The neuroregenerative effects of topical decorin on the injured mouse cornea.

BACKGROUND: The cornea is innervated with a rich supply of sensory nerves that play important roles in ocular surface health. Any injury or pathology of the corneal nerves increases the risk of dry eye disease and infection. This study aims to evaluate the therapeutic potential of topical decorin to improve corneal nerve regeneration in a mouse model of sterile epithelial abrasion injury. METHODS: Bilateral central corneal epithelial abrasions (2-mm, Alger Brush) were performed on young C57BL/6 J mice to remove the corneal sensory nerves. Decorin, or vehicle, was applied topically, three times per day for 1 week or every 2 h for 6 h. Spectral-domain optical coherence tomography was performed to measure the abrasion area and corneal thickness. Wholemount immunofluorescence staining was used to assess sensory nerve regeneration (ß-tubulin III) and immune cell density (CD45, Iba1, CD11c). To investigate the specific role of dendritic cells (DCs), Cx3cr1gfp/gfp mice, which spontaneously lack resident corneal epithelial DCs, were also investigated. The effect of prophylactic topical administration of recombinant human decorin (applied prior to the abrasion) was also investigated. Nerve tracing (NeuronJ software) was performed to compare recovery of basal nerve axons and superficial nerve terminals in the central and peripheral cornea. RESULTS: At 6 h after injury, topical decorin application was associated with greater intraepithelial DC recruitment but no change in re-epithelialisation or corneal thickness, compared to the vehicle control. One week after injury, sub-basal nerve plexus and superficial nerve terminal density were significantly higher in the central cornea in the decorin-treated eyes. The density of corneal stromal macrophages in the decorin-treated eyes and their contralateral eyes was significantly lower compared to saline-treated corneas. No significant improvement in corneal nerve regeneration was observed in Cx3cr1gfp/gfp mice treated with decorin. CONCLUSIONS: Decorin promotes corneal epithelial nerve regeneration after injury. The neuroregenerative effect of topical decorin was associated with a higher corneal DC density during the acute phase, and fewer macrophages at the study endpoint. The corneal neuroregenerative effects of decorin were absent in mice lacking intraepithelial DCs. Together, these findings support a role for decorin in DC-mediated neuroregeneration following corneal abrasion injury.

Bilateral Effect of the Unilateral Corneal Nerve Cut on Both Ocular Surface and Lacrimal Gland.

Purpose: This study investigated the effect of a unilateral cut of the corneal nerve on the bilateral ocular surface and tear secretory function. Methods: Seven-week-old female BALB/c mice were divided into control and nerve-cutting (NC) groups (n = 60). The left cornea was partially incised with a 2-mm circular trephine through the upper half of the stromal layer. Lissamine green corneal staining and tear volume measurements were conducted, and corneal whole-mount staining using class III ß-tubulin antibody was performed to assess corneal nerves. Flow cytometric analyses for dendritic cells (DCs), CD4+/CD8+ and regulatory T cells and ELISA for neuropeptides were performed. Results: The grading of corneal staining increased in the NC group, while the tear volume decreased over the 4 weeks. The nerve density decreased in bilateral corneas over 2 weeks. At day 14, CD11b+ or CD11c+ DCs and the mature DCs expressing CD86 or MHCII increased in bilateral cornea/conjunctiva. At day 28, CD11c+CD86hi, CD11c+MHCIIhi, Th17 and IFN-γ-secreting CD8+ T cells highly increased in bilateral draining lymph nodes. CD4+CD25hiFoxp3hi and CD8+CD25hiFoxp3hi regulatory T cells notably increased in the spleen. In ELISA, neuropeptide Y, calcitonin gene-related peptide, and vasoactive intestinal peptide were generally suppressed in the extraorbital lacrimal glands at day14. Conclusions: The unilateral corneal nerve severing resulted in activation of the immune cells on the ocular surface and dysregulated lacrimal secretion bilaterally through the bidirectional neuronal signals. It suggests that the unilateral corneal nerve damage may alter immune homeostasis and mechanistically participate in the development of bilateral inflammatory disorders such as dry eye.

Induction of Contrasuppressor Cells and Loss of Immune Privilege Produced by Corneal Nerve Ablation.

Purpose: Severing of corneal nerves in preparation of corneal transplantation abolishes immune privilege of subsequent corneal transplants placed into either eye: a phenomenon termed sympathetic loss of immune privilege (SLIP). SLIP is due to the disabling of T regulatory cells (Tregs) by CD11c+ contrasuppressor (CS) cells. This study characterized the induction, function, and manipulation of CS cell activity and the effect of these cells on Tregs induced by anterior chamber-associated immune deviation (ACAID). Methods: CS cells were induced using a 2.0-mm trephine to score the corneal epithelium. CD11c+ CS cells were evaluated by adoptive transfer and by their capacity to disable CD8+ ACAID Tregs in local adoptive transfer (LAT) of suppression assays. CD11c+ cells were deleted from the ocular surface by subconjunctival injection of clodronate-containing liposomes. Results: CD11c+ CS cell were radiosenstive and long lived. As few as 1000 CS cells blocked the suppressive activity of previously generated CD8+ ACAID Tregs, indicating that CS cells act at the efferent arm of the immune response. Depletion of resident CD11c+ cells at the ocular surface prevented the generation of CS cells. Conclusions: Corneal nerve injury that occurs during keratoplasty converts ocular surface CD11c+ cells into CS cells that block CD8+ Tregs, which are induced by introducing antigens into the anterior chamber (i.e., ACAID Tregs). Depletion of CD11c+ cells at the ocular surface prevents the generation of CS cells and may be a useful strategy for preventing SLIP and enhancing the survival of second corneal transplants.

Orbital apex syndrome after trauma in a 6-year-old - a rare occurrence.

Orbital apex syndrome is rare, but can occur as a consequence of trauma from fracture of the medial orbit. This case report highlights the fact that a high index of suspicion is needed when a patient presents with a facial injury, especially in children who cannot give an account of the actual events that transpired. Radiological investigation should be done early when an underlying injury is suspected in a trauma patient. A low threshold for computed tomography should be maintained when proptosis and vision loss are present.

Recent advances in laser in situ keratomileusis-associated dry eye.

Dry eye is the most common complication after laser in situ keratomileusis (LASIK). The major cause of LASIK-associated dry eye is corneal nerve damage. Early identification and treatment of post-operative dry eye are essential to prevent further ocular surface damage. This article reviews the recent studies of LASIK-associated dry eye, including clinical features, aetiology, risk factors, evaluations and treatment. The applications of novel technologies in LASIK-associated dry eye evaluation like anterior segment spectral-domain optical coherence tomography (SD-OCT) and corneal confocal microscopy are also introduced in this review.

Neurotrophic keratitis after transscleral diode laser cyclophotocoagulation. / Queratitis neurotrófica posciclofotocoagulación transescleral con láser diodo.

OBJECTIVE: To study the relationship between treatment with diode laser transscleral cyclophotocoagulation and development a neurotrophic keratitis due to the damage of the sensitive corneal innervation. METHODS: A study was conducted on 5 eyes of 5 patients who were treated with diode laser transscleral cyclophotocoagulation and soon developed neurotrophic ulcers. Personal characteristics of the patients were collected, as well as refraction and risk factors for corneal hypoesthesia, and the parameters of the laser used in the surgery. RESULTS: It was found that the 5 patients had predisposing factors of corneal hypoesthesia prior to surgery (chronic use of topical beta blockers, surgery with corneal incisions, diabetes mellitus, or corneal dystrophies); however none had developed neurotrophic keratitis until the cyclophotocoagulation was performed. It also showed that 4 of them were highly myopic, and they all were treated with high laser parameters (with an average of 2880 mW for 3s at an average surface of 275°), triggering neurotrophic ulcers between 10 and 35 days after surgery. CONCLUSION: Neurotrophic keratitis is a rare complication that can occur after diode laser transscleral cyclophotocoagulation, secondary to the damage of the long ciliary nerves. The emergence of this disorder can be triggered by the existence of previous risk factors, including high myopia, thus it is important to respect the recommended treatment parameters to prevent the development of this disorder.

A rare case of trigeminal trophic syndrome with an extensive scalp, forehead, and upper eyelid ulceration in a patient with undiagnosed Alzheimer disease.

BACKGROUND: Trigeminal Trophic Syndrome (TTS) is a rare presentation of facial ulceration, which is characterized by the triad of anesthesia, paraesthesia, and damage of trigeminal sensory branches. MAIN OBSERVATIONS: We report a unique case of TTS as an extensive forehead and scalp ulceration in a patient with undiagnosed Alzheimer disease. CONCLUSIONS: Treatment options for trigeminal trophic syndrome are limited and disappointing especially in older patients with dementia. Family education and behavioral modification therapies may be well tolerated option in this population.

The PEDF Neuroprotective Domain Plus DHA Induces Corneal Nerve Regeneration After Experimental Surgery.

PURPOSE: To compare a 44-mer pigment epithelial-derived factor (PEDF) peptide with neurotrophic activity, and a 34-mer PEDF with antiangiogenic properties in association with docosahexaenoic acid (DHA) in corneal nerve regeneration after experimental surgery. METHODS: A corneal stromal dissection was performed in rabbits. Treatment groups received topical 44-mer, 34-mer, or full PEDF plus DHA. Corneal sensitivity and Schirmer's test were performed weekly. Rabbits were euthanized at 2 and 4 days and 8 weeks. Two- and 4-day samples were stained for neutrophils and CD11b+ cells. Corneal nerves were stained with ßIII tubulin and calcitonin gene-related peptide (CGRP) antibodies in specimens collected at 8 weeks. Subepithelial nerve plexus density was calculated. A PEDF-receptor (PEDF-R) was analyzed in rabbit corneal epithelial cells (RCEC) by Western blot and immunofluorescence. RESULTS: Infiltration of CD11b+cells and neutrophils was reduced by treatment with 44-mer PEDF+DHA. A 3-fold increase in subepithelial corneal nerves and CGRP-positive nerves was found in the 44-mer PEDF+DHA-treated group compared with the 34-mer PEDF+DHA- and vehicle-treated groups. There was a 75% recovery of corneal sensitivity by week 7, and Schirmer's test reached control values in the 44-mer PEDF+DHA-treated corneas at 7 weeks. A PEDF-R protein with homology to calcium-independent phospholipase A2ς was expressed in RCEC. CONCLUSIONS: The 44-mer PEDF+DHA, but not the 34-mer PEDF+DHA, promotes functional regeneration of damaged corneal nerves. Forty four-mer PEDF, by activating a corneal epithelial receptor, in conjunction with DHA could be a novel therapeutic agent for the treatment of neurotrophic keratitis and dry eye that develops as a result of corneal nerve damage.

Early corneal nerve damage and recovery following small incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK).

PURPOSE: We compared early corneal nerve changes after small incision lenticule extraction (SMILE) and laser in situ keratomileusis (LASIK). METHODS: A total of 12 rabbits underwent LASIK in one eye and SMILE in the fellow eye. Baseline and follow-up evaluations at 1, 2, and 4 weeks postoperatively were performed with in vivo confocal microscopy to evaluate 5 different areas within the treated zone: center, superior, inferior, nasal, and temporal. Cryosections of the corneas and whole mount of the extracted SMILE lenticules were analyzed with immunostaining of ßIII-tubulin. RESULTS: One week after SMILE and LASIK, a decrease in nerve length and density was observed in all evaluated areas. A trend toward greater subbasal nerve length and density (SLD), more eyes with subbasal nerves (ESN), more eyes with subbasal nerves longer than 200 µm (SNL), and higher mean number of subbasal nerves by frame (NSN) in SMILE than in LASIK groups was observed at subsequent follow-up time points. Only the SMILE group showed a recovery of SLD, ESN, and NSN by week 4 (P > 0.05). A trend toward more eyes with sprouting subbasal nerves and greater mean number of sprouting nerves was observed in LASIK than in SMILE, indicating that more subbasal nerves were disrupted and undergoing regeneration after LASIK. Immunostaining at postoperative week 4 revealed a faster stromal nerve recovery in post-SMILE eyes compared to post-LASIK eyes. CONCLUSIONS: Our findings suggest that SMILE results in less nerve damage and faster nerve recovery than LASIK.

Involvement of pigment epithelium-derived factor, docosahexaenoic acid and neuroprotectin D1 in corneal inflammation and nerve integrity after refractive surgery.

Alterations in corneal innervations result in impaired corneal sensation, severe dry eye and damage to the epithelium that may in turn lead to corneal ulcers, melting and perforation. These alterations can occur after refractive surgery. We have discovered that pigment epithelium-derived factor (PEDF) plus docosahexaenoic acid (DHA or the docosanoid bioactive neuroprotectin D1 (NPD1)) induces nerve regeneration after corneal surgery that damages the stromal nerves. We found that PEDF is released from corneal epithelial cells after injury, and when DHA is provided to the cells it stimulates the biosynthesis of NPD1 by an autocrine mechanism. The combination of PEDF plus DHA also decreased the production of leukotriene B4 (LTB4), a neutrophil chemotactic factor, thereby decreasing the inflammation induced after corneal damage. These studies suggest that PEDF plus DHA and its derivative NPD1 hold promise as a future treatment to restore a healthy cornea after nerve damage.

[Efficacy observation on electroacupuncture in the treatment of oculomotor impairment caused by ophthalmic nerve injury].

OBJECTIVE: To observe the difference in the clinical efficacy on oculomotor impairment between electroacupuncture and acupuncture and explore the best therapeutic method in the treatment of this disease. METHODS: Sixty cases of oculomotor impairment were randomized into an electroacupuncture group and an acupuncture group, 30 cases in each one. In the electroacupuncture group, the points were selected on extraocular muscles, the internal needling technique in the eye was used in combination of electroacupuncture therapy. In the acupuncture group, the points and needling technique were same as the electroacupuncture group, but without electric stimulation applied. The treatment was given 5 times a week, 15 treatments made one session. After 3 sessions of treatment, the clinical efficacy, palpebral fissure size, pupil size, oculomotor range and the recovery in diplopia were compared before and after treatment in the two groups. RESULTS: In the electroacupuncture group, the palpebral fissure size was (9.79+/-2.65)mm and the eyeball shifting distance was (18.12+/-1. 30)mm, which were hig-her than (8.23+/-2.74)mm and (16.71+/-1. 44)mm respectively in the acupuncture group. In the electroacupuncture group, the pupil diameter was (0. 44 +/-0. 42)mm, which was less than (0. 72 +/- 0. 53)mm in the acupuncture group, indicating the significant difference (all P<0. 05). The cured rate was 63. 33% (19/30) and the total effective rate was 93.33% (28/30) in the electroacupuncture group, which was better than 36.67% (11/30) and 83. 333 (25/30) in the acupuncture group separately, indicating the significant difference (all P<0. 05). CONCLUSION: Electroacupuncture presents the obvious advantages in the treatment of oculomotor impairment, characterized as quick and high effect, short duration of treatment and remarkable improvements in clinical symptoms, there are important significance for the improvement of survival quality of patients.

Non-traumatic supraorbital neuralgia: a clinical study of 13 cases.

INTRODUCTION: Supraorbital neuralgia (SON) is an uncommon disorder characterized by pain in the area supplied by the supraorbital nerve, which covers the medial aspect of the forehead, together with tenderness over the supraorbital notch or along the course of the nerve. Few hospital-based series of non-trauma SON have been published. METHODS AND RESULTS: We prospectively analyzed 13 patients (11 females, two males) diagnosed with SON in a headache outpatient clinic over a four-year period. Background pain was mostly dull and of moderate intensity. In addition, nine patients reported sharp, burning or stabbing exacerbations of severe intensity. Eight cases were treated with an anesthetic blockade and achieved complete relief lasting from two to six months. Three patients also received gabapentin, with no or only slight improvement. CONCLUSION: Non-traumatic SON is an uncommon disorder in our headache clinic. Female preponderance and clinical features are comparable to the data collected in previous studies. A spontaneously remitting pattern is not uncommon, and anesthetic blockades are not always required.

Peripheral painful traumatic trigeminal neuropathy: clinical features in 91 cases and proposal of novel diagnostic criteria.

AIMS: To field-test carefully designed criteria for pain following trigeminal nerve trauma. METHODS: In order to characterize the clinical phenotype, posttraumatic pain patients were studied and compared with classical trigeminal neuralgia patients (CTN, defined according to the International Headache Society's criteria). Based on etiology and features, trigeminal pain following trauma was defined as "peripheral painful traumatic trigeminal neuropathy" (PPTTN). Data were analyzed with t tests, ANOVA, chi-square, and regression analyses. RESULTS: A total of 145 patients were included: 91 with PPTTN and 54 with CTN. Findings indicated that PPTTN criteria are clinically applicable in the detection and characterization of relevant cases. In contrast to accepted characteristics for PPTTN, the observed profile included both continuous and paroxysmal pain that was stabbing and/or burning. The quality, duration, and intensity were significantly different from the CTN patients (P < .05). PPTTN was consistently accompanied by trigeminal sensory abnormalities (96%) that were mostly allodynia, hyperor hypoalgesia, and only 1% of the PPTTN cases had anesthesia. CONCLUSION: Overall, the proposed PPTTN criteria have proven to be clinically useful. In view of these results, modified PPTTN diagnostic criteria are proposed for use in future research.

Recovery of corneal sensitivity, calcitonin gene-related peptide-positive nerves, and increased wound healing induced by pigment epithelial-derived factor plus docosahexaenoic acid after experimental surgery.

OBJECTIVE: To assess function of regenerated corneal nerves in correlation with epithelial wound healing after experimental nerve damage in rabbits treated with pigment epithelial-derived factor (PEDF) plus docosahexaenoic acid (DHA). METHODS: An 8-mm stromal dissection was performed in the right eyes of adult New Zealand rabbits. Treatment with PEDF+DHA was for 6 weeks. Corneal sensation was measured weekly by Cochet-Bonnet esthesiometer. After 8 weeks, immunofluorescence with ßIII-tubulin, calcitonin gene-related peptide, and substance P antibodies was performed to quantify nerves. Also, rabbits were treated with PEDF+DHA for 4 weeks after lamellar keratectomy, followed by 8-mm epithelial debridement and epithelial defect assessment. One week after surgery, corneas were stained with anti-Ki67 antibody to assess cell proliferation. RESULTS: Eight weeks after surgery, calcitonin gene-related peptide-positive nerve fibers in the PEDF+DHA group were similar to normal rabbit corneas but were decreased in the vehicle. Substance P was localized in the subepithelial plexus but appeared in epithelial cells after nerve injury regardless of treatment. Five weeks after surgery, an increase in corneal sensitivity occurred in the PEDF+DHA group and reached normal values by 8 weeks. Pigment epithelial-derived factor plus DHA increased epithelial wound healing after lamellar keratectomy. One week after epithelial injury, Ki67-positive cells increased in the limbal area. CONCLUSION: Pigment epithelial-derived factor plus DHA promotes regeneration of calcitonin gene-related peptide-positive corneal nerves, accelerating wound healing and return of corneal sensitivity. CLINICAL RELEVANCE: Pigment epithelial-derived factor plus DHA represents a new approach to regenerate nerves and a potential treatment for prevention of severe dry eye after surgery or diseases of the ocular surface.

[Treatment of a neurotrophic corneal ulcer with solid platelet-rich plasma and Tutopatch®]. / Tratamiento de úlcera corneal neurotrófica con plasma rico en plaquetas y Tutopatch®.

CASE REPORTS: We present the case of a patient with neurotrophic queratitis in the left eye treated with a Tutopatch® cover and platelet-rich plasma (PRP). Solid autologous PRP was placed in the bed of the ulcer and Tutopatch® was sutured to the conjunctiva. DISCUSSION: We found this form of treatment very effective for progressive ulcers. Tutopatch® may constitute an alternative to amniotic membrane transplantation.

Cranial nerve injury after Le Fort I osteotomy.

A Le Fort I osteotomy is widely used to correct dentofacial deformity because it is a safe and reliable surgical method. Although rare, various complications have been reported in relation to pterygomaxillary separation. Cranial nerve damage is one of the serious complications that can occur after Le Fort I osteotomy. In this report, a 19-year-old man with unilateral cleft lip and palate underwent surgery to correct maxillary hypoplasia, asymmetry and mandibular prognathism. After the Le Fort I maxillary osteotomy, the patient showed multiple cranial nerve damage; an impairment of outward movement of the eye (abducens nerve), decreased vision (optic nerve), and paraesthesia of the frontal and upper cheek area (ophthalmic and maxillary nerve). The damage to the cranial nerve was related to an unexpected sphenoid bone fracture and subsequent trauma in the cavernous sinus during the pterygomaxillary osteotomy.

Traumatic neuroma of the infraorbital nerve subsequent to inferomedial orbital decompression for Graves' orbitopathy.

PURPOSE: To present and discuss the occurrence of a traumatic neuroma subsequent to inferomedial orbital decompression surgery in Graves' orbitopathy. METHODS: Case report. RESULTS: Approximately 1 month after surgery, a patient who underwent bilateral rehabilitative inferomedial orbital decompression developed a mass with clinical and radiologic characteristics compatible with a traumatic neuroma of the left infraorbital nerve. The lesion, which was thought to be the result of unnoticed nerve trauma at the time of surgical dissection of the infraorbital canal, remained stable in shape and other imaging characteristics during the 39-month follow-up period. Symptoms of trigeminal neuralgia could be only partially controlled with medical therapy (oral pregabalin 75 mg 3 times daily). CONCLUSIONS: The second branch of the trigeminal nerve may be damaged in the course of orbital floor removal decompression for Graves' orbitopathy. This may potentially induce the formation of traumatic or amputation neuromas. Such lesions should be included in the potential complications of decompressions when counseling patients about to undergo this type of surgery, as they are difficult to treat and may cause persistent and disabling pain.

Post-traumatic external nasal pain syndrome (a trigeminal based pain disorder).

Little has been written about persistent external nasal pain after injury to the nose in the neurologic or headache literature. In clinical practice, this can be a disabling and treatment refractory condition. The external portion of the nose is highly innervated by branches of the ophthalmic and maxillary divisions of the trigeminal nerve including the nasociliary nerve, external nasal nerve, infratrochlear nerve, anterior ethmoidal nerve, and infraorbital nerve. As these nerves are located on the external portion of the nose just deep enough to the skin they can be easily traumatized with any impact to the nose. Four patients with what is termed the post-traumatic external nasal pain syndrome are reported in this paper, describing the clinical presentation of the disorder and providing treatment options. Post-traumatic external nasal pain syndrome appears to be a novel form of trigeminal-based pain not previously reported in the neurologic literature.

[Post-traumatic supraorbital neuralgia: a benign condition]. / Neuralgia supraorbitaria postraumática: una entidad benigna.

INTRODUCTION: Supraorbital neuralgia has only recently been described. Most of the cases reported involve patients suffering from chronic idiopathic neuralgias that are difficult to treat and sometimes require surgery to release the nerve. We present our experience in patients with a variant of this neuralgia which has a known causation, is commonly seen and has a benign prognosis. CASE REPORTS: We studied five patients, four females and one male, with a mean age of 55 years (range: 29-69 years). They had all suffered direct banal traumatic injury to the frontal region due to different causes. Four of them developed continuous, piercing or burning-type pain; three of them had paroxysmal pain and one had itching. There were no autonomic manifestations. All of them were found to be abnormally sensitive in the affected area, with tactile hypaesthesia, hyperalgesia or allodynia and a positive Tinel's sign. Neuroimaging tests were normal. Two patients were treated with gabapentin and amitriptyline. One was treated with an anaesthetic blockade, which afforded temporary relief. Three of them received no treatment at all. After one year of follow-up, all of them had improved and three were no longer in pain, although sensory alterations persisted in all cases. CONCLUSIONS: Post-traumatic supraorbital neuralgia is a frequent condition, although it is probably underdiagnosed. It has its own characteristic clinical and developmental features that distinguish it from idiopathic supraorbital neuralgia. Progress is usually good and it responds favourably to symptomatic treatment, if needed.

Superior orbital fissure syndrome: current management concepts.

The superior orbital fissure syndrome is an uncommon complication of craniofacial fractures: middle-third facial fractures and lesions of the retrobulbar space. This article reviews the anatomy and etiology of the superior orbital fissure as it relates to pathophysiology and physical findings. Cases reported in the literature are reviewed, emphasizing diagnosis and established treatment options. Two cases are presented and their management discussed, including the use of pre- and postoperative steroids as an adjunct to standard fracture reduction and stabilization therapy.