Encroachment of the retina and choroid onto the nasal portion of the optic nerve head in high myopia: visual and anatomical manifestations

Abstract

Myopia (short-sightedness/near-sightedness) is widespread and is increasing rapidly worldwide! We study a common, but rarely considered complication of high myopia known as nasal myopic super-traction (or super-involution), or encroachment of the retina and choroid onto the optic nerve head (disc) , and associated anatomical, physiological, and visual manifestations. This paper provides the foundation for associated extended SCE-1 studies. Here, histological records are presented; optical coherence tomographic (OCT) findings of this disorder are introduced; and perimetric data were obtained using fundus camera perimetry. We relate these data to visual functions measured upon and adjacent to the optic nerve head of the eye (the disc). In a separate paper in this issue (Chang et al., J. Mod. Opt. 2009, 20, 2272), the Stiles–Crawford effect of the first kind (SCE-1) was used to study photo-receptor alignments, and associated transient changes in photoreceptor alignments recorded using the same test subjects. We sought to understand better nasal myopic super-traction and its complications. We considered associated affects on the retinal pigment epithelium (RPE), nerve fiber bundles on the optic nerve head, etc. We assessed visual functions upon and about the optic nerve head. We demonstrated unique OCT properties in the disc-area in high myopia, evidence of disc hyperemia, reported the presence of maintained on-the-disc visual responses in over-ride tissues, and recorded reductions in visual sensitivity in retinal tissues translated onto/upon the disc. On-the-disc retinal and choroidal over-rides in high myopia remain viable, but exhibit reduced visual sensitivity; reveal time-varying alterations in photoreceptor alignments; and there exists evidence for on-going physical changes occurring in these over-ride tissues.

Keywords:

• myopia–high and pathological myopia
• nasal myopic super-traction, or super-involution, and/or encroachment of the retina and choroid onto the optic nerve head
• myopia
• high–measurements of visual functions and Optical Coherence Tomography (OCT)
• Stiles–Crawford effect of the first kind
• fundus camera perimetry

Acknowledgements

The authors greatly appreciate the efforts of the ever-loyal subjects and assisting graduate and undergraduate student experimenters participating in these studies! We welcomed comments made on aspects of this work by Profs. (at UC Berkeley): Gerald Westheimer, Clifton Schor, Christine Wildsoet, Paola Timeras (now deceased); (at UC San Francisco) Dan Schwartz, Jacque Duncan; and (at U Waterloo, Ontario, Canada) Vasudevan Lakshminarayanan; and others. In addition, Prof. Hans Grossniklaus (at Emory U) kindly provided a number of applicable histological sections to us, and the AFIP, Walter-Reed Army Hospital, Washington, DC, provided a number of photo-records of valuable and well documented histological materials.

We also acknowledge with thanks a Faculty Research Grant Award from the University of California at Berkeley Committee on Research. There has been no conflict of interest by any of the participants.

Notes

^†Now at New England College of Optometry, Boston, MS, USA

Notes

1. Note: Leopold Weiss, 1848/1849?–1901, was a German ophthalmologist, who trained in Giessen, and who later became Chairman of the Department of Ophthalmology at Heidelberg in 1895. He was particularly active in studies of myopia in the latter part of the nineteenth century, e.g. Weiss 1897, 1898 51,52. His achievements included Weiss' reflex, a curved retinal reflection on the nasal side of the disc (this was associated with myopia), and Weiss' ring, a residuum of vitreous connective tissue which had been attached at the disc, and which can be observed in a posterior vitreous detachment. Also, please refer to Figure 7.

2. Myopic nasal super-traction of the nerve head, measurements were made at 22° in the nasal retina (past, but near the optic nerve head) and also on top of the optic nerve: the Stiles–Crawford effect) was measured before, just after, and after recovery from OKN stimuli.

3. Data obtained from the same eye appeared in 14–16.

4. Some material in this article was subsequently withdrawn, but not the data cited here.

Additional information

Notes on contributors

Stacey S. Choi†

†Now at New England College of Optometry, Boston, MS, USA