Reliability of a computerized system for strabismus screening.

AIM: To evaluate the reliability of Photo-Hirschberg screening for global strabismus performed by non-specialized personnel. METHODS: Participants at three sites were enrolled. One person at each site was trained in visual acuity measurement and use of the computerized system. Visual acuity was measured, and strabismus testing was performed using two flash photographs. All data from the three primary observers were sent to an experienced assistant researcher, who was blinded to the primary results, for re-evaluation. The primary and re-evaluation results of the Photo-Hirschberg screenings using weighted kappa for agreement were compared. RESULTS: The study included 181 participants (88 males and 93 females) and the results for primary and re-evaluation screenings were corresponded. Ten participants with contrasting results presented with unclear corneal light reflex. Sensitivity and specificity were 100% [95% confidence interval (CI): 29.0%-100%] and 99.4% (95%CI: 96.6%-100%), respectively, based on the Agresti test of the primary evaluation, considering the re-evaluated classification as true. CONCLUSION: The computerized system can be used for primary strabismus screening by non-specialized personnel, with 98.8% agreement with specialists. However, it cannot be used as a substitute for professional examination.

Clinical characteristics, radiologic features, and histopathology of biopsied lacrimal gland tumors.

Herein, we described the clinicopathologic and radiologic features of biopsied lacrimal gland tumors. A retrospective case series of 79 patients treated between 2004 and 2021 was reviewed. The median age was 48.9 years (range 18.3-88.3 years), with 51.9% females. The histopathologic diagnoses were as follows: immunoglobulin G4-related disease (IgG4-RD) = 23, reactive lymphoid hyperplasia = 14, lymphoma = 14, nonspecific inflammation = 10, adenoid cystic carcinoma (ACC) = 9, and pleomorphic adenoma = 9. The proportion of histopathologic diagnoses did not differ significantly over the range of symptom durations (≤ 1 month, > 1-3 months, > 3 months). Patients with ACC had significantly shorter symptom duration and more frequent proptosis than those with pleomorphic adenoma (p = 0.040 and p = 0.009, respectively). Patients with IgG4-RD were older (median 54.3 years) than those with nonspecific inflammation (36.2 years; p = 0.046). Patients with ACC were more likely to present with diplopia than those with lymphoma (p < 0.001). The superior wedge sign increased the likelihood of ACC compared with that of non-epithelial non-malignant lacrimal gland tumors (relative risk ratio = 13.44, p = 0.002). The overall survival of patients with ACC and lymphoma did not differ significantly. Although these patients present with a short symptom duration, urgent orbital imaging, tissue biopsy, and prompt treatment should be performed in patients with lacrimal gland tumors.

Risk factors for globe removal after open-globe injury in agricultural regions.

This study aimed to identify the prevalence and risk factors for globe removal among patients with open-globe injuries (OGIs) in agricultural regions. A retrospective chart review of patients with OGIs was performed between January 2010 and December 2019. Univariable and multivariable logistic regression models were used to identify the factors associated with globe removal in OGI. This study included 422 patients (422 eyes). The highest prevalence of OGI was observed in the middle age group (> 20 to 40 years). The most common cause of OGIs was agriculture-related injury (54.7%), followed by industry or workplace-related injury (20.4%), and assault (5.0%). Intraocular foreign bodies, endophthalmitis, and panophthalmitis were reported in 57.6%, 28.4%, and 5.7% of cases, respectively. Eight eviscerations and 43 enucleations were performed, accounting for 12.1% of OGIs. The most common indication for globe removal was panophthalmitis. Multivariable analysis revealed that the predictive factors significantly associated with globe removal were assault injuries (adjusted odds ratio (aOR) = 5.53; p = 0.026), presenting logarithm of the minimum angle of resolution visual acuity (aOR = 311.79; p < 0.001), and endophthalmitis and panophthalmitis (aOR = 3.58 and 734.94, respectively; p < 0.001). This knowledge would aid in patient counseling and encourage health promotion.

Determining vertical fusion values from digital photographs of healthy eyes.

PURPOSE: To determine the mean difference of vertical corneal light reflex (VCLR) among healthy eyes via digital photography. STUDY DESIGN: Retrospective study. METHODS: The study enrolled 155, healthy eyes participants, 71 males and 84 females with a mean age of 14.7 years (range 12-19 years). The participants received complete eye examinations and 2 digital photographs were taken, with the flash on, while participants fixated their eyes on a near and a distant target. Two hundred and eighty qualified photographs were analyzed by Photo-Hirschberg testing using computer software. The vertical corneal light reflex ratio (VCLRR) was calculated as the distance of the corneal light reflex (CLR) to the inferior limbus or to the pupillary border divided by the horizontal corneal diameter, defined as VCLRR1 or VCLRR2. VCLRR was analyzed using Spearman's correlation. RESULTS: The mean ± SD of horizontal corneal diameter in near and distance photographs was 11.47 ± 0.62 and 11.37 ± 0.58 mm, respectively. For correlation analysis, at 1 m fixation and 6 m fixation, the number of participants within an acceptable range of vertical fusion were 94.6% and 100% of participants. The 95th percentiles (estimated as the mean ± 1.64SD) in VCLRR1 between the two eyes at near and at distance fixation were 0.0316 and 0.0272, respectively; whereas the corresponding values for VCLRR2 were 0.0309 and 0.0240, respectively. CONCLUSIONS: The normal range of the vertical corneal light reflex ratio suggests that the Photo-Hirschberg test could be used for screening vertical strabismus cases depending on iris pigment.

Ocular Malformations with Presumable Intraocular Calcification.

This is a case of ocular malformations with presumable intraocular calcification based on computed tomography (CT) imaging, magnetic resonance imaging (MRI) and ocular ultrasound (US) findings. The authors presented the clinical, imaging and pathological findings of this case. Intraocular calcification is the most important finding in retinoblastoma, which requires aggressive management. It is important to distinguish it from other intraocular lesions, especially intraocular calcified hematoma.

The Calibration of the Corneal Light Reflex to Estimate the Degree of an Angle of Deviation.

OBJECTIVE: To measure the conversion factor for the size of an angle of deviation from the clinical photographs of the corneal light reflex. MATERIAL AND METHOD: In this cross-sectional study, 19 normal subjects with 20/20 visual acuity were photographed with a digital camera while staring at targets placed five prism diopters (PD) apart from one another on a screen. The subjects were tested at a distance of 1 meter (m) and 4 m from a screen. Measurement of the corneal light reflex displacement for each fixed target was obtained from the photographs. The calibration of the corneal light reflex displacement in millimeters (mm) against the angle of deviation in PD was then analyzed with repeated measure linear regression analysis. RESULTS: At 1 m, the values of 0.047 mm/PD and 0.058 mm/PD were obtained as the conversion factor from reflex displacement to deviated angle for the nasal side and temporal side respectively. At 4 m, the values were 0.050 mm/PD and 0.064 mm/PD for the nasal side and the temporal side respectively. There were significant differences between the values obtained at the different distances, regardless of nasal or temporal side. CONCLUSION: Conversion factors were presented for estimating the strabismic angle at different distances and gazes. For clinical practice, the use of photographs to estimate the strabismic angle should use different values for different distances and strabismic types.

Assessing the accuracy and feasibility of a refractive error screening program conducted by school teachers in pre-primary and primary schools in Thailand.

INTRODUCTION: As part of the development of a system for the screening of refractive error in Thai children, this study describes the accuracy and feasibility of establishing a program conducted by teachers. OBJECTIVE: To assess the accuracy and feasibility of screening by teachers. METHODS: A cross-sectional descriptive and analytical study was conducted in 17 schools in four provinces representing four geographic regions in Thailand. A two-staged cluster sampling was employed to compare the detection rate of refractive error among eligible students between trained teachers and health professionals. Serial focus group discussions were held for teachers and parents in order to understand their attitude towards refractive error screening at schools and the potential success factors and barriers. RESULTS: The detection rate of refractive error screening by teachers among pre-primary school children is relatively low (21%) for mild visual impairment but higher for moderate visual impairment (44%). The detection rate for primary school children is high for both levels of visual impairment (52% for mild and 74% for moderate). The focus group discussions reveal that both teachers and parents would benefit from further education regarding refractive errors and that the vast majority of teachers are willing to conduct a school-based screening program. CONCLUSION: Refractive error screening by health professionals in pre-primary and primary school children is not currently implemented in Thailand due to resource limitations. However, evidence suggests that a refractive error screening program conducted in schools by teachers in the country is reasonable and feasible because the detection and treatment of refractive error in very young generations is important and the screening program can be implemented and conducted with relatively low costs.

The central corneal light reflex ratio from photographs derived from a digital camera in young adults.

OBJECTIVE: To determine the normal range of Central Corneal Light Reflex Ratio (CCLRR) from photographs of young adults. MATERIAL AND METHOD: A digital camera equipped with a telephoto lens with a flash attachment placed directly above the lens was used to obtain corneal light reflex photographs of 104 subjects, first with the subject fixating on the lens of the camera at a distance of 43 centimeters, and then while looking past the camera to a wall at a distance of 5.4 meters. Digital images were displayed using Adobe Photoshop at a magnification of l200%. The CCLRR was the ratio of the sum of distances between the inner margin of cornea and the central corneal light reflex of each eye to the sum of horizontal corneal diameter of each eye. Measurements were made by three technicians on all subjects, and repeated on a 16% (n=17) subsample. RESULTS: Mean ratios (standard deviation-SD) from near/distance measurements were 0.468 (0.012)/0.452 (0.019). Limits of the normal range, with 95% certainty, were 0.448 and 0.488 for near measurements and 0.419 and 0.484 for distance measurements. Lower and upper indeterminate zones were 0.440-0.447 and 0.489-0.497 for near measurements and 0.406-0.418 and 0.485-0.497 for distance measurements. More extreme values can be considered as abnormal. The reproducibility and repeatability of the test was good. CONCLUSION: This method is easy to perform and has potential for use in strabismus screening by paramedical personnel.

The normal range of central corneal light reflex ratio in Thai children.

OBJECTIVE: To determine the range of central corneal light reflex ratio (CCLRR) in Thai children. MATERIAL AND METHOD: Sixty-three students identified as having a visual acuity of poorer than 20/40 screening by a research assistant underwent a complete assessment including a visual acuity test, orthoptic examination, refraction, and cover tests were enrolled in the present study. Corneal light reflex photographs were obtained using a compact camera. The subject was photographed head-on, the photos were taken at a distance of one (near) and six (distance) meters, and each image was measured twice using the Adobe Photoshop software program. The CCLRR was the ratio of the summated bilateral distances between the central corneal light reflex (CCLR) and nasal limbus to the summated bilateral corneal diameters. Normal range of CCLRR was estimated based on a hypothetical normal range defined by mean +/- 1.58 standard deviations. RESULTS: The present study included 63 students with a best correct visual acuity of better than 20/40 and a mean age of 9.18 (SD 1.72) years, comprising 36 males (57.1%) and 27 females (42.9%). The alternate prism cover test (APCT) at near/at distance, a certified diagnosis, revealed 29 (46.05%)/54 (85.7%) orthophoria, 29 (46.05%)/6 (9.5%) exophoria, 4 (6.3%)/ 1 (1.6%) intermittent exotroria, 0 (0%)/2 (3.2%) exotropia, and 1 (1.5%)/0 (0%) esotropia. The mean of stereopsis was 59.05 +/- 50.47 (range of 40 to 400) seconds of arc. The normal range of CCLRR at near/at distance was 0.446 to 0.484/0.421 to 0.482, while the indeterminate groups at near were 0.435 to 0.445, and 0.485 to 0.495, and at distance 0.403 to 0.420 and 0.483 to 0.500. The cases that had lower or higher ratios should be considered as suspected strabismus. CONCLUSION: Normal range of CCLRR in Thai children is established.

Pupil dilatation after single and triple doses of mydriatic agent in preterm infants.

OBJECTIVE: To compare the pupillary response to a single drop and three drops of a combination of eye drops (0.2% cyclopentolate and 1.0% phenylephrine) in preterm infants. DESIGN: Prospective comparative study. MATERIAL AND METHOD: Preterm infants scheduled to undergo their first retinopathy of prematurity (ROP) screening in the Neonatal Intensive Care Unit, Songklanagarind Hospital, between 1 August 2007 and 30 August 2008, were enrolled in the present study. An eyelid speculum was placed after the topical anesthetic, 0.5% tetracaine, application to measure the baseline horizontal pupil diameter with a Vernier caliper. Then each eye was randomized to either receive a drop of mixture of 0.2% cyclopentolate and 1.0% phenylephrine single dose for group A, or triple doses of 10-minute interval for group B. The pupil diameter was measured at 45 and 60 minutes after instillation and a fundus examination was performed afterward. RESULTS: Seventy preterm infants, 45 males and 25 females, were included in the present study. The mean gestational age was 30.49 +/- 2.34 weeks (range of 24-36 weeks) and the mean birth weight was 1,368.00 +/- 438.99 grams (range of 640-2,850 grams). At baseline, the mean pupil diameter was 2.18 +/- 0.44 mm in group A and 2.19 +/- 0.44 mm in group B (p = 0.90). The mean pupil diameter at 45 minutes after instillation was 5.50 +/- 0.80 mm in group A and 6.02 +/- 0.56 mm in group B (p < 0.01). At 60 minutes after instillation, the mean pupil diameter was 6.13 +/- 0.82 mm in group A and 6.77 +/- 0.41 mm in group B (p < 0.01). CONCLUSION: The pupil size of preterm infants was significantly larger after three drops of the eye drop mixture (0.2% cyclopentolate and 1.0% phenylephrine) than after a single drop. However, a dilated pupil diameter > or = 6 mm was adequate for the peripheral retina examination.

Cost effectiveness analysis of a visual screening program for primary school children in Thailand.

OBJECTIVE: To analyze the cost-effectiveness of a visual screening program for primary school children in southern Thailand. MATERIAL AND METHOD: The visual acuity of 1900 primary school children from 11 schools in southern Thailand was assessed using the Snellen chart, Hirschberg test, an eye examination by penlight, and observation of the red reflex by direct ophthalmoscope, between April 2006 and March 2007. Children with visual acuity of < 20/40 or an abnormal observation in either eye were referred for further eye examination and refraction measurement, at which time they were categorized, according to the severity of the eye condition(s). A cost analysis was then performed for various severity-of-condition groupings. RESULTS: One hundred sixty eight children (8.8%) were found with referable problems, of which 122 parents signed a consent formforfurther testing. The mean age was 8.7 years (range 6-12 years). One hundred seven of the 122 subjects (87.7%) were considered to have a refractive error with or without one or more other eye conditions. The mean direct cost for visual screening by the assistant researcher, not including project management and traveling expenses, was 14.9 Baht per student (approximately 0.5 USD, 0.3 Euro). For nationwide implementation, the per head expenditure for children with treatable problems would be 1018.4 Baht if children with mild, moderate and severe abnormal eye conditions were targeted, and increased to 2270.1 Baht if only children with moderate and severe conditions were targeted CONCLUSION: The results of the present study indicate that this visual screening program is efficient and useful for preliminary school children in Thailand.

Accuracy of noncycloplegic refraction in primary school children in southern Thailand.

OBJECTIVE: To evaluate the accuracy of noncycloplegic refraction compared with cycloplegic refraction in diagnosing refractive error in primary school children in southern Thailand. MATERIAL AND METHOD: This is a cross-sectional study. One hundred twenty children aged from 6-13 years who had visual acuity of 20/40 or worse in at least one eye were included. All the children underwent autorefraction using a Nikon model NRK-8000, retinoscopy and subjective refraction without cycloplegia followed by cycloplegic refraction. The spherical power (SP), cylindrical power (CP), cylindrical axis (CA), and spherical equivalence (SE) from each noncycloplegic technique were compared to cycloplegic refraction using the mean difFerence. The authors also showed the percentage agreement between the data obtainedfrom the three noncycloplegic techniques with those from cycloplegic refraction. RESULTS: The SE mean diFference of noncycloplegic autorefraction, retinoscopy and subjective refraction with cycloplegic refraction were -0.85, -0.19, and -0.26, respectively (p < 0.0001). The data for the SP was similar The cylindrical power mean diFferences were -0.18, -0.13, and -0.02, respectively. The percentage agreements of SE between noncycloplegic autorefraction, retinoscopy, and subjective refraction with cycloplegic refraction within +/- 0.5 diopter (D) were 31.25%, 80.84%, and 81.66%, respectively. For the cylindrical power, the percentages of patients who were within +/- 0.5 D were 87.50%, 94.58%, and 97.50%. The percentages of patients who were within 10 degrees of the cylindrical axis were 73.46%, 96.91%, and 97.53%. CONCLUSION: Noncycloplegic retinoscopy and subjective refraction are clinically accurate and can be applied for refractive error screening in primary school children. Noncycloplegic autorefraction has a tendency towards minus over-correction.

Outcomes of scleral buckling for stage 4 retinopathy of prematurity in Thai children.

OBJECTIVE: To evaluate the anatomical and visual results of a primary scleral buckling procedure for the treatment of stage 4A and 4B retinopathy of prematurity (ROP) in Thai patients. MATERIAL AND METHOD: The data of premature infants treated with a primary scleral buckling procedure for stage 4 ROP from December 2000 to May 2004 were retrospectively reviewed The outcomes measures were anatomical success, visual outcomes, and refractive error at the end of follow-up. RESULTS: Sixteen eyes of ten patients underwent a scleral buckling procedure and had the mean follow-up period of 17.3 months (range 3-44 months). The anatomical success was 100% (8 of 8 eyes) in stag 4A and 50% (4 of 8 eyes) in stage 4B. At the end of the follow-up, the buckle was removed in 92% (11 of 12 eyes) of retina-attached eyes and showed a mean myopic refraction of-8.68 diopters (range -4. 75 to 13.50). Favorable visual outcome was 50% (4 of 8 eyes) in stage 4A and 12.5% (1 of 8 eyes) in stage 4B. CONCLUSION: Scleral buckling appears to play a role in reducing the progression from stage 4 to stage 5 ROP The anatomical success rate was excellent but the visual results remain challenging for these cases.

Mutations in the NDP gene: contribution to Norrie disease, familial exudative vitreoretinopathy and retinopathy of prematurity.

BACKGROUND: To examine the contribution of mutations within the Norrie disease (NDP) gene to the clinically similar retinal diseases Norrie disease, X-linked familial exudative vitreoretinopathy (FEVR), Coat's disease and retinopathy of prematurity (ROP). METHODS: A dataset comprising 13 Norrie-FEVR, one Coat's disease, 31 ROP patients and 90 ex-premature babies of <32 weeks' gestation underwent an ophthalmologic examination and were screened for mutations within the NDP gene by direct DNA sequencing, denaturing high-performance liquid chromatography or gel electrophoresis. Controls were only screened using denaturing high-performance liquid chromatography and gel electrophoresis. Confirmation of mutations identified was obtained by DNA sequencing. RESULTS: Evidence for two novel mutations in the NDP gene was presented: Leu103Val in one FEVR patient and His43Arg in monozygotic twin Norrie disease patients. Furthermore, a previously described 14-bp deletion located in the 5' unstranslated region of the NDP gene was detected in three cases of regressed ROP. A second heterozygotic 14-bp deletion was detected in an unaffected ex-premature girl. Only two of the 13 Norrie-FEVR index cases had the full features of Norrie disease with deafness and mental retardation. CONCLUSION: Two novel mutations within the coding region of the NDP gene were found, one associated with a severe disease phenotypes of Norrie disease and the other with FEVR. A deletion within the non-coding region was associated with only mild-regressed ROP, despite the presence of low birthweight, prematurity and exposure to oxygen. In full-term children with retinal detachment only 15% appear to have the full features of Norrie disease and this is important for counselling parents on the possible long-term outcome.

Prevalence of abnormal vision in one-year-old Thai children, based on a prospective cohort study of Thai children (PCTC).

OBJECTIVES: To collect preliminary data on the prevalence of abnormal vision in one-year-old Thai children. MATERIAL AND METHOD: A retrospective study was conducted using data collected from a prospective cohort study of Thai children (PCTC) carried out during 2000-2002, to examine the prevalence of abnormal vision in one-year-olds. Data from five districts in five provinces were examined. One-year-old children in the present study underwent vision screening and eye examination performed by non-medical research assistants. RESULTS: There were records from 3,898 children in five districts, 49.7% females and 50.2% males. Their eye examinations showed very good vision in 77.8% (9.8 cy/cm at 38 cm), good vision in 21.5% (6.5 cy/cm at 38 cm), and fair vision in 0.7% (< or = 1.6 cy/cm at 38 cm). Normal ocular motility was found in 99.7% and 99.9% had normal anterior segment and lens. No strabismus was found in 99.4%, 99.9% had normal pupil light reflex, 99.8% had normal red reflex, 93.6% could fix and follow at 3 months of age, 85.7% could detect a falling object at 6 months, and 78.5% of mothers and 46.5% of fathers regularly played with the children. Logistic regression analysis indicated that some factors had statistical significance, such as "fix and follow" by 1 month of age, and lack of father-child interaction, but these were not clinically significant. Using Kappa analysis, the authors combined groups 1 (very good vision) and 2 (good vision) to create a "normal vision" category. If children had 2 abnormal eye examinations (eye exam for strabismus, cornea, anterior chamber, lens, pupil and red reflex), the authors recommended sending them to a specialist. The sensitivity and specificity of the visual screening and eye examination instruments were 19.23% and 99.38%, respectively. The Kappa statistic was 0.17. These instruments are not appropriate for eye screening in one-year-old children. CONCLUSION: More than 99% of the children examined had normal results. The majority of children could fix and follow from 2-3 months of age. The early fix and follow development may be related to better visual acuity. The interaction between father and child may be associated with eye development. However, eye screening of one-year-old children by assistant researchers may be inappropriate due to lack of expertise and experience.

Botulinum A toxin therapy on esotropia in children.

A prospective descriptive study was conducted to determine the results of Botulinum Toxin Type A (BTA) injection on esotropia in children, as this may be an alternative to incisional surgery for strabismus. Between September 1998 and February 2002, eleven patients (6 boys and 5 girls) with esotropia were treated with BTA at the Department of Ophthalmology, Songklanagarin Hospital. The average ages at the time of the first and second treatments were 26.8 months (range 14-40 months) and 32.3 months (range 19-54 months), respectively. An open sky procedure was used to inject the BTA. Alignment within +/- 10 prism of orthotropia was considered a successful outcome of BTA treatment in the patients. If the result of the first injection was an incomplete paralysis and the strabismus remained undercorrected, the subsequent dose was increased up to double the initial dose. The mean deviation angle was 40.4 prism diopter (PD) before the first injection and 24.5PD before the second injection. Eight of 11 (72.7%) cases had a sucessful outcome. BTA injection in childhood esotropia may be an alternative to incisional strabismus surgery.