NANOSNET

I've been using spectralis for the past 9 years, although not exclusively. Here are some of the tips:

1. As with RNFL, it is better for progression rather than using absolute cut-offs as there is wide anatomic variance and other conditions may impact baseline GCL
2. I use the 1,2,3 mm ring, some general guidelines:
   a. 0.30 mm3 volume and above is normal
   b. 0.26-0.3 mm3 would be borderline
   c. 0.22-0.26 mm3 would be mild thinning
   d. 0.18-0.22 mm3 would be moderate thinning
   e. <0.18 mm3 would be severe thinning - it tends to bottom out around 0.12-0.14 mm3
3. for chiasmal disease specifically on the Spectralis, you can compare the macula GCL nasal quadrant to temporal quadrant (macula nasal-temporal ratio = mNTR): When distinguishing chiasmal compression from POAG, an optimal diagnostic mNTR threshold of <0.99 was identified (nasal thinner than temporal), which was associated a specificity of 100% and a sensitivity of 84%. When comparing with healthy controls, a mean mNTR threshold of <0.96 was associated with a specificity of 100% and a sensitivity of 77% in identifying chiasmal compression and an NTR threshold of >1.06 was associated with a specificity of 88% and a sensitivity of 60% in identifying glaucoma - (Kleerekooper et al. Differentiating glaucoma from chiasmal compression using optical coherence tomography: the macular naso-temporal ratio. Br J Ophthalmol. 2024 May).

Best,

Drew

Andrew,

Thank you very much. This is very helpful.

Nancy

I've been using spectralis for the past 9 years, although not exclusively. Here are some of the tips:

1. As with RNFL, it is better for progression rather than using absolute cut-offs as there is wide anatomic variance and other conditions may impact baseline GCL
2. I use the 1,2,3 mm ring, some general guidelines:
   a. 0.30 mm3 volume and above is normal
   b. 0.26-0.3 mm3 would be borderline
   c. 0.22-0.26 mm3 would be mild thinning
   d. 0.18-0.22 mm3 would be moderate thinning
   e. <0.18 mm3 would be severe thinning - it tends to bottom out around 0.12-0.14 mm3
3. for chiasmal disease specifically on the Spectralis, you can compare the macula GCL nasal quadrant to temporal quadrant (macula nasal-temporal ratio = mNTR): When distinguishing chiasmal compression from POAG, an optimal diagnostic mNTR threshold of <0.99 was identified (nasal thinner than temporal), which was associated a specificity of 100% and a sensitivity of 84%. When comparing with healthy controls, a mean mNTR threshold of <0.96 was associated with a specificity of 100% and a sensitivity of 77% in identifying chiasmal compression and an NTR threshold of >1.06 was associated with a specificity of 88% and a sensitivity of 60% in identifying glaucoma - (Kleerekooper et al. Differentiating glaucoma from chiasmal compression using optical coherence tomography: the macular naso-temporal ratio. Br J Ophthalmol. 2024 May).

Best,

Drew

I've been using spectralis for the past 9 years, although not exclusively. Here are some of the tips:

1. As with RNFL, it is better for progression rather than using absolute cut-offs as there is wide anatomic variance and other conditions may impact baseline GCL
2. I use the 1,2,3 mm ring, some general guidelines:
   a. 0.30 mm3 volume and above is normal
   b. 0.26-0.3 mm3 would be borderline
   c. 0.22-0.26 mm3 would be mild thinning
   d. 0.18-0.22 mm3 would be moderate thinning
   e. <0.18 mm3 would be severe thinning - it tends to bottom out around 0.12-0.14 mm3
3. for chiasmal disease specifically on the Spectralis, you can compare the macula GCL nasal quadrant to temporal quadrant (macula nasal-temporal ratio = mNTR): When distinguishing chiasmal compression from POAG, an optimal diagnostic mNTR threshold of <0.99 was identified (nasal thinner than temporal), which was associated a specificity of 100% and a sensitivity of 84%. When comparing with healthy controls, a mean mNTR threshold of <0.96 was associated with a specificity of 100% and a sensitivity of 77% in identifying chiasmal compression and an NTR threshold of >1.06 was associated with a specificity of 88% and a sensitivity of 60% in identifying glaucoma - (Kleerekooper et al. Differentiating glaucoma from chiasmal compression using optical coherence tomography: the macular naso-temporal ratio. Br J Ophthalmol. 2024 May).

Best,

Drew