Insights on the Choice and Preparation of the Donor Nerve in Corneal Neurotization for Neurotrophic Keratopathy: A Narrative Review.

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.

Synergic Action of Insulin-like Growth Factor-2 and miRNA-483 in Pterygium Pathogenesis.

Pterygium is a multifactorial disease in which UV-B is speculated to play a key role by inducing oxidative stress and phototoxic DNA damage. In search for candidate molecules that are useful for justifying the intense epithelial proliferation observed in pterygium, our attention has been focused on Insulin-like Growth Factor 2 (IGF-2), mainly detected in embryonic and fetal somatic tissues, which regulate metabolic and mitogenic functions. The binding between IGF-2 and its receptor Insulin-like Growth Factor 1 Receptor (IGF-1R) activates the PI3K-AKT pathway, which leads to the regulation of cell growth, differentiation, and the expression of specific genes. Since IGF2 is regulated by parental imprinting, in different human tumors, the IGF2 Loss of Imprinting (LOI) results in IGF-2- and IGF2-derived intronic miR-483 overexpression. Based on these activities, the purpose of this study was to investigate the overexpression of IGF-2, IGF-1R, and miR-483. Using an immunohistochemical approach, we demonstrated an intense colocalized epithelial overexpression of IGF-2 and IGF-1R in most pterygium samples (Fisher's exact test, p = 0.021). RT-qPCR gene expression analysis confirmed IGF2 upregulation and demonstrated miR-483 expression in pterygium compared to normal conjunctiva (253.2-fold and 12.47-fold, respectively). Therefore, IGF-2/IGF-1R co-expression could suggest their interplay through the two different paracrine/autocrine IGF-2 routes for signaling transfer, which would activate the PI3K/AKT signaling pathway. In this scenario, miR-483 gene family transcription might synergically reinforce IGF-2 oncogenic function through its boosting pro-proliferative and antiapoptotic activity.

Rebound macular edema following oral acetazolamide therapy for juvenile X-linked retinoschisis in an Italian family.

BACKGROUND: Juvenile X-linked retinoschisis (RS1, OMIM: 312700) is a hereditary vitreoretinal dystrophy characterized by bilateral foveal schisis and, in half of the patients, splitting through the nerve fiber layer in the peripheral retina. In the first decade of life, patients usually develop a decrease in visual acuity. Long-term visual outcomes can be poor due to the limited number of known successful treatments. PURPOSE: The purposes of this study were to present, for the first time, a p.Arg197Cys missense mutation in the RS1 gene (OMIM: 300839) in a four-generation Italian family with RS1 and to examine the clinical response to the treatment with acetazolamide tablets alone or in combination with dorzolamide eye drops as assessed by spectral-domain optical coherence tomography (SD-OCT). METHODS: Eleven individuals, including two brothers with RS1 (patients 1 and 2), underwent a full medical history examination and a comprehensive ocular assessment that involved SD-OCT, fluorescein angiography, electroretinography and DNA analysis. Each RS1 patient received oral acetazolamide (375 mg daily) during the first three months. Thereafter, patient 1 continued only with dorzolamide eyedrops three times a day for a period of three months, while patient 2 spontaneously stopped both medications. RESULTS: Sequence analysis of the RS1 gene identified a hemizygous c.589C>T (p.Arg197Cys) missense mutation in exon 6, which has not been previously reported in an Italian family. A different response to the medical therapy was observed in the four eyes of the two affected brothers hemizygous for this abnormality. Of note, after acetazolamide interruption, a rebound effect on cystoid macular edema reduced the beneficial effects of the initial therapy for RS1 from p.Arg197Cys mutation. Indeed, a minimal rebound effect on cystoid macular edema, and an improvement in visual acuity, was observed in patient 1 during the six months of treatment. Conversely, in patient 2, an initial improvement in cystoid macular edema was not associated with visual acuity changes, followed by a marked rebound effect. CONCLUSION: This study showed that the sequential use of acetazolamide tablets and dorzolamide eye drops should be considered and studied further as a possible treatment for macular edema and visual impairment in patients with RS1 from a hemizygous p.Arg197Cys mutation.

Simultaneous occlusion of three cilioretinal arteries following scleral buckling surgery under local anesthesia.

BACKGROUND: Cilioretinal artery (CRA) occlusions are rare in young patients. In these cases, the most commonly associated causes are considered to be the same as those implicated in central retina artery occlusions, such as vasculitic processes, migraine, cardiac disorder, and coagulation abnormality. The aim of this article was to report for the first time the medical records and investigational results of an unusual case of simultaneous occlusion of three CRAs after scleral buckling surgery under local anesthesia. METHODS: A complete ophthalmic examination, including color fundus image, fundus fluorescein angiography, optical coherence tomography, visual field, as well as systemic and laboratory assessments, was performed. RESULTS: A case of contemporaneous blockage of three CRAs after ab externo surgery for retinal detachment in a 29-year-old Caucasian woman was reported. The interdisciplinary approach and the imaging results have allowed us the clinical definition of such a very rare case. CONCLUSION: Here, we reported that optical coherence tomography is an indispensable tool to better delineate the pathological process and follow atrophic changes in the macula, especially in cases in which fundus fluorescein angiography and systemic tests may be poorly informative.