Perforating scleral vessels
Dr. Shreya Jaiswal, Dr. Prabhat Nangia, Dr. Sarang Lambat, Dr. Vinay Nangia
Suraj Eye Institute, 559 New Colony, Nagpur
Case Description
A female, 70 years of age, came for a routine examination. She had a history of systemic hypertension and hypothyroidism since 20 years and diabetes mellitus since 4 years. She had a history of cataract extraction with intraocular lens implantation surgery done in both eyes 15 years back, and 3 doses of intravitreal anti vascular endothelial growth factor (VEGF) injection in left eye 11 years back. Her best corrected visual acuity was 6/12, N18 in right eye and 6/36, N36 in left eye. She had an axial length of 28.93 mm in right eye and 27.50 mm in the left eye. Anterior segment examination showed pseudophakia in both eyes. Intraocular pressure was 12 mmHg and 16 mmHg in right and left eye respectively.
Figure 2 shows colour fundus photograph of left eye with clear media, a horizontally oval disc and a vertical cup to disc ratio of 0.8:1 with large parapapillary atrophy (Yellow arrow). There is a large chorioretinal atrophy involving macula (Green arrow) with choroidal tessellations, suggestive of category 4 myopic macular degeneration.
Figure 4 shows SD-OCT RNFL thickness map, which shows normal thickness of RNFL in all the quadrants.
Another hypo-reflective structure (Yellow arrow) can be seen bifurcating and forming a direct communication with the choroid at the posterior pole, most likely being the short posterior ciliary artery supplying the choroid and retina.
Discussion
A decrease in the choroidal and scleral thickness is often noted with high myopia, which allows better visualisation of deeper structures such as blood vessels within the sclera, using an SD-OCT. Our patient was a highly myopic patient, where we could see the presence of long and short ciliary artery along with possible draining macular vortex vein. However, it is possible to understand the choroidal vasculature better using indocyanine green angiography. The OCT does however outline vessels in the sclera that go to supply and or drain the choroid or sub Bruch’s Retinal Pigment Epithelial area when the choroid thins considerably.
Studies by Querques G et.al (3) and Ishida T et.al (4) suggest a significant correlation of presence of lacquer cracks and choroidal neovascular membrane with perforating scleral vessels. Thus it is important to study the intra-scleral vascular structures as any alterations in these may lead to development of chorio-retinal complications or optic nerve damages in patients with pathologic myopia. These vessels may also prove to be important in early identification of choroidal and outer retinal changes and may be a target for development of ocular vascular therapies in the future.
ReadWise
- Quaranta M, Arnold J, Coscas G, Francais C, Quentel G, Kuhn D, Soubrane G. Indocyanine green angiographic features of pathologic myopia. American journal of ophthalmology. 1996 Nov 1;122(5):663-71. https://doi.org/10.1016/S0002-9394(14)70484-2
- Ohno-Matsui K, Morishima N, Ito M, Yamashita S, Futagami S, Tokoro T, Nakagawa T. Indocyanine green angiography of retrobulbar vascular structures in severe myopia. American journal of ophthalmology. 1997 Apr 1;123(4):494-505. https://doi.org/10.1016/S0002-9394(14)70175-8
- Querques G, Corvi F, Balaratnasingam C, Casalino G, Parodi MB, Introini U, Freund KB, Bandello F. Lacquer cracks and perforating scleral vessels in pathologic myopia: a possible causal relationship. American journal of ophthalmology. 2015 Oct 1;160(4):759-66. https://doi.org/10.1016/j.ajo.2015.07.017
- Ishida T, Watanabe T, Yokoi T, Shinohara K, Ohno-Matsui K. Possible connection of short posterior ciliary arteries to choroidal neovascularisations in eyes with pathologic myopia. British Journal of Ophthalmology. 2019 Apr 1;103(4):457-62. http://dx.doi.org/10.1136/bjophthalmol-2018-312015
Correspondence
Dr Vinay Nangia
MS, FRCS, FRCOphth
Director
Suraj Eye Institute
Nagpur
Email –education@surajeye.org