Background: Retinopathy of prematurity (ROP) is considered as the most common reason for blindness in children, particularly in preterm infants. The disease is characterized by the dysregulation of angiogenic mechanisms due to preterm birth, leading ultimately to vascular abnormalities and pathological neovascularization (NV). Retinal detachment and vision loss could represent a concrete risk connected to the most severe forms of ROP, also characterized by inflammation and retinal cell death.
Methods: During the last decades, many animal models of oxygen-induced retinopathy (OIR) have been recognized as useful tools to study the mechanisms of disease, since they reproduce the hallmarks typical of human ROP. Indeed, modulation of retinal vascular development by exposure to different oxygen protocols is possible in these animals, reproducing the main pathological phenotypes of the disease. The easy quantification of abnormal NV and the possibility to perform electrophysiologic, histological and molecular analyses on these models, make OIR animals a fundamental instrument in studying the pathophysiology of ROP and the effects of novel treatments against the disease.
Discussion: Here, the most commonly used OIR protocols in rodents, such as mice and rats, are described as well as the main pathological outcomes typical of these models. Despite their limitations and variables which should be considered whilst using these models, OIR models display several characteristics which have also been confirmed in human patients, validating the usefulness of such animals in the pre-clinical research of ROP.
Background: Spontaneously resolved primary congenital glaucoma is rare and the mechanism remains unknown. Previous literature described the phenomenon of spontaneous resolution of primary congenital glaucoma, with no further reports on follow-up visits and visual development of patients. We report a case of unilateral spontaneously resolved primary congenital glaucoma at a 7-year follow-up visit and describe the differential development of axial length (AL) between affected eye and healthy eye.
Case Description: A 6-year-old boy firstly presented at Zhongshan Ophthalmic Center with expanded corneas and ruptures in Descemet’s membranes (Haab’s striae) and apparently thin retinal nerve fiber layer (RNFL) in the left eye (LE), but normal intraocular pressure (IOP) of both eyes without anti-glaucoma medications or surgeries. At 7-year follow-up, the IOPs of bilateral eyes were stable ranging from 8 to 11 mmHg. A cup to disc ratio and the RNFL was stable in the LE at the following visit. The AL increased almost 3 mm in the right eye (RE) but 1.5 mm in the LE. Without anti-glaucoma medications or surgeries, the primary congenital glaucoma was spontaneously resolved.
Conclusions: It may figure out the development and influence of the affected eye of the patient, including AL and refraction state with regular ophthalmic examination at periodic follow-up.
Background: Axonal degeneration caused by damage to the optic nerve can result in a gradual death of retinal ganglion cells (RGC), leading to irreversible vision loss. An example of such diseases in humans includes optic nerve degeneration in glaucoma. Glaucoma is characterized by the progressive degeneration of the optic nerve and the loss of RGCs that can lead to loss of vision. The different animal models developed to mimic glaucomatous neurodegeneration, all result in RGC loss consequent optic nerve damage.
Methods: The present article summarizes experimental procedures and analytical methodologies related to one experimental model of glaucoma induced by optic nerve crush (ONC). Point-by-point protocol is reported with a particular focus on the critical point for the realization of the model. Moreover, information on the electroretinogram procedure and the immunohistochemical detection of RGCs are described to evaluate the morpho-functional consequences of ONC.
Discussion: Although the model of ONC is improperly assimilated to glaucoma, then the ONC model simulates most of the signaling responses consequent to RGC apoptosis as observed in models of experimental glaucoma. In this respect, the ONC model may be essential to elucidate the cellular and molecular mechanisms of glaucomatous diseases and may help to develop novel neuroprotective therapies.
Background and Objective: Subthreshold laser therapy has emerged as a therapeutic alternative to traditional laser photocoagulation for certain ophthalmic diseases including central serous chorioretinopathy (CSCR), diabetic macular edema (DME), macular edema secondary to branch retinal vein occlusion (BRVO), and age-related macular degeneration (AMD). The objective of this paper is to review and discuss the clinical applications of subthreshold laser and the mechanisms of different subthreshold laser techniques including subthreshold micropulse laser (SMPL), selective retina therapy (SRT), subthreshold nanosecond laser (SNL), endpoint management (EpM), and transpupillary thermotherapy (TTT).
Methods: A narrative review of English literature and publicly available information published before November 2021 from literature databases and computerized texts. We discuss the currently available subthreshold laser systems and the advancements made to perform different subthreshold laser techniques for various ophthalmic diseases. We highlight various clinical studies and therapeutic techniques that have been conducted to further understand the effectiveness of subthreshold laser in the clinical setting. We conclude the article by covering emerging subthreshold laser systems that are currently being developed for future clinical use. The PubMed database was utilized for peer-reviewed articles and pertinent information on subthreshold systems was cited from publicly available online websites covering specific systems.
Key Content and Findings: Various subthreshold laser systems have been developed to treat certain retinal diseases. Several systems are currently in development for future clinical applications.
Conclusions: While conventional laser photocoagulation has been effective in treating various retinal diseases, subthreshold laser systems aim to provide a therapeutic effect without visible signs of damage to the underlying tissue. This technology may be particularly effective in treating macular disorders. Further clinical studies are needed to evaluate their role in the management of retinal diseases.
Background and Objective: Vitreoretinal surgery requires fine micro-surgical training and handling of delicate tissue. To aid in the training of residents and fellows, unique educational modalities exist to help facilitate the development of these microsurgical skills. From virtual simulators to artificial eye models, simulation of the posterior segment has gained an increased focus in vitreoretinal surgical training programs. Development of surgical curricula for vitreoretinal training and attainment of surgical milestones has been a key component in integrating these educational training modalities. We will explore various simulators, eye models, and potential rubrics and discuss unique ways each may help and complement one another to train future vitreoretinal surgeons.
Methods: We conducted a systematic PubMed search of various review studies (from publications in English ranging from January 1978 to December 2020) discussing surgical simulators, eye models, and surgical rubrics for vitreoretinal surgery and their potential impacts upon training.
Key Contents and Findings: Our review assesses the benefits and applicability of various simulators, eye models, and surgical rubrics upon training.
Conclusions: Utilization of vitreoretinal surgical training tools may aid in complementing the hands-on surgical training experience for vitreoretinal surgical fellows. By using simulators and rubrics, we may better be able to standardize training for reaching vitreoretinal surgical milestones and providing adequate feedback to improve surgical competency and ultimately patient outcomes.
Ocular ischemia syndrome (OIS), featuring as chronic ocular hypoperfusion, is an eye disease caused by a series of incentives. It is relatively rare in clinical practice, but has a great impact on vision. The symptoms of OIS mainly include transient amaurosis, ischemic eye pain, permanent vision loss, etc. In recent years, with the rise of the Aesthetic Medicine industry, the technology of autologous fat filling has been increasingly adopted. The OIS caused by the surgery of autologous fat filling is nonnegligible. In this paper, by means of analyzing a case that an autologous fat filling surgery resulted in the OIS, discusses features of fundus angiography of OIS.
Cat scratch disease (CSD) is a zoonotic disease caused by Bartonella, which not only has a variety of systemic manifestations, but also may have various ocular complications that endanger vision. With the increasing number of pets kept at home, its incidence shows an increasing trend year by year. Therefore, ophthalmologists should pay attention to this disease. The clinical manifestations of CSD are various, which easily lead to misdiagnosis. The medical history of contact with cats and other pets and serum immunoglobulin G antibody with high titer are the key to diagnosis, and polymerase chain reaction is also helpful to diagnosis. Because CSD is usually a self-limiting infection of individuals with strong immune ability, antibiotic treatment is usually not required. However, when immunity is low or infection is severe, doxycycline is the most commonly used antibiotic.
