Interpretation of SD-OCT

Gella Laxmi

2009PHXF013P

How to go about….

• Interpretation should proceed sequentially from vitreous towards choroid

• Evaluate each layers

Gray scale or conventional colors?

• Gray scale images – qualitatively superior

• Color images – misleading

ReflectivityHyper reflective Lesions (Red ) Hypo reflective Lesions (Black) (Fluid)

ME

PED

SRF

FovealschisisERM

CNVM

DRUSEN

HE

ThicknessIncreased

(edema, CNVM) Decreased

Morphology

“Missing" retina "Extra" retinal tissue

Before advising OCT ......

Answer 2 questions...

“Why OCT in this case?” “What to look for in OCT?”

Diabetic Macular Edema

• Classify (FFA better)

• To R/O Foveolar detachment

• To R/O VMT ( Difficult clinically)

• Post treatment follow up

• Swelling – Focal /Diffuse / Cystoid

• Hard exudates

• Foveolar detachment

• Status of posterior hyaloid

• CWS, Hemorrhage

OCT classification of macular edema

Diffuse Retinal Thickening (DRT)

Cystoid Macular Edema (CME)

Neurosensory Detachment (NSD)

Schitic Retinal Thickening (SRT)

Macular Hole

• Confirmation• Staging• Surgical planning• Patient education

• FTMH • LMH• VMT

What to look for? Why OCT?

OCT Staging of macular hole

Stage 1B(Full thickness pseudocyst)

Stage 2 (Partial opening of pseudooperculum focal Vitreous attachment )

Stage 3(Operculated FTMH Vitreous traction released)

Stage 4(With complete PVD)

Post surgery

Surgical prognosis

Preoperative macular hole configuration and size determined by OCT showed good correlation with anatomical and functional outcomes after surgery

• HFF > 0.9 - 100 % PRIMARY CLOSURE

HFF = 0.5 - 67 % PRIMARY CLOSURE

HFF < 0.5 - Poor closure rates

ARMD

• Diagnosis - Dry or Wet• Response to treatment

Drusens

• Lipofusin deposits

• Bumpy RPE

• High reflective

• Normal inner retinal layers

• No shadowing

Types of PEDFibrovascular

SerousHemorrhagic

Drusanoid

Types of CNVM• Occult • Classic

Intraretinal fluid is associated with the presence of neovascular membrane

• Disruption of RPE band• Irregular thickening below RPE• CNVM not adequately visualized • Optical shadowing by detached RPE

• Continuous RPE band• Well defined , Hyperreflective fusiform thickening above RPE• Marked , posterior shadowing

Central Serous Retinopathy

• RPE defect

• SRF

• Cystoid spaces

• Foveal atrophy/thinning

• Subretinal fibrin

• CNVM

• Compare the reflectivity with

vitreous

• Granular outer segment in

chronic cases

Parafoveal Telangiectasia

• Cystic spaces• Minimum/ moderate thickening• Defect at the level of photoreceptor layer• Intraretinal high reflective areas causing

shadow (migrated pigments)

OCT in ERM and VMT

• Confirmation• Topographic localization• Surgical planning • R/O coincidental pathology like macular hole /pseudohole

References

• M Brar, D-U G Bartsch. Colour versus grey-scale display of images on high-resolution spectral OCT. Br J Ophthalmol. 2009; 93: 597-602.

• Brian Y. Kim, Scott D. Smith, et al. Optical Coherence Tomographic patterns of Diabetic Macular Edema. Am J Ophthalmol. 2006; 142;405-412.

• S Ullrich, C Haritoglou, C Gass, M Schaumberger, M W Ulbig. Macular hole size as a prognostic factor in macular hole surgery. Br J Ophthalmol. 2002 April; 86(4): 390–393.

• Kusuhara S, Teraoka Escano MF, Fujii S et al. Prediction of postoperative visual outcome based on hole configuration by optical coherence tomography in eyes with idiopathic macular holes. Am J Ophthalmol 2004; 138: 709–16.

• Lisandro M Sakata, Julio DeLeon-Ortega et al. Optical coherence tomography of the retina and optic nerve – a review. Clinical and Experimental Ophthalmology 2009; 37: 90–99.