COVID-19 cases, hospitalizations and deaths after vaccination: a cohort event monitoring study, Islamic Republic of Iran.

Objective: To investigate the incidence of coronavirus disease 2019 (COVID-19) cases, hospitalizations and deaths in Iranians vaccinated with either AZD1222 Vaxzevria, CovIran® vaccine, SARS-CoV-2 Vaccine (Vero Cell), Inactivated (lnCoV) or Sputnik V. Methods: We enrolled individuals 18 years or older receiving their first COVID-19 vaccine dose between April 2021 and January 2022 in seven Iranian cities. Participants completed weekly follow-up surveys for 17 weeks (25 weeks for AZD1222) to report their COVID-19 status and hospitalization. We used Cox regression models to assess risk factors for contracting COVID-19, hospitalization and death. Findings: Of 89 783 participants enrolled, incidence rates per 1 000 000 person-days were: 528.2 (95% confidence interval, CI: 514.0-542.7) for contracting COVID-19; 55.8 (95% CI: 51.4-60.5) for hospitalization; and 4.1 (95% CI: 3.0-5.5) for death. Compared with SARS-CoV-2 Vaccine (Vero Cell), hazard ratios (HR) for contracting COVID-19 were: 0.70 (95% CI: 0.61-0.80) with AZD1222; 0.73 (95% CI: 0.62-0.86) with Sputnik V; and 0.73 (95% CI: 0.63-0.86) with CovIran®. For hospitalization and death, all vaccines provided similar protection 14 days after the second dose. History of COVID-19 protected against contracting COVID-19 again (HR: 0.76; 95% CI: 0.69-0.84). Diabetes and respiratory, cardiac and renal disease were associated with higher risks of contracting COVID-19 after vaccination. Conclusion: The rates of contracting COVID-19 after vaccination were relatively high. SARS-CoV-2 Vaccine (Vero Cell) provided lower protection against COVID-19 than other vaccines. People with comorbidities had higher risks of contracting COVID-19 and hospitalization and should be prioritized for preventive interventions.

Addressing Individual Ophthalmic Health in Public Health Research.

In pediatric cohort studies, disclosing findings and providing treatment counseling to parents, legal guardians, or other authorized representatives is an ethical imperative. Keratoconus (KC) is a corneal degenerative disease that can progress to severe vision impairment and need for corneal transplantation. This report concerns the disclosure of results to the parents of children who were diagnosed with KC in the Shahroud Schoolchildren Eye Cohort Study and received essential treatment in a timely manner.

Psychometric properties of the Persian version of the Geriatric Anxiety Inventory (GAI-PV) and its short form.

Background: Despite studies about anxiety in the older adult, the prevalence of anxiety in this age group is not exactly clear, which may be due to the use of tools and criteria that were not born for this age group. One of the instruments designed to assess anxiety in the elderly is the Geriatric Anxiety Inventory (GAI). The aim of this research was to analyze the psychometric properties of the Persian version of the Geriatric Anxiety Inventory (GAI-PV) and its short form (GAI-PV-SF) in a sample of older adults in Iran. Methods: In this cross-sectional study, a sample of 150 community-dwelling and a psychogeriatric sample of 48 adults older than 60 years completed the GAI-PV and GAI-PV-SF, the anxiety sub-scale of the General Health Questionnaire (GHQ-28), the Geriatric Depression Scale (GDS-15), and the Structured Clinical Interview for DSM-IV (SCID-I). Different types of validity and reliability were evaluated for GAI-PV and GAI-PV-SF using SPSS and the LISREL software. Results: Both the GAI-PV and GAI-PV-SF exhibited excellent internal consistency (over 80 %) and desirable concurrent validity against GHQ-28 and GDS-15. The optimal cutpoint score to detect current generalized anxiety disorder (GAD) was 10/11 and 13/14 for GAI-PV in the community-dwelling and psychogeriatric samples, respectively, and 3/4 for GAI-PV-SF in both study samples. Good test-retest reliability (correlation coefficient: 0.96 and 0.88 for GAI-PV and GAI-PV-SF, respectively) and a single-factor structure were also demonstrated. Conclusion: Sound psychometric properties of the GAI-PV in both subsamples suggest that the instrument could be used successfully as an accurate screening instrument in the elderly Iranian population.

Keratoconus after 40 years of age: a longitudinal comparative population-based study.

PURPOSE: To determine 5-year changes in keratoconus indices and corrected distance visual acuity in 40-64-year-old keratoconus compared with normal subjects. METHODS: In this prospective population-based cohort study, 5-year changes in Belin grading system indices including the average radii of curvature in the 3 mm zone surrounding the thinnest point in the anterior (ARC-3 mm) and posterior (PRC-3 mm) cornea, corrected distance visual acuity, minimum corneal thickness, maximum Ambrosio's relational thickness (ART-max), and maximum anterior keratometry indices centered on steepest point in the central 3 mm (Kmax-3 mm), 4 mm (Kmax-4 mm), and 5 mm (Kmax-5 mm) zones were compared between keratoconus and normal participants. In the analysis, comparisons were made between all keratoconus eyes and the right eyes of normal participants. RESULTS: The mean age in the keratoconus (n = 16 eyes) and normal (n = 1986 eyes) groups (48.31 ± 4.78, 49.37 ± 5.79 years, respectively) was not statistically different (P = 0.327). The two groups differed in terms of changes in PRC-3 mm (- 0.07 ± 0.15 vs. + 0.001 ± 0.14 mm, respectively, P = 0.042) and ART-max (- 6.28 ± 25.19 vs. + 15.8 ± 72.7 µm, respectively, P = 0.003). There were significant correlations between the reduction in PRC-3 mm and its baseline value (ß = - 0.20, P < 0.001) and keratoconus (ß = - 0.26, P < 0.001). The reduction in ART-max significantly correlated with its baseline value (ß = - 0.43, P < 0.001) and keratoconus (ß = - 111.74, P < 0.001). CONCLUSION: According to these findings, posterior corneal steepening and thinning in keratoconus patients continue after the age of 40 years, but it is clinically negligible. The changes are independent of normal age-related changes and appear to be slower in cases with steeper and thinner corneas.

Photopic, Mesopic, and Scotopic Visual Acuity After 18 mW/cm2 Accelerated Corneal Cross-Linking.

OBJECTIVES: One-year changes in uncorrected (UDVA) and corrected (CDVA) distance visual acuity under different lighting conditions after accelerated cross-linking (CXL) in patients with progressive keratoconus in comparison with nontreated cases. METHODS: In this nonrandomized clinical trial, the sample included 50 eyes in the CXL group and 40 eyes in the control group. Visual acuity was tested under photopic (100 lux), mesopic (20 lux), and scotopic (0.5 lux) lighting conditions at 6 months and 1 year. RESULTS: Changes in all studied variables were similar in the two groups (all P>0.05) after adjusting for age, but the 0.02±0.17 logMAR reduction in scotopic UDVA in the CXL group showed a difference of marginal significance compared with the control group (P=0.061). In cases with baseline UDVA≤20/40, 1-year adjusted results in the CXL and control groups were, respectively, 0.61±0.34 and 0.83±0.35 logMAR for photopic UDVA (P=0.021), 0.48±0.22 and 0.68±0.27 logMAR for mesopic UDVA (P=0.033), and 0.21±0.14 and 0.26±0.07 logMAR for mesopic CDVA (P=0.056). In those with baseline UDVA greater than 20/40, 1-year adjusted results in the CXL and control groups were, respectively, 0.12±0.20 and 0.06±0.10 logMAR for mesopic UDVA (P=0.034) and 0.15±0.18 and 0.07±0.06 logMAR for scotopic UDVA (P=0.024). Other vision indices showed no significant intergroup differences (all P>0.05). CONCLUSION: Poor vision (UDVA≤20/40) keratoconus cases are more likely to achieve improved vision or a halt in its deterioration after CXL. In cases with good vision (UDVA>20/40), however, although further photopic vision impairment is halted, they may experience worse vision under mesopic and scotopic conditions.

Self-medication among the elderly in Iran: a content analysis study.

BACKGROUND: Self-medication is described as the use of drugs without a physician's prescription to treat self-recognized illness or symptoms, and an important health issue among the elderly. Despite the wide range of different definitions, recognizing all forms of self-medication among older adults, particularly, in developing countries, help healthcare professionals and providers to reduce harmful effects of self-medication. The purpose of this study is to describe the practice of self-medication and its related factors among elderly people in Iran based on the experiences of people who are involved in this phenomenon. METHODS: This qualitative study was conducted using content analysis. Purposive sampling was used to select the participants and continued until saturation. The participants were the elderly, their care-givers, physicians, and pharmacists. Data was collected using semi-structured interviews, and analysis was done using an inductive approach. The theory of planned behavior was used as a framework to explain the role of the emerged factors in the occurrence of self-medication behavior. RESULTS: Based on the expressed experiences of the participants, factors related to the practice of self- medication among the elderly in Iran fit in these 5 categories: "patient's attitudes towards disease, treatment, and physicians", "living with disease", "unfriendly environments", "enabling health system", and "influential others". CONCLUSIONS: Based on the results of this study, self-medication of the elderly in Iran has commonalities with many countries in regard to over-the-counter medications and complementary and alternative medicine; however, self-medication is also seen with drugs that require a prescription but can easily be obtained from pharmacies. Contributing factors, apart from the elderly themselves, include their families, caregivers, and social circle, the physical environment where they live, and the health system from which they receive services.

Hyperimmunoglobulin E syndrome: Genetics, immunopathogenesis, clinical findings, and treatment modalities.

The hyperimmunoglobulin E syndromes (HIESs) are very rare immunodeficiency syndromes with multisystem involvement, including immune system, skeleton, connective tissue, and dentition. HIES are characterized by the classic triad of high serum levels of immunoglobulin E (IgE), recurrent staphylococcal cold skin abscess, and recurrent pneumonia with pneumatocele formation. Most cases of HIES are sporadic although can be inherited as autosomal dominant and autosomal recessive traits. A fundamental immunologic defect in HIES is not clearly elucidated but abnormal neutrophil chemotaxis due to decreased production or secretion of interferon γ has main role in the immunopathogenesis of syndrome, also distorted Th1/Th2 cytokine profile toward a Th2 bias contributes to the impaired cellular immunity and a specific pattern of infection susceptibility as well as atopic-allergic constitution of syndrome. The ophthalmic manifestations of this disorder include conjunctivitis, keratitis, spontaneous corneal perforation, recurrent giant chalazia, extensive xanthelasma, tumors of the eyelid, strabismus, and bilateral keratoconus. The diagnosis of HIES is inconclusive, dependent on the evolution of a constellation of complex multisystemic symptoms and signs which develop over the years. Until time, no treatment modality is curative for basic defect in HIES, in terms of cytokines/chemokines derangement. Of note, bone marrow transplant and a monoclonal anti-IgE (omalizumab) are hoped to be successful treatment in future.

Distribution of cataract surgical rate and its economic inequality in Iran.

PURPOSE: To determine the distribution of the cataract surgical number per million population per year (CSR), the CSR in the population older than 50 years (CSR 50+) in the provinces of Iran, and their economic inequality in 2010. METHODS: As part of the cross-sectional 2011 CSR survey, the provincial CSR and CSR 50+ were calculated as the total number of surgeries in major and minor centers divided by the total population and the population older than 50 years in each province. Economic inequality was determined using the average province income, the average urban and rural household incomes, and the percentage of urban and rural population in each province. RESULTS: Tehran and Ilam provinces had the highest and lowest CSR (12,465 vs. 359), respectively. Fars and Ilam provinces had the highest and lowest CSR 50+ (71,381 vs. 2481), respectively. Low CSR (<3000) was detected in 9 provinces where 2.4 to 735.7% increase is needed to reach the minimum required. High CSR (>5000) was observed in 14 provinces (45.2%) where rates were 0.6 to 59.9% higher than the global target. Cataract surgical rate increased at higher economic quintiles. Differences between the first, second, and fifth (poorest) quintiles were statistically significant. The CSR concentration index was 0.1964 (95% confidence interval, 0.0964 to 0.2964). CONCLUSIONS: In line with the goals of the Vision 2020 initiative to eliminate cataract blindness, more than 70% of geographic areas in Iran have achieved the minimum CSR of 3000 or more. However, a large gap still exists in less than 30% of areas, mainly attributed to the economic status.

Alcohol-assisted debridement in PRK with intraoperative mitomycin C.

PURPOSE: To compare corneal stromal and endothelial cells after photorefractive keratectomy with intraoperative mitomycin C in alcohol-assisted versus mechanical epithelial debridement using confocal microscopy. METHODS: This prospective randomized comparative study was performed on 88 eyes (44 patients) with myopia up to -6.00 diopters. The right eye of each patient was randomly assigned to either mechanical or alcohol-assisted groups, and the left eye was assigned to the alternate group. Confocal microscopy was performed preoperatively and at 3 months postoperatively. The main outcome measures were epithelial thickness; number of keratocytes in the anterior, mid-, and posterior stroma; and characteristics of the central corneal endothelial cells in terms of density, mean cell area, and polymegathism and hexagonality. RESULTS: Three months after surgery, no statistically significant difference was noted between the study groups in terms of epithelial thickness. We also found no statistically significant difference in central corneal endothelial cells regarding cell density, mean cell area, hexagonality, or polymegathism. Compared with baseline values, the density of mid- and posterior stromal keratocytes showed no significant change in either group, whereas it decreased significantly in the anterior stroma in both groups 3 months after surgery. CONCLUSIONS: We found that the adverse effects of photorefractive keratectomy with mitomycin C on central corneal endothelial cells were comparable between the mechanical and alcohol-assisted epithelial debridement groups and the significant decrease in postoperative keratocyte density in anterior stroma was comparable between the two groups. The choice of their application could be left to the discretion of the ophthalmologist.

Prevalence of dry eye syndrome in an adult population.

BACKGROUND: To determine the prevalence of dry eye syndrome in the general 40- to 64-year-old population of Shahroud, Iran. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Through cluster sampling, 6311 people were selected and 5190 participated. Assessment of dry eye was done in a random subsample of 1008 people. METHODS: Subjective assessment for dry eye syndrome was performed using Ocular Surface Disease Index questionnaire. In addition, the following objective tests of dry eye syndrome were employed: Schirmer test, tear break-up time, and fluorescein and Rose Bengal staining using the Oxford grading scheme. MAIN OUTCOME MEASURES: Those with an Ocular Surface Disease Index score ≥23 were considered symptomatic, and dry eye syndrome was defined as having symptoms and at least one positive objective sign. RESULTS: The prevalence of dry eye syndrome was 8.7% (95% confidence interval 6.9-10.6). Assessment of signs showed an abnormal Schirmer score in 17.8% (95% confidence interval 15.5-20.0), tear break-up time in 34.2% (95% confidence interval 29.5-38.8), corneal fluorescein staining (≥1) in 11.3% (95% confidence interval 8.5-14.1) and Rose Bengal staining (≥3 for cornea and/or conjunctiva) in 4.9% (95% confidence interval 3.4-6.5). According to the Ocular Surface Disease Index scores, 18.3% (95% confidence interval 15.9-20.6) had dry eye syndrome symptoms. The prevalence of dry eye syndrome was significantly higher in women (P = 0.010) and not significantly associated with age (P = 0.291). The objective dry eye syndrome signs significantly increased with age. CONCLUSIONS: Based on the findings, the prevalence of dry eye syndrome in the studied population is in the mid-range. The prevalence is higher in women. Also, objective tests tend to turn abnormal at higher age. Pterygium is associated with dry eye syndrome and increased its symptoms.

Tear function evaluation in candidates of corneal laser refractive surgery for myopia.

OBJECTIVE: To assess the tear function in a young to middle age myopic population and finding possible associations of abnormal tear function with gender and age. METHODS: Dry eye workup was conducted in patients undergoing screening for myopic laser keratorefractive surgery. All patients completed the McMonnies dry eye questionnaire (MQ) and also underwent evaluation of the fluorescein break-up time (FBUT) and the Schirmer tests with anesthesia (STA). Patients with contraindications for keratorefractive surgery or any condition interfering with tear function were excluded from the database. RESULTS: In this prospective study, we evaluated 655 eyes of 216 women and 116 men with a mean age of 27.3±6.1 years. Results of right eyes only are reported. The FBUT and STA were abnormal in 30.8% (95% confidence interval [CI]: 25.7-35.8) and 14.6% (95% CI 10.7-18.4) of cases, respectively. According to MQ scores, 15.9% (95% CI: 11.8-20.0) of patients showed abnormal results. In the assessment of abnormal cases, MQ scores were significantly higher (P<0.001) and FBUT was significantly lower in women (P=0.003) and older ages. Abnormal STA results were not significantly correlated with age or gender. CONCLUSION: In an otherwise normal population seeking keratorefractive surgery for myopia, some cases may demonstrate abnormal tear functions, especially women and older ages. A timely diagnosis and treatment can help avoid complications related to such abnormalities after refractive surgery.

Keratometry with five different techniques: a study of device repeatability and inter-device agreement.

The purpose of this study was to determine and compare the repeatability of keratometry measurements with the Javal manual keratometer, Topcon automated kerato-refractometer, IOLMaster, EyeSys Corneal Analysis System, and Pentacam Scheimpflug Topography System, and determine the agreement of measurements of the latter four devices with the Javal keratometer as the gold standard. In this cross-sectional study, 21 people with no history of ocular disease or surgery were examined twice with each device. Minimum, maximum, and average keratometry readings were recorded in diopters (D) for each eye and used in the analyses. For statistical analysis, we determined correlation coefficients and used the Bland-Altman method and calculated the 95 % limits of agreement (LoA). All repeatability coefficients were satisfactorily high. Best repeatability for minimum keratometry and maximum keratometry readings was seen with IOLMaster (95 % LoA -0.23 to 0.19 D and -0.31 to 0.32 D, respectively). Agreement with Javal manual keratometry was best with Topcon and IOLMaster for minimum keratometry readings (95 % LoA -0.67 to 0.28 D and -0.57 to 0.38 D, respectively), and with Topcon for maximum keratometry readings (95 % LoA -0.85 to 0.63 D). In our series of normal eyes, keratometry readings with Topcon, IOLMaster, and Pentacam showed very good agreement with Javal measurements, and inter-device agreements were better than the repeatability of the manual gold standard. However, differences between Javal and EyeSys may not be clinically acceptable, and these two devices should not be used interchangeably. Further studies are needed to investigate these issues in non-virgin eyes.

Color vision deficiency in a middle-aged population: the Shahroud Eye Study.

The aim of this study was to determine the prevalence of color vision defects in the middle-age population of Shahroud, Iran. We selected 6,311 people from the 40- to 64-year-old population through random cluster sampling. Color vision testing was performed with the Farnsworth D-15. Cases with similar and symmetric results in both eyes were classified as hereditary, and those with asymmetric results were considered acquired. Cases that did not conform to standard patterns were classified as unknown category. Of 5,190 respondents (response rate 82.2 %), 5,102 participants underwent the color vision test. Of these, 14.7 % (95 % confidence interval 13.7-15.6) had some type of color vision deficiency. Of the 2,157 male participants, 6.2 % were hereditary and 10.2 % were acquired and of the 2,945 female participants, 3.1 % were hereditary and 10 % were acquired. Hereditary color deficiencies were mostly of the deutan form (63.8 %), and acquired deficiencies were mostly tritan (66.1 %). The prevalence of hereditary and acquired color vision deficiency, as well as different types of red-green and blue-yellow color vision defects significantly increased with age (p < 0.001). In conclusion, the pattern of color vision defects among the middle-aged population of Shahroud was significantly different from that seen in the younger population. This could be due to changes associated with age, gender, medical and ocular conditions, and differences in race and environment. Thus, results of previous examinations and the overall health status should be considered before making any judgment about the status of color vision in middle-aged people.

Performance of ChatGPT in Diagnosis of Corneal Eye Diseases.

PURPOSE: The aim of this study was to assess the capabilities of ChatGPT-4.0 and ChatGPT-3.5 for diagnosing corneal eye diseases based on case reports and compare with human experts. METHODS: We randomly selected 20 cases of corneal diseases including corneal infections, dystrophies, and degenerations from a publicly accessible online database from the University of Iowa. We then input the text of each case description into ChatGPT-4.0 and ChatGPT-3.5 and asked for a provisional diagnosis. We finally evaluated the responses based on the correct diagnoses, compared them with the diagnoses made by 3 corneal specialists (human experts), and evaluated interobserver agreements. RESULTS: The provisional diagnosis accuracy based on ChatGPT-4.0 was 85% (17 correct of 20 cases), whereas the accuracy of ChatGPT-3.5 was 60% (12 correct cases of 20). The accuracy of 3 corneal specialists compared with ChatGPT-4.0 and ChatGPT-3.5 was 100% (20 cases, P = 0.23, P = 0.0033), 90% (18 cases, P = 0.99, P = 0.6), and 90% (18 cases, P = 0.99, P = 0.6), respectively. The interobserver agreement between ChatGPT-4.0 and ChatGPT-3.5 was 65% (13 cases), whereas the interobserver agreement between ChatGPT-4.0 and 3 corneal specialists was 85% (17 cases), 80% (16 cases), and 75% (15 cases), respectively. However, the interobserver agreement between ChatGPT-3.5 and each of 3 corneal specialists was 60% (12 cases). CONCLUSIONS: The accuracy of ChatGPT-4.0 in diagnosing patients with various corneal conditions was markedly improved than ChatGPT-3.5 and promising for potential clinical integration. A balanced approach that combines artificial intelligence-generated insights with clinical expertise holds a key role for unveiling its full potential in eye care.

The effects of mitomycin C on tear function after photorefractive keratectomy: a contralateral comparative study.

PURPOSE: To assess the effects of adjuvant mitomycin C (MMC) on tear function tests after photorefractive keratectomy (PRK) for myopia. METHODS: In this prospective, randomized, double-blind study, one eye of myopic patients undergoing PRK was randomly chosen for PRK and the other eye was treated with PRK plus the application of 0.02% MMC for 20 seconds onto the ablated stroma. All patients had corneal esthesiometry, fluorescein break-up time testing, fluorescein and Rose Bengal staining, and Schirmer testing with anesthesia, and they also completed a questionnaire preoperatively and at 1.5, 3, 6, and 12 months after surgery. RESULTS: Twenty-seven patients with a mean age of 25 ± 3.27 years were enrolled. There were no statistically significant differences between the PRK and PRK+MMC groups regarding the symptoms and tear function tests preoperatively or at any postoperative follow-up visit. Preoperative and postoperative results in the total sample were also compared; statistically significantly different results were observed in fluorescein break-up time and dry eye symptoms at 1.5 months, which showed improvement thereafter. Corneal sensation was significantly lower at all postoperative follow-up visits compared with preoperative results. CONCLUSIONS: The intraoperative use of MMC during PRK did not induce tear deficiency, and it seems that MMC can be used safely when necessary.

National Eye Institute Visual Function Questionnaire: usefulness in glaucoma.

The National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) is the most commonly used patient-reported outcome measure to assess vision-related quality of life in patients with glaucoma. Glaucoma negatively affects the composite and several NEI-VFQ subscale scores; this effect is correlated with the severity of glaucomatous visual field loss. Contrast sensitivity, glare, and dark adaptation are potential items that could be added to the NEI-VFQ to make it more responsive to changes in vision-related quality of life in patients with glaucoma.

Femtosecond laser-assisted laser in situ keratomileusis for the correction of high myopia in Meesmann corneal dystrophy: a case report.

The patient was a 26-year-old woman who had manifest refraction and uncorrected and corrected distance visual acuities of -7.00 × -4.50 at 175°, 20/400, and 20/25, respectively, in the right eye, and -3.25 × -5.25 at 179°, 20/200, and 20/25, respectively, in the left eye. In the right and left eyes, the mean corneal thicknesses were 733 and 749 µm, and the maximum epithelial thicknesses were 70 and 68 µm, respectively. Myriads of intraepithelial cysts were observed in the slit-lamp examination. At 30 months after femtosecond laser-assisted laser in situ keratomileusis (femto-LASIK), the manifest refraction and uncorrected and corrected distance visual acuities were respectively 0.00 × -1.25 at 55°, 20/25, and 20/20 in right eye, and 0.00 × -0.50 at 135°, 20/20, and 20/20 in the left eye. In this case of Meesmann dystrophy, myopia was successfully treated with thick flap femto-LASIK without complications or ectasia.

Non-Cycloplegic and Cycloplegic Autorefraction with Retinomax: An Agreement Study in Preschoolers in Los Angeles, California.

PURPOSE: To evaluate the agreement between non-cycloplegic autorefraction (NCAR) and cycloplegic autorefraction (CAR) in an ethnically diverse population of preschool-aged children and the validity of the screening criteria used to refer for further evaluation. METHODS: This study included data from 7,073 preschoolers who underwent NCAR and CAR, which enabled refractive error classification based on the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) 2013 criteria. Right eye data of sphere and cylinder were used to compare NCAR to CAR via paired t-testing and vector analyses, and left eye data for an analysis on anisometropia. The sensitivity and specificity of screening referral criteria for refractive error were calculated. RESULTS: Mean values of sphere differed between NCAR and CAR by 1.95 ± 1.45 D (p < .05) with 95% limits of agreement (LoA) of -0.94 to 4.85 D, with less discrepancy found in myopic eyes. The mean values of cylinder differed by -0.08 ± 0.43 D (p < .05) with 95% LoA of -0.93 to 0.77 D. Power vector results reflected a similar lack of agreement. The sensitivity and specificity of our screening referral criteria were, respectively, 66% and 84% for myopia, 66% and 98% for hyperopia, and 98% and 58% for astigmatism. CONCLUSION: NCAR is insufficient in preschoolers for spherical refractive error referrals. Level of agreements was lower for spherical (15.5% within 0.5D) and higher for cylindrical refractive errors (89.6%) compared to CAR. In the absence of cycloplegic examination, screening programs using NCAR should utilize low referral thresholds for spherical refractive error.

Variability of CLMI-X parameters, zonal Kmax, and single-point Kmax in keratoconus progression.

OBJECTIVES: To compare the repeatability of Cone Location and Magnitude Index expanded (CLMI.X) parameters of 2 mm diameter zone of greatest corneal curvature (Cspot-Axi) and 1 mm diameter zone of thinnest pachmymetry (Spot-Pach) with the maximum single point keratometry (Kmax), 3 mm Zonal Kmax (Z-Kmax3), and thinnest single point pachymetry (TP) in keratoconus (KC). METHODS: In this Comparative repeatability study, data from 36 eyes of 36 normal individuals and 72 eyes of 72 KC patients (28 eyes with ≤50.0D and 44 eyes with >50.0D Z-Kmax3) were analyzed. For each enrolled eye, imaging was done 6 times (3 consecutive acquisitions with a half hour break). For each parameter, the within-subject standard deviation (Sw) was calculated from the data of the six exams. RESULTS: In the normal group, Cspot-Axi-Sw was different from Kmax-Sw (p = 0.0004). Also, Z-Kmax3-Sw was different from Kmax-Sw (p = 0.0297). The difference between Cspot-Axi-Sw and Z-Kmax3-Sw was statistically significant (p = 0.0482). In the KC group, Sw were significantly different between Cspot-Axi and Kmax (p < 0.0001), and between Z-Kmax3 and Kmax (p < 0.0001). In the Z-Kmax3 ≤ 50.0D subgroup, Sw were different between Cspot-Axi and Kmax (p = 0.0002). In the Z-Kmax3 > 50.0D subgroup, Sw were different between Cspot-Axi and Kmax (p < 0.0001), and between Z-Kmax3 and Kmax (p < 0.0001). Sw differences between Spot-Pach and TP were not significant in any of the study groups (all P > 0.05). CONCLUSIONS: In the diagnosis and follow up of KC, the zonal averages of Cspot-Axi and Z-Kmax3 are more reliable than the single point Kmax. The repeatability of Spot-Pach is similar to TP and both variables should suit the purpose equally.