Spark ImageWise 22

Branch Retinal Vein occlusion and Glaucoma 

Dr Swati. Mishra, Dr Prabhat Nangia, Dr Sarang Lambat, Dr Vinay Nangia 
Suraj Eye Institute, 559 New Colony, Nagpur 

Case Description
A female, 78 years of age, presented to us for a regular checkup. She was a known diabetic and hypertensive since past 4 years.  On examination the unaided visual acuity was 6/6p, N6 in right eye (RE) and 6/6, N6 in left eye (LE). The anterior segment showed pseudophakia in both eyes (BE). Intraocular pressure (IOP) measured with Goldman applanation tonometer was 16 mmHg in RE and 15 mmHg in LE. 

Figure 1: RE Colour fundus photograph shows supero-temporal BRVO with multiple collaterals (green arrows). Area of localized hemorrhages can be seen (red arrow). Hard exudates can be seen around the hemorrhages arranged in circinate fashion (black arrow). Disc shows glaucomatous changes with vertical cup disc ratio is 0.8:1 and inferior rim thinning (yellow arrow).
Figure 2: LE colour fundus photograph shows glaucomatous disc with vertical cup disc ratio of 0.8:1. 
Figure 3: RE RNFL OCT showed RNFL loss in inferotemporal sector (blue arrows) and reduction in global RNFL thickness.
Figure 4: LE RNFL OCT showed reduction in RNFL thickness in temporal and infero temporo sector (blue arrows) and global RNFL loss.

She was started on combination of brimonidine tartrate (0.2%), timolol maleate (5%) for glaucoma and carboxymenthycellulose drops for lubrication. 

Discussion

Venous occlusions are known to occur in association with glaucoma. In this patient in the RE there is the presence of superotemporal BRVO, which is associated with the presence of significant collaterals especially temporal to the fovea running vertically. BRVO is often known to be associated with loss of retinal nerve fiber layer in the segment of the optic disc associated with the area where the occlusion has occurred.   The retinal nerve fiber layer shows the presence of loss in the inferotemporal segment and global loss in the RE. The LE also shows generalised thinning of the RNFL. 

The possibility of developing a venous occlusion increases with age and in the Central India Eye and Medical Study the prevalence was found to be 0.42%.  Therefore one may always assess the macula to rule out the presence of BRVO in an eye with glaucoma and similarly one may rule out glaucoma in an eye with BRVO. This may be done by making an assessment of the optic disc and using structural and functional tests.  

A red herring would be – initially the swelling (false thickening) of the RNFL in the segment where there is BRVO due to the parapapillary oedema. This may hide the presence of pre-existing RNFL loss. Similarly following resolution of the BRVO induced oedema over a period of time, the segment of the neuroretinal rim coinciding with the area of BRVO may show pallor associated with RNFL loss, even in the absence of glaucoma. This RNFL loss in the absence of glaucoma may be wholly related to the BRVO.  

In this patient, there is also the presence of an area of hard exudates arranged in a circinate fashion superotemporally. It is likely that in the centre of this area lie microaneurysms or a macro-aneurysm. This could not be ascertained, since a FFA could not be done. The importance of such a lesion is that it interferes with the ganglion cell deviation and thickness map in this patient, since the segmentation may be inappropriate in this area of retinal oedema associated with the hard exudates. 

These differentiations are important, to understand the clinical picture of a patient with RNFL loss in association with both BRVO and or glaucoma. 

ReadWise

  1. 1.Yin X, Li J, Zhang B, Lu P. Association of glaucoma with risk of retinal vein occlusion: A meta-analysis. Acta Ophthalmol. 2019 Nov;97(7):652-659. doi: 10.1111/aos.14141. Epub 2019 May 24.
  2. 2. Lopilly Park HY, Jeon S, Lee MY, Park CK. Glaucoma Progression in the Unaffected Fellow Eye of Glaucoma Patients Who Developed Unilateral Branch Retinal Vein Occlusion. Am J Ophthalmol. 2017 Mar;175:194-200. doi: 10.1016/j.ajo.2016.10.009. 
  3. 3. Han JC, Eo DR, Lee TK, Shin JH, Kee C. Does Glaucoma Share Common Pathogenesis with Branch Retinal Vein Occlusion?. PLoS One. 2016;11(6):e0156966. Published 2016 Jun 15. doi:10.1371/journal.pone.0156966

Correspondence 

Dr Vinay Nangia
MS, FRCS, FRCOphth
Director 
Suraj Eye Institute
Nagpur
Email –education@surajeye.org

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