Bilateral morphometric analysis of corneal sub-basal nerve plexus in patients undergoing unilateral cataract surgery: a preliminary in vivo confocal microscopy study

Abstract

AimsTo evaluate bilateral morphometric changes of corneal sub-basal nerve plexus (CSNP) occurring after unilateral cataract surgery by in vivo confocal microscopy (IVCM) images analysed with automated software.MethodsIVCM was performed before (V0) and 1 month after surgery (V1) in both operated eyes (OEs) and unoperated eyes (UEs) of 30 patients. Thirty age and sex-matched subjects acted as controls. Corneal nerve fibre density (CNFD), corneal nerve branch density (CNBD), corneal nerve fibre length (CNFL), corneal nerve total branch density (CTBD), corneal nerve fibre area (CNFA), corneal nerve fibre width, corneal nerve fractal dimension (CNFrD) and dendritic cells density were calculated.ResultsMean CNFD, CNBD, CNFL, CTBD, CNFA and CNFrD significantly decreased at V1 versus V0 in both eyes (respectively, 15.35±7.00 vs 21.21±6.56 n/mm2 in OEs and 20.11±6.69 vs 23.20±7.26 in UEs; 13.57±12.16 vs 26.79±16.91 n/mm2 in OEs and 24.28±14.88 vs 29.76±15.25 in UEs; 9.67±3.44 mm/mm2 vs 13.49±3.42 in OEs and 12.53±3.60 vs 14.02±3.82 in UEs; 22.81±18.77 vs 42.25±24.64 n/mm2 in OEs and 38.06±20.52 vs 43.93±22.27 in UEs; 0.0040±0.0021 vs 0.0058±0.0020 mm2/mm2 in OEs and 0.0049±0.0016 vs 0.0057±0.0019 in UEs; 1.418±0.058 vs 1.470±0.037 in OEs and 1.466±0.040 vs 1.477±0.036 in UEs; always p<0.049).ConclusionPatients undergoing cataract surgery exhibit bilateral alterations of CSNP. This finding could have broad implications in the setting of sequential cataract surgery.

Protecting the Ocular Surface at the Time of Cataract Surgery: Intracameral Mydriatic and Anaesthetic Combination Versus A Standard Topical Protocol

“…In both groups, a significantly lower corneal subbasal plexus fiber density was observed at Days 5 and 15 compared to baseline. These results are in line with the observations recently published by Giannaccare et al who showed that patients undergoing cataract surgery exhibit bilateral alterations of the corneal sub-basal nerve plexus, which have a negative influence on the epithelial wound healing process [33]. The better TBUT observed at Day 15, together with less KA and Langerhan's cell infiltration, could be related to the lower toxicity of Mydrane.…”

<p>A Review of the Mechanism of Action of Cyclosporine A: The Role of Cyclosporine A in Dry Eye Disease and Recent Formulation Developments</p>

“…72 New confocal microscopic evidence from cataract surgeries demonstrates surgical insult to the first eye creates corneal nerve sub-basal changes in both eyes, which may compromise the lacrimal functional unit. 10 Cyclosporine A provides additional treatment options for patients with surgically induced dry eye. In a study of DED, dry eye symptoms increased at 1 month following laser-assisted in-situ keratomileusis (LASIK), but the use of topical cyclosporine A 0.05% emulsion improved post-LASIK dry-eye symptoms for up to 1 year, returning symptoms to preoperative baseline levels.…”

“…8,9 Surgical interventions to treat ophthalmic disorders and diseases can also cause dry eye due to the resultant inflammation from the length of time in surgery, incision site disruption to the corneal nerves, and type of post-surgical medication. [10][11][12] Post-trabeculectomy patients have elevated tear film osmolarity and symptoms of dry eye; 13 intraoperative use of lubricating substances can decrease post-surgical dry eye symptoms and treatment with dry eye medication postoperatively can help alleviate surgery-induced dry eye. 11,14 Dry eye symptoms following cataract surgery occur in 42%, 15%, and 9% of eyes of patients at 1 week, 1 month, and 3 months after surgery, respectively.…”

“…12 Additionally, new research demonstrates the bilateral impact on the corneal sub-basal nerve complex after cataract surgery, potentially explaining worse dry eye symptoms after cataract surgery on the second eye. 10 The Tear Film & Ocular Surface Society Dry Eye Workshop II (TFOS DEWS II) developed an evidencebased definition of DED in recognition of its multifactorial nature. 5 This key working definition of DED published in 2017 states:…”

“… 12 Additionally, new research demonstrates the bilateral impact on the corneal sub-basal nerve complex after cataract surgery, potentially explaining worse dry eye symptoms after cataract surgery on the second eye. 10 …”