Analgesic efficacy of Clonidine as an adjuvant in ultrasound-guided rectus sheath block for midline incisional hernia repair - A randomized double-blind controlled trial.

Background and Aims: Clonidine as an adjuvant has not been evaluated in rectus sheath block (RSB) for postoperative pain management in incisional hernia repair. The study aims to evaluate clonidine as an adjuvant in single-shot RSB along with general anesthesia (GA). Material and Methods: This randomized, double-blind controlled study was conducted following IEC-Human approval and written informed consent from 30 patients of either sex, aged 16 to 60 years, ASA physical status I or II undergoing midline incisional hernia repair under GA. All patients received ultrasound-guided bilateral RSB following administration of GA. The subjects enrolled in the study were randomly allocated to receive either normal saline 1 mL (group B) or clonidine 1 µg/kg diluted to 1 mL with normal saline (group BC) as adjuvant along with 9 mL bupivacaine hydrochloride 0.25%. Inj. tramadol 1 mg/kg was administered for rescue analgesia. The primary outcome was the time to first request for analgesia, and secondary outcomes were total consumption of rescue analgesic over 24 h, numerical rating score (NRS), patients' satisfaction, hemodynamics, and side effects. Unpaired t-test and Chi-square test were used. Results: On intergroup analysis, the mean time to first request for analgesia (in min) was significantly higher in group BC i.e., [9.60 (± 5.23) vs 5.33 (± 3.53); (P < 0.034]; whereas, the mean rescue analgesic consumption in 24 h (in mg) was higher in group B i.e., [(88.00 ± 60.97) vs (46.00 ± 48.08)]; (P < 0.045)]. Hemodynamic parameters i.e., mean blood pressure and heart rate were comparable between the two groups, and there were no side effects. Conclusion: Clonidine as an adjuvant in single-shot ultasonography (USG)-guided RSB along with GA is efficacious for postoperative pain management following midline incisional hernia repair.

Multidetector Computed Tomography Perfusion in Head and Neck Squamous Cell Carcinomas: Evaluation of a Dose Reduction Strategy.

Background Computed tomography perfusion (CTp), a useful technique in oncology, is not widely utilized due to the high radiation dose delivered from it. It involves scanning the region of interest every second for 50 seconds following intravenous contrast administration. Doubling sampling interval (SI) to 2 seconds will half the radiation dose, but may impact its effectiveness, which needs to be evaluated. Objectives To evaluate a dose reduction strategy in CTp by determining agreement between standard dose (SD) CTp (acquisition with SI 1 second) and low-dose CTp techniques with SI of 2 seconds (achieved either by reconstruction only or true low-dose acquisition). Materials and methods This cross-sectional study was conducted on histopathology-proven head and neck squamous cell carcinoma (HNSCC) patients who underwent CTp on 64 slice multidetector CT. A total of 56 patients had SD and 24 patients underwent true low dose (LD) acquisition. SD data were also reconstructed at SI 2 seconds to obtain a dataset simulating low dose (low-dose reconstruction [LDr]). Paired t -test was applied to compare CTp in SD and LDr groups and the Bland-Altman plot drawn to calculate 95% confidence limit of agreement. The Kolmogorov-Smirnov test compared CTp parameters for LDr and LD groups. Results There was no statistical difference in CTp parameters (except blood flow in malignant) in SD and LDr groups for both malignant and normal tissues. CTp of malignant tissue was not statistically different in LDr and LD groups but the radiation dose was half in the LD group. Conclusion Reduction of radiation dose to half achieved by doubling the SI does not affect the CTp parameters significantly. So LD acquisitions will increase the use of CTp in HNSCC.

Vertebral column length and abdominal girth as predictors for cephalad spread of intrathecal hyperbaric bupivacaine: A prospective observational study.

Introduction: In recent literature, there is some suggestion of vertebral column length (VCL) and abdominal girth (AG) in determining cephalad spread of spinal anesthetic. Bodily habitus including abdominal fat distribution, AG, and VCL may vary among individuals from different races/ethnicity. We thus aimed to evaluate the role of AG, and VCL measured with the patient in sitting as well as lateral position, in determining the cephalad spread of intrathecal hyperbaric bupivacaine. Methods: Prospective blinded study conducted in 60 consenting adult male patients of ASA status I or II, undergoing lower limb surgery using standardized combined spinal epidural performed. The cephalad spread of subarachnoid block was assessed using loss of discrimination to pin-prick and cold temperature. The VCL was measured from C7 vertebra to the sacral hiatus in sitting as well lateral decubitus position. The AG was measured at level of umbilicus during end of expiration. Results: The mean AG and VCL in sitting/lateral positions were: 78.4 ± 11.0, 60.9 ± 3.2, and 59.2 ± 3.2 cm, respectively. VCL in sitting position was significantly longer than in lateral position (P = 0.000). There was no significant correlation between the Smax (pin-prick) and AG (P = 0.138), or VCL in sitting position (P = 0.549), or VCL in lateral position (P = 0.323). Similar lack of correlation was noted with the Smax (cold) as well (P > 0.05). Conclusions: Contribution of AG or VCL on the extent of intrathecal drug spread is not a consistent finding.

Sonography in male infertility: a useful yet underutilized diagnostic tool.

PURPOSE: To assess the utility of comprehensive sonographic examination including scrotal sonography, Testicular Doppler and Transrectal Ultrasound (TRUS) to evaluate the male reproductive system and differentiate between obstructive (OG) and non-obstructive (NOG) causes of azoospermia. METHODS: 30 infertile men with azoospermia and 30 control subjects with normospermia underwent sonographic evaluation. FNAC/biopsy findings were used for assigning a final diagnosis of obstructive or non-obstructive azoospermia. Qualitative and quantitative imaging parameters were retrospectively compared between the groups using Chi-square/Fisher's exact test and unpaired t-test, respectively. P < 0.05 was considered significant. RESULTS: Ectasia of rete testis/epididymal tubules, altered epididymal echogenicity, dilated terminal vas deferens were significantly more common in OG while inhomogeneous testicular echo-texture and reduced testicular vascularity were more common in NOG (P < 0.05). Testicular volume and epididymal head size were significantly higher in OG than in NOG and controls (18.2 ml/10 mm Vs 8.2 ml/7.2 mm and 13.4 ml/8.8 mm respectively; P < 0.05); while Resistive Index (RI) of intra-testicular vessels was higher in NOG as compared to OG and controls (0.65 vs 0.54 and 0.52 respectively; P < 0.05). On ROC curve analysis, cut-off values of testicular volume (AUC: 0.939; P < 0.001), epididymal head size (AUC: 0.772; P = 0.001) and testicular RI (AUC: 0.761; P = 0.001) to differentiate between the groups were 12.1 ml (sensitivity-94.4%; specificity-83.3%), 9 mm (sensitivity-66.7%; specificity-71%) and 0.62 (sensitivity-62%; specificity-100%) respectively. CONCLUSION: Comprehensive sonographic evaluation can be used to differentiate obstructive from non-obstructive infertility and should be routinely incorporated in the diagnostic workup of infertile men with azoospermia.

Clinical outcome and computer tomography based tunnel placement evaluation following arthroscopic anteromedial portal anterior cruciate ligament reconstruction in non-athletic population.

BACKGROUND: The morphology of distal femur and proximal tibia varies between different ethnicities, and it can affect the tunnel dimensions and positions while doing ACL reconstruction which may affect the clinical outcome. There is limited data on the clinical outcome and CT based tunnel placement evaluation in femur and tibia of Indian nonathletic population. METHODS: Thirty non-athletic patients with mean age of 25.50±6.9 years and ACL rupture who underwent single bundle hamstring autograft arthroscopic ACL reconstruction by anteromedial portal were included in the study. Their preoperative IKDC Score, Lysholm-Tegner score, Tegner activity level were calculated and knee stability was assessed clinically using anterior drawer test, Lachman test and pivot shift test. The CT scan of the operated knee was done once the complete extension of the knee was achieved. Using the multimodality workstation available at the department of radio-diagnosis the tunnel parameters of femoral and tibial tunnel was calculated. After 6 months the patients were reassessed for clinical and radiological outcome. The postoperative outcome was compared with preoperative outcome. RESULTS: There was a significant difference in preoperative and postoperative score, the difference in IKDC score was 15.08 points, improvement of 14.65 points was seen in Lysholm-Tegner score and there was marked improvement in Tegner activity level. Tests for knee stability were normal in >90% of patients postoperatively. The CT evaluation showed that the femoral tunnels were positioned at 28.45%±3.69% (20.16%-38.35%) along the deep-shallow axis and 25.81%±3.819% (20.69%-37.35%), the mean tunnel obliquity compared to the femoral shaft axis were 47.34°±5.427° (37.68°-58.16°) in the coronal plane and 47.93°±7.023° (35.11°-63.95°), the mean tunnel length was 3.38 cm±0.331 cm (2.79 cm-4.18 cm). The tibial tunnel were positioned at 45.63%±5.832% (32.23%-58.23%) along the anterior-posterior axis and 47.70%±2.26% (42.40%-51.96%) along the medio-lateral axis. The tibial tunnel length was found to be 3.89 cm±0.519 cm (3.05 cm-5.06 cm). CONCLUSION: This study helps to ascertain that the ACL reconstruction via anteromedial portal technique using femoral offset zig followed by postoperative home-based rehabilitation technique gives favorable clinical outcomes in Indian non-athletic patients. All patients had improvement in stability of knee after the surgery. The position of femoral tunnels was anatomical but in comparison to Caucasian patients its placement was deeper and higher. Hence, we conclude that the anteromedial portal technique of ACL reconstruction provides favorable clinical outcome and adequate anatomical tunnel placement in Indian non athletic patients.

Clinico-radiological profile of the patients with empyema thoracis: A prospective analytical study.

BACKGROUND: Empyema thoracis is defined as the presence of pus in the pleural cavity and carries significant morbidity and mortality. This study aimed to explore the demographic and clinico-radiological characteristics of patients with empyema thoracis. MATERIAL AND METHODS: The present study was conducted in a tertiary care teaching hospital in North India. The patients diagnosed with empyema thoracis were included in the study. Demographic, etiologic, clinical, radiographic, and outcome data were prospectively collected and analyzed. RESULTS: The study included 48 patients. The median age of empyema thoracis patients was 37(IQR 26-45) years. Common presenting symptoms were breathlessness (n = 37,77%) and chest pain (n = 34,70%). Contrast-enhanced computed tomography (CECT) of the chest showed type III empyema in 52% (21) patients followed by type 1 and type II in 25% and 22%, respectively. CECT thorax showed the collapse of lung and consolidation in (n = 28, 70%) and (n = 24, 60%) patients, respectively. All the patients, except for one, were managed with underwater seal intercostal tube drainage (ICD) procedure for the management of empyema. The median time to remove the ICD tube among 35 patients was 14 (IQR 9-21) days. Forty patients (83.3%) responded to the treatment and were discharged. Eight patients (16.7%) deteriorated and succumbed to the disease. CONCLUSION: Patients of empyema thoracis required a prolonged period of chest tube drainage and carried significant morbidity and mortality.

High resolution ultrasound in subclinical diabetic neuropathy: A potential screening tool.

INTRODUCTION: Detection of subclinical neuropathy can aid in triage, timely intervention and dedicated care to reduce disease progression and morbidity. High resolution sonography has emerged as a promising technique for evaluation of peripheral nerves. The aim of the present study was to assess the utility of high resolution sonography in screening diabetic patients for subclinical neuropathy. METHODS: A total of 70 adult patients with type 2 diabetes mellitus and 30 controls were enrolled; those with clinical features of neuropathy constituted the diabetic polyneuropathy group and those without symptoms/normal nerve conduction the non-diabetic polyneuropathy group. After institutional ethical committee approval and informed consent, high resolution sonography was performed by two musculoskeletal radiologists. Nerves studied were median (elbow and wrist), ulnar (cubital tunnel and Guyon's canal), common peroneal (fibular head) and posterior tibial nerve (medial malleolus).The size (cross sectional area), shape, echogenicity and morphology of nerve were assessed and compared between the groups. RESULTS: The mean cross sectional area of all nerves was significantly higher both in diabetic polyneuropathy and non-diabetic polyneuropathy group compared to controls (p value < .001). Common peroneal nerve cross sectional area of 4.5 mm2 had the highest sensitivity (93%) and specificity (86%) for detecting nerve changes in the non-diabetic polyneuropathy group. The nerves were more rounded, hypoechoic and had an altered morphology in both study groups. CONCLUSION: Presence of sonographic nerve changes in asymptomatic diabetics depicted that morphological alterations in nerves precede clinical symptoms. High resolution sonography detected nerve changes with a good accuracy, and thus, can be a potential screening tool for detection of subclinical diabetic polyneuropathy.

COVID19 pneumonia with cavitation and cystic lung changes: multi-detector computed tomography spectrum of a gamut of etiologies.

The COVID19 pandemic since its beginning in March 2020, continues to wreak havoc causing great morbidity and mortality with each passing day. Ample literature is now available describing the imaging features of COVID19 infection; however, there is still a paucity of knowledge on the various causes of pulmonary cavitation and cystic lesions which can be associated with the virus albeit uncommonly. Cavitation in a COVID19 positive patient could be a consequence of the infection itself or a manifestation of sinister etiologies like coinfection with bacterial, fungal or mycobacterial pathogens, or incidental malignancy/metastasis. It could also be a result of multiple cavitating pulmonary nodules as a manifestation of septic emboli and infarct, Granulomatosis with polyangiitis or rheumatoid arthritis creating a diagnostic dilemma. Similarly, the causes of cystic air spaces on chest CT in COVID19 patient can be varied, either primarily due to the infection itself or secondary to coexistent cystic bronchiectasis, emphysema, interstitial lung disease or mechanical ventilation-associated barotrauma as well as complicated pulmonary cysts. Through this pictorial review, we aim to highlight these uncommon imaging manifestations of COVID19 and educate the reader regarding the various causes, MDCT features and differentials to be considered while approaching a cavity/cystic lesion amidst this pandemic.

Effect of Vitamin D3 Supplementation on Symptomatic Uterine Leiomyoma in Women with Hypovitaminosis D.

OBJECTIVE: The objective of this study is to evaluate the effect of Vitamin D3 on symptoms, uterine and leiomyoma volume in women with symptomatic leiomyoma and hypovitaminosis D. MATERIALS AND METHODS: In this pilot, interventional, prospective study, 30 premenopausal women with uterine leiomyoma and concomitant hypovitaminosis D (<30 ng/ml) received Vitamin D3 in doses of 60,000 IU weekly for 8 weeks followed by 60,000 IU every 2 weeks for another 8 weeks. Change in symptoms, uterine, and leiomyoma volume was evaluated at 8 weeks and 16 weeks. Serum Vitamin D3 levels were repeated at 16 weeks of therapy. RESULTS: A significant negative correlation was observed between the baseline 25-hydroxy Vitamin D (25(OH) Vitamin D3) and leiomyoma volume (r = -0.434, P < 0.001). There was significant reduction of menstrual blood loss by 29.89% (P = 0.003) and severity of dysmenorrhea, pelvic pain, and backache by 44.12%, 35%, and 50% (P < 0.001, 0.019, and 0.002), respectively, at 16 weeks. At end of therapy, there was 6% reduction in mean uterine volume and 11% in leiomyoma volume which was not significant. Serum 25(OH) Vitamin D3 was significantly higher than baseline level (17.44 ± 5.82 vs. 39.38 ± 8.22, P < 0.001) at end of therapy. CONCLUSION: Vitamin D3 supplementation is effective in reducing leiomyoma-related symptoms and stabilizing uterine and leiomyoma volume.

Incidentalomas of the female genital tract on 64-slice MDCT: a clinico-radiological pictorial review.

Sonography is the imaging modality of choice for diagnosing diseases of the female genital tract due to its high resolution, easy availability, low cost and lack of radiation. CT is not advocated for the primary evaluation of the female pelvis. However, with the advent of Multidetector CT (MDCT), females of all ages undergo CT scan of the abdomen and pelvis for myriad non-gynaecological diseases, e.g. subacute intestinal obstruction, abdominal lump, abdominal tuberculosis, appendicitis, ureteric colic, pancreatitis, oncological staging, follow-up, etc. Incidental female genital tract disorders were seen on these scans that are a dilemma for both, the radiologists and the clinicians. The objective of this pictorial review is to characterise the incidentally detected lesions of the female genital tract observed on 64-slice MDCT by correlating with sonography, if necessary, and establishing a clinico-radiological diagnosis. Our aim is to emphasise that the radiologist may be the first person to recognise a gynaecologic disorder and hence can play a significant role in patient management.

High presacral collection approached through the perineal route: A novel computed tomography-guided technique.

For a definitive diagnosis of abdomino-pelvic lesions, percutaneous aspiration or biopsy is often necessary; however, finding a safe 'window' for access is challenging. This case report discusses a novel method to approach a deep pelvic collection and also briefly reviews the various approaches to access such lesions. A sample was obtained from a non-resolving presacral collection using a CT-guided percutaneous, trans-perineal approach with repeated sessions of hydro-dissection. Successful aspiration and analysis revealed multi-drug resistant tuberculosis, thus guiding appropriate management.

Rare occurrence of dural arteriovenous fistula in a child: Multi-modality imaging and literature review.

A dural arteriovenous fistula (AVF) is a rare condition in a child and is not evident clinically. It is a type of an acquired cerebral vascular malformation that usually occurs after a thrombotic event of the cerebral venous sinuses. Dural AVF is not suspected clinically and is revealed through imaging done for evaluation of cranial symptoms. Therefore, it is essential to revisit the pathophysiology and the clinical situations leading to intracranial dural AVF. Equally crucial is identifying the imaging findings on computed tomography, or magnetic resonance imaging brain scans done as a preliminary work-up in these patients. However, for optimal management decision and prognostication of dural AVF, a digital subtraction angiography is essential. As the entire burden of establishing the diagnosis rests on the radiologists, we would like to present this rare case report highlighting both the clinical and imaging aspects and the management options available for dural AVFs.

A kaleidoscopic view of male urethral pathologies on 64-slice multidetector computed tomographic urethrography: A novel technique.

Pathologies of the male urethra are mostly obstructive in nature and require imaging to delineate the lesion type, site, extent and associated abnormality of the urinary bladder. Contrast urethrography (CU) is the gold standard investigation for urethral assessment but has many limitations. Cross-sectional imaging is infrequently used for the evaluation of the urethra but has been gaining importance recently. Multidetector computed tomographic urethrography (MDCTU) has the capability of evaluating the entire length of a male urethra in a single setting and overcomes many technical and patient limitations of CU. Being a novel technique, most radiologists are not familiar with MDCTU and the imaging spectrum of various urethral and bladder pathologies. This pictorial review attempts to present the imaging appearance of the normal male urethra and spectrum of pathological findings, with highlights on its advantages over the CU technique.

The diagnostic role of microRNA 21 in patients with nonsmall cell lung cancer: An exploratory study.

BACKGROUND: Although histopathological examination of the biopsy specimen is the gold standard for the diagnosis of non small cell lung cancer (NSCLC), a blood-based noninvasive test (liquid biopsy) may prove to be helpful in patients with repeatedly negative biopsy or for response assessment following neoadjuvant therapy. The present study was conducted to explore the diagnostic value of circulating serum microRNA (miRNA) 21 in patients with NSCLC. METHODS: This case-control analytical study was carried out in a tertiary care teaching hospital in Northern India. The study consisted of 30 cases of biopsy-proven NSCLC and 30 controls. Serum miRNA-21 expression levels were estimated by extracting total RNA from the serum sample, reverse transcribing it to cDNA and quantified in relation to U6 reference miRNA. RESULTS: A total of 30 patients with NSCLC and 30 controls were included in the study. The subjects were comparable in two groups with reference to age, gender, and smoking. Pathological types were adenocarcinoma in 19 (63.3%) and squamous cell carcinoma in 11 (36.6%) patients. Majority of the patients had advanced disease-AJCC stage III in 15 patients and AJCC Stage IV in 13 patients; two patients had stage II disease. There was a significant upregulation of serum miRNA 21 gene expression in the patients with lung cancer compared to controls (median fold change, 3.39 vs. -2.81, P = 0.00). A fourfold change in serum miRNA 21 is significantly associated with the diagnosis of NSCLC with a high specificity of 97% and area under curve of 0.84 (95% confidence interval of 0.74-0.94). CONCLUSION: Estimation of serum miRNA 21 expression has potential to be used as liquid biopsy for the diagnosis of NSCLC. Further studies with large sample sizes are warranted to confirm the diagnostic accuracy of serum miRNA 21 expression.

Tuberculosis, a great masquerader: A case series unveiling rare sites of musculoskeletal involvement through imaging.

Skeletal tubercular infections that do not involve the spine or large joints are rarely encountered. This case series aims to highlight the importance of imaging in diagnosing skeletal tuberculosis (TB) at uncommon sites in clinically unsuspected patients by demonstrating specific imaging findings. We present the clinical details and imaging findings of seven pathologically confirmed cases of extraspinal skeletal TB. A multimodality imaging approach including radiography, ultrasonography (USG) and computed tomography (CT) scan was used in most cases. The imaging studies revealed an infective soft tissue collection over different sites including the sternoclavicular joint, acromion process, chest wall and temporo-mandibular joint, along with destruction and erosion of the underlying or adjacent bones. In tubercular endemic countries, strong clinical suspicion should be entertained in cases presenting with a soft tissue collection, even around unusual skeletal sites.

Bilateral Hutch diverticula in an elderly male: Revelation of an unknown past.

Hutch diverticulum is a congenital diverticulum of the urinary bladder, reported infrequently in children and rare amongst adults. We present a 60-year-old male patient with bilateral Hutch diverticula, detected incidentally during an abdominal ultrasound examination performed for blunt abdominal trauma. This rare case highlights an unusual incidental presentation and opportunity to learn how to differentiate it from acquired bladder diverticula. The available treatment options are also discussed varying from simple follow-up to aggressive surgery.

Confirmation of placement of endotracheal tube - A comparative observational pilot study of three ultrasound methods.

BACKGROUND AND AIMS: Confirmation of endotracheal tube (ETT) position is necessary to ensure proper ventilation. The present study was conducted with the aim to compare the efficacy of three ultrasonographic (USG) techniques in terms of time taken for confirmation of ETT position. The time taken by each USG technique was also compared with that for auscultation and capnography. The ability of the three USG techniques to identify tracheal placement of ETT was evaluated in all patients. MATERIAL AND METHODS: Ninety adult American Society of Anesthesiologists (ASA) I/II patients requiring general anaesthesia with tracheal intubation were randomised into three groups (n = 30 each) depending upon the initial USG transducer position used to confirm tracheal placement of ETT: group T (tracheal), group P (pleural) and group D (diaphragm). The time taken for confirmation of tracheal placement of ETT by USG, auscultation and capnography was recorded for each of the groups. Subsequently, USG confirmation of ETT placement was performed with the other two USG techniques in all patients. RESULTS: The time taken for USG in group T was significantly less (3.8 ± 0.9 s) compared to group P (12.1 ± 1.6 s) and group D (13.8 ± 1.7 s); P < 0.001. USG was significantly faster than both auscultation and capnography in group T (P < 0.001), whereas in group P and group D, USG took longer time compared to auscultation (P = 0.014 and P < 0.001, respectively) but lesser time than capnography (P < 0.001 in both groups). CONCLUSION: USG is a rapid technique for identification of ETT placement. All the three USG techniques are reliable in identifying the tracheal placement of ETT.

Tubercular Retropharyngeal Abscess in Association with Aberrant Retropharyngeal Internal Carotid Arteries - A Rare Entity: Imaging Diagnosis and a Word of Caution.

Retropharyngeal (RP) abscess is rarely encountered in adults. Still rare is an abscess of tubercular etiology especially without involvement of the underlying cervical spine. We present a case of an immunocompetent woman with a tubercular RP abscess diagnosed on contrast-enhanced cervical computed tomography and confirmed on cytology. Another interesting feature was an aberrant RP course of the internal carotid arteries in this patient. This case report stresses the importance of imaging in establishing an unexpected diagnosis of an RP abscess, suggesting its likely cause, and also in demonstrating the aberration in regional vascular anatomy, and warns the clinician of life-threatening hemorrhagic complication in the event of any diagnostic or therapeutic intervention.

Sonography in acute ocular pathology: a kaleidoscopic view.

Ocular emergencies contribute to a large proportion of ocular pathologies. These may even be organ-threatening diseases such as central retinal artery and vein occlusion or globe rupture. Conventional physical examination may not always be feasible in emergency situations but decision-making in time is critical in the interest of patient in few of these conditions. Sonography in this setting plays an important role, allowing real-time, quick and dynamic evaluation. Common acute ocular pathologies such as retinal detachment, lens dislocation and globe rupture can be easily diagnosed by ultrasound. Vascular lesions can be identified using Doppler. This article illustrates the sonographic appearance in traumatic and non-traumatic acute ocular pathologies.