Category: Statistics

Indian J Ophthalmol. 2023 Feb;71(2):595-600. doi: 10.4103/ijo.IJO_1777_22.

ABSTRACT

PURPOSE: Our aim was to determine the various risk factors for secondary ocular hypertension (OHT) following pars plana vitrectomy (PPV) with silicone oil (SO) injection.

METHODS: A prospective cohort study was performed on 46 eyes of 42 patients who underwent PPV with SO injection under a single surgeon between January 2020 and July 2021. Complete ophthalmological examination including gonioscopy and Goldmann applanation tonometry was performed preoperatively and on three postoperative visits, that is, day 7, day 30, and day 90. Axial length and lens thickness were measured at baseline using immersion A-scan. Anterior segment optical coherence tomography (OCT) was used for measuring anterior chamber depth (ACD) at baseline and at 3 months.

RESULTS: There was a statistically significant increase in intraocular pressure (IOP) (>21 mmHg) on day 7 (4.70 ± 7.754 mmHg), day 30 (5.24 ± 7.481 mmHg), and day 90 (2.39 ± 5.659 mmHg) (P<0.01 for all). Age <50 years, rhegmatogenous retinal detachment (RRD), and pseudophakia had a strong association with short-term OHT on day 7. Preexisting glaucoma was the only independent risk factor for long-term OHT (day 90). Higher baseline IOP and SO emulsification also contributed to long-term OHT.

CONCLUSION: There was a statistically significant elevation in IOP at all postoperative visits. Short-term OHT was associated with younger age (<50 years), RRD, and pseudophakia. Patients with emulsified SO in the anterior chamber, higher baseline IOP, and preexisting glaucoma were at higher risk for long-term OHT.

PMID:36727369 | DOI:10.4103/ijo.IJO_1777_22

Indian J Ophthalmol. 2023 Feb;71(2):576-579. doi: 10.4103/ijo.IJO_1401_22.

ABSTRACT

PURPOSE: The past few years have been difficult in the lives of most glaucoma patients in view of the COVID-19 pandemic. Our aim was to find out patients’ perspective and disruption of their quality of life during the COVID-19 pandemic by conducting a telephone survey among glaucoma patients.

METHODS: This was a cross-sectional study involving the glaucoma patients of a tertiary eye care hospital in India. Patients who had completed at least five years of follow-up before 2020 were randomized by a random number generator. A validated (forward-backward translation and completed pilot analysis) set of 14 questionnaires was administered to the patients, the latter of whom were telephonically interviewed by one of the investigators in February 2022. The entire data was audio-recorded. Statistical Package for the Social Sciences (SPSS) version 26 was used.

RESULTS: Out of 1141 patients with >5 years of follow-up, 103 were selected by randomization. A large group of 46 patients (44.6%) admitted to glaucoma affecting their daily activities. Only 12 (11.6%) admitted to being irregular with their drops. Thirty-four (33%) patients felt that their glaucoma was deteriorating and 31 (30.1%) had fear of blindness. Ninety-five patients (92.7%) felt that they were safe under the care of the treating doctor. There were 46 (44.6%) out of 103 patients who did not turn up for follow-up for six months or more. Lockdown (36.2%) and travel-expenses (27.6%) were the two most common reasons for the loss to follow-up visits.

CONCLUSION: Nearly half of the long-term glaucoma patients were lost to follow-up during the COVID-19 pandemic. Glaucoma affecting daily lives and fear of losing vision turned out to be significant observations in the telephone survey. This fear seemed to be ameliorated by the majority still feeling safe by being in touch with their doctor for continued care even during the COVID-19 pandemic.

PMID:36727364 | DOI:10.4103/ijo.IJO_1401_22

Indian J Ophthalmol. 2023 Feb;71(2):560-566. doi: 10.4103/ijo.IJO_1676_22.

ABSTRACT

PURPOSE: To determine the economic burden of glaucoma on patients.

METHODS: A cross-sectional study was conducted on glaucoma patients diagnosed at least 6 weeks prior to the study and on topical anti-glaucoma medications. After consenting, patients were asked about their monthly income, education, occupation, treatment duration, drugs being used, cost of drugs, one bottle lasts for, financial dependence for treatment, glaucoma surgery, transportation means and cost, etc. Also, information regarding government reimbursement of medical costs was collected.

RESULTS: Seventy-four patients aged 60.18±11.5 years (40 males and 34 females) were enrolled. Majority were retirees (37.84%) and Homemakers (29.73%). Fifty (68%) participants didn’t earn anything. Sixty-three patients had bilateral involvement and 52.70% were on treatment for >3 years. Prostaglandin analogs were most commonly used drugs (34.21%). Average cost of medications and travelling was ₹669.46 per month and ₹203.38 per visit respectively. Majority were financially responsible for their own treatment (62.16%). Patients had an average monthly income of ₹7108.11. Low-income group spent 26.08 % of their monthly salary on glaucoma treatment. Low-moderate and high-income group spent 5.17% and 1.50% of their monthly income respectively. Only 4.05% were covered by government reimbursement. Gender (P=0.019), occupation (P=0.010), whether undergone surgery (P=0.007), whether accompanied (P=0.027), hours lost during each visit (P=0.016) and treatment impression (P=0.027) showed statistical significance when associated with financial dependence.

CONCLUSION: Treatment should be modified according to the patient’s socioeconomic status. Glaucoma education programs and screening camps in remote areas would help in early detection of the disease.

PMID:36727360 | DOI:10.4103/ijo.IJO_1676_22

Indian J Ophthalmol. 2023 Feb;71(2):547-552. doi: 10.4103/ijo.IJO_1160_22.

ABSTRACT

PURPOSE: While there are a few studies that show the prevalence of blindness and ocular morbidity in children, studies on socioeconomic factors in childhood cataracts are scarce. We aimed to study the socioeconomic status, education and occupation of the parents, consanguinity, and gender inequality among children presenting with cataracts.

METHODS: This was a hospital-based, prospective, descriptive study of 68 children with cataracts (aged 0-18 years). In addition to the data on clinical parameters and surgical management, we also collected data on age, gender, age at which the chief complaint was noticed, consanguinity of parents, socioeconomic class, and occupation and education of parents. All statistical analyses were performed using MedCalc statistical software (MedCalc Software 2019, Ostend, Belgium).

RESULTS: Sixty-eight children with pediatric cataract, out of which 36 were bilateral, were studied. Thirty children (44%) were in the age group of 1-5 years. Out of the 36 bilateral cataracts, 25 (69.44%) were males and 11 (30.56%) were females. Thirty (44.1%) had a delayed presentation. Also, 31% belonged to middle class and 28% belonged to lower middle class. Moreover, 65% of the mothers had an undergraduate education.

CONCLUSION: There is a gender-based inequality and late presentation of childhood cataracts. To improve early detection, red reflex screening should be mandatorily done. Further studies are required to identify barriers to access of eye care specific to girls, in order to plan interventions to improve uptake of treatment. The lower socioeconomic status of the patients should be taken into account in the management of this disease.

PMID:36727358 | DOI:10.4103/ijo.IJO_1160_22

Indian J Ophthalmol. 2023 Feb;71(2):535-540. doi: 10.4103/ijo.IJO_1641_22.

ABSTRACT

PURPOSE: Angle kappa has been considered to play a role in causing glare and haloes despite accurate centration during implantation of multifocal intraocular lenses following phacoemulsification. There is a lack of substantial data regarding whether angle kappa is a constant entity or changes following ocular surgical procedures. To answer this question, in this prospective observational study, we measured change in angle kappa following phacoemulsification, and studied the ocular biometric parameters correlating with this change.

METHODS: Angle kappa was measured objectively using synoptophore. Ocular Biometric parameters (Anterior Chamber Depth, Corneal White-to-White measurement, Lens Thickness, and Axial Length) using LenStar LS 900 Haag Streit Anterior Segment imaging system. outcome measures were a quantitative change in angle kappa from the preoperative value by one degree or more and observation of correlation between change in angle kappa and ocular biometric parameters. The Wilcoxin Signed Rank Test was used to determine the difference between pre-operative and post-operative measurements for angle kappa. A p-value of less than 0.05 was considered statistically significant. Pearson’s correlation coefficient was employed to find the relationship between preoperative ocular biometric parameters and a change in angle kappa. A linear regression model was used to derive an equation considering corneal white-to-white measurement as the predictor and change in angle kappa as the outcome measure.

RESULTS: A significant change in angle kappa was recorded, and a significant correlation was found with corneal white to white measurements. This change could be predicted preoperatively, for a known corneal white to white measurement using the standard equation y=mx+c.

CONCLUSION: This study explains the possible cause of dissatisfaction among seemingly ideal patients who undergo multifocal IOL implantation and the potential for better decision-making during patient selection for multifocal IOL implantation.

PMID:36727356 | DOI:10.4103/ijo.IJO_1641_22

Indian J Ophthalmol. 2023 Feb;71(2):530-534. doi: 10.4103/ijo.IJO_1661_22.

ABSTRACT

PURPOSE: To evaluate the per operative intra-ocular lens (IOL) power calculation using intra-operative aberrometry (ORA) and its comparison with conventional methods.

METHODS: Patients with cataract planned for phacoemulsification by a single surgeon under topical anesthesia were enrolled in this prospective observational study in this prospective observational study. All patients underwent pre-operative biometry (Manual SRK-II and IOLMaster^® 500) to determine the intra-ocular lens (IOL) power. Intra-operative aberrometry using ORA was also performed; however, IOL was inserted according to IOLMaster^® (SRK/T). Spherical equivalent (SE) was recorded on post-operative days 1, 7, and 30. Patients were divided into three groups based on axial lengths for analysis. Comparative analysis was performed for the calculated IOL powers and prediction errors of ORA with conventional methods. Adjusted IOL power to calculate the emmetropic IOL using the LiHue formula was also determined and was compared with existing methods. A P-value less than 0.05 was considered statistically significant.

RESULTS: A total of 115 eyes from 113 patients were included, with a median age of 54.90 ± 14.3 years. The mean axial length was found to be 23.94 ± 2.3 mm. There was good agreement (87%) between ORA and IOLMaster^® for calculated IOL powers with a mean difference of 0.047 ± 0.5D between the two (P = 0.33). A positive correlation was found between IOL power calculated using ORA, IOLMaster^®, SRK-II, and adjusted IOL.

CONCLUSION: The use of intra-operative aberrometry (ORA) to calculate IOL power in patients undergoing uncomplicated phacoemulsification is non-inferior relative to standard pre-operative measurement and planning.

PMID:36727355 | DOI:10.4103/ijo.IJO_1661_22

Indian J Ophthalmol. 2023 Feb;71(2):524-529. doi: 10.4103/ijo.IJO_1730_22.

ABSTRACT

PURPOSE: This study aimed to assess the severity of deoxyribonucleic acid (DNA) damage in lens epithelial cells (LECs) of senile cortical, nuclear, and posterior subcapsular cataracts.

METHODS: LECs were obtained from senile cortical, nuclear, and subcapsular types of cataracts after surgery. DNA damage in the cells was immediately assessed quantitatively using the CometScore^™ software.

RESULTS: Comets were found in cataractous LECs. The formation of “comets” in the DNA of LECs can be visualized using single-cell gel electrophoresis and indicates DNA strand breaks because the damaged DNA migrates at a different rate than the nondamaged DNA. Maximal damage was observed in Grade 3 cortical, nuclear, and subcapsular forms of cataracts. Statistically significant DNA damage was seen between grades 1 and 3 of cortical type of cataract, grades 1 and 3 of nuclear type of cataract, and grades 2 and 3 and grades 1 and 3 of posterior subcapsular type of cataract.

CONCLUSION: In patients with senile cataract, DNA of LECs was randomly damaged, and this type of damage was possibly caused by reactive oxygen species (ROS). Maximum DNA damage was found in patients with Grade 3 senile cortical, nuclear, and subcapsular type cataracts. The pathogenesis of senile cataracts is multifactorial and includes continuous molecular stress resulting from photooxidative stress, UV irradiation, and oxidative reactions.

PMID:36727354 | DOI:10.4103/ijo.IJO_1730_22

Indian J Ophthalmol. 2023 Feb;71(2):518-523. doi: 10.4103/ijo.IJO_1474_22.

ABSTRACT

PURPOSE: To evaluate the efficacy of liposomal amphotericin B (L-AMB) for the treatment of fungal keratitis.

METHODS: Patients with fungal keratitis confirmed by potassium hydroxide (KOH) smear and/or confocal microscopy were administered topical L-AMB and randomized into three groups treated with three different formulations. The medication was administered two hourly till clinical improvement was achieved, followed by six hourly till complete resolution. The outcome measures were time to clinical improvement, resolution of epithelial defect, stromal infiltrate, hypopyon, extent and density of corneal opacity, neovascularization, and best corrected visual acuity (BCVA) at 3 months.

RESULTS: Mean age of the patients was 46.6 ± 14.8 years, and trauma with vegetative matter was the most common predisposing factor. Aspergillus flavus (36%) was the most common fungus cultured, followed by Fusarium (23%). Mean time to clinical improvement, time to resolution of epithelial defect, mean time to resolution of infiltrate, and time to resolution of hypopyon were 3.45 ± 1.38, 25.35 ± 8.46, 37.97 ± 9.94, and 13.33 ± 4.90 days, respectively, and they were comparable among the three groups. There was a significant difference between treatment failure and success cases in terms of days of presentation (P < 0.01), size of the epithelial defect (P-value 0.04), and infiltrate size at presentation (P-value 0.04). At 3 months follow-up, no statistically significant difference was noted in BCVA and mean scar size among groups.

CONCLUSION: L-AMB in a gel form is an effective antifungal agent that promotes the healing of fungal ulcers with notably least vascularization and better tolerance.

TRIAL REGISTRATION NUMBER: CTRI/2020/04/024550.

PMID:36727353 | DOI:10.4103/ijo.IJO_1474_22

Indian J Ophthalmol. 2023 Feb;71(2):510-514. doi: 10.4103/ijo.IJO_913_22.

ABSTRACT

PURPOSE: To evaluate the knowledge and skills of clinicians in differentiating cases of Pythium from fungal keratitis based on their clinical appearance.

METHODS: Thirty slit-lamp photographs from culture-proven cases of Pythium and fungal keratitis were selected for conducting a prospective online-based photographic survey. The participants were asked to identify the causative organism and enlist the specific clinical features which helped in reaching the diagnosis. Both cornea specialists and clinical fellows/trainees participated in the survey. Sensitivity, specificity, and predictive values were estimated, and the factors associated with these, including the identification rates of clinical signs, were evaluated using bivariate and multivariate linear regression analyses. The identification rates between the consultants and fellows were compared.

RESULTS: A total of 42 cornea specialists (28 consultants and 14 clinical fellows) participated in the survey. Clinicians were able to differentiate Pythium from fungal etiology in only 56% of cases. The differentiating ability between the consultants and fellows was statistically insignificant. Average sensitivity, specificity, and positive and negative predictive values for differentiating Pythium from fungus were 56%, 65%, 56%, and 66%, respectively. The specific clinical features enlisted by the participants to differentiate Pythium from fungus were the presence of tentacles, peripheral guttering, dot-like infiltrates, and elevated plaques.

CONCLUSION: Clinical knowledge regarding the signs and symptoms and the microbiological identification of features for Pythium are still lacking among clinicians. As the treatment protocols are distinctly different for both, it is imperative to enhance the knowledge and diagnosing ability to tackle this emerging microorganism which causes high morbidity.

PMID:36727350 | DOI:10.4103/ijo.IJO_913_22

Nature. 2023 Feb;614(7946):48-53. doi: 10.1038/s41586-022-05478-3. Epub 2023 Feb 1.

ABSTRACT

Scattering of high energy particles from nucleons probes their structure, as was done in the experiments that established the non-zero size of the proton using electron beams¹. The use of charged leptons as scattering probes enables measuring the distribution of electric charges, which is encoded in the vector form factors of the nucleon². Scattering weakly interacting neutrinos gives the opportunity to measure both vector and axial vector form factors of the nucleon, providing an additional, complementary probe of their structure. The nucleon transition axial form factor, F_A, can be measured from neutrino scattering from free nucleons, ν_μn → μ^–p and [Formula: see text], as a function of the negative four-momentum transfer squared (Q²). Up to now, F_A(Q²) has been extracted from the bound nucleons in neutrino-deuterium scattering^3-9, which requires uncertain nuclear corrections¹⁰. Here we report the first high-statistics measurement, to our knowledge, of the [Formula: see text] cross-section from the hydrogen atom, using the plastic scintillator target of the MINERvA¹¹ experiment, extracting F_A from free proton targets and measuring the nucleon axial charge radius, r_A, to be 0.73 ± 0.17 fm. The antineutrino-hydrogen scattering presented here can access the axial form factor without the need for nuclear theory corrections, and enables direct comparisons with the increasingly precise lattice quantum chromodynamics computations^12-15. Finally, the tools developed for this analysis and the result presented are substantial advancements in our capabilities to understand the nucleon structure in the weak sector, and also help the current and future neutrino oscillation experiments^16-20 to better constrain neutrino interaction models.

PMID:36725994 | DOI:10.1038/s41586-022-05478-3