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Serra PL, Giannaccare G, Cuccu A, Bolognesi F, Biglioli F, Marcasciano M, Tarabbia F, Pagliara D, Figus A, Boriani F. Insights on the Choice and Preparation of the Donor Nerve in Corneal Neurotization for Neurotrophic Keratopathy: A Narrative Review. J Clin Med 2024; 13:2268. [PMID: 38673540 PMCID: PMC11050919 DOI: 10.3390/jcm13082268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/28/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
The article introduces neurotrophic keratopathy (NK), a condition resulting from corneal denervation due to various causes of trigeminal nerve dysfunctions. Surgical techniques for corneal neurotization (CN) have evolved, aiming to restore corneal sensitivity. Initially proposed in 1972, modern approaches offer less invasive options. CN can be performed through a direct approach (DCN) directly suturing a sensitive nerve to the affected cornea or indirectly (ICN) through a nerve auto/allograft. Surgical success relies on meticulous donor nerve selection and preparation, often involving multidisciplinary teams. A PubMed research and review of the relevant literature was conducted regarding the surgical approach, emphasizing surgical techniques and the choice of the donor nerve. The latter considers factors like sensory integrity and proximity to the cornea. The most used are the contralateral or ipsilateral supratrochlear (STN), and the supraorbital (SON) and great auricular (GAN) nerves. Regarding the choice of grafts, the most used in the literature are the sural (SN), the lateral antebrachial cutaneous nerve (LABCN), and the GAN nerves. Another promising option is represented by allografts (acellularized nerves from cadavers). The significance of sensory recovery and factors influencing surgical outcomes, including nerve caliber matching and axonal regeneration, are discussed. Future directions emphasize less invasive techniques and the potential of acellular nerve allografts. In conclusion, CN represents a promising avenue in the treatment of NK, offering tailored approaches based on patient history and surgical expertise, with new emerging techniques warranting further exploration through basic science refinements and clinical trials.
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Affiliation(s)
- Pietro Luciano Serra
- Plastic Surgery Unit, Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari University Hospital Trust, 07100 Sassari, Italy;
- Plastic Surgery and Microsurgery Unit, Department of Surgical Sciences, Faculty of Medicine and Surgery, University Hospital “Duilio Casula”, University of Cagliari, 09124 Cagliari, Italy; (A.F.); (F.B.)
| | - Giuseppe Giannaccare
- Eye Clinic, Department of Surgical Sciences, University of Cagliari, 09124 Cagliari, Italy;
| | - Alberto Cuccu
- Eye Clinic, Department of Surgical Sciences, University of Cagliari, 09124 Cagliari, Italy;
| | - Federico Bolognesi
- Department of Maxillo-Facial Surgery, Santi Paolo e Carlo Hospital, University of Milan, 20122 Milan, Italy; (F.B.); (F.B.); (F.T.)
| | - Federico Biglioli
- Department of Maxillo-Facial Surgery, Santi Paolo e Carlo Hospital, University of Milan, 20122 Milan, Italy; (F.B.); (F.B.); (F.T.)
| | - Marco Marcasciano
- Plastic and Reconstructive Surgery Unit, Division of Plastic and Reconstructive Surgery, Department of Surgery, China Medical University Hospital, Taichung, Taiwan, Magna Graecia University of Catanzaro, 88100 Catanzaro, Italy;
- Unit of Plastic and Reconstructive Surgery, Department of Experimental and Clinical Medicine, Magna Graecia University, 88100 Catanzaro, Italy
| | - Filippo Tarabbia
- Department of Maxillo-Facial Surgery, Santi Paolo e Carlo Hospital, University of Milan, 20122 Milan, Italy; (F.B.); (F.B.); (F.T.)
| | - Domenico Pagliara
- Plastic-Reconstructive and Lymphedema Microsurgery Center, Mater Olbia Hospital, 07026 Olbia, Italy;
| | - Andrea Figus
- Plastic Surgery and Microsurgery Unit, Department of Surgical Sciences, Faculty of Medicine and Surgery, University Hospital “Duilio Casula”, University of Cagliari, 09124 Cagliari, Italy; (A.F.); (F.B.)
| | - Filippo Boriani
- Plastic Surgery and Microsurgery Unit, Department of Surgical Sciences, Faculty of Medicine and Surgery, University Hospital “Duilio Casula”, University of Cagliari, 09124 Cagliari, Italy; (A.F.); (F.B.)
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Musa M, Enaholo E, Aluyi-Osa G, Atuanya GN, Spadea L, Salati C, Zeppieri M. Herpes simplex keratitis: A brief clinical overview. World J Virol 2024; 13:89934. [PMID: 38616855 PMCID: PMC11008405 DOI: 10.5501/wjv.v13.i1.89934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/28/2023] [Accepted: 01/22/2024] [Indexed: 03/11/2024] Open
Abstract
The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.
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Affiliation(s)
- Mutali Musa
- Department of Optometry, University of Benin, Benin 300283, Nigeria
- Department of Ophthalmology, Africa Eye Laser Centre, Km 7, Benin 300105, Nigeria
| | - Ehimare Enaholo
- Department of Ophthalmology, Africa Eye Laser Centre, Km 7, Benin 300105, Nigeria
- Department of Ophthalmology, Centre for Sight Africa, Nkpor 434101, Nigeria
| | - Gladness Aluyi-Osa
- Department of Ophthalmology, Africa Eye Laser Centre, Km 7, Benin 300105, Nigeria
| | | | - Leopoldo Spadea
- Eye Clinic, Policlinico Umberto I, "Sapienza" University of Rome, Rome 00142, Italy
| | - Carlo Salati
- Department of Ophthalmology, University Hospital of Udine, Udine 33100, Italy
| | - Marco Zeppieri
- Department of Ophthalmology, University Hospital of Udine, Udine 33100, Italy
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Daeschler SC, Woo JH, Hussein I, Ali A, Borschel GH. Corneal Neurotization: Preoperative Patient Workup and Surgical Decision-making. PLASTIC AND RECONSTRUCTIVE SURGERY-GLOBAL OPEN 2023; 11:e5334. [PMID: 37829104 PMCID: PMC10566830 DOI: 10.1097/gox.0000000000005334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/24/2023] [Indexed: 10/14/2023]
Abstract
Background The use of sensory nerve transfers to the anesthetic cornea has transformed the treatment of neurotrophic keratopathy by restoring ocular surface sensation and activating dysfunctional epithelial repair mechanisms. However, despite numerous reports on surgical techniques, there is a scarcity of information on the interdisciplinary management, preoperative assessment, and surgical decision-making, which are equally critical to treatment success. Methods This Special Topic presents a standardized, interdisciplinary preoperative workup based on our 10-year experience with corneal neurotization in 32 eyes of patients with neurotrophic keratopathy. Results Our assessment includes a medical history review, ophthalmic evaluation, and systematic facial sensory donor nerve mapping for light touch and pain modalities. This approach enables evidence-based patient selection, optimal surgery timing, and suitable donor nerve identification, including backup options. Conclusions Based on a decade-long experience, this special topic highlights the importance of interdisciplinary collaboration and provides a practical roadmap for optimizing patient selection and surgical decision-making in patients undergoing corneal neurotization.
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Affiliation(s)
- Simeon C. Daeschler
- From the SickKids Research Institute, Neuroscience and Mental Health Program, Toronto, Ontario, Canada
- Department of Hand, Plastic and Reconstructive Surgery, Burn Center, Department of Plastic and Hand Surgery, University of Heidelberg, BG Trauma Hospital, Ludwigshafen, Germany
| | - Jyh Haur Woo
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
- Singapore National Eye Centre, Singapore, Singapore
| | - Isra Hussein
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Asim Ali
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Gregory H. Borschel
- From the SickKids Research Institute, Neuroscience and Mental Health Program, Toronto, Ontario, Canada
- Division of Plastic and Reconstructive Surgery, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Ind
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, Ind
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Corneal Neurotization—Indications, Surgical Techniques and Outcomes. J Clin Med 2023; 12:jcm12062214. [PMID: 36983215 PMCID: PMC10059768 DOI: 10.3390/jcm12062214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/05/2023] [Accepted: 03/11/2023] [Indexed: 03/16/2023] Open
Abstract
Corneal neurotization is a promising surgical approach for the treatment of moderate to severe neurotrophic keratopathy. This technique aims to restore corneal sensation by transferring healthy nerves, either directly or via a conduit, to the anesthetic cornea. This review provides a report on the current state of development, evidence, and experience in the field. We summarize the data available from clinical reports and case series, placing an emphasis on the diversity of the surgical techniques reported. While these data are encouraging, they also highlight the need for a consensus in reporting outcomes and highlight how the next step will involve validating putative outcome parameters when researching and reporting corneal neurotization surgery.
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Saad S, Labani S, Goemaere I, Cuyaubere R, Borderie M, Borderie V, Benkhatar H, Bouheraoua N. Corneal neurotization in the management of neurotrophic keratopathy: A review of the literature. J Fr Ophtalmol 2023; 46:83-96. [PMID: 36473789 DOI: 10.1016/j.jfo.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 12/12/2022]
Abstract
Neurotrophic keratopathy (NK) is a rare degenerative disease in which damage to the corneal nerves leads to corneal hypoesthesia or anesthesia. Neurotrophic corneal ulcers are notoriously difficult to treat and can lead to blindness. Corneal neurotization (CN) is a recent surgical technique aimed at restoring corneal sensation and may offer a definitive treatment in the wake of NK. Herein, we review the surgical techniques utilized in direct and indirect CN. Technical considerations, outcomes, current limitations and future perspectives are also discussed. This article highlights the key points of this promising procedure and biological aspects that will help provide the best treatment options for patients with severe NK.
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Affiliation(s)
- S Saad
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France
| | - S Labani
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France
| | - I Goemaere
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France
| | - R Cuyaubere
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France
| | - M Borderie
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France
| | - V Borderie
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France; Sorbonne université, Inserm, CNRS, institut de la vision, 17, rue Moreau, 75012 Paris, France
| | - H Benkhatar
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France; Versailles Hospital Center, Department of Otorhinolaryngology-Head and Neck Surgery, Le Chesnay, France
| | - N Bouheraoua
- CHNO des Quinze-Vingts, IHU FOReSIGHT, Inserm-DGOS CIC 1423, 28, rue de Charenton, 75012 Paris, France; Sorbonne université, Inserm, CNRS, institut de la vision, 17, rue Moreau, 75012 Paris, France.
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Rathi A, Bothra N, Priyadarshini SR, Achanta DSR, Fernandes M, Murthy SI, Kapoor AG, Dave TV, Rath S, Yellinedi R, Nuvvula R, Dendukuri G, Naik MN, Ramappa M. Neurotization of the human cornea - A comprehensive review and an interim report. Indian J Ophthalmol 2022; 70:1905-1917. [PMID: 35647955 PMCID: PMC9359267 DOI: 10.4103/ijo.ijo_2030_21] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We present a comprehensive review of existing literature on surgical corneal neurotization (SCN) as a treatment modality for neurotrophic keratopathy (NK) with an interim report of seven cases where SCN was performed using the indirect approach and followed up till 18 months postoperatively to look for improvement in ocular surface, corneal sensations, and nerve regeneration by using in vivo confocal microscopy (IVCM). A literature search was performed for publications with keywords “corneal nerves,” “neurotization,” “esthesiometry,” “corneal anesthesia,” and “neurotrophic keratopathy.” All literature available till December 31, 2020 was reviewed and included to describe NK and its management options, particularly SCN. NK is associated with absent or reduced corneal sensations and is managed using a step-ladder algorithm ranging from medical management for symptomatic relief to surgical corneal neurotization. Both direct and indirect approaches of SCN have a favorable outcome with reduced surgical morbidity in the indirect approach using sural nerve graft. Post neurotization, corneal sensation recovery may take up to 3–6 months, while nerve regeneration on confocal microscopy can take as long as 6 months–1 year.
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Affiliation(s)
- Anubha Rathi
- The Cornea Institute, KAR Campus; Centre for Rare Eye Diseases and Ocular Genetics, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Nandini Bothra
- Ophthalmic Plastic Surgery Service, L V Prasad Eye Institute; Centre for Rare Eye Diseases and Ocular Genetics, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | | | - Divya S R Achanta
- The Cornea Institute, KAR Campus; Centre for Rare Eye Diseases and Ocular Genetics, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Merle Fernandes
- The Cornea Institute, KAR Campus, Hyderabad, Telangana; The Cornea Institute, GMRV Campus, L V Prasad Eye Institute, Vijayawada, Andhra Pradesh, India
| | | | - Anasua G Kapoor
- Ophthalmic Plastic Surgery and Aesthetics, Ocular Oncology, KVC Campus, L V Prasad Eye Institute, Vijayawada, Andhra Pradesh, India
| | - Tarjani V Dave
- Ophthalmic Plastic Surgery Service, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Suryasnata Rath
- Ophthalmic Plastic Surgery and Aesthetics, Ocular Oncology, L V Prasad Eye Institute, Bhubaneswar, Odisha, India
| | - Rajesh Yellinedi
- Basavatarakam, Indo American Cancer Hospital and Research Institute, Hyderabad, Telangana, India
| | - Rambabu Nuvvula
- Basavatarakam, Indo American Cancer Hospital and Research Institute, Hyderabad, Telangana, India
| | - Gautam Dendukuri
- Ophthalmic Plastic Surgery, Aesthetics and Faciomaxillary Surgery Service, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Milind N Naik
- Ophthalmic Plastic Surgery Service, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Muralidhar Ramappa
- The Cornea Institute, KAR Campus; Centre for Rare Eye Diseases and Ocular Genetics, L V Prasad Eye Institute; Jasti V Ramanamma Children's Eye Care Center, L V Prasad Eye Institute, Hyderabad, Telangana, India
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Corneal Neurotization: A Meta-analysis of Outcomes and Patient Selection Factors. Ann Plast Surg 2022; 88:687-694. [PMID: 35502965 DOI: 10.1097/sap.0000000000003117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Corneal neurotization describes reinnervation of the anesthetic or severely hypoesthetic cornea with a healthy local nerve or graft. Preliminary evidence has shown corneal neurotization to improve corneal sensation, visual acuity, and ocular surface health. Factors that improve patient selection and lead to better neurotization outcomes have yet to be elucidated, limiting ability to optimize perioperative decision-making guidelines. METHODS A systematic review with meta-analysis was performed of the MEDLINE and Embase databases using variations of "corneal," "nerve transfer," "neurotization," and "neurotization." The primary outcomes of interest were corrected visual acuity, NK Mackie stage, and central corneal sensation. Regression analyses were performed to identify the effects of surgical technique, duration of denervation, patient age, and etiology of corneal pathology on neurotization outcomes. RESULTS Seventeen studies were included. Corneal neurotization resulted in significant improvement in NK Mackie stage (0.84 vs 2.46, P < 0.001), visual acuity (logarithm of minimum angle of resolution scale: 0.98 vs 1.36, P < 0.001), and corneal sensation (44.5 vs 0.7, P < 0.001). Nerve grafting was associated with greater corneal sensation improvement than nerve transfer (47.7 ± 16.0 vs 35.4 ± 18.76, P = 0.03). Denervation duration was predictive of preneurotization visual acuity (logarithm of minimum angle of resolution scale; R2 = 0.25, P = 0.001), and older age (ß = 0.30, P = 0.03) and acquired etiology (ß = 0.30, P = 0.03) were predictive of improved visual acuity. CONCLUSIONS Corneal neurotization provides significant clinical improvement in visual acuity, NK Mackie staging, and corneal sensation in patients who experience NK. Both nerve grafting and nerve transfer are likely to yield similar levels of benefit and ideally should be performed early to limit denervation time.
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Woo JH, Daeschler SC, Mireskandari K, Borschel GH, Ali A. Minimally Invasive Corneal Neurotization Provides Sensory Function, Protects Against Recurrent Ulceration, and Improves Visual Acuity. Am J Ophthalmol 2022; 241:179-189. [PMID: 35513030 DOI: 10.1016/j.ajo.2022.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 04/23/2022] [Accepted: 04/24/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE To measure sensory recovery after minimally invasive corneal neurotization, and to identify and quantify the extent to which patient and technical factors influence sensory recovery, ulceration rate, and visual outcomes. DESIGN Retrospective case series. METHODS This study included 23 patients with neurotrophic keratopathy who underwent indirect corneal neurotization. The primary outcome measure was corneal sensitivity with Cochet-Bonnet aesthesiometry (CBA), and the secondary outcome measure was epithelial breakdown. RESULTS Over a 7-year period, 28 eyes of 23 patients (mean age, 15.6 ± 13.6 years) were included in the study. The CBA measurements improved from 3.5 ± 9.1 mm at baseline to 44.1 ± 18.2 mm at 24 months after surgery (P < .001). Maximum CBA was reached after 11.1 ± 6.2 months (median, 9 months). Compared to eyes neurotized with a contralateral donor nerve, eyes with an ipsilateral donor nerve achieved a higher mean CBA (36.0 ± 10.9 vs 10.4 ± 14.0 mm, P = .001) at 3 months. Both the number of fascicles (Spearman correlation coefficient, rs -0.474, P = .11) and insertions (rs -0.458, P = .014) negatively correlated with the final CBA. Nine eyes (32.1%) experienced at least 1 episode of epithelial breakdown after surgery. Visual acuity improved in the neurotized corneas from logMAR 0.57 ± 0.79 at baseline to 0.39 ± 0.66 at 12 months (P = .043). CONCLUSIONS Corneal sensation improves over time after corneal neurotization. There is resultant improvement in visual acuity and protection against epithelial breakdown. It is important to maximize sensory recovery to protect against recurrent ulceration.
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Kumar A, Yun H, Funderburgh ML, Du Y. Regenerative therapy for the Cornea. Prog Retin Eye Res 2022; 87:101011. [PMID: 34530154 PMCID: PMC8918435 DOI: 10.1016/j.preteyeres.2021.101011] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 12/13/2022]
Abstract
The cornea is the outmost layer of the eye, unique in its transparency and strength. The cornea not only transmits the light essential for vision, also refracts light, giving focus to images. Each of the three layers of the cornea has properties essential for the function of vision. Although the epithelium can often recover from injury quickly by cell division, loss of limbal stem cells can cause severe corneal surface abnormalities leading to corneal blindness. Disruption of the stromal extracellular matrix and loss of cells determining this structure, the keratocytes, leads to corneal opacity. Corneal endothelium is the inner part of the cornea without self-renewal capacity. It is very important to maintain corneal dehydration and transparency. Permanent damage to the corneal stroma or endothelium can be effectively treated by corneal transplantation; however, there are drawbacks to this procedure, including a shortage of donors, the need for continuing treatment to prevent rejection, and limits to the survival of the graft, averaging 10-20 years. There exists a need for new strategies to promote regeneration of the stromal structure and restore vision. This review highlights critical contributions in regenerative medicine with the aim of corneal reconstruction after injury or disease. These approaches include corneal stromal stem cells, corneal limbal stem cells, embryonic stem cells, and other adult stem cells, as well as induced pluripotent stem cells. Stem cell-derived trophic factors in the forms of secretomes or exosomes for corneal regeneration are also discussed. Corneal sensory nerve regeneration promoting corneal transparency is discussed. This article provides description of the up-to-date options for corneal regeneration and presents exciting possible avenues for future studies toward clinical applications for corneal regeneration.
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Affiliation(s)
- Ajay Kumar
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213
| | - Hongmin Yun
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213
| | | | - Yiqin Du
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; Department of Developmental Biology, University of Pittsburgh, Pittsburgh, PA, 15213, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA.
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Clinical Outcomes and Patient Satisfaction After Corneal Neurotization. Cornea 2021; 40:1377-1386. [PMID: 34633356 DOI: 10.1097/ico.0000000000002759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 03/10/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE The aim of this study was to assess clinical outcomes of corneal neurotization (CN) and determine patient perception of postoperative results. METHODS This was a retrospective study involving 29 eyes in 28 patients who underwent CN. Chart review data included demographic and clinical history; ophthalmic examination including visual acuity, ocular surface quality, and corneal sensation; surgical technique; and postoperative course. Subjective self-reported patient outcomes of surgical success were also assessed. Only eyes with at least 6 months of follow-up were included in the statistical analysis. RESULTS A total of 24 eyes and 23 patients were included in statistical analyses. The median postoperative follow-up time was 12.2 months (interquartile range 10.9-18.5 mo). Twenty-three eyes (92%) achieved improvement in ocular surface quality. Eleven of 13 (85%) demonstrated healing of persistent epithelial defects at their last follow-up. Patients gained a median of 2.3 cm in Cochet-Bonnet esthesiometry measurements of sensation. No significant difference was found between preoperative and postoperative visual acuity. All 17 patients who provided self-assessment of their surgical outcome indicated they would undergo CN again if given the choice. Most of the patients reported that the postoperative pain was tolerable, with a median pain score of 3.0 on a 10-point scale (interquartile range 0.0-4.0). Sixteen patients (94%) reported full or partial return of skin sensation along the donor nerve distribution. CONCLUSIONS CN provides improvement in corneal health and sensibility, with high patient satisfaction and minimal postoperative pain and morbidity.
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Vinee F, Grobnicu O, Errera C, Gomart G, Tuzin N, Heitz A, Liverneaux P, Bourcier T. Assessment of Tactile Sensitivity Threshold Using Cochet-Bonnet Esthesiometer and Semmes-Weinstein Monofilaments and Their Use in Corneal Neurotization. Ophthalmic Plast Reconstr Surg 2021; 37:S39-S43. [PMID: 32773513 DOI: 10.1097/iop.0000000000001788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Although the Cochet-Bonnet esthesiometer (CBE) measures corneal sensitivity, it has heretofore only been tested on the index pulp. Tactile skin sensitivity thresholds are measured with Semmes-Weinstein monofilaments (SWM). This study measured skin sensitivity thresholds in healthy individuals using CBE and SWM, and compared both instruments in territories involved in corneal neurotization. METHODS Overall, 27 healthy individuals were tested by a single examiner at 9 territories on the face, neck, forearm, and leg, using 20-thread SWM and CBE with a diameter of 0.12 mm. Both sides were tested. Thresholds were compared for both instruments and between the different territories using Bayesian methods. RESULTS Mean sensitivity levels for SWM ranged from 0.010 to 1.128 g, while mean sensitivity levels for CBE ranged from 0.006 to 0.122 g. Thresholds measured with SWM were significantly higher than with CBE. Both instruments demonstrated higher thresholds in the leg territory than the forearm. However, the forearm presented higher thresholds than the head territories. No significant differences were found between the head territories themselves. Overall, right-side territories exhibited lower thresholds than left-side territories. CONCLUSIONS We have reported the first mapping of skin sensitivity thresholds using CBE. Thresholds measured with CBE and SWM were coherent. The use of CBE on the skin is particularly relevant to the field of corneal neurotization.
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Affiliation(s)
- Frédéric Vinee
- Ophthalmology Department, Strasbourg University Hospital, FMTS
| | - Oana Grobnicu
- Hand Surgery Department, Strasbourg University Hospital, FMTS
| | | | | | - Nicolas Tuzin
- Biostatistics Department, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - Antoine Heitz
- Ophthalmology Department, Strasbourg University Hospital, FMTS
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Corneal Neurotization: A Game-Changing Surgical Procedure for Neurotrophic Keratopathy. Cornea 2021; 41:403-407. [PMID: 33859084 DOI: 10.1097/ico.0000000000002746] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/02/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study is to describe techniques, results, and open issues of corneal neurotization (CN) for the treatment of neurotrophic keratopathy (NK). METHODS An overview of the most important studies of CN is provided. The 2 main surgical approaches (namely, direct CN and indirect CN) with specific advantages and disadvantages are described. The results regarding changes of corneal sensitivity and clarity, visual acuity, and in vivo confocal microscopy metrics are summarized. Ex vivo studies with histopathology of the neurotized cornea are reported. Intraoperative and early and late postoperative complications are described along with current open issues to be further clarified. RESULTS Corneal sensitivity improves after both direct and indirect CN. Corneal reinnervation allows the healing of NK in almost the totality of the operated eyes, determining a corresponding improvement of corneal clarity and visual acuity. Regeneration of corneal nerve fibers is confirmed by means of either in vivo confocal microscopy or ex vivo histopathology. Few self-limiting complications are reported during the postoperative course. Current open issues concern the identification of the technique of choice, the use of autograft or allograft, and the timing of CN either when performed alone or when combined with other surgeries. CONCLUSIONS CN represents a game-changing surgical procedure for NK, which has the potential to restore corneal sensitivity in all stages of the disease regardless of the mechanism of denervation. Further long-term results are needed to confirm its efficacy over time. The design of randomized clinical trials comparing CN with noninterventional therapies could further validate the adoption of this technique.
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Liu CY, Arteaga AC, Fung SE, Cortina MS, Leyngold IM, Aakalu VK. Corneal neurotization for neurotrophic keratopathy: Review of surgical techniques and outcomes. Ocul Surf 2021; 20:163-172. [PMID: 33647470 PMCID: PMC8113161 DOI: 10.1016/j.jtos.2021.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 10/22/2022]
Abstract
Neurotrophic keratopathy is a degenerative disease in which damage to the corneal nerves leads to corneal hypoesthesia. Injuries to neurotrophic corneas are notoriously difficult to treat and have traditionally been approached with supportive management. However, recent progress in the field of corneal neurotization has given new direction for addressing nerve loss directly by stimulating new nerve growth onto the cornea from nearby sensory nerves transferred to the perilimbal region. Herein, we review the surgical techniques utilized in corneal neurotization, including direct transfers and the use of nerve grafts. Considerations in surgical approach, as well as factors that influence prognosis and outcomes of the surgical intervention are also discussed.
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Affiliation(s)
- Catherine Y Liu
- Viterbi Family Department of Ophthalmology, UC San Diego, San Diego, CA, USA.
| | - Andrea C Arteaga
- Illinois Eye and Ear Infirmary, Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois Chicago, Chicago, IL, USA
| | - Sammie E Fung
- Viterbi Family Department of Ophthalmology, UC San Diego, San Diego, CA, USA
| | - M Soledad Cortina
- Illinois Eye and Ear Infirmary, Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois Chicago, Chicago, IL, USA
| | - Ilya M Leyngold
- Duke University Medical Center, Department of Ophthalmology, Durham, NC, USA
| | - Vinay K Aakalu
- Illinois Eye and Ear Infirmary, Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois Chicago, Chicago, IL, USA
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Clinical and Morphologic Outcomes of Minimally Invasive Direct Corneal Neurotization. Ophthalmic Plast Reconstr Surg 2021; 36:451-457. [PMID: 32032169 DOI: 10.1097/iop.0000000000001586] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe clinical outcomes of a minimally invasive technique for direct corneal neurotization to treat neurotrophic keratopathy. METHODS All cases of corneal neurotization for neurotrophic keratopathy performed by a single surgeon using minimally invasive direct corneal neurotization were reviewed. The supraorbital donor nerve was directly transferred to the cornea through an upper eyelid crease incision using either a combination of endoscopic and direct visualization or direct visualization alone. Detailed ocular and adnexal examinations as well as Cochet-Bonnet esthesiometry of the affected cornea were performed. Corneal histopathology and in vivo confocal microscopy after minimally invasive direct corneal neurotization were reviewed in one patient who underwent simultaneous penetrating keratoplasty. RESULTS Five consecutive cases in 4 patients were included, with a mean follow up of 15.8 months (range: 11-23 months). Average denervation time was 17.8 months (range: 6-24 months). Baseline corneal conditions were Mackie stage 1 (20%), Mackie stage 2 (40%), and Mackie stage 3 (40%). All patients demonstrated improvements in corneal sensibility and appearance postoperatively. All patients demonstrated stable or improved visual acuity. No patients developed persistent epithelial defects postoperatively, and all achieved return of tactile skin sensation in the donor nerve sensory distribution. In vivo confocal microscopy after minimally invasive direct corneal neurotization and simultaneous penetrating keratoplasty demonstrated regeneration of corneal nerves. Complications included an asymptomatic small bony excrescence lateral to the supraorbital notch in one patient and cataract progression in the patient who underwent penetrating keratoplasty. CONCLUSIONS Minimally invasive direct corneal neurotization is a safe and effective treatment of neurotrophic keratopathy.
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Giannaccare G, Pellegrini M, Bolognesi F, Fogagnolo P, Lupardi E, Allevi F, Bernabei F, Lozza A, Plazza C, Marchetti C, Scorcia V, Biglioli F. Spotlight on corneal neurotization. EXPERT REVIEW OF OPHTHALMOLOGY 2021. [DOI: 10.1080/17469899.2021.1895751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Giuseppe Giannaccare
- Department of Ophthalmology, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Marco Pellegrini
- Ophthalmology Unit, Azienda Ospedaliero-Universitaria Di Bologna, University of Bologna, Bologna, Italy
| | - Federico Bolognesi
- Division of Oral and Maxillofacial Surgery, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Paolo Fogagnolo
- Eye Clinic, Head and Neck Department, ASST Santi Paolo E Carlo Hospital, University of Milan, Milan, Italy
| | - Enrico Lupardi
- Ophthalmology Unit, Azienda Ospedaliero-Universitaria Di Bologna, University of Bologna, Bologna, Italy
| | - Fabiana Allevi
- Unit of Maxillofacial Surgery, Head and Neck Department, ASST Santi Paolo E Carlo Hospital, University of Milan, Milan, Italy
| | - Federico Bernabei
- Ophthalmology Unit, Azienda Ospedaliero-Universitaria Di Bologna, University of Bologna, Bologna, Italy
| | | | - Christian Plazza
- Department of Aviation Medicine, Italian Air Force, Milan, Italy
| | - Claudio Marchetti
- Division of Oral and Maxillofacial Surgery, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Vincenzo Scorcia
- Department of Ophthalmology, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Federico Biglioli
- Unit of Maxillofacial Surgery, Head and Neck Department, ASST Santi Paolo E Carlo Hospital, University of Milan, Milan, Italy
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Ruiz-Lozano RE, Hernandez-Camarena JC, Loya-Garcia D, Merayo-Lloves J, Rodriguez-Garcia A. The molecular basis of neurotrophic keratopathy: Diagnostic and therapeutic implications. A review. Ocul Surf 2021; 19:224-240. [DOI: 10.1016/j.jtos.2020.09.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 09/13/2020] [Accepted: 09/22/2020] [Indexed: 12/11/2022]
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Direct Versus Indirect Corneal Neurotization for the Treatment of Neurotrophic Keratopathy: A Multicenter Prospective Comparative Study. Am J Ophthalmol 2020; 220:203-214. [PMID: 32659280 DOI: 10.1016/j.ajo.2020.07.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/01/2020] [Accepted: 07/02/2020] [Indexed: 11/24/2022]
Abstract
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.
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Corneal Neurotization and Novel Medical Therapies for Neurotrophic Keratopathy. CURRENT OPHTHALMOLOGY REPORTS 2020. [DOI: 10.1007/s40135-020-00254-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Abstract
Purpose of Review
Neurotrophic keratopathy (NK) is a degenerative corneal disease characterized by decreased corneal sensibility and impaired corneal healing. In this article, we review surgical techniques for corneal neurotization (CN) and novel medical therapies for the treatment of NK.
Recent Findings
In recent decades, there has been a paradigm shift in the treatment strategies for NK. New minimally invasive direct and indirect CN approaches have demonstrated efficacy at improving best-corrected visual acuity and central corneal sensation while decreasing surgical morbidity. In addition, several targeted medical therapies, such as recombinant human nerve growth factor (rhNGF), regenerating agents (RGTA), and nicergoline, have shown promise in improving corneal epithelial healing. Of these options, cenegermin (Oxervate®, Dompé), a topical biologic medication, has emerged as an approved medical treatment for moderate to severe NK.
Summary
NK is a challenging condition caused by alterations in corneal nerves, leading to impairment in sensory and trophic function with subsequent breakdown of the cornea. Conventional therapy for NK depends on the severity of disease and focuses primarily on protecting the ocular surface. In recent years, numerous CN techniques and novel medical treatments have been developed that aim to restore proper corneal innervation and promote ocular surface healing. Further studies are needed to better understand the long-term efficacy of these treatment options, their target populations, and the potential synergistic efficacy of combined medical and surgical treatments.
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