hyperopia

Children with autism spectrum disorder (ASD) may have impaired vision owing to high refractive errors and aversion to spectacles or contact lenses. Visual blurring is caused by near-sighted myopia, far-sighted hyperopia, or astigmatism in one or both eyes. Refractive surgery can restore sharp vision and eliminate the need for spectacles and contact lenses. Restoration of sharp vision may improve ASD behavior. We aimed to determine the refractive outcomes in this cohort using ophthalmic measures and behavioral and school performance alterations after refractive surgery by employing parent–proxy reports.

This interventional, retrospective case series included data from 267 children with refractive errors and neurodevelopmental disorders (NDDs) diagnosed as ASD alone or NDD with ASD-like behaviors over a 15-year period. One of three refractive surgery methods was employed, with the choice of method uniquely tailored to the child’s eye anatomy. Laser photorefractive keratectomy (PRK) was performed in 131 children, implantation of a phakic intraocular lens (pIOL) in 115 children, and removal of the crystalline lens and implantation of an intraocular lens (refractive lens exchange, RLE) in 21 children. All procedures were performed under brief general anesthesia, with the child returning home on the same day.

The median age at surgery was 10.9 years and the median follow-up period was 3.1 years. Pre-operative refractive errors ranged from a mean (standard deviation) +7.5 (0.09) D to -14.3 (4.8) D. Surgery corrected 87% of the children to normal focal length (± 1 D). Visual acuity improved an average of 0.6 logarithm of the minimum angle of resolution, the equivalent of 6 lines on a standard eye chart. Change in visual acuity was significant (all P < 0.01) between baseline and the most recent follow-up examination in each of subgroups. Change in spherical equivalent refractive error at 3, 12, 24, 36, 60, and > 60 months post-operatively were significant (all P < 0.01) between baseline and each follow-up visit in each of subgroups. Social interactions and ASD behaviors improved in 72% (192) of the treated children (P < 0.01). The incidence of sight-threatening complications was low.

Refractive surgery improves both visual function and behavior in most children with ASD and major myopia, hyperopia, or astigmatism. The PRK, pIOL, and RLE procedures appear to be effective and reasonably safe methods for improving refractive error, visual acuity, and behavior in many ametropic children with ASD and ASD-like NDDs.

 To determine the prevalence of refractive errors among elementary school students in Iranshahr, Iran.

 For this cross-sectional study, 1,745 students from elementary schools in Iranshahr city, Sistan and Baluchestan province, Iran, were chosen using a multi-staged cluster sampling method. The examinations included measuring uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), cycloplegic refraction, cover test, and ophthalmoscopy. In this study, the Refractive Error Study in Children (RESC) protocol was applied. Cycloplegic refraction spherical equivalent of less than or equal to -0.50 D was considered myopia, ≥ 2.00 D was considered hypermetropia, and a cylinder ≥ 0.50 D was considered astigmatism.

 Information was completed for 1,576 students (response rate: 90.31 %). Participants were on average 9.76 ± 1.86 years old. UCVA and BCVA of 20/20 or lower were found in 15.7 % and 2.5 % percent of the study population, respectively. The prevalence of hyperopia and myopia were 5.7  % and 7.3  % respectively.

 Elementary school children in Iranshahr city, Iran show a relatively high prevalence of refractive errors, particularly astigmatism. It is necessary for the health system to focus on identifying and correcting these refractive errors among this age group.

To compare the demographic and ocular characteristics of patients with low and high levels of anisometropia compared with non-anisometropic individuals.

This cross-sectional study was conducted on 1803 individuals (age range, 1 to 30 years) examined at strabismus clinics between January 2019 and December 2020. Of these, 203 subjects had anisometropia (11.2%); 66 cases were excluded due to the history of prior ocular surgery except from strabismus surgery. Finally, data from 137 subjects were analyzed. Spherical or cylindrical differences of 1.50 or 3.00D between the two eyes were defined as low or high anisometropia, respectively, and isometropic subjects (n = 1600) served as controls.

No significant difference was observed between cases and controls regarding age (10.25 ± 8.41 vs. 9.2 ± 1.7 years; P = 0.133) and sex (P = 0.051). History of ocular surgery was present in 33% of anisometropic patients versus 0.8 % of isometropic cases. The rate of amblyopia was 83% and 2.3% in anisometropic and non-anisometropic groups, respectively. Best corrected visual acuity (BCVA) was comparable in amblyopic eyes in both study groups, while BCVA of nonamblyopic eyes of non-anisometropic subjects was better (non-anisometropic: 0.01 ± 0.01 vs. anisometropic: 0.06 ± 0.17 LogMAR; P = 0.001). Eye deviation was significantly more prevalent among anisometropic patients (36.5% vs. 3.25%, P < 0.001) and exotropia was the common type of deviation. Anisohyperopia and anisomyopia were the most common refractive errors under low and high anisometropia categories, respectively. Simultaneous manifestation of amblyopia and strabismus were observed in 30.6% of anisometropic cases, while only 0.7% of subjects with isometropia had a similar status (P < 0.001).

High rates of amblyopia and strabismus in anisometropic subjects, especially with higher degrees of anomaly, indicate the necessity of early visual acuity and refractive error screening to improve detection and enhance the outcomes of treatment.

 The study aims to determine the age- and sex-adjusted prevalence of refractive errors and its related factors among the adult population of southeastern Iran.

 The current study included 9280 individuals aged 35 to 70 years using a multistage random sample method from October 2015 to January 2019 as a part of a Persian cohort study in Zahedan. Uncorrected and corrected vision, objective noncycloplegic, and subjective refraction were measured, with all participants undergoing ophthalmoscopy, slit-lamp biomicroscopy, fundoscopy, refraction, and retinoscopy. Data were analyzed using SPSS version 23.0 statistic software and described as percentage, odds ratio, and 95% confidence interval. Comparisons between groups and relationships among risk factors and refractive errors were performed with chi-square, nominal, and multiple regression analysis.

 The prevalence of low and moderate myopia, high myopia, low and moderate hyperopia, high hyperopia, low and moderate astigmatism, and high astigmatism was 24.2 (95% CI: 22.40 - 25.90), 1.5(95% CI: 0.00 - 3.53), 16.1(95% CI: 14.20 - 17.90), 1.3(95% CI: 0.00 - 3.30), 35.6 (95% CI: 33.90 - 37.30), and 3.8 (95% CI: 1.80 - 5.70) percent, respectively. The prevalence of refractive errors significantly varied across different age groups overall and by sex (P = 0.01). The proportion of refractive errors also significantly differed by education (P = < 0.001). The prevalence of against the rule, with the rule, and oblique astigmatism was 32.8 % (95% CI: 31.10 - 34.20), 42.1% (40.50 - 43.60), and 24.9% (23.10 - 26.60), respectively. The risk of astigmatism was significantly lower in men than in women (OR = 0.75; 95 % CI: 0.60 - 0.90). Based on multiple regression, the risk of myopia (OR = 2.07; 95 % CI: 1.60 - 2.60) and hyperopia (OR = 25.38; 95 % CI: 18.70 - 34.3) was higher in the age group 65 to 75 years compared to the younger group.

 The present study provided valuable information on the prevalence of refractive errors in the adult population in south-eastern Iran. The findings underscore the need for comprehensive eye care services, particularly for older individuals and those with lower education levels. Further prospective research is warranted to explore the factors contributing to refractive errors and to develop effective strategies for its prevention and management.

To investigate the outcomes of unilateral Supracor treatment to enhance near vision while maintaining good distance vision in hyperopic eyes.

This prospective interventional study includes consecutive hyperopic patients with presbyopia. All eyes underwent femtosecond laser‑assisted in situ keratomileusis treatment for hyperopia with an additional Supracor multifocal treatment algorithm in nondominant eyes. Monocular and binocular uncorrected and spectacle‑corrected distance visual acuity (UCDVA and SCDVA), monocular and binocular uncorrected near visual acuity (UNVA), and distance‑corrected near visual acuity at 40 cm and high‑order aberration changes and complications were evaluated for 6 months.

Sixty‑four patients with a mean age of 51.91 ± 3.64 were enrolled. After 6‑month follow‑up, the mean binocular UCDVA and UNVA were 0.03 ± 0.05 and 0.04 ± 0.06 logMAR, respectively. UCDVA (logMAR) of nondominant and dominant eyes was 0.30 ± 0.18 and 0.03 ± 0.05, respectively. Preoperative and postoperative mean ± standard deviation manifest refraction spherical equivalent was +1.84 ± 0.75 and −0.48 ± 0.57, respectively, in nondominant eyes and +1.77 ± 0.69 and +0.12 ± 0.33, respectively, in dominant eyes. No complications were observed.

Supracor procedure in nondominant eyes may improve functional near, intermediate, and distance vision without significant photic phenomena in presbyopic patients with low and moderate hyperopia.

This study aims to investigate the visual acuity and prognosis after photorefractive keratectomy among hyperopic patients with and without astigmatism.

In this interventional case series study, 74 eyes from 42 hyperopia patients with and without astigmatism who underwent photorefractive keratectomy using Allegretto EX500 excimer laser at Torfeh and Negah Eye Hospitals from 2014 to 2018 were enrolled. Pre-and postsurgical visual examination findings, including uncorrected distance visual acuity, corrected distance visual acuity, manifest refraction, cyclorefraction, and slit lamp examinations to measure ocular pressure and the presence or absence of haze, were recorded.

The mean age of participants was 34 ± 9 years, and 54.8 % were female. The preoperative mean uncorrected distance visual acuity was 0.55 ± 0.25 LogMAR, which significantly improved to 0.11 ± 0.14 at 6 months postoperatively (P < 0.0001). The predictive value for surgical outcomes at six months post-operation was 71.6 % within ± 0.5 diopter, 89.2 % within ± 1 diopter, and 97.3 % within ± 2 diopters. No eye lost corrected distance visual acuity of two lines or more, and only 16.6 % (12 eyes) experienced a one-line reduction in corrected distance visual acuity. No other notable complications occurred.

Photorefractive keratectomy using Allegretto EX500 excimer laser is an effective and safe method for correcting mild to moderate hyperopia with or without astigmatism.

This study was planned to compare Trans - epithelial Photorefractive Keratectomy (TPRK) and Alcohol Assisted Photorefractive Keratectomy (AAPRK) laser vision correction in hyperopia and compound hyperopic astigmatism. This quasi-experimental study was conducted on patients with hyperopia and hyperopic-astigmatism, whose eye laterality was randomly assigned to undergo TPRK versus AAPRK using SCHWIND AMARIS 1050RS (SCHWIND eye-tech-solutions, Germany). Follow up time was 1, 3, 6 and 12 months after surgery. 112 eyes of 56 patients with mean age of 32.6 years included, of which 51.8% were female and 48.2% were male. Both TPRK and AAPRK methods were able to correct hyperopia and astigmatism safely and efficiently (p<0.05 in all cases). Postoperative vision characteristics were similar in both methods (p=0.23 for sphere, p=0.52 for cylinder, p=0.064 for axis, and p=0.35 for BCVA) postoperatively. Corneal haze was observed in 44% of the patients with a direct strong correlation with hyperopia severity (r=0.607). Post-operative pain was observed in 60% of the patients with a direct weak correlation with hyperopia severity (r=0.27). Mild photophobia was seen in 42% of the patients with a direct weak correlation between photophobia and hyperopia severity (r=0.36). Epithelial healing time lasted an average of 3.48 days and there was a direct and moderate correlation with hyperopia severity (r=0.4). Safety index in TPRK and AAPRK was 0.54 and 0.45, respectively, with no significant difference (p=0.42); Efficacy index was 0.96 and 0.9 in TPRK and AAPRK, respectively and there was no significant difference between two groups (p=0.23). No complication was observed in all of the patients. TPRK and AAPRK laser vision correction are both safe and efficient in hyperopia and compound hyperopic astigmatism. There is no significant difference regarding epithelial healing time, post-operative pain and haze formation between two procedures.

The purpose of the present study was to determine the refractive profile of strabismic children under 8 in a tertiary referral center in Tehran, Iran.

This retrospective cross-sectional study was conducted on the medical records of 357 patients under the age of 8 who had one type of strabismus in Farabi Hospital, Tehran, Iran, between 2015 and 2019. All routine ophthalmic examinations were done for all patients. Cycloplegic refraction was performed after the instillation of two drops of cyclopentolate 1% with an interval of 5 minutes, and the refractive error was measured after 30 minutes. The diagnostic criteria were based on cycloplegic refraction in which myopia, hyperopia, and astigmatism were defined when the refractive error was -0.25, +0.75, and -0.50 diopter (D) or more, respectively. The cycloplegic results were classified into different groups with an interval of 1.00 D, and astigmatism was also assessed separately.

In this study, the most common type of refractive error in esotropic patients was hyperopia, with the +2.00 to +4.00 D range having a higher prevalence. In exotropic patients, hyperopia was also prevalent; the most common range of hyperopia was between +0.75 to +1.00 D. Astigmatism had a prevalence of 37.8% in esotropic patients, and 17.2% in exotropic patients with the most common range from -0.50 to -1.00. Myopia was present in 2.8% of patients with esotropia and 3.2 % of patients with exotropia with the most common range from -0.25 to -1.00.

In strabismic Iranian children, hyperopia was the most prevalent refractive error in both esotropic and exotropic patients, with higher degrees of hyperopia in esotropic patients. Low astigmatism was twice as prevalent in patients with esotropia as in patients with exotropia. Low myopia was the least prevalent in both esotropic and exotropia.

We aimed to report the five-year results of Trans-epithelial Photorefractive Keratectomy (TPRK) in treating all kinds of refractive errors. In this retrospective cohort study, we quantitatively compared the clinical findings and assessment of optical and refractive parameters, including slit-lamp, corneal topography, Best Corrected Visual Acuity (BCVA), and Uncorrected Distance Visual Acuity (UDVA) in 172 eyes of myopic, hyperopic, and astigmatic patients before and five years after trans-PRK. The average time for post-surgery epithelial healing was 2.97 0.83 days in male and 2.94 0.87 days in female patients; the pain score in a week following the operation was 1.88 0.68 in males and 2.25 0.73 in females. Corneal haze was observed in five patients. No long-term adverse effect was reported. The pre-operative UDVA was 0.84 0.32 in male and 0.87 0.34 in female patients; while the postoperative UDVA was -0.02 0.04 in male and -0.01 0.02 in female patients. There was a highly significant correlation (P<0.001) in all indices except UDVA, which was almost near to being significant (P=0.07). In this survey, the mean safety and index were nearly 1.00. TPRK is a safe and efficient therapeutic procedure to treat all types of refractive errors, including myopia, hyperopia, and astigmatism, with no significant adverse effect. Being touchless and having a short recovery time are two main characteristics of this refractive surgery.

To assess the prevalence and distribution of refractive errors in Madang Province, Papua New Guinea (PNG).

A retrospective hospital‑based study was conducted at Madang Provincial Hospital Eye Clinic. It is a free eye clinic and spectacle costs are further subsidized by a nongovernmental organization. Nonprobability purposive sampling was used to retrieve patients’ records at the eye clinic from January to December 2016. Only demographic and clinic data on the patients’ first visit to the eye clinic were recorded and these included their age, gender, location, presenting visual acuity (VA), and refractive correction.

One thousand and one hundred eighty‑four patients’ records were retrieved, of which 622 (52.53%) had refractive error. The mean age of refractive error presentation was 49.68 ± 16.29 years with a range of 9–86 years. There were more males (55%) than females. About a quarter of the patients (21.2%) presented with moderate visual impairment. There was a statistically significant relationship between visual impairment and age group (P < 0.001). Myopia (53.1%) was the most common type of refractive error followed by hyperopia (32.5%) and astigmatism (14.4%). The uptake of spectacle correction was very high (95.3%) among the patients. More than one‑tenth of the patients(12.5%) reported from other provinces. Almost one‑third of the patients (31.4%) could not obtain a VA of 6/6 after refraction. About one‑fifth (17.0%) of the patients were suspected of functional amblyopia.

Uncorrected refractive error (URE) is a significant cause of visual impairment in PNG. There is a need for the integration of eye care services into primary health care for early detection, treatment, and prevention of visual impairment caused by UREs.

To evaluate the corneal topographic patterns in an adult Iranian population and investigate its correlation with the refractive status of the eye.

In a cross‑sectional study named “Tehran Study,” 1023 samples were selected by the cluster sampling method from the downtown area of Tehran. Eight hundred and forty-nine adults aged over 15 years participated. All selected participants were refracted and underwent topography imaging.

The patients’ ages ranged from 15 to 91 years with a mean of 40.33 ± 16 years. The most frequent topographic patterns were symmetric bowtie (SB) (34%), SB with inferior steepening (SB‑IS) (14.1%), and round (10.5%). The orders changed in categorization by refractive status: The most frequent pattern in all subgroups (emmetropia, myopia, and hyperopia) was SB with frequencies 32.7%, 35.8%, and 22.5%, respectively. Although the second order was asymmetric bowtie (AB) with AB-IS in the emmetropic and myopic subgroups, in the hyperopic subgroup, round pattern had the second place. The third place was different in all groups. The rarest patterns in the whole were SB with skewed radial axis (SRAX) and AB with SRAX. The first prevalent topographic pattern was SB in all age groups and in both genders. The prevalence of round pattern, irregular pattern, and SRAX significantly increased in older ages, and the prevalence of SB decreased in older ages. The first observed prevalent pattern was SB in both sexes, but the second most prevalent pattern was AB-IS and round in females and males, respectively.

Corneal topographic pattern might be related to the refractive status of the eye. The information about normal topographic patterns provides a reference for comparison with diseased corneas.

To evaluate the effect of soft contact lens induced myopia and hyperopia on optic nerve head measurements of normal eyes using spectral domain optical coherence tomography (SD-OCT).

This cross sectional study was performed on 114 emmetropic eyes of 57 participants. Each participant underwent a complete ophthalmic examination including determination of best-corrected visual acuity, intraocular pressure, dry and cycloplegic refraction as well as axial length measurement. SDOCT measurement was performed in all ayes while different levels of refraction strength were induced by wearing soft contact lenses of five different diopters (- 10.00, - 5.00, Plano, + 5.00, + 10.00).

The mean measured thicknesses of retinal nerve fiber layer were 123.29 ± 10.56 micrometer, 123.17 ± 11.61 micrometer, 122.77 ± 11.61 micrometer, 123.37 ± 11.15 micrometer and 123.42 ± 11.45 micrometer in contact lens induced high myopia, moderate myopia, emmetropic, moderate hyperopia, and high hyperopia groups, respectively (P = 0.721). Also, corresponding evaluations for mean rim area (P = 0.781), mean optic disc area (P = 0.601), mean cup area (P = 0.53), and mean cup to disc area ratio (P = 0.414) showed no statistically significant difference.

Our findings indicate that refractive error variation at the corneal plane caused by contact lens wear has no significant effect on thickness of retinal nerve fiber layer, disc area, cup area, rim area and mean cup to disc area ratio measured by SD-OCT.

Patients with high hyperopia are generally confined to either spectacle wear or contact lenses as a primary means of refractive correction. For this patient population, the surgical corrective methods, such as hyperopic laser assisted in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) are imperfect options due to induction of higher-order aberrations, optical regression, and loss of best corrected distance visual acuity. Recently, there has been growing interest in lenticule implantation underneath a flap via lenticule intrastromal keratoplasty (LIKE) for high hyperopia correction (+3 diopters to +10 diopters). We instead propose a modified surgical technique (small-incision lenticule intrastromal keratoplasty, sLIKE), in which the lenticule is implanted inside an intrastromal pocket thereby causing less injury to the subbasal nerve plexus injury, less postoperative dry eye symptoms, less reduction in biomechanical strength, and lower chances for epithelial ingrowth. We provide an overview of these novel surgical techniques to treat high hyperopia, and compare the associated advantages and disadvantages. In addition, we will discuss the enhancement options and methods of optimization for both surgical techniques.

To determine the prevalence of hyperopia and myopia and their associations with age and gender in 5- to 15-year-old children in underserved rural areas in Iran.
In this cross-sectional study, sampling was done using a multistage cluster sampling method from two underprivileged rural regions in Iran, and 3851 persons over 1 year old of age were invited to the study. After inviting the selected participants, examinations were conducted at a designated site in the selected villages. All participants underwent measurements of uncorrected and corrected visual acuity, manifest refraction, and a slit-lamp examination. Cycloplegic refraction was done by instilling cyclopentolate 1% eye drops in under 15-year-old participants.
Of the 3851 selected persons, 3314 subjects participated (86.5%), and of these, 602 were in the 5–15 year age group. The prevalence of myopia and hyperopia in the studied children was 2.60% [95% confidence interval (CI): 1.10–4.10] and 4.00% (95% CI: 1.84–6.15), respectively. The prevalence of myopia in male and female children was 2.65% and 2.55%, respectively (P = 0.951). The prevalence of hyperopia in male and female children was 2.83% and 5.25%, respectively (P = 0.130). The prevalence of myopia in the villages of southwest and north was 2.42% and 3.09%, respectively (P = 0.618), and the prevalence of hyperopia was 4.71% and 2.10%, respectively (P = 0.0056).
The present report is a brief description of the status of refractive errors in children residing in underprivileged villages of two rural districts in Iran. As presented, the prevalence of myopia is not high, although the prevalence of hyperopia is in the mid-range compared to previous studies.

Laser vision correction is a safe and effective method of reducing spectacle dependence. Photorefractive Keratectomy (PRK), Laser In Situ Keratomileusis (LASIK), and Small-Incision Lenticule Extraction (SMILE) can accurately correct myopia, hyperopia, and astigmatism. Although these procedures are nearing optimization in terms of their ability to produce a desired refractive target, the long term cellular responses of the cornea to these procedures can cause patients to regress from the their ideal postoperative refraction. In many cases, refractive regression requires follow up enhancement surgeries, presenting additional risks to patients. Although some risk factors underlying refractive regression have been identified, the exact mechanisms have not been elucidated. It is clear that cellular proliferation events are important mediators of optical regression. This review focused specifically on cellular changes to the corneal epithelium and stroma, which may influence postoperative visual regression following LASIK, PRK, and SMILE procedures.

Purpose The aim of the study was a systematic review of refractive errors across the world according to the WHO regions.
Methods To extract articles on the prevalence of refractive errors for this meta-analysis, international databases were searched from 1990 to 2016. The results of the retrieved studies were merged using a random effect model and reported as estimated pool prevalence (EPP) with 95% confidence interval (CI).
Results In children, the EPP of myopia, hyperopia, and astigmatism was 11.7% (95% CI: 10.5–13.0), 4.6% (95% CI: 3.9–5.2), and 14.9% (95% CI: 12.7–17.1), respectively. The EPP of myopia ranged from 4.9% (95% CI: 1.6–8.1) in South–East Asia to 18.2% (95% CI: 10.9–25.5) in the Western Pacific region, the EPP of hyperopia ranged from 2.2% (95% CI: 1.2–3.3) in South-East Asia to 14.3% (95% CI: 13.4–15.2) in the Americas, and the EPP of astigmatism ranged from 9.8% in South-East Asia to 27.2% in the Americas. In adults, the EPP of myopia, hyperopia, and astigmatism was 26.5% (95% CI: 23.4–29.6), 30.9% (95% CI: 26.2–35.6), and 40.4% (95% CI: 34.3–46.6), respectively. The EPP of myopia ranged from 16.2% (95% CI: 15.6–16.8) in the Americas to 32.9% (95% CI: 25.1–40.7) in South-East Asia, the EPP of hyperopia ranged from 23.1% (95% CI: 6.1%–40.2%) in Europe to 38.6% (95% CI: 22.4–54.8) in Africa and 37.2% (95% CI: 25.3–49) in the Americas, and the EPP of astigmatism ranged from 11.4% (95% CI: 2.1–20.7) in Africa to 45.6% (95% CI: 44.1–47.1) in the Americas and 44.8% (95% CI: 36.6–53.1) in South-East Asia. The results of meta-regression showed that the prevalence of myopia increased from 1993 (10.4%) to 2016 (34.2%) (P = 0.097).
Conclusion This report showed that astigmatism was the most common refractive errors in children and adults followed by hyperopia and myopia. The highest prevalence of myopia and astigmatism was seen in South-East Asian adults. The highest prevalence of hyperopia in children and adults was seen in the Americas.

The aim of this study was to determine the agreement between Pentacam HR (Scheimpflug imaging, Oculus) and Orbscan II (scanning slit topography, Bausch and Lomb) in measuring corneal parameters after photorefractive keratectomy (PRK) for hyperopia.
In this prospective cross‑sectional study, 38 hyperopic eyes undergoing PRK were examined before refractive surgery and 8 to 10 months postoperatively using Pentacam HR and Orbscan II. Ultrasound (US) pachymetry was also used to measure central corneal thickness (CCT). The radius of anterior (A‑) and posterior (P‑) best‑fit sphere size (BFS), central elevation (CE), and anterior maximum tangential power in 3 mm (TG3) and 3‑5 mm (TG5) zones, anterior chamber depth (ACD), and central corneal thickness (CCT) were collected and used in the analyses. To study the agreement between the measurements made by the two devices, the method described by Bland and Altman was used and the 95% limits of agreement were calculated.
The 95% limits of agreement show reasonable agreement between the measurements by Pentacam HR and Orbscan II for A‑BFS, P‑BFS, A‑TG3, and CCT, but not for A‑CE, P‑CE, A‑TG5, or ACD. CCT values obtained by both Pentacam HR and Orbscan II correlated well with the values determined by US pachymetry.
Pentacam HR and Orbscan II after PRK for hyperopia show reasonable agreement for determining A‑BFS, P‑BFS, A‑TG3, and CCT, but not for A‑CE, P‑CE, A‑TG5, or ACD. CCT measurements with Pentacam HR have reasonable agreement with US pachymetry.

Te aim of this study is to evaluate the results of photorefractive keratectomy (PRK) in the management of postoperative hyperopia and astigmatism in patients with history of radial keratotomy (RK).
Tis prospective nonrandomized noncomparative interventional case series enrolled consecutive eyes treated with PRK after RK. In cases, in which (1) wavefront (WF) scan was undetectable during primary examinations; and/or, (2) WF data were not transferable to the excimer laser device, patients were treated with the tissue-saving (TS) mode. Patients with detectable/transferable WF were assigned to WF-guided advanced personalized treatment (APT).
Tirty-two and 47 eyes were managed by APT and TS modes, respectively. Pooled analysis of both APT and TS groups showed improvement in uncorrected distant visual acuity and corrected distant visual acuity. Te amount of sphere, cylinder, corneal cylinder, spherical equivalent, defocus equivalent, and total aberration showed improvement as well.
PRK seems to bring favorable outcome and safety profile in the management of post-RK hyperopia and astigmatism. It is crucial for practitioners to warn their patients about the fact that they may still have progressive refractive instability regardless of their choice on the laser method of vision correction.

Te aim of this study is to evaluate the results of photorefractive keratectomy (PRK) in the management of postoperative hyperopia and astigmatism in patients with history of radial keratotomy (RK).
Tis prospective nonrandomized noncomparative interventional case series enrolled consecutive eyes treated with PRK after RK. In cases, in which (1) wavefront (WF) scan was undetectable during primary examinations; and/or, (2) WF data were not transferable to the excimer laser device, patients were treated with the tissue-saving (TS) mode. Patients with detectable/transferable WF were assigned to WF-guided advanced personalized treatment (APT).
Tirty-two and 47 eyes were managed by APT and TS modes, respectively. Pooled analysis of both APT and TS groups showed improvement in uncorrected distant visual acuity and corrected distant visual acuity. Te amount of sphere, cylinder, corneal cylinder, spherical equivalent, defocus equivalent, and total aberration showed improvement as well.
PRK seems to bring favorable outcome and safety profile in the management of post-RK hyperopia and astigmatism. It is crucial for practitioners to warn their patients about the fact that they may still have progressive refractive instability regardless of their choice on the laser method of vision correction.