Sensory Innervation of the Upper Eyelid and Its Implication for Upper Eyelid Surgery.

PURPOSE: Sensory alterations of the upper eyelid skin and eyelashes are frequently encountered after upper eyelid surgery. The objective of this study was to provide information on the exact course and distribution of sensory nerve fibers through the anatomic planes in the upper eyelid. METHODS: Ten formalin-fixed hemifaces were dissected. The nerve branches of the ophthalmic nerve in the upper eyelid were traced in an anterograde fashion. RESULTS: A total of 151 nerve fibers were recorded during dissection. The infratrochlear, supratrochlear, supraorbital, and lacrimal nerve contributed each to both the upper eyelid skin innervation and the upper eyelid rim plexus in different distribution patterns. The mean distance from the eyelid margin at which nerve fibers pierced from preseptal into the orbicularis muscle was 14 ± 1.1 mm for nerve fibers targeting the eyelid dermis and 3.7 ± 1.2 mm for nerve fibers targeting the eyelid rim plexus ( p < 0.001). The mean intraorbicular course of nerve fibers was 3 mm (0-17; standard deviation 4.1). The mean distance from the eyelid margin at which nerve fibers pierced from the orbicularis muscle into the preorbicular plane was 10 ± 1 mm for nerve fibers innervating the eyelid dermis and 1.3 ± 0.8 mm for nerve fibers innervating the eyelid rim plexus ( p < 0.001). The mean distance of the preorbicular course of nerve fibers was 2 mm (0-15; standard deviation 3.6). CONCLUSIONS: Based on the findings, a certain degree of postoperative eyelid skin numbness is inevitable while eyelash innervation may be spared in upper blepharoplasty.

How the Lifting Amount of Endoscopic Brow Lifts Is Influenced by Supraorbital Nerve Tension and Brow Gliding-Layer Mobility.

BACKGROUND: Sensory nerve tension and gliding-layer mobility in the brow may be significant factors affecting postoperative brow level in an endoscopic brow lift, yet they have rarely been studied. METHODS: To investigate the effects of sensory nerve tension and gliding-layer mobility, the following measurements were performed alongside the endoscopic brow lift in 50 fresh cadaveric hemifaces: amount of brow elevation, critical lifting amount (as sensory nerves became tense), laxity of sensory nerve courses, and mobility of brow-gliding layers. The sensory nerve situations in the subperiosteal and subgaleal dissections were also observed. RESULTS: Supraorbital nerve tension limited the cephalic advancement of the forehead flap. The mean elevation of the brow was 5.8 ± 1 mm (range, 3.5 to 8.6 mm). The mean critical lifting amount was 5.3 ± 1.1 mm (range, 4.0 to 7.3 mm). The mean amount of laxity in the supraorbital nerve (the permissible amount of lift) was 4.1 ± 0.9 mm (range, 2.5 to 5.5 mm). The galeal fat pad was responsible for 60% of brow mobility. The sensory nerve was more protected by a subgaleal dissection in the brow and inferior forehead and by a subperiosteal dissection in the middle and upper forehead. CONCLUSIONS: Cephalic movement of the forehead flap is limited by supraorbital nerve tension. The permitted lifting amount varies from 2.5 to 5.5 mm. Gliding-layer mobility in the brow offsets the postoperative amount of cephalic advancement of the forehead flap. Consideration of supraorbital nerve tension and gliding-layer mobility is recommended to obtain an optimal brow level in endoscopic brow lifts.

Factors Associated With Long-Term Risk of Recurrence After Percutaneous Radiofrequency Thermocoagulation of the Gasserian Ganglion for Patients With Trigeminal Neuralgia Involving the Ophthalmic Division: A Retrospective Study.

OBJECTIVE: To evaluate risk factors associated with recurrence after radiofrequency thermocoagulation (RFT) of the gasserian ganglion among patients with ophthalmic trigeminal neuralgia (TN) and prognostic factors in terms of recurrence-free survival (RFS) during a long-term follow-up. METHODS: From January 2005 to December 2017, 300 patients with ophthalmic TN underwent RFT. A retrospective analysis of 14-year outcomes was performed. Kaplan-Meier analysis was used for RFS after the procedure. Univariate and multivariate Cox regression analyses were performed to identify risk factors for pain recurrence. RESULTS: The initial effective rate of RFT for ophthalmic TN was 92%. The mean follow-up time was 77.38 ± 43.24 months. The cumulative probability of RFS was 86.94% at 1 year, 80.03% at 2 years, 77.27% at 3 years, 74.01% at 5 years, and 59.92% at 10 years after RFT. The mean duration of RFS was 114.67 months (95% confidence interval [CI] 106.27 to 123.06 months). In multivariate analysis, atypical pain (hazard ratio [HR] = 2.831, 95% CI 1.759 to 4.554, P < 0.001) and mild facial hypesthesia (HR = 2.540, 95% CI 1.309 to 4.931, P = 0.006) before RFT were independently associated with pain recurrence. Patients with a prognostic index (PI) > 1.27 were at high risk for pain recurrence. Major complications included troublesome dysesthesia (0.7%), keratitis (10.9%), diplopia (0.4%), facial paresthesia (6.2%), and masseter weakness (12.7%). Masseter weakness was more common in patients with V3 branch involvement. Three patients lost their sight due to keratitis. CONCLUSION: Our study investigated long-term outcomes and complications of RFT for ophthalmic TN. Patients at high risk for pain recurrence were identified, which might provide a basis for clinical decision making before RFT.

Direct Versus Indirect Corneal Neurotization for the Treatment of Neurotrophic Keratopathy: A Multicenter Prospective Comparative Study.

PURPOSE: To analyze the comparative safety and efficacy of two techniques of corneal neurotization (CN) (direct corneal neurotization [DCN] vs indirect corneal neurotization [ICN]) for the treatment of neurotrophic keratopathy (NK). DESIGN: Multicenter interventional prospective comparative case series. METHODS: This study took place at ASST Santi Paolo e Carlo University Hospital, Milan; S.Orsola-Malpighi University Hospital, Bologna; and Santa Maria alle Scotte University Hospital, Siena, Italy. The study population consisted of consecutive patients with NK who underwent CN between November 2014 and October 2019. The intervention procedures included DCN, which was was performed by transferring contralateral supraorbital and supratrochlear nerves. ICN was performed using a sural nerve graft. The main outcome measures included NK healing, corneal sensitivity, corneal nerve fiber length (CNFL) measured by in vivo confocal microscopy (IVCM), and complication rates. RESULTS: A total of 26 eyes in 25 patients were included: 16 eyes were treated with DCN and 10 with ICN. After surgery, NK was healed in all patients after a mean period of 3.9 months without differences between DCN and ICN. Mean corneal sensitivity improved significantly 1 year after surgery (from 3.07 to 22.11 mm; P < .001) without differences between the 2 groups. The corneal sub-basal nerve plexus that was absent before surgery in all patients, except 4, become detectable in all cases (mean CNFL: 14.67 ± 7.92 mm/mm2 1 year postoperatively). No major complications were recorded in both groups. CONCLUSIONS: CN allowed the healing of NK in all patients as well as improvement of corneal sensitivity in most of them thanks to nerve regeneration documented by IVCM. One year postoperatively, DCN and ICN showed comparable outcomes.

Intradural "limited drill" technique of anterior clinoidectomy and optic canal unroofing for microneurosurgical management of ophthalmic segment and PCOM aneurysms-review of surgical results.

To evaluate the safety and efficacy of intradural "limited drill" technique (ILDT) of anterior clinoidectomy (AC) and optic canal unroofing (OCU) for microneurosurgical management of ophthalmic segment and posterior communicating artery (PCOM) aneurysms. All the patients with ophthalmic segment and PCOM aneurysms who underwent AC and OCU by ILDT for microneurosurgical management of ophthalmic segment and PCOM aneurysms during 4-year period (2013-2016) at our Institute were included in this study. In ILDT of AC and OCU, the use of power drill is restricted to AC only and OCU is done exclusively with 1-mm Kerrison punch. AC and OCU by ILDT were done in 24 patients with 29 ophthalmic segment and 7 PCOM aneurysms. AC and OCU by ILDT helped in mobilization of optic nerve/internal carotid artery (ICA) and provided excellent exposure for all these aneurysms. There was no injury to ICA or optic nerve during drilling. AC and OCU facilitated clip ligation of 34 of these aneurysms. Remaining 2 aneurysms were considered not suitable for clipping. Check angiogram done for 33 aneurysms revealed complete obliteration of 26 aneurysms, very small residual neck in 5 aneurysms, and small residual aneurysm in 2 aneurysms. Deterioration in vision was noted in 1 patient (4.1%). In 6 patients with preoperative visual deficits, significant improvement in vision was noted in 4 patients (4/6-66.6%) after surgery. Good outcome (MRS < 2) was noted in 91.6% (22/24) of these patients. ILDT is a safe and effective technique of AC and OCU which provide good exposure for ophthalmic segment and PCOM aneurysms.

Corneal neurotization.

PURPOSE OF REVIEW: Neurotrophic keratopathy is a devastating corneal condition that can lead to ocular morbidity and blindness. Current medical and surgical treatments poorly tackle the essential problem of corneal aesthesia and hence fail to provide a permanent cure. Recent advances in corneal neurotization techniques have shown promise to restore corneal nerves in neurotrophic keratopathy. This article aims at reviewing the current surgical advances, along with the current thoughts and evidence available for corneal nerve regeneration. RECENT FINDINGS: Corneal neurotization was first introduced in 2009 by Terzis et al., but recently picked up more interest since 2014. Direct and indirect neurotization are being developed, and different nerves (sural nerve, great auricular nerve) have been explored for interposition between frontal nerve branches and the cornea. New endoscopic techniques are introduced for less invasive approaches. On the corneal front, confocal microscopy and esthesiometry studies have established that the regeneration of the corneal nerves is happening 6 months after the procedure. SUMMARY: Neurotization is a budding revolutionary technique that shows promise of cure for neurotrophic corneas, but at this stage, it is still reasonably invasive and still reserved for selected patients.

Minimally Invasive Corneal Neurotization With Acellular Nerve Allograft: Surgical Technique and Clinical Outcomes.

PURPOSE: To describe a minimally invasive surgical technique and its clinical outcomes with the use of acellular nerve allograft to re-establish corneal sensibility in patients with neurotrophic keratopathy. METHODS: Acellular nerve allograft was coapted to an intact supraorbital, supratrochlear, or infraorbital nerve and transferred to the affected eye. Donor nerve pedicles were isolated through a transpalpebral or transconjunctival approach. Retrospective evaluation of preoperative and postoperative corneal sensibility, ocular surface, and best-corrected visual acuity was performed in all patients. Mean follow-up period was 6 months (range: 3-10 months). RESULTS: Corneal neurotization with acellular nerve allograft was successfully performed in 7 patients with restoration of corneal sensibility and corneal epithelial integrity. In vivo confocal microscopy demonstrated increased nerve density in corneal stroma at 4 months after surgery. CONCLUSIONS: The use of acellular nerve allograft allows for a minimally invasive approach to successful corneal neurotization.

Endoscopic Corneal Neurotization: Technique and Initial Experience.

PURPOSE: The authors describe a minimally invasive surgical technique to re-establish corneal sensibility in a patient with neurotrophic keratopathy with the supraorbital nerve harvested endoscopically. METHODS: Pedicled contralateral supraorbital nerve was harvested endoscopically through small eyelid crease and scalp incisions and transferred to the affected eye. RESULTS: Endoscopic corneal neurotization was successfully performed with restoration of corneal sensibility and corneal epithelial integrity. CONCLUSIONS: The use of an endoscope allows for a minimally invasive approach to successful corneal neurotization with the supraorbital nerve.

Corneal neurotization from the supratrochlear nerve with sural nerve grafts: a minimally invasive approach.

Corneal anesthesia is a debilitating condition which can ultimately lead to blindness from repetitive corneal injury and scarring. We have developed a minimally invasive technique for corneal re-innervation that we have used with excellent results in ten eyes. This article and accompanying video describes the relevant anatomy and demonstrates the technique in detail.

Use of sensory and motor action potentials to identify the position of trigeminal nerve divisions for radiofrequency thermocoagulation.

OBJECT: The objective of this study was to develop an electrophysiological method for intraoperative localization of the trigeminal nerve branches during radiofrequency thermocoagulation (RFTC). METHODS: Twenty-three patients who were scheduled to undergo RFTC were included. The trigeminal nerve root was stimulated through the foramen ovale using the radiofrequency cannula. Antidromic responses were recorded from the target division through supraorbital, infraorbital, and mental foramina electrodes, and an additional electrode at the masseter muscle. Sensory and motor action responses, as well as verbal and masseter contraction responses, were recorded and correlated. RESULTS: The antidromic responses were easily recorded in the target division in all 23 patients, and they were invariably correlated with the patient's verbal responses. The potentials were recorded successively from V1 to V3. The amplitude in each division before and after RFTC showed little difference in response to electrical stimulation with the same current. The motor trigeminal nerve action potentials were recorded in 10 patients; 7 of these patients had postoperative masseter muscle weakness, while the remaining 3 had normal masseter muscle function. Potentials with low amplitudes were usually obtained from neighboring divisions, but no unexpected denervation of any branches was observed. All the patients experienced immediate pain relief after the procedure. CONCLUSIONS: This technique is sensitive and easy to apply. The sensory and motor potentials matched the verbal responses and the complications. Although it cannot completely substitute for the patient's verbal response, this approach is helpful in uncooperative patients, and it predicts and reduces the incidence of masseter muscle weakness. The use of these complementary techniques could increase the chances of treatment success.

Randomized, double-blind, controlled study to evaluate the effect of vidian nerve cauterization on lacrimation.

BACKGROUND: After vidian neurectomy, low reported rates of dry eye syndrome (DES) seemed incompatible with the high success rate of nerve severance in previous studies. This study aimed at understanding of the pathophysiology of lacrimation and evaluating the effect of thermal injury through the distal stump on the sphenopalatine ganglion (SPG) after vidian neurectomy. METHODS: A randomized, double-blind, controlled study was performed to evaluate the DES. Eighty precise vidian neurectomies were randomized in a 1:1 ratio to groups 1 and 2. Group 1 represented the cauterization and was used in both distal and proximal nerve stumps, whereas only the proximal nerve stump was cauterized in group 2 subjects. The DES was evaluated with Schirmer's test and ocular surface disease index (OSDI) before and after surgery at 7-10 days and 30 days, respectively. RESULTS: In group 1, the Schirmer's test showed a mean decline of 20 mm (20/30, 66%) at 7-10 days and 15 mm (15/30, 50%) at 30 days. In group 2, the Schirmer's test revealed significantly lesser dry eye problems, with a mean decline of 16 mm (16/30; 52%) at 7-10 days and 2 mm (2/30; 6%) at 30 days. The significantly less postoperative dry eye problems in group 2 can be shown by the OSDI at 7-10 days, but not at 30 days. The mean follow-up period was 24 months. No recurrence of nasal allergy symptoms was noted in the follow up period. CONCLUSION: The significant advantage of preservation of the SPG function is justified by Schirmer's test, although the effect did not appear to be comparable with the clinical manifestations evaluated by OSDI at 30 days. Nevertheless, the preservation of distal stump from preventive cauterization can still offer better eye ball moisture in the early evaluation of DES.

Restoration of corneal sensation with regional nerve transfers and nerve grafts: a new approach to a difficult problem.

IMPORTANCE: Corneal anesthesia is recalcitrant to conventional treatment and can lead to permanent visual loss. OBJECTIVE: To assess the outcomes of a novel sensory reconstructive technique for the treatment of corneal anesthesia. DESIGN, SETTING, AND PARTICIPANTS: This prospective study evaluating a new technique was conducted at a tertiary referral center. Four eyes in 3 patients with corneal anesthesia underwent nerve transfers with nerve grafting to restore corneal sensation. Corneal sensory reconstruction was performed using a segment of the medial cutaneous branch of the sural nerve. Two patients with unilateral trigeminal nerve anesthesia-one following basal skull fracture and another following large posterior fossa tumor resection-underwent corneal sensory reconstruction using the contralateral supratrochlear nerve as the donor sensory nerve. One patient with a history of cerebellar hypoplasia and bilateral congenital corneal anesthesia underwent bilateral corneal sensory reconstruction using the respective ipsilateral supratrochlear nerves as the sensory donor nerves. Corneal anesthesia was evaluated preoperatively and postoperatively in the center of the cornea and in 4 corneal quadrants using a Cochet-Bonnet esthesiometer (Luneau). Complications of the procedure were also documented. MAIN OUTCOMES AND MEASURES: Esthesiometry scores. RESULTS: All eyes had prior complications of corneal anesthesia and had no measurable corneal sensation in the affected eye(s) preoperatively. Two patients-one with cerebellar hypoplasia and the other with posterior fossa tumor resection-had markedly improved corneal sensation 6 months postsurgery (3 eyes; mean [SD] central esthesiometry, 55 [5] mm). A third patient with a history of basal skull fracture underwent unilateral corneal neurotization and recovered 15-mm esthesiometry score centrally after 7.5 months of follow-up. None of the operated on eyes have developed corneal anesthesia-related complications since reconstruction. CONCLUSIONS AND RELEVANCE: Corneal sensory reconstruction provides corneal sensation in previously anesthetic corneas. This can be achieved with minimal morbidity using sural nerve grafts, which surgeons commonly use to reconstruct nerve gaps elsewhere. This multidisciplinary approach restores an ocular defense mechanism and may enable subsequent corneal transplant in these patients.

Endoscopic microdebrider-assisted inferior turbinoplasty with and without posterior nasal neurectomy.

OBJECTIVE: Endoscopic microdebrider-assisted inferior turbinoplasty (EMAIT) has been recognized as an efficient surgical technique in the management of hypertrophied inferior turbinate. In an attempt to further increase surgical successful outcomes, posterior nasal neurectomy (PNN) was developed. The aim of this retrospective case-control study was to assess the position of PNN in the surgery of hypertrophied turbinate. METHODS: Seventy patients were assigned to the two treatment groups: Group A (EMAIT) and Group B (EMAIT and PNN). Subjective outcomes were represented by symptom score and quality of life scores (Rhinoconjunctivitis Quality of Life Questionnaire - RQLQ). Objective outcomes were nasal resistance, saccharin transit time and acoustic rhinometry parameters. RESULTS: The survey demonstrated that symptoms and objective parameters improved postoperatively in both groups, with no statistical significant differences in objective and subjective outcomes between the surgical groups. CONCLUSION: The addition of PNN appears to offer no additional benefit in the subjective and objective outcome related with surgery of hypertrophied inferior turbinate. However, longer follow-up studies and larger number of patients are required in order to validate our results.

Supratrochlear and supraorbital nerves: an anatomical study and applications in the head and neck area.

BACKGROUND: This article elucidates the anatomical details of the course and territory of the supraorbital (SO) and supratrochlear (ST) nerves. Possible applications of the SO and ST nerves for sensory nerve transfer are also examined. METHODS: The dissection of 3 fresh cadaver heads (6 hemifaces) was performed. In each hemiface, the ST and SO nerves were identified. The following data were recorded: 1) number of branches, 2) skin boundaries, 3) communicative branches, and 4) branch length. The feasibility of specific nerve-transfer procedures was also examined. RESULTS: In 4 hemifaces the SO nerve exited from the SO notch and in 2 hemifaces from the SO foramen. The position was lateral to the midline, with a mean distance of 1.93 cm. In all dissections, a maximum of 4 SO branches (range 2-4) were identified. The ST nerve exited the orbital rim medial to the SO nerve, and lateral to the midline with a mean distance of 0.866 cm. The mean distance between the SO and ST nerves at the level of the SO rim was 1.06 cm. In 5 of 6 hemifaces, several sub-branches emerged from the main trunk of the ST nerve. In 1 hemiface the ST nerve was divided in 2 main branches. CONCLUSIONS: The data presented in the current study are in agreement with previous anatomical studies. Both ST and SO nerves can be used as sensory nerve donors in the head and neck area for numerous expanding applications.

Supraorbitary to infraorbitary nerve transfer for restoration of midface sensation in face transplantation: cadaver feasibility study.

BACKGROUND: The collected experience from facial allotransplantations has shown that the recovery of sensory function of the face graft is unpredictable. Unavailability of healthy donor nerves, especially in central face defects may contribute to this fact. Herein, the technical feasibility of transferring the supraorbitary nerve (SO) to the infraorbitary nerve (IO) in a model of central facial transplantation was investigated. METHODS: Five heads from fresh cadavers were dissected with the aid of 3× loupe magnification. Measurements of the maximum length of dissection of the SO nerve through a supraciliary incision and the IO nerve from the skin of the facial flap to the infraorbital foramen were performed. The distance between supraorbital and infraorbital foramens and the calibers of both nerves were also measured. In all dissections, we simulated a central allotransplantation procedure and assessed the feasibility of directly transferring the SO to the IO nerve. RESULTS: The average maximum length of dissection for the IO and SO nerve was 1.4 ± 0.3 cm and 4.5 ± 1.0 cm, respectively. The average distance between the infraorbital and supraorbital foramina was 4.6 ± 0.3 cm. The average calibers of the nerves were of 1.1 ± 0.2 mm for the SO nerve and 2.9 ± 0.4 mm for the IO nerve. We were able to perform tension-free SO to IO nerve coaptations in all specimens. CONCLUSION: SO to IO nerve transfer is an anatomically feasible procedure in central facial allotransplantation. This technique could be used to improve the restoration of midfacial sensation by the use of a healthy recipient nerve in case of the recipient IO nerves are not available secondary to high-energy trauma.

Location of the abducent nerve within the cavernous sinus.

AIM: Knowing the distance between the superior and inferior border of Parkinson's triangle and the location of the abducent nerve within the cavernous sinus is important to decrease the complications which may occur during surgery. We aimed to investigate the cavernous sinus to decrease the complications that may occur during surgery to this area. MATERIAL AND METHODS: Fifty MRIs without pituitary gland abnormality were chosen for radiological assessment of CS. These images were from 18 males and 32 females, with ages ranging from 9 to 58 years and a median age of 28 years. We evaluated structures within and on the lateral wall of the cavernous sinus (especially Parkinson's triangle) with magnetic resonance imaging. The position of the abducent nerve and its level according to the cranial nerves running close the lateral wall were examined. RESULTS: At the level of pituitary stalk, the distance between the trochlear nerve and the ophthalmic nerve ranged from 1 to 4 mm bilaterally. The abducent nerve was located between the trochlear and the ophthalmic nerves in 30% cases bilaterally. CONCLUSION: The knowledge of the position of the abducent nerve will provide a great benefit in minimizing the rate of complications that may occur during the resection of tumors of the cavernous sinus.

In vivo serial imaging of regenerating corneal nerves after surgical transection in transgenic thy1-YFP mice.

PURPOSE: To determine the effect of lamellar transection surgery on the nerve fiber density (NFD) and pattern of nerve regeneration in the cornea of thy1-YFP transgenic mice. METHODS: Wide-field stereo fluorescence microscopy was used to obtain serial images of nerves in live thy1-YFP mice, which express a fluorescent protein in their axons. NFD (mm/mm(2)) was calculated from maximum intensity projection images as the total length of fibers within the area of the contour in which nerves were traced. Whole-mount confocal microscopy was performed to analyze the arrangement of nerves and the types of regenerating fibers. RESULTS: NFD in normal corneas was 35.3 ± 1.8 mm/mm(2). Stereo fluorescence microscopy revealed the presence of a subbasal hairpin nerve layer and an intrastromal nerve trunk layer. After surgery, regenerative sprouting was observed from transected distal ends of intrastromal nerve trunks. NFD also increased, with this increase being maximal between 4 and 6 weeks after surgery. NFD approximated baseline values at 6 weeks and did not change any further at 8 weeks. Regenerated nerves did not readopt the normal corneal nerve arrangement. A dense interlacing network of regenerated nerves was present in the corneal bed. Branches from this network traversed the flap to innervate the epithelium. Immunofluorescence staining revealed that regenerating fronds contained peptidergic nociceptive fibers (positive for calcitonin gene-related peptide and substance P) and myelinated non-nociceptive fibers (positive for neurofilament 200). CONCLUSIONS: Although corneal NFD recovers to normal levels by 8 weeks after nerve transection, the arrangement of regenerated nerves is abnormal.