Maxillofacial trauma and ocular injuries: reports from a prospective study from Pondicherry, India.

PURPOSE: To report the spectrum and the factors affecting the visual outcome of ocular injuries associated with maxillofacial trauma. METHODOLOGY: A prospective observational study was carried out from January 2019 to June  2020 on patients of maxillofacial trauma at a rural tertiary care centre, in Pondicherry, India. Detailed history was obtained. Investigations including imaging was done as indicated. Predictors of eye injuries and prognostic factors for vision were assessed. RESULTS: A total of 135 eyes of 126 patients were evaluated. Males constituted 92.06%. Road traffic accident (RTA), domestic injuries, assault, and work-place-related injuries accounted for 86.5%, 4.7%, 2.3%, and 2.3%. Alcohol consumption (42.06%) and lack of eye protective device (94.4%) and injury to posterior segment were the major risk factors. On presentation 80.6% had visual acuity ≥ 6/12. Orbital and maxillofacial fractures were noted in 70.6% of cases. Closed-globe injury was seen in 83 (61.4%) and open-globe injury in 2 (1.4%). Majority (86.7%) suffered soft tissue injuries. Common sight-threatening injuries were traumatic optic neuropathy (4.4%), vitreous haemorrhage (0.7%), retrobulbar haemorrhage (0.7%), and commotio retinae (0.7%). CONCLUSION: Most of the injuries in this population occurred from RTA, with associated fractures, adnexal and globe injuries. Alcohol consumption and lack of eye protective device were the major risk factors. Patients with open-globe injuries and injuries with posterior segment involvement had poor visual outcome.

Diurnal variation of central corneal thickness and intraocular pressure in eyes with pseudoexfoliation.

Purpose: Pseudoexfoliation syndrome (PXS) is an age related microfibrillopathy characterized by deposition of whitish flaky material over various ocular tissues. PXS eyes are known to have thinner corneas and thus can lead to an underestimation in intraocular pressure measurement. The purpose of this study was to find if there is any variation in central corneal thickness and intraocular pressure in PXS eyes and if there was any relationship between them. Methods: A prospective observational study was done on 141 eyes of 85 patients with PXS without glaucoma between November 2015 to April 2017 in the department of Ophthalmology in a tertiary hospital. CCT and IOP were measured by a handheld ultrasonic pachymeter (DGH Technology INC. Pachette 2, USA) and Goldmann applanation tonometer respectively at 4 different times during office hours. Results: A significant reduction of about 10 µm in mean CCT and 1.4 mmHg in mean IOP was noted over the 4 sessions which was statistically significant (P < 0.001). A significant correlation exists between IOP and CCT in PXS eyes at all times during the day (P < 0.001). Conclusion: The CCT measurements show significant thinning throughout the day, similar drop in IOP was also noted. Our study shows that there is a significant correlation between diurnal variation of CCT and IOP. Hence, it is prudent to measure CCT along with IOP at all times.

A comparative clinical study on the generation of nitrosative stress in cataractous lenses of smokers and non-smoker tobacco patients.

AIM:: To quantify the levels of nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine in cataractous lenses of smokers and smokers who chewed tobacco in comparison with non-smokers and non-smokers who chewed tobacco. STUDY DESIGN:: A total of 80 cataractous lenses from smokers, non-smokers, smokers with tobacco chewing habit, and non-smokers with tobacco chewing habit were collected from the patients who had enrolled in the Department of Ophthalmology, Mahatma Gandhi Medical College & Research Institute, Puducherry. METHODS:: Levels of nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine were quantified using commercially available enzyme-linked immunosorbent assay kits. RESULTS:: The mean concentrations of lens nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine are as follows: (a) smokers-112.01, 59.57, and 88.91 µmol/L; (b) smokers who chewed tobacco-175.15, 93.95, and 128.72 µmol/L; (c) non-smokers-76.15, 40.65, and 70.20 µmol/L; and (d) non-smokers who chewed tobacco-96.56, 52.87, and 83.88 µmol/L, respectively. CONCLUSION:: Nitric oxide, inducible nitric oxide synthase, and 3-nitrotyrosine at high levels are the major causative agents for cataractogenesis. The results of this study suggest that smoking and tobacco chewing habit generate nitrosative stress that could enhance the pathogenesis for early cataractogenesis.

Comparison of Central Corneal Thickness using Anterior Segment Optical Coherence Tomography Versus Ultrasound Pachymetry.

INTRODUCTION: Corneal thickness is an important and sensitive indicator of corneal health. It is useful in monitoring corneal diseases such as corneal oedema and keratoconus, and selecting patients for refractive surgery. Central Corneal Thickness (CCT) is a risk factor for Primary Open-Angle Glaucoma (POAG). AIM: To compare CCT using ultrasound pachymetry and Anterior Segment Optical Coherence Tomography (AS-OCT), and also to find out the reproducibility of AS-OCT readings for both central and pericentral corneal areas. MATERIALS AND METHODS: This prospective cross-sectional study was conducted on 120 patients above 40 years of age, and with clinically normal corneas, who underwent CCT measurements by both ultrasound and AS-OCT. Both the eyes were analysed. Two measurements by AS-OCT and 25 measurements by ultrasound pachymetry were taken. The readings were averaged and compared by paired t-test. Repeatability of the OCT pachymetry map sector averages, was assessed by pooled standard deviation, obtained from the two measurements taken from each eye. RESULTS: The CCT in right eye by OCT and ultrasound was 516.28±29.76 µm and 532.42±29.71 µm, respectively. The CCT in left eye by OCT and ultrasound was 515.82±29.88 µm and 532.36±29.83 µm, respectively. The difference in CCT measurement by AS-OCT and ultrasound was statistically significant (p<0.001); mean ultrasound CCT being 16.14 µm and 16.54 µm greater than the mean AS-OCT, CCT in right eye and left eye respectively. For AS-OCT, intra-session repeatability was measured. Repeatability of the OCT mapping was 0.01 µm to 1.6 µm and 0.01 µm to 1.9 µm in the right eye and left eye respectively. CONCLUSION: The CCT measurement by ultrasound pachymetry gives higher values compared to AS-OCT measurement. Hence, they cannot be interchangeably used in clinical practice. The AS-OCT provides highly repeatable pachymetry map measurements both centrally and pericentrally.

Microperimetry - A New Tool for Assessing Retinal Sensitivity in Macular Diseases.

INTRODUCTION: Macular disease is the leading cause of low vision in the Western world. Drusen and pigmentary irregularities are common among the rural Northern Indian population. The disease process leads to loss of central vision, metamorphopsia, macropsia or micropsia and colour vision defect. AIM: To study the retinal sensitivity changes in macular diseases using microperimetry. MATERIALS AND METHODS: It was an observational study, conducted in the Department of Ophthalmology at a rural tertiary care hospital. This study was started from December 2014 until June 2016, in all patients with macular disease above the age of 20 years attending the outpatient department. Microperimetry was done for 84 eyes of 52 patients with macular disease. Mean retinal Sensitivity (MS) and fixation stability was evaluated. The statistical analysis of mean retinal sensitivity, central 2° and 4° fixation was done by calculating the mean and standard deviation using 95% confidence interval. RESULTS: The range of age was between 20-81 years. Majority were 32 males (62%) and 20 females (38%). Out of the 84 eyes studied, majority of the macular disease were Age-Related Macular Degeneration (AMD) (50%). Rest 50% were other macular diseases. The mean retinal sensitivity (dB) shown by microperimetry was 10.83 in AMD, 9.12 in Cystoid Macular Oedema (CME), 10.34 in Epiretinal Membrane (ERM), 10.74 in Pigment Epithelial Detachment (PED), 8.96 in Central Serous Chorioretinopathy (CSCR), 6.43 in macular dystrophy, 7.15 in Lamellar Hole (LMH), 9.8 in Pseudomacular Hole (PMH), 3 in geographic atrophy, 11.1 in macular telangiectasia, 5.6 in Berlin oedema, 12.3 in macular scar and 15.2 in haemorrhage in macula. The study showed 64% of the eyes had stable 2° central fixation, 35% had relatively unstable fixation and 1% had unstable fixation. No significant correlation between retinal sensitivity and retinal thickness in AMD was found. CONCLUSION: This study shows that microperimetry can be a useful tool for objective evaluation of macular function and progression of the disease.

A rare case of branch retinal vein occlusion following Sirsasana.

Sirsasana is a type of headstand postural yoga in which the body is completely inverted. It is performed with or without wall support. In this position, the body is held upright supported by the forearms, while the crown of the head rests lightly on the floor. This is an advanced pose and should be attempted under the supervision of a qualified yoga instructor. The practice of Sirsasana is postulated to increase blood flow to the brain, improving memory, and other intellectual functions. It is also known to cause causes raised intraocular pressure, decompression retinopathy, glaucomatous visual field defects, central retinal vein occlusion, progression of glaucoma, optic neuropathy, and conjunctival varix thrombosis. We report a case of branch retinal vein occlusion following Sirsasana in a patient with systemic hypertension.

Role of Optical Coherence Tomography in Assessing Anterior Chamber Angles.

INTRODUCTION: Gonioscopy is the gold standard in assessing anterior chamber angles. However, interobserver variations are common and there is a need for reliable objective method of assessment. AIM: To compare the anterior chamber angle by gonioscopy and Spectral Domain Optical Coherence Tomography (SD-OCT) in individuals with shallow anterior chamber. MATERIALS AND METHODS: This comparative observational study was conducted in a rural tertiary multi-speciality teaching hospital. A total of 101 eyes of 54 patients with shallow anterior chamber on slit lamp evaluation were included. Anterior chamber angle was graded by gonioscopy using the shaffer grading system. Angles were also assessed by SD-OCT with Trabecular Iris Angle (TIA) and Angle Opening Distance (AOD). Chi-square test, sensitivity, specificity, positive and negative predictive value to find correlation between OCT parameters and gonioscopy grading. RESULTS: Females represented 72.7%. The mean age was 53.93 ±8.24 years and mean anterior chamber depth was 2.47 ± 0.152 mm. Shaffer grade ≤ 2 were identified in 95(94%) superior, 42(41.5%) inferior, 65(64.3%) nasal and 57(56.4%) temporal quadrants. Cut-off values of TIA ≤ 22° and AOD ≤ 290 µm were taken as narrow angles on SD-OCT. TIA of ≤ 22° were found in 88(92.6%) nasal and 87(87%) temporal angles. AOD of ≤ 290 µm was found in 73(76.8%) nasal and 83(83%) temporal quadrants. Sensitivity in detecting narrow angles was 90.7% and 82.2% for TIA and AOD, while specificity was 11.7% and 23.4%, respectively. CONCLUSION: Individuals were found to have narrow angles more with SD-OCT. Sensitivity was high and specificity was low in detecting narrow angles compared to gonioscopy, making it an unreliable tool for screening.

Spontaneous expulsive suprachoroidal hemorrhage caused by decompensated liver disease.

Expulsive suprachoroidal hemorrhage can be surgical or spontaneous. Spontaneous expulsive suprachoroidal hemorrhage (SESCH) is a rare entity. Most of the reported cases of SESCH were caused by a combination of corneal pathology and glaucoma. We are reporting a rare presentation of SESCH with no pre-existing glaucoma or corneal pathology and caused by massive intra- and peri-ocular hemorrhage due to decompensated liver disease.

Two cases of bilateral ischemic optic neuropathy following coronary artery bypass grafting.

Postoperative vision loss (POVL) after major non-ocular surgery is a very rare but devastating complication since it has the potential to cause bilateral, severe and permanent loss of vision. The common major procedures resulting in POVL are cardiac and spinal procedures. We are reporting two patients who presented with features of bilateral anterior ischaemic optic neuropathy after coronary artery bypass grafting.