Switching to ziv-aflibercept in resistant diabetic macular edema non responsive to ranibizumab injection.

BACKGROUND: Diabetic macular edema (DME) is a leading cause of visual loss in diabetic patients and is managed using multiple anti-vascular endothelial growth factor (VEGF) agents such as bevacizumab, ranibizumab and aflibercept. The present study evaluates effectiveness of intravitreal injection of ziv-aflibercept in resistant diabetic macular edema. METHODS: This is a prospective interventional study that was carried out on 59 eyes of 40 diabetic patients with diabetic macular edema resistant to three prior consecutive ranibizumab injections. On all patients, thorough ophthalmic evaluation including optical coherence tomography was performed. In patients with persistent intraretinal or subretinal fluid, ziv- aflibercept 1.25 mg (0.05 ml) was administered by intravitreal injection monthly during the 6 month study period from June to December 2019. RESULTS: The central macular thickness (CMT) decreased significantly from 395.08 ± 129.9 um at baseline to 282.39 ± 95.278, 245.36 ± 79.861 and 201.17 ± 54.042 after 1, 3 and 6 months of treatment respectively (p < 0.001). Best corrected visual acuity (BCVA) in log MAR units was significantly improved from 0.95 ± 0.21 to 0.51 ± 0.23 after 6 months (p = 0.001). After treatment, negative correlations were detected between age, number of injections, duration of DM and level of glycated hemoglobin (HbA1c) and variation of both CMT and BCVA. The only significant predictor for low final CMT after 6 months of injection was the CMT after 3 months of injection (p = 0.001). CONCLUSION: Ziv-aflibercept is a highly effective and safe drug in cases of DME resistant to previous ranibizumab injections especially in low-income countries. TRIAL REGISTRATION: This study was retrospectively registered at clinicaltrials.gov (ID: NCT04290195) on 28-2-2020.

Prevalence and topographical characteristics of keratoconus in patients with refractive errors in the Egyptian delta.

PURPOSE: To study the prevalence of keratoconus (KC) and the topographical characteristics of the affected corneas in patients with refractive errors who were seeking refractive surgery in the Egyptian delta. METHODS: A retrospective study covering four and half years (Jan 2012-June 2016) where the topographical data of 8124 participants were obtained from the records of a refractive center in the Nile delta region, Egypt. The diagnosis of KC was based on the Holladay criteria in one or both eyes, using the Pentacam scans, whereas grading of KC was based on the Amsler-Krumeich classification. RESULTS: The prevalence of KC was 1.12% (91/8124 participants) with 95% confidence interval 0.91-1.3. Of all the affected cases, 5 cases (5.5%) had unilateral, and the other 86 cases (94.5%) had bilateral KC. The affected and unaffected subjects did not show any significant difference regarding gender. Sixty-eight (38.4%) eyes had stage 1 KC, 53 eyes (29.9%) had stage 2, 27 eyes (15.3%) had stage 3, and 29 eyes (16.4%) had stage 4 KC. It was most prevalent (1.2%) among cases with astigmatism (P < 0.001). CONCLUSION: Keratoconus was found in 1.12% of patients seeking refractive surgery, with no gender preference. Most cases had bilateral affection. Astigmatism was the most common refractive error to be associated with keratoconus.

The neuro-ophthalmological effects related to long-term occupational exposure to organic solvents in painters.

PURPOSE: Organic solvents are widely used in many industries, and usually, exposure occurs with mixtures of solvents. Organic solvent mixtures are known for their ability to affect tissues of high lipid content including the myelin sheath in the nervous system. The purpose of this work was to study the evidence that long-term (more than 10 years) exposure to organic solvent mixtures among painters can induce neuro-ophthalmological effects on the function of retinal ganglion cells and the optic tract. METHODS: Twenty workers with long-term occupational exposure to mixed organic solvents were compared to 40 control subjects. The controls were matched for age, gender, and demographic characteristics but were not occupationally exposed to any known organic solvents, using the following comparators: visual evoked potential (VEP), electroretinogram (ERG), color vision (CV), and contrast sensitivity (CS) testing. Environmental monitoring was done in the work environment with consideration to the American Conference of Governmental Industrial Hygienists Threshold Limit Values (ACGIH-TLVs). RESULTS: The exposed group had significantly longer latency and higher amplitude of VEP waves especially P100, higher Color Confusion Index (CCI), especially affecting the blue-yellow spectrum, and lower Log CS. There was no significant difference between exposed and nonexposed groups in full-field flash ERG response; however, in the pattern ERG, the exposed group had significantly longer latency of P50, which reflects changes in the retinal ganglion cell. CONCLUSION: Long-term occupational exposure to mixed organic solvents appeared to affect the optic tract functions in the form of increasing latency of VEP response, affecting the quality of CV and decreasing CS. It also affects the retinal ganglion cell layer with increased latency of P50 of the pattern ERG response.

Concurrent and Post COVID-19 Ophthalmological Implications.

BACKGROUND AND AIM: COVID-19 infection is a respiratory disease but it can have ophthalmological manifestations as well. This study aimed to investigate the ophthalmological implications of COVID-19 either during the course of the disease or after recovery. METHODS: A retrospective study included the records of 425 COVID-19 patients, proved by positive PCR swabs. The records were collected from three isolation hospitals in Gharbeya Governorate, Egypt. RESULTS: The mean age of the studied group was 41.73 ± 13.59, and 216 (50.8%) of them were males. One hundred and thirty one (30.8%) patients had ophthalmological manifestations. Among the entire patients, the most common ophthalmological presentation was conjunctivitis in 111 patients (26.1%), followed by neuro-retinal affection in 9 (2.1%), secondary fungal orbital cellulitis in 6 (1.4%), episcleritis in 3 (0.7%) and keratitis in 2 (0.5%) patients. All of the observed ophthalmological implications occurred either during the course of the disease (concurrent) or after recovery, except for the fungal orbital cellulitis which occurred only after recovery. CONCLUSION: COVID-19 could cause different eye manifestations. Recovery from the main disease does not guarantee eye safety, especially in high-risk patients.

Results of Pars Plana Vitrectomy for Different Types of Macular Holes.

PURPOSE: To compare different types of macular holes regarding the anatomic and functional success following pars plana vitrectomy (PPV) and internal limiting membrane (ILM) removal. METHODS: A retrospective review of all patients with macular holes treated by PPV, ILM removal with gas tamponade from January 2014 to July 2017 in Magrabi Eye Hospital. RESULTS: One hundred fifty-seven eyes of 153 patients were analyzed. The eyes were classified according to the etiology of macular hole into four groups: 79 eyes with idiopathic macular hole (IMH), 51 eyes with traumatic macular hole (TMH), 16 eyes with macular hole in diabetic patients (DMH) and 11 eyes with myopic macular hole (MMH). We classified the IMH group based on the International Vitreomacular Traction Study Classification according to size into 3 subgroups; subgroup 1: ≤250µ, subgroup 2: >250 to 400µ and subgroup 3: ≥400 µ. All types of macular hole showed statistically significant postoperative improvement in BCVA compared to the baseline except cases with MMH. Anatomic postoperative hole closure was achieved in 86.1%, 60.7%, 43.65%, an 45.46% of eyes with IMH, TMH, DMH and MMH, respectively. In eyes with IMH, closure rate in subgroup 1 was significantly higher than in subgroups 2, and 3. CONCLUSION: PPV, ILM peel and C2F6 technique yielded variable anatomic and functional outcomes in different types of macular holes. Anatomic results were most favorable in IMH and least favorable in MMH. The smaller the diameter of the hole the better the results. The underlying pathogenetic mechanisms that lead to different types of macular holes are pivotal in determining the final outcome.

Computational fluid dynamics analysis of the upper airway after rapid maxillary expansion: a case report.

BACKGROUND: Assessment of the upper airway volume, morphology, and mechanics is of great importance for the orthodontic patient. We hypothesize that upper airway dimensions have significant effects on the dynamics of the airway flow and that both the dimensions and mechanics of the upper airway are greatly affected by orthodontic and orthopedic procedures such as rapid maxillary expansion (RME). The aim of the current study was to assess the effect of RME on the airway flow rate and pattern by comparing the fluid dynamics results of pre- and post-treatment finite element models. METHODS: Customized pre- and post-treatment computational fluid dynamics models of the patient's upper airway were built for comparison based on three-dimensional computed tomogram. The inhalation process was simulated using a constant volume flow rate for both models, and the wall was set to be rigid and stationary. Laminar and turbulent analyses were applied. RESULTS: Comparisons between before and after RME airway volume measurements showed that increases were only detected in nasal cavity volume, nasopharynx volume, and the most constricted area of the airway. Pressure, velocity, and turbulent kinetic energy decreased after dental expansion for laminar and turbulent flow. Turbulent flow shows relatively larger velocity and pressure than laminar flow. CONCLUSIONS: RME showed positive effects that may help understand the key reasons behind relieving the symptom of breathing disorders in this patient. Turbulence occurs at both nasal and oropharynx areas, and it showed relatively larger pressure and velocity compared to laminar flow.

Aloe vera gel facilitates re-epithelialization of corneal alkali burn in normal and diabetic rats.

PURPOSE: To investigate the efficacy of topical applied aloe vera (AV) and to facilitate the repair of the standardized alkaline corneal ulcer in normal and diabetic rats. MATERIALS AND METHODS: The corneal alkali-burn injury model was established unilaterally in Wistar rats by filter paper saturated with 0.01 M NaOH contacting the eyes for 45 seconds. Rats were divided into four groups: normal control (NC), normal AV (NAV), diabetic control (DC), and diabetic AV (DAV). NAV and DAV groups were treated with AV gel eye drops four times daily, and NC and DC groups were treated with normal saline for 3 days. Corneal epithelial wound closure and degree of edema were recorded using slit lamp and optical coherence tomography at 0, 24, 48, and 72 hours postwounding. Histological examination was conducted to evaluate the degree of inflammation and the healing effect. RESULTS: Corneal epithelial wound healing was better in the NAV group than in the NC group, and it was significantly higher in the DAV group than in the DC group (P<0.05). In comparison to the DC group, DAV treated with AV demonstrated a marked reduction in edema at 48 and 72 hours. Histologically, corneal re-epithelialization was complete and higher in DAV group than that in DC group; moreover, the inflammatory cells were increased in DC group than DAV group (P<0.05). CONCLUSION: This study demonstrated the efficacy of AV for enhanced corneal re-epithelialization, as well as reduced inflammatory response after alkali burn in rats; therefore, it could be useful as a therapy for diabetic keratopathy.

Peripheral fundus autofluorescence is increased in age-related macular degeneration.

PURPOSE: To evaluate peripheral fundus autofluorescence (FAF) in patients with AMD. METHODS: A consecutive series of 71 normal eyes, 71 eyes with neovascular AMD having received anti-VEGF treatment, and 43 eyes with untreated AMD were investigated. In all subjects, wide-field FAF imaging was performed, applying a wide-field scanning laser ophthalmoscope. FAF was quantified by image analysis software after defining peripheral and perifoveal central measurement zones with a grid scheme; age correction was performed by regression model. RESULTS: Fundus autofluorescence increased with age not only in the perifoveal retinal area, but also in the retinal periphery. For age-corrected measurements, peripheral FAF was significantly increased for both, treated and untreated AMD groups compared with normal subjects. No significant difference was observed in peripheral FAF between AMD eyes having received anti-VEGF treatment and those without treatment. Age-corrected normal FAF in the retinal center differed significantly from the anti-VEGF-treated group (P < 0.01), but not the untreated AMD group. Age-corrected peripheral FAF irregularity, defined as the standard deviation in the measurement field, was significantly increased in both AMD groups compared with normal subjects. CONCLUSIONS: Detection of peripheral in addition to central FAF may provide additional information potentially helpful to detect and monitor the development of AMD. No differences in autofluorescence were observed in the retinal periphery between anti-VEGF-treated and untreated eyes.

Wide-field fundus autofluorescence corresponds to visual fields in chorioretinitis patients.

BACKGROUND AND OBJECTIVES: Detection of peripheral fundus autofluorescence (FAF) using conventional scanning laser ophthalmoscopes (SLOs) is difficult and requires pupil dilation. Here we evaluated the diagnostic properties of wide-field FAF detected by a two-laser wavelength wide-field SLO in uveitis patients. STUDY DESIGN/MATERIALS AND METHODS: Observational case series of four patients suffering from different types of posterior uveitis/chorioretinitis. Wide-field FAF images were compared to visual fields. Panretinal FAF was detected by a newly developed SLO, which allows FAF imaging of up to 200° of the retina in one scan without the need for pupil dilation. Visual fields were obtained by Goldmann manual perimetry. RESULTS: Findings from wide-field FAF imaging showed correspondence to visual field defects in all cases. CONCLUSION: Wide-field FAF allowed the detection of visual field defect-related alterations of the retinal pigment epithelium in all four uveitis cases.