Idiopathic intracranial hypertension in Omani adults: A tertiary center experience.

BACKGROUND: To evaluate the clinical profile, risk factors, and ophthalmic diagnostic and monitoring tools in Omani patients with idiopathic intracranial hypertension (IIH) using optical coherence tomography (OCT). METHODS: A retrospective single institutional cohort study on Omani patients with a fulfilled diagnosis of IIH from January 1, 2014, to January 1, 2020, was conducted. The data obtained from the neuro-ophthalmic clinic contained age of onset of the disease, gender of patients, body mass index (BMI), presence of other associated conditions, and medication use. RESULTS: Our study group comprised 21 patients with IIH with an annual incidence rate of 2.8 per 100,000 population. Female-to-male ratio was 9.5:1 with a mean age of 27.24 ± 7.1. Headaches appeared to be the most prevalent symptom in 21 (100%) patients, followed by transient obscuration of vision in 9 (42.9%) patients and diplopia in 3 (14.3%) patients, and the least common symptom was pulsatile tinnitus in 2 (9.5%) patients. Increased BMI was seen in 19 (90.5%) patients and noted to be the most prevalent predisposing factor among our study group. The use of oral contraceptive pills was documented in 4 (19%) patients and 1 (4.8%) patient was noted to have polycystic ovary syndrome. All patients (100%) had a best-corrected visual acuity of 1.0 in both eyes pre- and postrecovery and 7 (33.3%) patients had an enlarged blind spot on visual field testing. All patients had papilledema on presentation and an average of 14.1 months to resolve to normal clinically and on OCT monitoring. All patients were treated with medications and only 1 (4.8%) continued to have intractable headaches that did not respond to maximum medical therapy and required surgery. CONCLUSION: The incidence of IIH in the Omani population was found to be less than neighboring countries but comparable worldwide. OCT is considered a useful tool to confirm and document papilledema and more importantly monitor recovery.

Nummular keratitis: A rare manifestation of brimonidine allergy.

A 32-year-old male, with juvenile open-angle glaucoma on chronic antiglaucoma therapy and recently introduced brimonidine eye drops to the treatment regimen, developed bilateral follicular conjunctivitis with subepithelial infiltrates (SEIs) initially resembling common infectious keratoconjunctivitis entities. The persistent nature of the conjunctivitis, the lack of positive conjunctival cultures, the absence of systemic symptoms, the full resolution of the condition upon discontinuation of antiglaucoma drops, and the commencement of topical steroids, along with the reappearance of SEIs upon reintroducing brimonidine; suggested an immune-mediated drug reaction secondary to a Benzalkonium chloride (BAK) preserved brimonidine tartrate 0.2% formulation. The interval between the initiation of brimonidine and the onset of the drug reaction was 13 months and shortened to 1 week upon re-exposure to the drug. The condition fully resolved without further sequelae off brimonidine. Brimonidine is notoriously known for causing ocular allergic reactions, the most common being follicular conjunctivitis, but very few reports exist describing its adverse effects on the cornea. This case highlights that brimonidine may directly or indirectly induce an immune reaction affecting the cornea in the form of SEIs. Brimonidine is, thus, capable of mimicking more commonly recognized infectious disease entities causing keratoconjunctivitis. This is the second report of a similar manifestation linked to its use.

Factors affecting the labelling accuracy of brain MRI studies relevant for deep learning abnormality detection.

Unlocking the vast potential of deep learning-based computer vision classification systems necessitates large data sets for model training. Natural Language Processing (NLP)-involving automation of dataset labelling-represents a potential avenue to achieve this. However, many aspects of NLP for dataset labelling remain unvalidated. Expert radiologists manually labelled over 5,000 MRI head reports in order to develop a deep learning-based neuroradiology NLP report classifier. Our results demonstrate that binary labels (normal vs. abnormal) showed high rates of accuracy, even when only two MRI sequences (T2-weighted and those based on diffusion weighted imaging) were employed as opposed to all sequences in an examination. Meanwhile, the accuracy of more specific labelling for multiple disease categories was variable and dependent on the category. Finally, resultant model performance was shown to be dependent on the expertise of the original labeller, with worse performance seen with non-expert vs. expert labellers.

Deep learning to automate the labelling of head MRI datasets for computer vision applications.

OBJECTIVES: The purpose of this study was to build a deep learning model to derive labels from neuroradiology reports and assign these to the corresponding examinations, overcoming a bottleneck to computer vision model development. METHODS: Reference-standard labels were generated by a team of neuroradiologists for model training and evaluation. Three thousand examinations were labelled for the presence or absence of any abnormality by manually scrutinising the corresponding radiology reports ('reference-standard report labels'); a subset of these examinations (n = 250) were assigned 'reference-standard image labels' by interrogating the actual images. Separately, 2000 reports were labelled for the presence or absence of 7 specialised categories of abnormality (acute stroke, mass, atrophy, vascular abnormality, small vessel disease, white matter inflammation, encephalomalacia), with a subset of these examinations (n = 700) also assigned reference-standard image labels. A deep learning model was trained using labelled reports and validated in two ways: comparing predicted labels to (i) reference-standard report labels and (ii) reference-standard image labels. The area under the receiver operating characteristic curve (AUC-ROC) was used to quantify model performance. Accuracy, sensitivity, specificity, and F1 score were also calculated. RESULTS: Accurate classification (AUC-ROC > 0.95) was achieved for all categories when tested against reference-standard report labels. A drop in performance (ΔAUC-ROC > 0.02) was seen for three categories (atrophy, encephalomalacia, vascular) when tested against reference-standard image labels, highlighting discrepancies in the original reports. Once trained, the model assigned labels to 121,556 examinations in under 30 min. CONCLUSIONS: Our model accurately classifies head MRI examinations, enabling automated dataset labelling for downstream computer vision applications. KEY POINTS: • Deep learning is poised to revolutionise image recognition tasks in radiology; however, a barrier to clinical adoption is the difficulty of obtaining large labelled datasets for model training. • We demonstrate a deep learning model which can derive labels from neuroradiology reports and assign these to the corresponding examinations at scale, facilitating the development of downstream computer vision models. • We rigorously tested our model by comparing labels predicted on the basis of neuroradiology reports with two sets of reference-standard labels: (1) labels derived by manually scrutinising each radiology report and (2) labels derived by interrogating the actual images.

Bilateral serous retinal detachment: An initial presentation of mixed phenotype acute leukemia in an adult.

A 60-year-old female presented with acute onset painless loss of vision in both eyes. Clinical examination and ocular investigations revealed bilateral serous retinal detachments (SRDs) over the macula. There was no obvious intraocular or extraocular cause to the presentation. A blood count showed leukocytosis with the presence of blast cells on the peripheral smear. Further workup confirmed the diagnosis of Philadelphia chromosome-positive mixed phenotype acute leukemia with central nervous system disease stage three. Anatomic improvement in the SRD followed intensive intravenous and intrathecal chemotherapy. Limited functional improvement was attributed to the development of pigment epitheliopathy manifesting as leopard spot chorioretinopathy. This permanent disturbance could be attributed to leukemic infiltration and ischemia to the choroid.

Postprocedural Endophthalmitis or Postprocedural Intraocular Inflammation: A Diagnostic Conundrum.

We experienced an atypical endophthalmitis occurring post consecutively performed in-office procedures; an intravitreal injection (IVI) of ranibizumab followed by an anterior chamber (AC) paracentesis performed twice in an eye with neovascular glaucoma (NVG). A 52-year-old diabetic male who was asymptomatic developed signs of endophthalmitis and decreased vision without pain in his left eye a few days post-IVI and AC paracentesis. The condition worsened after an initial vitreous tap and injection of antibiotics. Cultures of vitreous and aqueous samples were negative. Complete resolution occurred after a pars plana vitrectomy with IVI of antibiotics and steroid with removal of a dense "yellowish-brown" fibrinous plaque. The absence of pain, presence of a peculiar colored fibrin, mild-to-moderate vitritis without retinitis, negative cultures, and complete recovery despite the fulminant presentation; favor a diagnosis of inflammation over infection. We hypothesize that a micro-leak from a 26-gauge AC tap tract might have served as an entry port for 5% povidone-iodine from the ocular surface thus inciting inflammation. However, an exuberant inflammatory response that can be typically seen in NVG eyes after intraocular procedures cannot be excluded. Various causes of inflammation post-procedures, both toxic and nontoxic should be considered in atypical culture-negative fulminant endophthalmitis cases with good outcome posttreatment. Any minor ocular procedure may carry a risk of such complication. Patient counseling and care must be exercised in performing these procedures.

Molecular epidemiology of COVID-19 in Oman: A molecular and surveillance study for the early transmission of COVID-19 in the country.

BACKGROUND: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been proven to be lethal to human health, which affects almost every corner of the world. The objectives of this study were to add context to the global data and international genomic consortiums, and to give insight into the efficiency of the contact tracing system in Oman. METHODS: We combined epidemiological data and whole-genome sequence data from 94 samples of SARS-CoV-2 in Oman to understand the origins, genetic variation, and transmissibility. The whole-genome size of sequence data was obtained through a customized SARS-COV-2 research panel. Amplifier methods ranged from 26 Kbp to 30 Kbp and were submitted to GISAID. FINDINGS: The study found that P323L (94.7%) is the most common mutation, followed by D614G (92.6%) Spike protein mutation. A unique mutation, I280V, was first reported in Oman and was associated with a rare lineage, B.1.113 (10.6%). In addition, the study revealed a good agreement between genetic and epidemiological data. INTERPRETATION: Oman's robust surveillance system was very efficient in guiding the outbreak investigation processes in the country, the study illustrates the future importance of molecular epidemiology in leading the national response to outbreaks and pandemics.

The Impact of COVID-19 Pandemic on Ophthalmic Referrals within a Tertiary Academic Center in Oman.

PURPOSE: To investigate the impact of coronavirus infection disease-19 (COVID-19) pandemic on ophthalmic referrals within an academic tertiary center in Oman. METHODS: Retrospective chart review of internal referrals received and evaluated by the ophthalmology department between March 1and August 31, 2020 (COVID-19 period) compared to a corresponding period in 2019 (pre COVID-19). Data included patient demographics, referral details, ocular diagnosis, intervention, and discharge plan. RESULTS: Referral volume significantly decreased by 58.2%; from 2019 prepandemic to 510 (P = 0.001), with the lowest in April and May 2020. Patient demographics did not differ significantly, but "urgent" referrals reduced by 96.2% (P < 0.001). Main reasons for referrals were reduced vision and screening in both periods. During pandemic, referrals for screening purposes increased from 30.3% to 37.9% (P = 0.013) and for reduced vision decreased from 30% to 23.3% (P = 0.021). Dry eye syndrome increased in frequency during 2020 (from 2.9% to 7.3%, P = 0.002) but cataracts and conjunctivitis both decreased (from 4.7% to 2.1%, P = 0.046 and from 2.3% to 0.3%, P = 0.013, respectively). Ocular trauma remained stable (from 0.8% to 0.3%, P = 0.456), but the proportion of chemical injuries increased by 13.7% (P = 0.025). There was a drastic decrease in interventions from 37% to 26.1% (P < 0.001) and an increase in discharge rate from 61.2% to 75.8% (P < 0.001). CONCLUSION: The impact of COVID-19 pandemic on ophthalmic referrals within a tertiary academic centre in oman referral reductions and changes in pattern and characteristics as an epiphenomenon of COVID-19 reflect the extent of impact specifically in an Omani context. This information is vital for planning proper resource utilization, the adoption of innovative care delivery, and improving referral system pathways.

Short-Term Efficacy of Selective Laser Trabeculoplasty in Omani Eyes with Glaucoma: A Single Institutional Study.

PURPOSE: There is some evidence suggesting a different nature of response to selective laser trabeculoplasty (SLT) among different races. Therefore, we aimed to assess the short-term efficacy, safety and nature of outcome of SLT in Omani eyes. PATIENTS AND METHODS: A retrospective review was performed of patients with open-angle glaucoma (OAG) or ocular hypertension (OHTN) who underwent a single session of 360-degree SLT between January 1, 2017 and December 31, 2018. The main outcome was mean IOP reduction and attainment of treatment success at 5 weeks and 12 weeks post treatment defined as at least 20% IOP reduction from baseline without further medications or interventions. Secondary outcomes were frequency of adverse events and factors predicting success. RESULTS: A total of 33 eyes of 33 Omani patients who underwent treatment with SLT were analyzed. The nature of response to laser followed a gradual pattern as the mean IOP reduction from baseline was 20.2% (5.21 mm Hg, P <0.001) at 5 weeks and further enhanced to 27.2% (6.95 mm Hg, P <0.001) at 12 weeks. Short-term success was achieved in 51.5% and 72.2% of eyes at 5 and 12 weeks, respectively. SLT was most effective in OHTN subgroup and those with higher baseline IOP (both P <0.001). Side effects were an infrequent occurrence, minor and transient. CONCLUSION: The short-term success of SLT in Omani eyes was clinically relevant and comparable to the gradual pattern seen in patients of Indian ancestry. It is a safe therapeutic option in selective Omani eyes.

Eye drop administration in patients attending and not attending a glaucoma education center.

BACKGROUND: To assess the technique of glaucoma eye drop instillation in patients who have and have not attended glaucoma education sessions. To compare this with their subjective perception of eye drop use and identify factors associated with improved performance. PATIENTS AND METHODS: An observational study of 55 participants who instill their topical glaucoma medication for more than 1 year. Twenty-five patients attended (A) glaucoma teaching sessions >1 year before the study and were compared to thirty patients who never attended (NA). Patients completed a self-reporting questionnaire. They instilled their eye drop, and the technique was video-recorded digitally and later graded by two masked investigators. The results were analyzed using Fisher's exact test and Chi-square test. Predictors were assessed using logistic regression models. RESULTS: There was no significant difference in overall performance scores between the two groups. Good technique was observed in 16% of (A) group versus 23% (NA) group, (P = 0.498). There was a mismatch between patient's subjective and actual performance. Female gender and higher educational level were found to be predictors of good performance of drop instillation on univariable logistic regression analysis. CONCLUSION: Glaucoma patients are challenged with eye drop instillation despite receiving education on drop administration. There is a discrepancy between patient's perceptions and observed technique of drop administration.

Under-reporting of osteoporotic vertebral fractures on computed tomography.

PURPOSE: Osteoporotic vertebral fractures are frequently asymptomatic. They are often not diagnosed clinically or radiologically. Despite this, prevalent osteoporotic vertebral fractures predict future osteoporotic fractures and are associated with increased mortality and morbidity. Appropriate management of osteoporosis can reduce future fracture risk. Fractures on lateral chest radiographs taken for other conditions are frequently overlooked by radiologists. Our aim was to assess the value of computed tomography (CT) in the diagnosis of vertebral fracture and identify the frequency with which significant fractures are missed. MATERIALS AND METHODS: The thoracic CT scans of 100 consecutive male and 100 consecutive female patients over 55 years were reviewed. CT images were acquired on General Electric Lightspeed multi-detector (MD) CT scanners (16 or 32 row) using 1.25mm slice thickness. Midline sagittal images were reconstructed from the 3D volume images. The presence of moderate (25-40% height loss) or severe (>40% height loss) vertebral fractures between T1 and L1 was determined using an established semi-quantitative method and confirmed by morphological measurement. Results were compared with the formal CT report. RESULTS: Scans of 192 patients were analysed (95 female; 97 male); mean age 70.1 years. Thirty-eight (19.8%) patients had one or more moderate to severe vertebral fractures. Only 5 (13%) were correctly reported as having osteoporotic fractures in the official report. The sensitivity of axial CT images to vertebral fracture was 0.35. CONCLUSION: Incidental osteoporotic vertebral fractures are under-reported on CT. The sensitivity of axial images in detecting these fractures is poor. Sagittal reformations are strongly recommended to improve the detection rate.

Compliance of amblyopic patients with occlusion therapy: A pilot study.

BACKGROUND: Increasing evidence shows that good compliance with occlusion therapy is paramount for successful amblyopia therapy. PURPOSE: To study the degree of compliance and explore factors affecting compliance in patients undergoing occlusion therapy for amblyopia in our practice. DESIGN: Nonrandomized clinical intervention study. MATERIALS AND METHODS: A total of 31 families with a child (aged 2-12 years), undergoing unilateral amblyopia treatment at the pediatric ophthalmology clinic of Sultan Qaboos University Hospital, Oman, were recruited for this one month study. Parents were interviewed and completed a closed-ended questionnaire. Clinical data including, visual acuity, refraction, diagnosis and treatment, for each patient was collected from the hospital chart and was entered in a data collection sheet. Compliance with occlusion therapy was assessed by self-report accounts of parents and was graded into good, partial, or poor. Association between various factors and degree of compliance was studied using logistic regression modeling. RESULTS: Only 14 (45%) patients showed good compliance to occlusion therapy. 17 (55%) patients were noncompliant. Improvement in visual acuity strongly correlated with compliance to patching (P = 0.008). Other variables that were studied included, age at onset of therapy; gender; degree of amblyopia; type of amblyopia; use of glasses; and compliance with glasses. These did not emerge as significant predictors of compliance. All but one family with poor compliance stated that the main challenge in following the recommendation to patch for requisite hours was in getting their child to cooperate. Only in one instance, the family cited nonavailability of patches as the main hindrance to compliance. 10/31 (32%) families expressed a desire for more information and 18/31 (58%) parents did not understand that amblyopia meant decreased vision. CONCLUSION: Poor compliance is a barrier to successful amblyopia therapy in our practice. Improvement in visual acuity is associated with better compliance with patching. Parents find it difficult to comprehend and retain verbal explanations of various components regarding occlusion therapy for amblyopia. Future study with a larger sample of patients is recommended to investigate the factors affecting compliance with amblyopia therapy and determine predictors for poor compliance.