Characterization of retinal hemorrhages delimited by the internal limiting membrane

Clinically, hemorrhages at the vitreoretinal interface have been termed as 'pre-retinal' in location. However, there is a careful distinction to be made between sub-hyaloid and sub-internal limiting membrane (ILM) planes of blood collection. In the past half-century, a body of literature has accrued on sub-internal limiting membrane hemorrhage. We characterize the etiopathological, clinical, anatomical, and imaging characteristics of this entity (often misconstrued as sub-hyaloid hemorrhage). Management decisions are briefly described, and a unifying term of sub-internal limiting membrane macular hemorrhage is proposed to aid in further research.

Gene Therapy for Inherited Retinal Diseases: From Laboratory Bench to Patient Bedside and Beyond

This comprehensive review provides a thorough examination of inherited retinal diseases (IRDs), encompassing their classification, genetic underpinnings, and the promising landscape of gene therapy trials. IRDs, a diverse group of genetic conditions causing vision loss through photoreceptor cell death, are explored through various angles, including inheritance patterns, gene involvement, and associated systemic disorders. The focal point is gene therapy, which offers hope for halting or even reversing the progression of IRDs. The review highlights ongoing clinical trials spanning retinal cell replacement, neuroprotection, pharmacological interventions, and optogenetics. While these therapies hold tremendous potential, they face challenges like timing optimization, standardized assessment criteria, inflammation management, vector refinement, and raising awareness among vision scientists. Additionally, translating gene therapy success into widespread adoption and addressing cost-effectiveness are crucial challenges to address. Continued research and clinical trials are essential to fully harness gene therapy's potential in treating IRDs and enhancing the lives of affected individuals.

Radiation chorioretinopathy: unusual occurrence of intervortex venous anastomosis

A woman in her 60s presented with vision blur in both eyes, a year post-radiotherapy for oral cancer. The best corrected visual acuity was 20/40 in both eyes. Posterior segment examination was remarkable for a unilateral intervortex venous anastomosis in choroid in her right eye, on the side of her face that had received radiation. Ultra-wide field indocyanine green angiography complimented the clinical findings. We discuss the ramifications of detection of this entity and suggest non-invasive methods of detection.

Prevalence of diabetic retinopathy in urban and rural India: A systematic review and meta-analysis

A systematic review and meta-analysis were conducted to estimate the prevalence of diabetic retinopathy (DR) in India’s urban and rural areas. Medline, Scopus, and ScienceDirect databases were searched for population-based studies published in English between January 1990 and April 2021, wherein the prevalence of DR among Indian residents with type 2 diabetes mellitus (DM) was reported. A random-effects model was used to estimate the overall, rural, and urban prevalence. Data from 10 eligible studies were aggregated for meta-analysis. The prevalence of DR was 17.44% (95% confidence interval [CI], 14.33–20.55) in urban and 14.00% (95% CI: 9.13–18.86) in rural population (P = 0.24). The overall DR prevalence was 16.10% (95% CI: 13.16–24.32), and the population prevalence was 1.63% [95% CI: 0.94–2.32]. Prevalence of DR in people with diabetes was lower in the age group of 40–49 years [13.57% (95% CI: 7.16–19.98)] than in the age group of 50–59 years [16.72% (95% CI: 12.80–20.64)] and the age group of 60 years and above [16.55% (95% CI: 12.09–21.00)]. Variability in studies was high: urban (I² = 88.90%); rural (I² = 92.14%). Pooled estimates indicate a narrow difference in DR prevalence among people with diabetes in rural and urban India. The fast urbanization and increasing diabetes prevalence in rural areas underscore the need for providing equitable eye care at the bottom of the health pyramid.

Fulminant fungal endogenous endophthalmitis following SARS-CoV-2 infection: A case report

Systemic corticosteroids and immunocompromised state following SARS-CoV-2 infection can predispose individuals to endogenous endophthalmitis. A 66-year-old gentleman presented with complaints of diminution of vision and redness one week post discharge after hospitalization for COVID-19 infection. Clinical examination suggested fulminant endogenous endophthalmitis which responded poorly even after aggressive treatment requiring evisceration. Culture and gene sequenced analysis confirmed Aspergillus fumigatus to be the causative organism. A high degree of suspicion is warranted in the presence of recent onset of floaters in COVID-19-infected individuals to facilitate early diagnosis and outcomes.

Quantitative response of wheat to sowing dates and irrigation regimes using CERES-Wheat model

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2014-15 and 2015-16, keeping four sowing dates {25th Oct (D₁), 10th Nov (D₂), 25th Nov (D₃) and 10th Dec (D₄)} in main plots and five irrigation schedules {irrigation at 15 (FC₁₅), 25 (FC₂₅), 35 (FC₃₅) and 45 (FC₄₅) % depletion of soil moisture from field capacity (FC) and a conventional practice} in sub plots. The objective of the study was to evaluate the performance of CERES-Wheat model for simulating yield and water use under varying planting and soil moisture regimes. The simulated and observed grain yield was higher in D₁, with irrigation applied at FC₁₅ as compared to all other sowing date and irrigation regime combinations. Simulated grain yield decreased by 19% with delay in sowing from 25th October to 10th December because of 8% reduction in simulated crop evapotranspiration. Simulated evapotranspiration decreased by 16%, wheat grain yield by 23% and water productivity by 15% in drip irrigation at 45% depletion from field capacity as compared to drip irrigation at 15% of field capacity. It was further revealed that the model performed well in simulating the phenology, water use and yield of wheat.

Perceived difficulties and complications in learners of phacoemulsification: A principal component analysis model

Purpose:

To evaluate the difficulty perceived of each step of phacoemulsification and analyze the factors affecting them.

Methods:

Overall, 12 trainee residents were allotted 10 cases of phacoemulsification of eyes with senile cataract, under a single observer, and the steps of each surgery were rated from very easy to very difficult with a questionnaire. The completion rates of steps and complications of each surgery were noted. Principal component analysis of the responses to the difficulty level questionnaire was conducted to obtain factors resulting in the perceived difficulty.

Results:

The lowest difficulty scores were for initial step of incision creation (1.63 ± 0.84), followed by intraocular lens insertion (2.51 ± 0.8). The most difficult step was divide/chop of the nucleus (3.74 ± 0.97) followed by phacoemulsification (3.32 ± 0.82). Highest completion rates were seen for the initial steps of the surgery and the lowest for divide/chop. We identified two major patterns of difficulty among the trainees – one for steps involving high amount of binocularity and the other, for steps involving high precision of hand control. The rate of complication of our study was within acceptable range.

Conclusion:

Although trainees have practiced phacoemulsification steps on simulation, real-life situation may bring in unprecedented level of difficulty and challenges, which may be documented and used for targeted improvement of surgical skills. Stereopsis and hand control training should form a major part of training modules of cataract surgery both on simulation and real-life scenarios.

Small incision lenticule extraction (SMILE) techniques: patient selection and perspectives

Refractive lenticule extraction is becoming the procedure of choice for the management of myopia and myopic astigmatism owing to its precision, biomechanical stability, and better ocular surface. It has similar safety, efficacy, and predictability as femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and is associated with better patient satisfaction. The conventional technique of small incision lenticule extraction (SMILE) involves docking, femtosecond laser application, lenticule dissection from the surrounding stroma, and extraction. It has a steep learning curve compared to conventional flap-based corneal ablative procedures, and the surgical technique may be challenging especially for a novice surgeon. As SMILE is gaining worldwide acceptance among refractive surgeons, different modifications of the surgical technique have been described to ease the process of lenticule extraction and minimize complications. Good patient selection is essential to ensure optimal patient satisfaction, and novice surgeons should avoid cases with low myopia (thin refractive lenticules), difficult orbital anatomy, high astigmatism, or uncooperative, anxious patients to minimize complications. A comprehensive MEDLINE search was performed using “small incision lenticule extraction,” “SMILE,” and “refractive lenticule extraction” as keywords, and we herein review the patient selection for SMILE and various surgical techniques of SMILE with their pros and cons. With increasing surgeon experience, a standard technique is expected to evolve that may be performed in all types of cases with optimal outcomes and minimal adverse effects.

Complications during the waiting period for carotid endarterectomy

We conducted a retrospective analysis to determine the number of cerebrovascular complications occurring in the period between initial presentation and operation in patients undergoing carotid endarterectomy. The notes of patients undergoing carotid endarterectomy during a 2-year period were used to quantify delays between initial presentation and surgery and complications occurring in this time period. A group of 49 patients was analyzed. The median time period between referral following initial cerebrovascular event and carotid endarterectomy was 62 days. During this time period 12 (24.5%) ischemic complications occurred including six transient ischemic attacks. Delays occurred at a variety of levels but included a median of 36 days before patients seen in the stroke clinic were referred to a surgeon and a median of 23 days before operation once patients had seen a surgeon. Significant delays still exist between initial presentation and carotid endarterectomy and can lead to further ischemic episodes prior to surgery.

A comparative study on lipid peroxidation, activities of antioxidant enzymes and viability of cattle and buffalo bull spermatozoa during storage at refrigeration temperature

A comparative study was conducted to monitor the activities of some antioxidant enzymes, lipid peroxidation and viability of cattle and buffalo bull spermatozoa during storage of semen at refrigeration temperature over a period of 72 h. Semen samples, collected from six cross bred cattle bulls (group I) and six Murrah buffalo bulls (group II), were diluted in egg-yolk-citrate and the spermatozoa were separated from seminal plasma by centrifugation at 4 degrees C in a refrigerated centrifuge. The malondialdehyde (MDA) production in group I increased from 1.17+/-0.29 at 0 h to 7.50+/-0.52 nmol/10(8)spermatozoa after 72 h of storage while in group II it increased from 1.99+/-0.26 to 8.70+/-0.10 nmol/10(8)spermatozoa in the same period. However, buffalo bull spermatozoa had a significantly higher (p<0.05) lipid peroxidation at 0 h as well as at 12, 24 and 48 h (p<0.01) periods. The activities of antioxidant enzymes viz. SOD, GPx and G6PD in both the groups showed a similar pattern of change i.e. the activities declined successively in spermatozoa and increased in the seminal plasma. However, the activities of these three enzymes remained significantly higher in the cattle bull spermatozoa than that in buffalo bull spermatozoa. Amount of MDA produced in spermatozoa of both the groups was negatively correlated while SOD, GPx and G6PD activities in spermatozoa were positively correlated to the motility and viability of spermatozoa. Sperm motility as well as viability was significantly less (p<0.05) in group II than that in group I. SOD, GPx and G6PD activities in spermatozoa of both the groups were negatively correlated to lipid peroxidation of spermatozoa cell membrane. The results showed that the less activities of antioxidant enzymes in buffalo bull spermatozoa was due to higher lipid peroxidation that indicated that they were more prone to oxidative stress as compared to cattle bull spermatozoa when stored at refrigeration temperature.

Optic neuritis in children: clinical features and visual outcome

BACKGROUND

The purpose of this paper is to study the clinical spectrum of pediatric optic neuritis. We evaluated the presenting features, neuroimaging findings, cerebrospinal fluid abnormalities, associated systemic disease, and visual outcome in patients with this condition.

METHODS

A retrospective analysis was performed on all patients who came to Baylor College of Medicine with optic neuritis during a 6-year period from 1991 to 1997. The degree of initial visual loss, subsequent visual recovery, and associated disease were reviewed. Magnetic resonance images and cerebrospinal fluid findings were also analyzed.

RESULTS

Twenty-five patients (39 eyes) 21 months of age to 18 years of age were included in the study, with a mean follow-up of 11 months. Fourteen patients (56%) had bilateral optic neuritis, and 11 patients (44%) had unilateral disease. Thirty-three of 39 eyes (84%) had visual acuity of 20/200 or less at presentation. Twenty-one of 25 patients (84%) were given intravenous methylprednisolone (10 to 30 mg/kg/day). Thirty of 39 eyes (76%) recovered 20/40 visual acuity or better. Three of 39 eyes (7%) recovered vision in the 20/50 to 20/100 range. Six of 39 eyes (15%) recovered vision of 20/200 or less. Twenty-three of 25 patients (92%) underwent magnetic resonance imaging of the brain. A normal magnetic resonance image of the brain was associated with recovery of 20/40 or better visual acuity in 6 of 6 affected eyes (100%). Seven patients were 6 years of age or younger at presentation. Six of 7 (85%) had bilateral disease, and 12 of 13 (92%) affected eyes recovered 20/40 visual acuity or better. Eighteen patients were 7 years of age or older at presentation. Eight of 18 (44%) had bilateral disease, and 10 of 18 patients (56%) had unilateral disease. Eighteen of 26 affected eyes (50%) recovered 20/40 visual acuity or better.

CONCLUSION

Pediatric optic neuritis is usually associated with visual recovery; however, a significant number (22%) remain visually disabled. A normal magnetic resonance image of the brain may be associated with a better outcome. Younger patients are more likely to have bilateral disease and a better visual prognosis.

Assessment of residual gastric volume and thirst in patients who drink before gastroscopy

BACKGROUND

Before endoscopy patients undergo an uncomfortable fluid fast to reduce the risk of gastric acid aspiration and to ensure good endoscopic views are obtained. However, fluids rapidly leave the stomach and thus a long fluid fast before endoscopy may not be required.

AIMS

The object of this study was to establish whether drinking before endoscopy is safe and relieves patients' symptoms of thirst.

PATIENTS AND METHODS

88 patients with American Society of Anaesthesiologists classification of physical status grades I and II were recruited in a controlled randomised single blind trial. The volume and pH of gastric aspirate obtained at gastroscopy was assessed in patients who drank 330 ml of water a minimum 90 minutes before their endoscopy and compared with values in patients who starved overnight.

RESULTS

44 patients who drank ('drinkers') 330 ml of water a mean 117 minutes before their morning gastroscopy had a similar volume and pH of gastric aspirate compared with 44 patients starved overnight ('starvers'); median volume 12.5 ml versus 10 ml, median pH 2.0 versus 2.0; 'drinkers' versus 'starvers' (NS). Before endoscopy patients were asked to score their thirst and hunger ratings as either none, mild, moderate or severe. Ratings for moderate and severe thirst were grouped together for analysis. The percentage of drinkers compared with starvers in each group with no thirst, mild thirst, and moderate severe thirst was 63%, 46%, and 37% respectively (chi 2 test for trend p < 0.05). Hunger ratings were similar in the two groups.

CONCLUSIONS

It is safe for elective day cases to drink a significant volume of water two hours before endoscopy and this alleviates symptoms of thirst.