Adaptive Optics inOCT
As mentioned earlier, the diagnostic capacity of OCT is dependent on the severity of glaucoma. The OCT is more effective in discriminating healthy from moderate and advanced diseases than early
glaucoma. In addition, wide anatomic variations of the optic nerve head, several sources of error, and the database having a limited number of subjects of any single ethnicity limit the diagnostic perfor­mance of OCT in detecting glaucoma [12]. Adaptive optics (AO) could ll this gap in retinal imaging for the early diagnosis of glaucoma by compensating for ocular aberrations. It has been combined with a fundus camera, scanning laser ophthalmoscope, and OCT to help with a better understanding of the disease process (Fig.20.3). The OCT system has an excellent axial resolution, and with the addition of AO, its lateral resolution improves dramatically [13]. The AO-OCT system has the best spot size (in terms of axial and lateral resolution) among all the other AO systems.
AO-OCT can be used in the following ways:
1. To quantify morphological changes in the photoreceptor cells in the abnormal areas of the cone-mosaic.
20 OCT inGlaucoma
237
2. To detect optic nerve head changes and abnor­malities for monitoring glaucoma progression.
3. Imaging subtle changes in the RNFL at the preclinical stage and visualization of the indi­vidual RNFL bundles in vivo could help detect and monitor glaucoma progression early.
Adaptive optics is an evolving technology; it is not without limitations. Its greatest limitation is the narrow eld of imaging; only 0.225mm is covered in a single image [14]. The technology is adversely affected by media opacity, dry eye, poor pupillary dilatation, and high refractive error. The focal plane of reference needs adjust­ment each time to obtain images at a particular depth. In addition, ocular motion artifacts can affect the quality of images. The technology demands expertise, and acquiring images can be time-consuming.
20.4.2 Enhanced Depth Imaging andArticial Intelligence Application inOCT Glaucoma
Enhanced depth imaging (EDI) is used in OCT imaging to enhance the visualization of the deeper structures within the eye, particularly the optic nerve head and the lamina cribrosa [1518]. EDI-OCT imaging allows for a more detailed and accurate assessment of the optic nerve head and the lamina cribrosa, both critical structures in the development and progression of glaucoma (Fig.20.4). EDI-OCT imaging has proven to be a valuable tool in the early detection and monitor­ing of glaucoma and is increasingly used in clini­cal practice.
20.4.2.1 Principle
The principle behind EDI-OCT imaging is simi­lar to that of traditional OCT imaging. However, EDI-OCT uses a specialized technique to enhance
Fig. 20.3 Adaptive optics (prototype) setup at L V Prasad eye institute, Hyderabad, India
238
Fig. 20.4 An EDI Spectralis image through the optic disc showing segmentation of various retinal layers (original photograph)
K. G. Pratinya et al.
the depth resolution of the image, allowing for better visualization of deeper structures. In EDI­OCT, the light source used to produce the image is positioned closer to the eye, bringing the deeper portion so the eye is closer to the zero­delay line of the highest sensitivity. This enables greater penetration of the light into the tissues. This results in a sharper and more detailed image of the deeper structures, such as the optic nerve head and the lamina cribrosa.
In contrast, high-penetration OCT is an OCT imaging technique that uses longer wavelength light to increase the depth of penetration of the OCT signal. This technique allows for better visualization of deeper structures in the eye, such as the choroid and sclera.
Some of the commercially available OCT sys­tems that offer EDI imaging are Spectralis OCT (Heidelberg Engineering), Cirrus HD-OCT (Carl Zeiss Meditec), Topcon 3D OCT-1 Maestro (Topcon Medical Systems), RTVue XR Avanti (Optovue), Triton Swept Source OCT (Topcon Medical Systems), AngioVue OCT (Optovue), DRI OCT Triton Plus (Topcon Medical Systems), and Envisu R2210 OCT (Bioptigen, Inc.).
EDI-OCT imaging is a powerful tool for studying the complex anatomical and physiologi­cal changes associated with glaucoma and is increasingly used in clinical practice and research.
20.4.2.2 Clinical Applicability ofEDI Imaging onOCT
A. EDI-OCT imaging is very useful for studying
laminar bowing. In this phenomenon, the lamina cribrosa (a thin, sieve-like structure within the optic nerve head) bows inward or outward in response to changes in intraocular pressure. Laminar bowing is an important factor in the development and progression of glaucoma, and understanding this phenomenon is critical for diagnosing and managing the disease. EDI-OCT imaging allows better visualization of the lamina cribrosa, located deep within the eye and dif­cult to see using other imaging techniques [1517]. This can help to understand the mechanisms underlying laminar bowing bet­ter and may lead to improved diagnostic and treatment approaches for glaucoma.
B. EDI-OCT imaging is used to evaluate other
structural changes within the optic nerve head and the surrounding tissues, such as changes in the size and shape of the optic cup and the presence of uid-lled spaces within the retina.
C. EDI-OCT imaging can also be used to evalu-
ate the efcacy of glaucoma treatments by monitoring changes in the optic nerve head, lamina cribrosa, RNFL, and ganglion cell layer (GCL) over time. The early detection of
20 OCT inGlaucoma
239
changes in these structures can enable clini­cians to adjust treatment plans to manage the disease better and improve patient outcomes.
The following laminar parameters can be studied using EDI imaging on OCT in glaucoma:
1. Lamina cribrosa depth is the distance
between the anterior surface of the lamina cribrosa and the reference plane, usually the Bruch’s membrane or the retinal pigment epithelium. A deeper lamina cribrosa is asso­ciated with an increased risk of glaucoma progression.
2. Lamina cribrosa thickness is the thickness of
the lamina cribrosa at its thinnest point. A thinner lamina cribrosa is associated with an increased risk of glaucoma progression.
3. Lamina cribrosa position is its position rela-
tive to the optic nerve head rim. A more poste­riorly positioned lamina cribrosa is associated with an increased risk of glaucoma progression.
4. Lamina cribrosa curvature is the curvature of
the lamina cribrosa surface. A more curved lamina cribrosa is associated with an increased risk of glaucoma progression.
5. Pre-laminar tissue thickness is the thickness
of the tissue anterior to the lamina cribrosa, including the retinal nerve ber layer and the pre-laminar tissue. Thinning of the pre­laminar tissue is associated with an increased risk of glaucoma progression.
20.5 Articial Intelligence (AI)
Applications inGlaucomaOCT
1. AI has several potential applications in OCT
imaging for glaucoma [16, 1820]. AI algo­rithms can be trained to detect subtle changes in the optic nerve head and surrounding tis­sues that may indicate glaucoma. This can help clinicians identify patients at risk of developing the disease and initiate appropri­ate monitoring and treatment.
AI in OCT imaging for glaucoma is useful in monitoring disease progression. AI algo­rithms can analyze longitudinal datasets of OCT images to identify changes in the optic nerve head and surrounding tissues over time. This can help clinicians detect subtle changes that may indicate disease progression.
AI can also be used to assist in the manage­ment of glaucoma by predicting the efcacy of different treatment options. By analyzing datasets of OCT images from patients who have undergone different treatment modali­ties, AI algorithms can predict the likelihood of success for different treatments in individ­ual patients.
2. New developments in AI-based applications on OCT in glaucoma are listed below.
(a) Multimodal imaging: Combining differ-
ent types of imaging modalities, such as OCT, fundus photography, and visual elds, can provide a more comprehensive view of the eye and improve the accuracy of glaucoma diagnosis and monitoring.
(b) Personalized medicine: AI algorithms can
analyze large datasets of patient informa­tion and OCT images to identify individ­ualized risk factors for glaucoma and tailor treatment plans accordingly.
(c) Real-time monitoring: Real-time moni-
toring of RNFL parameters using AI­based algorithms can help to identify changes in disease progression earlier and adjust treatment plans accordingly.
(d) Big data analysis: AI-based algorithms
can analyze large datasets of OCT images and patient data to identify trends and patterns indicative of glaucoma. This can help improve our understanding of the disease and guide future research.
(e) Automated reporting: AI algorithms can
generate automated reports based on the analysis of OCT images, reducing the need for manual interpretation by clinicians.
3. Several AI platforms exist for OCT analysis of RNFL, optic disc, and macula for glau­coma. Some of the novelties in different AI platforms are listed below.