This document discusses the use of multimodal imaging to diagnose and monitor MacTel-2, a progressive retinal disease. It describes how digital color fundus photography, multicolor scanning laser fundus photography, optical coherence tomography, and dye-based angiography can be combined to identify early disease features like loss of foveal autofluorescence and subtle retinal changes. Over time, imaging reveals complications such as subretinal neovascularization and macular holes. By concurrently assessing different retinal structures, multimodal imaging improves understanding, evaluation, and treatment of MacTel-2.

1. Multimodal Imaging in MacTel -2
Amira M. Mostafa
Retinal Imaging Unit
iCare Eye Hospital

2. • “Multimodal Retinal Imaging” is a trending concept of combining different imaging
modalities to improve preclinical assessment, diagnostics, and therapeutic monitoring.1,2
• Hybrid imging platforms
• Including:
1. Digital color fundus photography
2. Multicolor scanning laser fundus photography
3. cSLO
4. Dye-based angiography
5. FAF
6. SD-OCT
1. Keane PA, Sadda SR. Retinal imaging in the twenty-first century: state of the art and future directions. Ophthalmology. 2014;121(12):2489-2500.
2. Yannuzzi LA, Ober MD, Slakter JS, et al. Ophthalmic fundus imaging: today and beyond. Am J Ophthalmol. 2004;137(3):511-524.

3. • Concurrent assessment of different retinal structures:3-5
1. Better understanding and evaluation of retinal diseases
2. Adding up new entities to the spectrum of retinal diseases
3. Improving treatment modalities
4. Improving interpretation of newer modalities e.g. OCT-A
3. Kim YG, Baek SH, Moon SW, Lee HK, Kim US. Analysis of spectral domain optical coherence tomography findings in occult macular dystrophy. Acta
Ophthalmol. 2011;89(1):e52-56.
4. Park SJ, Woo SJ, Park KH, Hwang JM, Chung H. Morphologic photoreceptor abnormality in occult macular dystrophy on spectral-domain optical
coherence tomography. Invest Ophthalmol Vis Sci. 2010;51(7):3673-3679.
5. Christenbury JG, Klufas MA, Sauer TC, Sarraf D. OCT angiography of paracentral acute middle maculopathy associated with central retinal artery
occlusion and deep capillary ischemia. Ophthalmic Surg Lasers Imaging Retina. 2015;46(5):579-581.

4. Retinal Telangiectasia

5. • The term of “retinal telangiectasia” has been used to describe dilated retinal
vessels on all three components of the circulation; arterioles, capillaries, and
venules, and ass. abnormalities such as aneurysmal dilatations, vascular
leakage and exudation.6,7
• Classifications:7-9
6. Aung KZ, Wickremasinghe SS, Makeyeva G, et al.: The prevalence estimates of macular telangiectasia type 2. Retina. 30:473-478 2010.
7. Gillies MC, Zhu M, Chew EY, et al.: Familial asymptomatic macular telangiectasia type 2. Ophthalmology. 116:2422-2429 2009.
8. Gass JD, Blodi BA: Idiopathic juxtafoveolar retinal telangiectasis. Update of classification and follow-up study. Ophthalmology. 100:1536-1546 1993.
9. Yannuzzi LA, Bardal AM, Freund KB, et al.: Idiopathic macular telangiectasia. Arch Ophthalmol. 124:450-460 2006

6. • MacTel Research Group classification:8-10
• MacTel-1……”congenital or developmental”
• MacTel-2 …… “idiopathic”
10.Clemons TE, Gillies MC, Chew EY, et al.: Baseline characteristics of participants in the natural history study of macular telangiectasia (MacTel) MacTel
Project Report No. 2.Ophthalmic Epidemiol. 17:66-73 2010

7. • Bilateral
• Asymmetric
• Females
• 6th decade
• Systemic HTN “52%”, DM “28%”
MacTel-2

8. MacTel-2
• Degeneration of parafoveal retinal Müller cells with subsequent vascular
changes:
1. Pericyte degeneration and lipid accumulation in capillary walls.
2. Multilaminated basement membrane.
3. Dilation and proliferation of retinal capillaries into the outer retinal,
subretinal, and preretinal spaces.

9. MacTel-2
• Diagnostic challenge ????????????
1. Bilateral, Vision threatening
2. Progressive
3. Usually asymptomatic , Easily over-looked
4. Overlapping retinal vascular diseases such as DR
5. Complications as a presenting signs such as SRNVM, MH

10. • Appropriate combination of imaging modalities
• Including:
1. BAF
2. Multicolor scanning laser fundus photography
3. SD-OCT
4. cSLO Dye-based angiography

11. • Appropriate combination of imaging modalities
• Including:
1. BAF
2. Multicolor scanning laser fundus photography
3. SD-OCT
4. cSLO Dye-based angiography

12. BAF
• Identification of early disease process
• Before evidence of vascular changes
• Pathognomonic loss of normal foveal hypo-AF caused by luteal pigment
depletion
Normal MacTel2

13. BAF
• Features of progressing disease:
• Telangiectatic vascular changes
TEMPORAL to the fovea

14. BAF
• Features of progressing disease:
• Pigmentary migration

15. • Appropriate combination of imaging modalities
• Including:
1. BAF
2. Multicolor scanning laser fundus photography
3. SD-OCT
4. cSLO dye-based angiography

16. • Earliest fundoscopic feature:
• Subtle loss of TEMPORAL perifoveal retinal
transparency
Multicolor cSLO Fundus Photography

17. • Parafoveal TEMPORAL capillary
dilatation
Multicolor cSLO Fundus Photography

18. • Crystalline deposits at vitreoretinal
interface
Multicolor cSLO Fundus Photography

19. • Blunted diluted “diving” venule
Multicolor cSLO Fundus Photography

20. • Pigment migration along dilated capillaries
Multicolor cSLO Fundus Photography

21. • Complications:
1. SRNVM & disciform scarring
Multicolor cSLO Fundus Photography

22. • Complications:
2. Macular hole formation
Multicolor cSLO Fundus Photography

23. • Appropriate combination of imaging modalities
• Including:
1. BAF
2. Multicolor scanning laser fundus photography
3. SD-OCT
4. cSLO dye-based angiography

24. • Diagnosis & Monitoring
• Outer nuclear and/or photoreceptor
layer loss
• Disruption of the photoreceptor IS/OS
junction
SD-OCT

25. • Hyporeflective inner retinal cavities
• Hyporeflective outer retinal cavities
SD-OCT

26. • Pseudolamellar MH
• Outer retinal atrophy
SD-OCT

27. • SRNVM
SD-OCT

28. • Appropriate combination of imaging modalities
• Including:
1. BAF
2. Multicolor scanning laser fundus photography
3. SD-OCT
4. cSLO dye-based angiography

29. • Traditional
• Camera vs. cSLO
• Hallmark…… characteristic
telangiectactic ? leaking capillaries
TEMPORAL to the fovea.
cSLO Fluorescein Angiography

30. • Progression …… entire perifoveal
involvement
cSLO Fluorescein Angiography

31. • Overlapping conditions
cSLO Fluorescein Angiography

32. • Overlapping conditions
cSLO Fluorescein Angiography

33. • Bilateral assessment
cSLO Fluorescein Angiography

34. Take Home Message
• MacTel-2 is a primary neurodegenerative macular disease with secondary vascular
involvement.
• One of the earliest changes reported in MacTel-2 is the pathognomonic loss of normal
foveal hypo-AF in BAF.
• Clinico-pathological correlation demonstrates that loss of perifoveal Müller cells correlate
with areas of luteal pigment loss
• Data provided by multimodal imaging approach may help understanding finding
provided by newer technologies such as OCT-A.
• Future development of the therapeutic agents that rescue Müller cells