Abstract
Purpose :
Long Posterior Ciliary Nerves (LPCNs) are conventionally described at the horizontal meridian. However, very limited imaging and clinical studies have been published that substantiate this traditionally understood position. LPCN position has clinical implications for ophthalmic surgery and laser procedures, particularly with procedures such as trocar insertion during vitrectomy or cyclodiode laser where the ciliary nerves cannot be directly visualized. Thus, we investigated the LPCN position as visualized by fundal ultra-widefield imaging.
Methods :
We performed a retrospective chart review of 100 patients with choroidal nevi who underwent Optos ultra-widefield retinal imaging. The distribution of the LPCNs were analyzed using the ImageJ software. The position of the LPCNs was expressed in degrees, with 30 degrees representing 1 clock hour from the horizontal meridian. A line segment from the centre of the optic nerve to the position of the LPCN was measured relative to the horizontal meridian. The horizontal meridian was defined by a line segment delineated through the centre of the optic nerve to the centre of the fovea. Images with poor quality, media opacity or retinal pathology which precludes view of the LPCNs were excluded.
Results :
Two-hundred images were reviewed from 100 patients. The mean age of patients in the cohort was 63 years-old (SD 15.4, range 19-93) and 58% were female. The temporal ciliary nerve position was identified in 76.0% (152 of 200) and the nasal ciliary nerve position was identified in 45.5% (91 of 200). Temporal LPCNs were found at a mean angle of 5.5° (SD 4.8, range 0.1-30.6°) and nasal LPCNs were found at 4.4 (SD 5.6, range 0.4-14.9°). Ninety-nine percent (99%) of LPCNs were within 30° of the horizontal meridian. There was no statistical significance in the inter-ocular variability of the temporal (p=0.92) and nasal (p=0.72) LPCN angles.
Conclusions :
Our results demonstrate a predominant distribution of LPCNs along the horizontal meridian. To the best of our knowledge, this is the first ultra-widefield imaging study that quantifies and confirms the traditionally reported anatomic distribution. Confidence in the position of the LPCNs can guide Ophthalmic surgeons and help to minimize potential complications related to compromise of the LPCN.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.