Lighting Standards Revisited: Introduction of a Mathematical Model for the Assessment of the Impact of Illuminance on Visual Acuity.

PURPOSE: Primary objective of present study is to introduce a contemporary methodology for the lighting standards update addressing both normophakic and pseudophakic patients. METHODS: For the sake of our study, we theoretically estimated the intraocular-to-crystalline lens iIluminance ratio (ICIR) and the intraocular lens (IOL) luminous efficiency function VIOL(λ) as a new lighting benefit metric. Then, in a sample of 24 pseudophakic patients (38 eyes) implanted with the trifocal diffractive IOL Panoptix (SG) and in a control group (CG) of 28 normophakic participants (50 eyes), uncorrected distance visual acuity (UDVA) was measured at illuminance of 550lx (optimal UDVA). Following dark adaptation, illuminance was gradually raised from 20 lx until illuminance level that the patient reached his/her optimal UDVA. This measured illuminance at this point was defined as the minimum required illuminance level (MRIL). MRIL and UDVA for illuminance levels between 20 and 550lx in SG were compared with the corresponding values in CG. MRIL calculation allowed the construction of a predictive mathematical model that estimates the impact of environmental lighting on UDVA. RESULTS: ICIR for Panoptix eyes ranged from 54.00% to 55.99%. Both groups had significantly higher UDVA at 550lx compared to 20lx (p < 0.05). CG had significantly higher UDVA than SG at 20lx (7.20 letters, p = 0.045), while no significant difference was detected at 550lx (0.40 letters, p = 0.883). SG required significantly more illuminance than CG to maintain their UDVA (MRILSG= 191.05lx, MRILCG= 122lx, p = 0.007). Our predictive model suggests suboptimal UDVA in a series of lighting directives for normophakic and Panoptix eyes. CONCLUSION: This is the first study to introduce the VIOL(λ) as a new lighting benefit metric and a mathematical model that quantifies the impact of illuminance on UDVA in normophakic and pseudophakic patients. CLINICALTRIALSGOV IDENTIFIER: NCT04263636.

Serpiginous Choroiditis Complicated with Choroidal Neovascular Membrane Detected using Optical Coherence Tomography Angiography: A Case Series and Literature Review

Serpiginous choroiditis (SC) is a rare, chronic, recurrent, progressive disease of unknown origin. The inflammatory process of SC can disrupt Bruch's membrane, allowing occasional choroidal vascular growth, leading to significant visual loss even in the healed stages of the disease. Optical coherence tomography angiography (OCTA) can help in the detection of choroidal neovascular membrane (CNV), leading to a definitive diagnosis and thereby guide the initiation of intravitreal anti-vascular endothelial growth factor (anti-VEGF) treatment. We report herein two cases of SC complicated with a CNV detected with OCTA and treated with a series of anti-VEGF injections.

Determinants of compliance to the facemask directive in Greece: A population study.

PURPOSE: Primary objective of this study was to identify potential difficulties and/or discomfort when using a facemask. Moreover, to explore the impact of spectacles, contact lenses and visual acuity on the compliance to the facemask directive. METHODS: This is a prospective study that was conducted at the Department of Ophthalmology, University Hospital of Alexandroupolis, Greece between June 2020 and August 2020. Greek speaking citizens with permanent residency in Greece above 18 years old were included. A custom questionnaire (DeMask-20) was constructed and validated, which pertained to the perceived difficulty and discomfort when using a facemask. It contained 20 items grouped in 8 subscales (driving, near vision, distance vision, ocular discomfort, role limitation, collaboration, dependency on others, emotional stress). Perceived difficulty and discomfort when using a facemask, compliance and correlations of compliance with DeMask-20 scores, demographics, spectacle and/or contact lens use, and visual acuity were evaluated. RESULTS: The number of factors was determined through factor analysis. Cronbach's alpha ranged from 0.716 for the "Role limitation" subscale to 0.938 for "Ocular discomfort" subscale. 1,214 participants (402 men, 812 women, mean age 36.79±12.50 years) completed the DeMask-20 instrument. Mean DeMask-20 score of all study participants was 3.79±0.71. Significant differences in DeMask-20 score were detected in gender (p = 0.009), spectacle use (p = 0.034), contact lens use (p = 0.049), and binocular distance visual acuity (bDVA) (p = 0.001). Mean compliance of all participants was 4.05±0.96. Men, people <50 years and spectacle wearers showed significantly worse compliance (p<0.05). Moreover, professional workers and professional drivers demonstrated significantly better compliance (p = 0.008 and p = 0.047). Significant correlation was detected between compliance and DeMask-20 score (p<0.001, R2 = 0.471). Significant correlations were detected with driving, near vision, distance vision, collaboration, role limitation, emotional stress (p<0.05, R2: 0.386-0.493). CONCLUSIONS: Factor analysis suggested that the DeMask-20 instrument demonstrates adequate validity, while Cronbach's alpha indicated sufficient internal consistency of all subscales. This study provided the necessary methods that could evaluate compliance trends and the efficacy of healthcare interventions against COVID-19. Our outcomes suggest that young males who use spectacles should be targeted by Greek Healthcare authorities in order to improve compliance rates.

Corneal Graft Success Rates in HSV Keratitis: A Systematic Review.

Herpes Simplex Virus (HSV) has worldwide prevalence. The primary objective of this systematic review was to compare penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) regarding the efficacy and complications of the treatment of corneal scarring caused by herpes simplex keratitis. Out of the 469 articles identified during the combined search of the literature based on the PubMed and Cochrane libraries, 10 retrospective and 2 prospective studies published from January 2010 to December 2019 were included. The study outcomes indicated that both surgical approaches resulted in a comparable improvement of visual acuity (VA). However, DALK demonstrated fewer complications in the majority of studies. Higher graft survival rates were associated with higher acyclovir (ACV) doses (above 800 mg/day), topical steroid and antibiotic drops. In conclusion, in terms of postoperative VA, both PK and DALK demonstrate comparable efficacy. However, DALK, which is applied in less severe HSK cases, is associated with fewer complications and better graft survival rates. High dosages of ACV, topical steroids and antibiotics contribute significantly to improved postoperative outcomes.

Corneal ectasia following cataract extraction surgery in a patient with keratoconus: a case report.

BACKGROUND: According to experimental and clinical published studies, patients with keratoconus have a genetic predisposition to corneal ectasia; however, ectasia might not be activated or reactivated unless an additional stressful event triggers the disease. Triggering factors are sources of reactive oxidative stress; among them, mechanical trauma (vigorous eye rubbing, poorly fit contact lenses), exposure to ultraviolet light, and atopy/allergies. The aim of this case report is to present for the first time a case of rapidly progressive corneal ectasia in a patient with keratoconus following uncomplicated phacoemulsification surgery for cataract removal. CASE PRESENTATION: A 38-year-old Caucasian man was referred to our out-patient's service due to bilateral cataract. He also had bilateral keratoconus and had undergone corneal cross-linking in both his eyes 5 years prior to his referral. Ever since the corneal cross-linking, keratoconus had been stable. He underwent a full ophthalmological examination including slit-lamp biomicroscopy, optical biometry, Scheimpflug tomography, corneal biomechanical assessment, and fundus examination. He presented advanced centrally located cataract with count fingers for preoperative best-corrected visual acuity. An uncomplicated cataract extraction surgery was performed. Preoperative flat keratometry reading was 40.5 diopters, steep keratometry reading was 41.8 diopters, astigmatism was 1.3 diopters, corneal hysteresis was 8.2, corneal resistance factor was 7.5, and thinnest corneal thickness was 503 µm. Within 3 months, he demonstrated rapidly progressing corneal ectasia in his operated eye, while 6 months postoperatively, flat keratometry reading was 45.5 diopters, steep keratometry reading was 48.3 diopters, astigmatism was 2.8 diopters, corneal hysteresis = 6.8, corneal resistance factor = 7.5, and thinnest corneal thickness = 318 µm. CONCLUSIONS: To the best of our knowledge, this is the first report to describe corneal ectasia in a patient with keratoconus following phacoemulsification surgery. Cataract surgeons should provide extra caution to patients with keratoconus and take into consideration this rare but potentially sight-threatening complication.

Human pericardium graft in the management of bleb's complication performed in childhood: a case report.

BACKGROUND: To report a case with hypotony due to late leakage of the filtering bleb performed during childhood and treated surgically using human pericardium graft. CASE PRESENTATION: A man with hypotony related to bleb's leakage in his right eye was presented. During his childhood trabeculectomy was performed to manage ocular hypertension due to pediatric glaucoma. Biomicroscopy revealed choroidal tissue incarcerated in the sclerectomy under the conjunctiva. Bleb revision was performed. Human pericardium graft was used to cover the sclerectomy and a new bleb with controlled outflow was created. The intraocular pressure (IOP) and Seidel test represent the main outcomes. Intraoperative and postoperative complications were recorded. Fifteen days postoperatively the IOP was of 7 mmHg and the bleb seemed to filter properly. Five months later the IOP was 9 mmHg and no complications were noticed. During the follow up time, the Seidel test was negative. CONCLUSION: We used human pericardium graft with no complications in a case of bleb leakage performed for pediatric glaucoma.

Perfluorocarbon liquids in vitreoretinal surgery: a review of applications and toxicity.

Since their introduction by Chang et al. in 1987, perfluorocarbon liquids (PFCLs) have become a useful tool in vitreoretinal surgery. They are synthetic compounds with carbon-fluorine chemical chains that have specific physico-chemical properties, which make them valuable for the intraoperative management of the retina by simplifying vitreoretinal surgical maneuvers in a variety of settings. These maneuvers include retinal detachments associated with proliferative vitreous retinopathy, following penetrating trauma, giant retinal tears, dislocated lenses or lens implants and complications from proliferative diabetic vitreoretinopathy. Purified PFCLs are generally considered to be biologically inert. Despite the stability of PFCLs during vitreoretinal surgery, several studies have indicated that these compounds may be associated with toxicity in ocular tissues. The purpose of this review is to report the use and toxicity of PFCLs in vitreoretinal surgery and to present the latest perspectives on modified PFCLs (hydrofluorocarbon liquids (HFCLs) and HFCL-oligomers).

Comparative studies of RNFL thickness measured by OCT with global index of visual fields in patients with ocular hypertension and early open angle glaucoma.

PURPOSE: To compare the functional changes in visual fields with optical coherence tomography (OCT) findings in patients with ocular hypertension, open angle glaucoma, and suspected glaucoma. In addition, our purpose is to evaluate the correlation of global indices with the structural glaucomatous defect, to assess their statistical importance in all the groups of our study, and to estimate their validity to the clinical practice. METHODS: One hundred sixty nine eyes (140 patients) were enrolled. The patients were classified in three groups. Group 1 consisted of 54 eyes with ocular hypertension, group 2 of 42 eyes with preperimetric glaucoma, and group 3 of 73 eyes with chronic open angle glaucoma. All of them underwent ophthalmic examination according to a prefixed protocol, OCT exam (Stratus 3000) for retinal nerve fiber layer (RNFL) thickness measurement with fast RNFL thickness protocol and visual fields (VF) examination with Octopus perimeter (G2 program, central 30-2 threshold strategy). Pearson correlation was calculated between RNFL thickness and global index of VF. RESULTS: A moderate correlation between RNFL thickness and indices mean sensitivity (MS), mean defect (MD) and loss variance (LV) of VF (0.547, -0.582, -0.527, respectively; P <0.001) was observed for all patients. Correlations of the ocular hypertension and preperimetric groups are weak. Correlation of RNFL thickness with global indices becomes stronger as the structural alterations become deeper in OCT exam. Correlation of RNFL thickness with the global index of VF, in respective segments around optic disk was also calculated and was found significant in the nasal, inferior, superior, and temporal segments. CONCLUSION: RNFL average thickness is not a reliable index for early diagnosis of glaucoma and for the follow-up of patients with ocular hypertension. Segmental RNFL thickness seems to be a more reliable index. Deep structural alterations with OCT examination constitute an important indication of early functional changes, even if they are not still detected with achromatic perimetry. The MD index of VF seems to be more sensitive for the follow-up of patients with ocular hypertension.