Background and Objective: Limbal stem cell deficiency (LSCD) describes the clinical condition when there is dysfunction of the corneal epithelial stem/progenitor cells and the inability to sustain the normal homeostasis of the corneal epithelium. The limbal stem cells are located in a specialized area of the eye called the palisades of Vogt (POV). There have been significant advances in the diagnosis and management of LSCD over the past decade and this review focuses on the pathophysiology of LSCD, its clinical manifestations, diagnosis, and causes.Methods: Papers regarding LSCD were searched using PubMed to identify the current state of diagnosis and causes of LSCD published through to June 2022.
Key Content and Findings: LSCD is clinically demonstrated by a whorl-epitheliopathy, loss of the POV, and conjunctivalization of the cornea. The diagnosis of this condition is based on clinical examination and aided by the use of impression cytology, in vivo confocal microscopy, and anterior segment optical coherence tomography (asOCT). There are many causes of LSCD, but those which are most common include chemical injuries, aniridia, contact lens wear, and Stevens-Johnson syndrome (SJS).Conclusions: While this condition is most commonly encountered by corneal specialists, it is important that other ophthalmologists recognize the possibility of LSCD as it may arise in other co-morbid eye conditions.
The prevalence of diabetic retinopathy (DR) continues to increase in pregnant females; these individuals are also at a higher risk of disease progression. The lack of evidence regarding the safety and efficacy of current treatment options in pregnancy makes disease management particularly challenging.All pregnant women with diabetes should have a prenatal DR screening, as well as receive counseling regarding the progression and management of DR during pregnancy. Optimal blood glucose and blood pressure control should be encouraged. For patients with proliferative diabetic retinopathy (PDR) in the absence of visually significant diabetic macular edema (DME), panretinal photocoagulation (PRP) remains a safe and effective treatment option. Visually significant DME can be treated with focal laser if areas of focal leakage are identified in the macula on fluorescein angiogram, intravitreal steroids or anti-vascular endothelial growth factor (VEGF) agents, The theoretical risk of anti-VEGF agents to the fetus should be considered and the patients should be extensively counselled regarding the risks and benefits of initiating anti-VEGF therapy before initiating treatment. When the decision is made to treat with anti-VEGF agents, Ranibizumab should be the agent of choice. In conclusion, ophthalmologists should make treatment decisions in pregnant patients with DR on a case-by-case basis taking into consideration disease severity, risk of permanent threat to vision, gestational age, and patient preferences.
Background: Necrotising fasciitis (NF) is a rare but severe necrotising infection of the subcutaneous tissues. We report a case of periocular NF associated with a concurrent COVID-19 infection and explore potential mechanisms of pathogenesis of COVID-19 infection and necrotising superinfections.
Case Description: A 33-year-old previously healthy female presented with right-sided progressive periocular swelling, erythema, pain and fever, two days after sustaining a laceration to the right superolateral brow from a clenched fist. She had a concurrent COVID-19 infection, detected on nasopharyngeal polymerase chain reaction swab thirteen days prior to presentation and again at presentation. She did not have an oxygen requirement. There was a large bulbous collection of the right upper lid with fluctuance and overlying erythema, and a communicating sinus drained frank pus from the superolateral brow. Pre-operative T2-weighted MRI demonstrated fascial hyperintensity involving the pre-septal tissues and extending to the anterior temporal fossa. She was commenced on intravenous meropenem, clindamycin and vancomycin, and underwent early surgical debridement. Initial debridement demonstrated right upper lid necrosis involving the dermal and pre-septal layers, including the orbicularis, but sparing the tarsus. Streptococcus pyogenes was isolated, and she was continued on a prolonged course of intravenous antibiotic. Periocular defects were repaired with a right-sided brow adipo-fascial flap based on the supratrochlear artery, browpexy and dual full thickness skin grafts on the right upper lid and flap.
Conclusions: NF is an acute fulminant infection rarely affecting the periocular tissues. This represents a unique case of periocular NF associated with a concurrent COVID-19 infection.
Abstract: Retinopathy of prematurity (ROP) is a proliferative disorder of the developing retina in premature and low birth weight infants. Recently, the role of vascular endothelial growth factor (VEGF) in the pathophysiology of ROP has been well studied and anti-VEGF drugs have been used in phase 2 to treat ROP patients in many ways. At first, ophthalmologists began to give intravitreal bevacizumab (IVB) or ranibizumab off-label to treat ROP as a salvage treatment after failure in laser photocoagulation or in combination with laser as an adjuvant treatment for patients had media opacity or rigid pupil. Now anti-VEGF drugs are also used as monotherapy in type I ROP or perioperative use in stage 4/5 ROP. Questions remain regarding long-term safety, dose, timing, visual outcomes and long-term effects, including systemically.
Background: To explore the safety and effectiveness of Sclera patch grafts in the management of scleral defects.
Methods: This is a retrospective uncontrolled study. Medical records were retrospectively reviewed for 8 eyes of 8 patients with sclera patch grafts. Two patients had necrotizing scleritis, 2 patients had scleral melting/perforation secondary to thermal burns, 4 patients had scleral staphyloma secondary to surgery. Sclera was reconstructed with allogenic sclera patch grafts, 6 in 8 patients combined autologous conjunctival pedicle flap, 1 patient combined partial medial rectus translocation, 1 patient combined autologous pedicle tenon graft, simultaneously. Treatment outcomes were evaluated using structural integrity, best corrected visual acuity (BCVA), scleritis remission, sclera rejection and melt, and ocular symptoms.
Results: Eight patients were reviewed. In all of these cases, satisfactory anatomic and functional outcomes were achieved. In the at least half a year follow-up, the BCVA of all the eight patients were no worse than that of preoperative. No eye pain, foreign body sensation and other discomforts showed in all the patients, except one woman, who showed sclera rejection and melt 1 month postoperative. In addition, one patient showed high intraocular pressure (28 mmHg), which can be controlled by a kind of medicine.
Conclusions: In this series, sclera patch grafts is an effective method for management scleral defects in the at least half a year following-up. Attention should be paid to the sclera patch rejection and melt post operatively.
Background: To settle the fundamentals of a numerical procedure that relates retinal ganglion-cell density and threshold sensitivity in the visual field. The sensitivity of a generated retina and visual pathways to virtual stimuli are simulated, and the conditions required to reproduce glaucoma-type defects both in the optic-nerve head (ONH) and visual fields are explored.
Methods: A definition of selected structural elements of the optic pathways is a requisite to a translation of clinical knowledge to computer programs for visual field exploration. The program is able to generate a database of normalized visual fields. The relationship between the number of extant receptive fields and threshold sensitivity is plotted for background sensitivity and corresponding automated perimetry. A solution in two planes to the 3D distribution of axons in the ONH is proposed. Visual fields with induced damage in the optic disc are comparable in pattern and quantity to glaucomatous records.
Results: The two-level simulation of the ONH facilitates the analysis of optic-cup/retinal defects. We can generate the virtual optic pathways tailored to the age and morphology of the patient’s eye, and it is possible to reproduce glaucomatous damage by “reverse engineering” engineering. The virtual cortical model renders a quantitative relationship between visual defect and neural damage.
Conclusions: A two-level computing of the retina/optic nerve facilitates the analysis of neuroretinal defects and can be incorporated to automatic perimeters to facilitate visual field analysis.
Abstract: High speed and small gauge vitrectomy systems have made surgical intervention in complications of diabetic retinopathy (DR) safer. The availability of anti-vascular endothelial growth factor (anti-VEGF) compounds for use in DR has significantly improved intraoperative and postoperative outcomes. This review discusses the indications for surgical intervention in DR. The role of anti-VEGF compounds is discussed as surgical adjuvants with an emphasis on timing of treatment before surgery.
Abstract: Despite appropriate management of the systemic disease, patients with diabetes may develop severe forms of diabetic retinopathy that require surgery. Non-clearing vitreous haemorrhage (VH), traction retinal detachment involving the macula, combined traction and rhegmatogenous retinal detachment, progressive fibrovascular proliferation (PFP) and rubeosis with acute VH represent the main indications for surgery. Vitrectomy techniques and surgical tools have developed dramatically in the last decade in order to help the surgeon succeed in these challenging cases.
