Scleral thickness in normal Indian eyes measured using spectral domain anterior segment optical coherence tomography

Purpose: To establish normative data on anterior scleral thickness using the spectral domain anterior segment optical coherence tomography (AS?OCT). Methods: In total, 200 eyes of 100 healthy subjects underwent AS?OCT scans in the temporal and nasal quadrants. The scleral + conjunctival complex thickness (SCT) was measured by a single examiner. Mean SCT was analyzed for differences across age groups, gender, and location (nasal versus temporal). Results: Mean age was 46.4 ± 18.3 (21–84) years; male to female ratio was 54:46. Mean SCT (nasal + temporal) of the right eye (RE) was 682.3 ± 64.2 ?m in males and 660.6 ± 57.1 ?m in females. In the left eye (LE), it was 684.6 ± 64.9 ?m in males and 661.8 ± 49.3 ?m in females. These differences between male and female for both eyes were statistically significant (P = 0.006 and P = 0.002). The mean SCT of temporal and nasal quadrants in the RE was 678.54 ± 57.50 and 666 ± 66.2 ?m, respectively. In the LE, the temporal mean SCT quadrant was 679.6 ± 55.8 ?m, and the nasal was 668.6 ± 63.6 ?m. Age had a negative correlation with SCT (?0.62 ?m/year; P = 0.03), and males had a higher temporal SCT than females (22 ?m higher; P = 0.03). After adjusting for age and gender in a multivariate analysis, temporal SCT was significantly (P < 0.001) higher than nasal SCT. Conclusion: In our study, mean SCT decreased with age and males had a higher temporal SCT. This is the first study to evaluate scleral thickness in the Indian population, and the data can be used as a baseline for comparing variations in scleral thickness in disease.

Lost-to-follow-up: A study on corneal transplantation from Eastern India

Purpose: This study aims to analyze the pattern of follow?ups and the reasons for follow?up loss in keratoplasty cases in a tertiary eye care center. Methods: This is a single?center retrospective cross?sectional study. During the study period, 165 eyes underwent corneal transplantation. The data on the demographic features of the recipients and the indications of keratoplasty, including visual acuity before and after surgery, duration of follow?up, and the condition of the graft at the last follow?up, were collected. The primary outcome was to determine the factors causing lost?to?follow?up (LTFU) among graft recipients. LTFU was defined when a patient failed to adhere to any of the following seven follow?up visits since the surgery: 4 ± 2 weeks, 3 ± 1 months, 6 ± 1 months, 12 ± 2 months, 18 ± 2 months, 24 ± 3 months, and 36 ± 6 months. The secondary outcome was to analyze the best?corrected visual acuity (BCVA) among patients available for the final follow?up. Results: The recipient follow?up rates at 6, 12, 18, 24, and 36 months were 68.5%, 57.6%, 47.9%, 42.4%, and 35.2%, respectively. Old age and distance to the center were significant factors for lost?to?follow?up. A failed graft as an indication for transplantation and those undergoing penetrating keratoplasty for optical purposes were significant factors for completing follow?up. Conclusion: The inability to follow?up after corneal transplantation is a common challenge. Elderly patients and those living in remote areas must be prioritized for follow?ups.

Clinical differentiation of keratitis due to fungus and Pythium: A photographic survey

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

Factors affecting the epithelial integrity of human donor corneas

Purpose: To evaluate various factors affecting the integrity of human donor corneal epithelium. Methods: Donor corneal buttons were evaluated for epithelial defect (ED) and exposure. The slit?lamp photographs were taken on day 01, and the data such as age and gender of the donor, cause of death, refrigeration of cadavers, death?to?preservation time (DPT), experience of technician, and distance from site of collection to eye bank were collected. Results: A total of 100 consecutive corneal buttons belonging to 56 donors were evaluated. The median age of donors was 50 years. Males constituted 45 (80.4%). The mean DPT was 9.7 ± 5.3 hours. After death, 34 donors (60.7%) were refrigerated before the collection/retrieval. Most of the corneas (80%) were recovered by technicians having an experience of 0–5 years. Thirty?one donors (55.3%) were located at 1–50 km from the eye bank. The mean area of exposure was 15 ± 4.3 mm2. The mean area of ED was 28.7 ± 5.9 mm2. ED was significantly associated with refrigeration of cadavers and longer DPT. On multivariate analysis, only DPT was found to be significantly associated (P = 0.006; odds ratio [OR] = 1.54 ± 0.24) with the presence of ED. After transplantation, only two corneas had persistent epithelial defects and were treated successfully using various interventions. Conclusion: Integrity of donor corneal epithelium is mainly influenced by the refrigeration of cadavers and DPT.

Objectively measuring anterior segment alterations in the eyes of mucopolysaccharidoses: Its utility in early diagnosis of glaucoma

Purpose: Our study aimed to evaluate the utility of the anterior segment morphometry for objectively assessing anterior segment architectural changes of corneal clouding in the mucopolysaccharidoses (MPS) cohort and to investigate whether these measurements correlate with the slit?lamp findings on the cornea and early diagnosis of glaucoma. Methods: This retrospective study involved 70 eyes of 35 children with cloudy cornea due to MPS variants. Anterior segment architectural alterations were measured using anterior segment imaging and biometry in MPS children and compared with controls. Results: Mean age of the cohort at the time of assessment was 7.9 ± 4.5 years. Males constituted two?thirds of the cohort. Variants of MPS with cloudy cornea were as follows: Type I (62%), Type IV (11%), and Type VI (22%). Morphometric measurements were available in 22 eyes of 11 MPS children and an age?matched healthy control group. There were significant differences between MPS cohort and controls in refraction in Diopters (5.03 ± 0.39 and 0.01 ± 0.04; P < 0.0001), axial length (AXL) in mm (21.39 ± 0.28 and 23.04 ± 0.28; P = 0.0002), average keratometry in Diopters (40.67 ± 0.44 and 42.83 ± 0.44; P < 0.0001), anterior chamber depth (ACD) in mm (2.92 ± 0.07 and 3.65 ± 0.07; P < 0.0001), and intraocular pressure (IOP) in mmHg (25.2 ± 2.0 and 14.1 ± 2.3; P = 0.0003). Secondary glaucoma was observed in 28% of the MPS cohort. Conclusion: The anterior segment morphometry in the cloudy cornea due to MPS provides an objective measurement of anterior segment architectural changes, thus diagnosing early?onset secondary glaucoma. These findings highlight that cloudy cornea due to MPS variants merits close monitoring throughout life

Vitamin B12 deficiency in a large cohort of healthcare professionals across the network of an eyecare organization in India

Purpose: To evaluate Vitamin B12 levels in healthcare professionals at a tertiary eyecare centre in India. Methods: This was a cross?sectional study conducted among healthcare professionals working at a tertiary eyecare centre in India. The sample included 2,374 employees. Chemiluminescent immunoassay method (reference range, 211–911 pg/ml) was used to assess serum vitamin B12 levels. Effect of age and gender was analyzed in vitamin B12 normal and vitamin B12 deficient groups. To evaluate risk factors, questions related to vitamin B12 deficiency were asked to the study participants in a survey. Results: The mean age of employees was 29.2 ± 0.7 years. Around 26% of them were vitamin B12 deficient. The proportion of males in the vitamin B12 deficient group (61.2%) was significantly higher (P < 0.0001) than that of the vitamin B12 normal group (44.9%). There was no effect of age on vitamin B12 levels in both vitamin B12 normal and vitamin B12 deficient groups. Mean vitamin B12 levels in males (289.1 ± 22.2 pg/ml) was significantly lower (P < 0.0001) than that of females (338.7 ± 30.0 pg/ml). Conclusion: This is the first such study on eyecare professionals. One?fourth of the eyecare professionals were vitamin B12 deficient. The proportion of males was higher in the vitamin B12 deficiency group. Males had lower vitamin B12 levels than females. Annual blood tests for vitamin B12 are recommended for timely diagnosis and management of vitamin B12 deficiency, particularly in males.

Secondary developmental glaucoma in eyes with congenital aphakia

Purpose: To describe the clinical spectrum and management of glaucoma in congenital aphakia. Methods: The demographics and clinical spectrum of eyes with congenital aphakia with and without glaucoma were compared, and management outcomes of congenital aphakia cases with glaucoma were studied retrospectively between April 2000 and June 2020. Results: There were a total of 168 eyes (84 subjects) with a diagnosis of congenital aphakia, of which 29 eyes of 18 subjects were diagnosed with glaucoma. Corneal opacity was the presenting complaint in 26/29 eyes with glaucoma and 139/139 eyes without glaucoma. The (interquartile range (IQR)) horizontal corneal diameter was 10.5mm (IQR, 9.0?12.5) and 8mm (IQR, 5?10) in eyes with and without glaucoma (P = 0.01), respectively. The median (IQR) axial length was 17.5mm (IQR, 13.5?19.5) and 15mm (IQR, 14?16) mm in eyes with and without glaucoma (P = 0.03), respectively. Nineteen eyes with glaucoma had adequate intraocular pressure (IOP) control with one medication. Three eyes underwent transscleral diode cyclophotocoagulation and maintained IOP without medications. Three eyes underwent trabeculectomy and trabeculotomy, trabeculectomy followed by penetrating keratoplasty, and trabeculectomy, respectively, of which two eyes became phthisical. At the last follow?up, the median (IQR) IOP was 14 mm Hg (IQR, 14?17) Hg. The median (IQR) follow?up duration was 4.53 months (IQR, 2.03? 48.06). Conclusion: One?fifth of the eyes with congenital aphakia had secondary developmental glaucoma. The corneal diameter and axial lengths were higher in the eyes with glaucoma compared to eyes without glaucoma. Medical management is the preferred short?term mode of IOP control. Transscleral cyclophotocoagulation may be preferred over surgical intervention.

Sensitivity and specificity of potassium hydroxide and calcofluor white stain to differentiate between fungal and Pythium filaments in corneal scrapings from patients of Pythium keratitis

Purpose: To assess the sensitivity of potassium hydroxide and calcofluor white (KOH+CFW) mount in the diagnosis of Pythium keratitis and concordance among microbiologists. Methods: Three microbiologists evaluated the microscopic images of KOH + CFW mounts of confirmed cases of Pythium and fungal keratitis seen between January 2019 and February 2021. The filaments were compared using specific differentiating features. The sensitivity and specificity of KOH + CFW in diagnosing Pythium infection were evaluated along with concordance among the microbiologists. Results: Sixty consecutive cases with confirmed growth of fungus or Pythium insidiosum (n = 29) were evaluated. The sensitivity of KOH + CFW in the correct identification of Pythium filaments ranged from 79.3% to 96.5% among three microbiologists. There was good interobserver (k = 0.76–0.90) and intraobserver (k = 0.70–0.97) agreements among three microbiologists. The differentiating findings (P < 0.0001) suggestive of Pythium filaments were the absence of septae in 23 (79.3%) and collapsed walls in 22 (75.9%) cases. Conclusion: KOH + CFW has good sensitivity and specificity in the diagnosis of Pythium keratitis with good interobserver and intraobserver concordance.

Outcome of transplanted donor corneas with more than 6 h of death‑to‑preservation time.

Purpose: In tropical countries, physicians are skeptic in using corneas with death‑to‑preservation time (DTPT) >6 h, concerns being endothelial cell viability and microbial contamination on prolonged DTPT. The objective of the study was to investigate these concerns by analyzing the outcomes of corneal transplants performed using donor corneas with DTPT >6 h. Materials and Methods: The study was a retrospective case series of 65 transplants performed in 2013 with donor corneas that had DTPT >6 h (range, 6.1–9.8 h). The information on donor cornea tissues and the recipient details were collected from the eye bank and the medical records department of our tertiary eye care center. The main outcome measures were slit lamp assessment of the donor corneas, primary graft failure, graft survival, and postoperative adverse reactions, especially infections, if any. Results: Median DTPT was 7 h. Forty‑four (67.7%) corneas were evaluated as optical grade and 21 (32.3%) were deemed as therapeutic grade; 36 (55.4%) were used for optical indications. There was no relationship between DTPT and the tissue grading of corneas or endothelial cell density. Of the 23 keratoplasties for purely optical indications with a minimum follow‑up of 3 months, 15 (65.2%) remained clear whereas 7 (30.4%) failed (mean follow‑up 15.1 ± 6.7 months). The causes of failure were primary graft failure (n = 1) and secondary graft failure (n = 6). Conclusion: The donor corneas with DTPT 6 h to 10 h can be utilized for optical indications provided that they meet the criteria of tissue acceptance for optical use.

Growth of the human lens in the Indian adult population: Preliminary observations.

Context: The eye lens grows throughout life by the addition of new cells inside the surrounding capsule. How this growth affects the properties of the lens is essential for understanding disorders such as cataract and presbyopia. Aims: To examine growth of the human lens in the Indian population and compare this with the growth in Western populations by measuring in vitro dimensions together with wet and dry weights. Settings and Design: The study was conducted at the research wing of a tertiary eye care center in South India and the study design was prospective. Materials and Methods: Lenses were removed from eye bank eyes and their dimensions measured with a digital caliper. They were then carefully blotted dry and weighed before being placed in 5% buffered formalin. After 1 week fixation, the lenses were dried at 80 °C until constant weight was achieved. The constant weight was noted as the dry weight of the lens. Statistical Analysis Used: Lens parameters were analyzed as a function of age using linear and logarithmic regression methods. Results: Data were obtained for 251 lenses, aged 16–93 years, within a median postmortem time of 22 h. Both wet and dry weights increased linearly at 1.24 and 0.44 mg/year, respectively, throughout adult life. The dimensions also increased continuously throughout this time. Conclusions: Over the age range examined, lens growth in the Indian population is very similar to that in Western populations.