Health professions students' approaches towards practice-driven ethical dilemmas; a case-based qualitative study.

BACKGROUND: In healthcare practice, ethical challenges are inevitable and their optimal handling may potentialy improve patient care. Ethical development in medical education is critical for the transition from a medical and health sciences student to an ethical healthcare practitioner. Understanding the health professions students' approaches towards practice-driven ethical dilemmas could harness i the effective ethical development in their medical education. This study attempts to identify the health professions students' approaches towards practice-driven ethical dilemmas. METHODS: An inductive qualitative evaluation was conducted on six recorded videos of health professions students' case-based online group discussions, followed by a one-hour online ethics workshop. The online ethics workshop was organized with students from the College of Medicine, College of Dental Medicine and College of Pharmacy at the University of Sharjah, and the College of Medicine at the United Arab Emirates University. . The recorded videos were transcribed verbatim and imported to the qualitative data analysis software of MAXQDA 2022. Data were analyzed applying four stages of review, reflect, reduce and retrieve and two different coders triangulated the findings. RESULTS: Six themes emerged from the qualitative analysis of the health professions students' approaches to the practice-based ethical dilemmas; (1) emotions, (2) personal experiences, (3) law and legal system, (4) professional background, (5) knowledge of medical research and (6) inter-professional education. In addition, during the case-based group discussions in the ethics workshop, students efficiently applied the relevant ethical principles of autonomy, beneficence, non-maleficence and justice in their reasoning process to reach an ethical decision. CONCLUSION: The findings of this study explained how health professions students resolve ethical dilemmas in their ethical reasoning process. This work sheds light on ethical development in medical education by gaining students' perspectives in dealing with complex clinical scenarios. The findings from this qualitative evaluation will aid academic medical institutions in developing medical and research-based ethics curriculum to transform students to ethical leaders.

Personal protective eyewear usage among industrial workers in small-scale enterprises.

BACKGROUND: Work-related eye injury causes significant vision loss. Most of these injuries are preventable with appropriate eye safety practices. We aimed to study industrial workers' perceptions of Personal Protective Eyewear (PPE) and its usage in a high income developing country. METHODS: A field-based cross-sectional study in small-scale industrial entities was performed in Al-Ain City, UAE during the period of October 2018 to June 2019. Five hundred workers completed a pretested structured questionnaire. Data on demographics, occupational history, work hazard awareness, and PPE usage at their work place were collected. RESULTS: The workers were experienced, with a median of 15 years in practice. The majority (80%) learned their work skills through apprenticeship (i.e., on-the-job) training. Most (85%) were involved with activities presenting eye injury risk, and were highly aware of this. None of the workers used safety goggles or glasses all the time for activities that need PPE usage. Five percent never used PPE in the workplace. The main reason for not using PPE was the work demands (95%) and poor vision through the lenses (75%). Young age and less work experience were associated with less PPE usage (P < 0.0001). Wearing prescription spectacles had a positive correlation with usage of safety goggles (P = 0.005) and a negative correlation with welding helmet usage (P < 0.0001). CONCLUSIONS: There was a high level of awareness about the value of PPE in the workplace which was not translated into real practice. Educational programs promoting eye safety practices and proper PPE usage should be adopted by workers in small-scale industrial settings.

Surgical management of pediatric eye injuries.

BACKGROUND: Eye injury is a leading cause of unilateral childhood blindness. The purpose of this research was to study the management and visual outcome of pediatric eye injuries necessitating hospitalization and surgical repair. MATERIALS AND METHODS: This is a retrospective study of children having eye injury that needed surgical repair over the period of 2012 and 2017. Demographic data, place of occurrence, activity at the time of injury, place and cause of injury, presenting signs, surgical interventions, visual acuity (VA) before and after surgery, and causes for vision limitations were studied. RESULTS: Thirty-nine eyes of children were surgically treated. The mean (range) age of the patients was 3 years (1-15 years). Nearly 61.5% were males. Almost 80% of injuries occurred at home and while playing (71.8%). Trauma with sharp objects (35.8%) was the most common cause of injury. Majority presented to the hospital in <6 h (89%), mainly with eye pain (95%). Corneal laceration (53.8%), traumatic cataract (15.3%), and foreign body (15.3%) were the most common clinical findings. Twenty-one (53.8%) eyes sustained open-globe injuries. Fifteen percent had vision of 20/200 or worse at follow-up. The VA improved significantly at follow-up (P < 0.05). The major cause of vision limitation was the cornea (33%). CONCLUSIONS: Eye injury is a major cause of vision loss in children. Despite early presentation to our hospital and prompt interventions, significant number of our pediatric patients sustained limited VA in ruptured globe injuries.

Relationships and boundaries: Learning needs and preferences in clerkship medical environments.

PURPOSE: Relationship boundaries recognition is an essential element of medical practice. The aim of the study was to assess final year medical students' perceived need for education regarding professional boundaries. MATERIALS AND METHODS: This was a cross-sectional study. An anonymous paper questionnaire was distributed to 128 final year medical students. Standard descriptive statistics, unpaired t-test to evaluate differences between male and female groups and Pearson correlation to determine relationships between variables were used. RESULTS: The survey was completed by 84.4% of students who identified the need for more emphasis in the curriculum for all of topics during training and practice pertaining to boundaries and relationships (mean 6.61±1.32 on a scale of 0 to 9; and 6.66±1.27 respectively). Topics with a high interest ranking requiring additional attention were mistreatment of medical students (mean 7.22±1.96), coping with mistakes in clinical care (mean 7.25±1.63), reporting of medical mistakes (mean 7.58±1.36), and gender bias in clinical care (mean 7.10±1.82). Women perceived a greater need for attention to all topics in the curriculum. Significant differences between the perceptions of female and male students were observed regarding topics such as responding to an impaired colleague (p<0.001), and a physician's social responsibilities (p = 0.001). CONCLUSION: Medical students recognized the need for more education and training in the undergraduate medical ethics curriculum regarding patient-physician relationship boundaries.

Eye Injuries and Related Risk Factors among Workers in Small-scale Industrial Enterprises.

PURPOSE: We aimed to study eye injuries and their risk factors among workers at small-scale industrial enterprises. METHODS: Cross-sectional descriptive study. Five hundred workers at small-scale industrial enterprises in Al-Ain City, United Arab Emirates were included. A pre-tested structured questionnaire was used to collect data by direct interviews during the period of October 2018 through June 2019. The outcome measures included self-reported eye injuries, risk factors, and outcomes in the past 12 months. The study adhered to the guidelines of the Declaration of Helsinki. RESULTS: One-hundred seventy-five (35%) workers reported eye injury, 25 (14.3%) had recurrent injuries. Twenty-five (15%) received treatment for eye injury. Five percent were hospitalized. Workers who had an eye injury were less educated compared with those who did not (p < .0001), received less safety training (p < .0001), had less work experience (p < .0001), used more spectacle correction glasses (p < .0001), and had less usage of the safety eye goggles and safety eyeglasses (p < .0001) compared with those who had no eye injury. Arc welding (76; 43.4%), chipping (25; 14.3%), and drilling (24; 13.7%) were associated with high risk for eye injury. Twenty-eight percent of eye injuries occurred to observers or working assistants. CONCLUSIONS: This study has shown a high percentage of eye injury incidents among workers at small-scale industrial enterprises. This was associated with low usage of the safety eye goggles and glasses. Arc welding posed significant risks for eye injury. This information is useful for safety promotion and development of work-related eye injury prevention legislations.

Eye injuries caused by date palm thorns and leaves.

PURPOSE: To describe the clinical presentation, management, and outcome of hospitalized patients having date palm tree eye injuries. METHODS: This is a retrospective study of consecutive patients who were admitted to Al-Ain hospital following date palm tree eye injuries between 2012 and 2017. Patients' demography, symptoms and signs at presentation, surgical intervention, visual acuity (VA) before and after treatment, hospital stay, and causes for VA limitation were studied. RESULTS: Sixteen patients were studied. Their median (range) age was 38.5 (7-58) years, all were males. Majority (87.5%) were from the Indian subcontinent and had their injuries at farms. Eye pain (94 %) was the most common presenting symptom while keratitis (62.5%) and corneal perforation (43.8%) were the most common physical findings. Vision showed a statistical trend for improvement after treatment (P = 0.1, Wilcoxon singed rank test). Five patients (31%) were blind in the injured eye. CONCLUSION: Palm date tree eye injuries which mainly occur at farms are a significant cause for visual loss at United Arab Emirates (UAE). Use of eyes protective goggles combined with legislative eye safety regulations will reduce palm tree eye injuries.

Management of infective corneal ulcers in a high-income developing country.

Microbial keratitis is a major risk for corneal blindness worldwide. We aimed to study the clinical presentation and outcome of hospitalized patients having infective corneal ulcers.All patients who were diagnosed as microbial keratitis and were admitted to Al-Ain Hospital during the period July 2011-Dec 2016 were retrospectively studied. Patients' demography, predisposing factors, symptoms and signs at presentation, time to presentation after onset of symptoms, microbial isolates, hospital stay, and visual acuity (VA) outcome were studied.74 patients with corneal ulcers were hospitalized. 79.7% were males. The median (range) age was 44 years (1-91). 36.5% had trauma as a risk factor. The main presenting symptoms were pain (90.5%), red eye (79.7%), and decreased vision (63.5%). All patients had stromal infiltrate while 39.2% had hypopyon at presentation. The average time from the start of the symptoms to hospital presentation was 11 (1-90) days. The mean (range) hospital stay was 10.6 (1-60) days. Forty eyes were culture positive. Bacteria were identified in 27 eyes and fungus in 16. Pseudomonas aeruginosa (9 eyes) and Staphylococcus epidermis (5 eyes) were the most common bacterial islolates. Aspergillus (6 eyes) was the most common fungus species. 95.2% of the bacterial isolates were susceptible to the quinolone antibiotics group. Twenty eight (51.9%) patients had a vision worse than 6/60 in the affected eye.Corneal ulcer poses a significant threat to the sight of an affected eye. Trauma was the most common risk factor for corneal ulcers. Usage of eyes personal protective equipment for high risk occupations and earlier accessibility to health care may reduce the impact of corneal ulcers in our community.

Epidemiology of eye injuries in a high-income developing country: An observational study.

Vision loss following eye trauma is a serious health problem worldwide. The aim of the study was to report the epidemiology of eye injury that requires hospitalization and surgery at a secondary referral center in a high-income developing country so as to give recommendations regarding its prevention.All patients who had an eye injury that required surgical intervention between 2012 and 2017 at Al-Ain Hospital were retrospectively studied. Demography, cause of injury, and visual acuity before and after treatment were studied.Results revealed that 141 patients were operated, 96 eyes with open globe and 48 with other injuries. The median (IQR) age was 25 (11.5-37) years, 89% were males. Majority of injuries occurred at work (50.4%) followed by home (31.2%). Sharp objects (24.1%) and blunt trauma (16.3%) were the most common mechanism of injury. Eye injury was less during the weekends (Friday and Saturday) and during the summer vacation. Cornea injuries (48.2%) were the most frequent cause for visual acuity deterioration followed by lens/cataract (23.4%). Among injured eyes, 30 eyes (21.3%) retained intraocular foreign bodies. There was significant improvement of the visual acuity after surgery (P < .0001, Wilcoxon signed rank test).Our study has shown that eye injury is a major risk for visual loss of young people which is mainly work-related. Use of personal protective equipment for the eyes and adopting legislative eye safety regulations will reduce the impact of eye injuries in our community.

Globe rupture caused by a camel bite.

Camel bites are uncommon. They are more common during the rutting season where male camels become more aggressive. Herein, we report a unique case of a 25-year-old man who was repeatedly bitten to his face and neck by an aggressive camel that resulted in left eye evisceration, parotid duct, and facial nerve injury. To our knowledge, Globe rupture caused by a camel bite has not been previously reported.

Informed consent learning: Needs and preferences in medical clerkship environments.

PURPOSE: Limited information exists regarding students' routine educational needs in support of ethics and professionalism practices faced in real clinical practice. As such the authors aimed to explore medical students learning needs and preferences for informed consent and relevant ethical issues in the clerkship environments. MATERIALS AND METHODS: A cross-sectional study using a self-administered, printed survey distributed to final year clinical clerks. RESULTS: 84% completed the survey. Students indicated the need for more attention to all topics related to informed consent (mean = 7.1 on a scale of 0 to 9; ±1.2). Most additional instructional attention was requested for topics raised in discussions with patients concerning the risks, benefits and alternatives to recommended treatments (7.3 ±1.4). The cohort expressed the need for education in the care of vulnerable patients (7.2 ±1.2) with a maximum score for the care of abused children. Women perceived greater need for education concerning informed consent than male respondents (p>0.05). There were significant differences between students who scored high or low on the item "being treated in professional manner" and "endorsement of educational needs for care of adolescents" (p = 0.05). CONCLUSION: There was heightened perception among final year medical students of the need for greater attention to be paid to informed consent education.

Outcome Analysis of Visual Acuity and Side Effect after Ruthenium-106 Plaque Brachytherapy for Medium-sized Choroidal Melanoma.

PURPOSE: The purpose of this study is to report on treatment outcomes for medium-sized choroidal melanoma treated with Ruthenium-106 (Ru-106) plaque brachytherapy. METHODS: A retrospective case series of 28 patients received Ru-106 brachytherapy treatment for choroidal melanoma. The prescribed tumor dose was 85 Gy to a depth of 5 mm. RESULTS: Median follow-up was 31.2 months. At 12 and 24-month postirradiation, the best corrected visual acuity ≥20/70 (LogMar ≥-0.54) was 53.8% and 64.2%, respectively. Median time to tumor regression was estimated to be 10 months (95% CI = 9-18 months), with 100% of response rate by 32 months. Radiation-induced side effects were limited, and there were no postradiation enucleations. CONCLUSIONS: The majority of patients maintained good visual acuity, with no enucleations and minimal side effects. In this cohort, the Ru-106 plaque brachytherapy proved to be an efficacious and safe treatment option for patients with medium-sized choroidal melanomas with a maximal tumor height of 5 mm.

Ethics teaching in a medical education environment: preferences for diversity of learning and assessment methods.

BACKGROUND: Ethics and professionalism are an integral part of medical school curricula; however, medical students' views on these topics have not been assessed in many countries. OBJECTIVE:  The study aimed to examine medical students' perceptions toward ethics and professionalism teaching, and its learning and assessment methods. DESIGN: A self-administered questionnaire eliciting views on professionalism and ethics education was distributed to a total of 128 final-year medical students. RESULTS: A total of 108 students completed the survey, with an 84% response rate. Medical students reported frequently encountering ethical conflicts during training but stated only a moderate level of ethics training at medical school (mean = 5.14 ± 1.8). They noted that their education had helped somewhat to deal with ethical conflicts (mean = 5.39 ± 2.0). Students strongly affirmed the importance of ethics education (mean = 7.63 ± 1.03) and endorsed the value of positive role models (mean = 7.45 ± 1.5) as the preferred learning method. The cohort voiced interest in direct faculty supervision as an approach to assessment of knowledge and skills (mean = 7.62 ± 1.26). Female students perceived greater need for more ethics education compared to males (p = < 0.05). Students who claimed that they had experienced some unprofessional treatment had a more limited view of the importance of ethics as a subject (P = 0.001). CONCLUSION: Medical students viewed ethics education positively and preferred clinically attuned methods for learning.

An Enhancement-focused framework for developing high quality single best answer multiple choice questions.

BACKGROUND: The primary goal of any assessment of students is to provide valid and reliable evaluations of students' knowledge and skills as well as provision of accurate feedback to students about their performance. Contrary to best practice guidelines for development of multiple choice questions (MCQs), however, items used within medical schools are often flawed. This disappoints students and discourages examiners from using in-house MCQ databases. Vetting and reviewing items can improve the quality of MCQs. In this paper, we describe our approach to standardize the format used for MCQ assessment and provide recommendations for quality enhancement of high-stakes assessment. METHODS: A collaborative enhancement-focused vetting and review approach to development of high quality single best answer MCQs has been described. RESULTS: Implementation of a collaborative strategy to blueprint, vet, review and standard set MCQ items for high stakes examinations can effectively contribute to assessment quality assurance. Similarly, shared responsibility for post examination analyses of items may reveal the psychometric properties of items in need of improvement and contribute to closure of the assessment outcomes feedback loop. DISCUSSION: Devolving responsibility for implementation of assessment processes as an integral part of educational practices and values can maximize reliability and standards of assessment processes. We contend that while logistics and time constraints are of concern to busy faculty members, judicious utilization of resources to develop well-written MCQ items are well worth the effort to produce reliable and valid examinee scores. An enhancement-focused approach can be institutionally rewarding and lead to improved quality of high stakes assessments.

Vehicle occupant restraint systems impact on eye injuries: a review.

Vehicle occupant trauma to the eyes and associated facial structures has evolved rapidly in conjunction with safety-oriented vehicle design, including restraint systems. Trends vary worldwide with culture, personal factors, vehicle safety equipment, and the traffic environment-including physical, legislative, and enforcement. Wearing safety belts is essential to occupant protection. Airbags were designed as a supplement to protect the head from hard surfaces in frontal crashes, not as a primary countermeasure. Even where vehicle fleets are new with high airbag prevalence, but safety culture and knowledge of restraints is less than robust, injury attributable to not wearing seatbelts is frequent, especially in countries where high-powered vehicles are prevalent. Upper bodies of rapidly forward-moving unrestrained occupants collide with rearward-accelerating airbags. Airbag deployment produces injuries such as corneal abrasions, alkali burns, and the effects of globe compression.

Intraoperative sonographically assisted radioactive iodine 125 plaque brachytherapy for choroidal melanoma: visual acuity outcome.

OBJECTIVES: The purpose of this study was to present a retrospective series of cases from a single Canadian academic center assessing visual acuity outcomes after intraoperative sonographically assisted iodine 125 ((125)I) plaque brachytherapy treatment. METHODS: The cases of 28 patients (16 male and 12 female; mean age ± SD diagnosis, 62.3 ± 15 years) with choroidal melanoma treated with (125)I plaque brachytherapy using intraoperative sonography between 1997 and 2002 were reviewed. RESULTS: The mean longitudinal, transverse, and depth dimensions were 11.4, 10.6, and 4.7, respectively. The median follow-up was 48 months (range, 3-102 months) for our cohort of patients. The prescribed dose was 85 Gy to a height of 5 mm (for an apex height ≤5 mm) or to the tumor apex (for an apex height >5 mm). Five years after (125)I plaque brachytherapy, all tumors had regressed in their longitudinal, transverse, and depth dimensions. The prebrachytherapy tumor depth (P = .023) and sclera dose (P = .036) were found to significantly affect visual acuity after plaque brachytherapy at 24 months. One recurrence was recorded 6 years after plaque brachytherapy. CONCLUSIONS: This study supports (125)I plaque brachytherapy as an efficacious treatment for patients with choroidal melanoma, and intraoperative sonography may help with optimizing tumor control. In addition, to our knowledge, this study is the first to report the sclera dose as a significant predictor of visual acuity.

Long-term visual and refractive outcomes following surface ablation techniques in a large population for myopia correction.

PURPOSE: To evaluate the visual and refractive outcome for four wavefront-guided surface ablation (WGSA) techniques (LASEK, LASEK flap-off [LASEK FO], Epi-LASIK, and Epi-LASIK flap-off [Epi-LASIK FO]) in a large myopic population. METHODS: This retrospective review included 1000 myopic eyes (spherical equivalent [SE] -1.0 to -8.0 diopters [D]) treated with WGSA (VISX STAR S4 with IR) using four different epithelial management techniques. Flaps were either retained (163 Epi-LASIK, 361 LASEK) or discarded (277 Epi-LASIK FO, 199 LASEK FO). Eyes in each group were stratified to either low, mild, moderate, or high myopia based on preoperative SE. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), predictability, lines lost, and haze were compared at 3, 6, and 12 months. RESULTS: At 1 year, UDVA and CDVA of ≥20/20 and 20/15 were comparable across the four procedure groups and within each subgroup of myopia. Predictability was less than or equal to ±0.5 D of intended correction in 96% to 99% of eyes. LASEK FO and Epi-LASIK FO outperformed the EPI-LASIK in achieved MRSE, especially in the high myopia category (-0.012, 0.040, and -0.27 D, respectively, P < 0.05). No eyes lost more than one line of CDVA; and 50% to 60% of eyes in each group gained one or more lines. No significant haze was recorded in any group. There was no statistically significant difference between groups in the preoperative MRSE and efficacy indices except for LASEK FO. CONCLUSIONS: At 1 year, there was no statistically significant difference in visual outcomes between techniques for any degree of myopia. However, the MRSE achieved with LASEK FO and Epi-LASIK FO were closer to emmetropia.

Advanced corneal surface ablation efficacy in myopia: changes in higher order aberrations.

OBJECTIVE: To evaluate the change of ocular and corneal higher order aberrations (HOAs) after wavefront-guided advanced surface ablation (WF-ASA) for myopia using 4 different epithelial management techniques (AA-PRK, LASEK, Epi-PRK, and Epi-LASIK). DESIGN: Retrospective single centre excimer database analysis. PARTICIPANTS: Two hundred and forty eyes equally divided between the 4 WF-ASA techniques, matched for mean and range of required spherical correction. METHODS: Ocular wavefront aberrations were measured using the wavescan aberrometer and corneal aberrations were obtained from corneal topography elevation maps and calculated by ray-tracing. All data were collected preoperatively and 3 months following treatment. The aberrations were described as Zernike polynomials, and analysis focused on total HOAs and spherical aberration (SA). RESULTS: Three months postoperatively, there was a statistically significant surgically induced increase in total HOAs and SA both for ocular and corneal analysis (p < 0.001). There was no statistically significant difference in the induced ocular SA and HOAs between the groups, but the differences in induced corneal SA and HOAs were significant (p < 0.010). Ocular changes in SA were weakly correlated to preoperative SA (20.30, p < 0.001) but strongly correlated to applied spherical correction (20.68, p < 0.001). Surgically induced corneal SA was weakly correlated to preoperative corneal SA (20.34, p < 0.001) and applied spherical correction (20.46, p < 0.001). CONCLUSIONS: Three months postoperatively, all procedures resulted in an increase in ocular and cornealHOAs and SA. Induced aberrations were most strongly correlated to the applied spherical power correction. Modifying the existing ablation pattern to compensate for induced HOAs might improve the outcome.

Comparison of antibiotic-only and antibiotic-steroid combination treatment in corneal ulcer patients: double-blinded randomized clinical trial.

OBJECTIVE: To determine the benefit of early addition of corticosteroids to antibiotics in the treatment of corneal ulcers. DESIGN: Randomized clinical trial. PARTICIPANTS: Thirty eyes of 30 patients, over the age of 12 years, with bacterial corneal ulcer confirmed by culture. METHODS: Patients were randomized before enrollment; 15 were treated with gatifloxacin (Zymar) and a masked placebo and the other 15 were treated with gatifloxacin and masked dexamethasone 0.1% (Maxidex). Primary outcome was residual ulcer size at 10 weeks based on digital photographs. Secondary outcomes included residual ulcer area by clinician estimate, visual acuity, VF-14 score, and time to healing. RESULTS: All subjects (n = 30) demonstrated a reduction in ulcer size over the study period. There was no significant difference between the 2 groups in terms of the primary outcome. There was a significant difference between the 2 groups in 1 of the secondary outcomes. The mean residual ulcer size compared with the baseline by clinician estimate (slit-lamp) was -0.789 mm2 for the antibiotic-only group and -4.206 mm2 for the antibiotic-steroid group (p = 0.05). Among the other secondary outcomes there were no significant differences between the 2 groups. CONCLUSIONS: No benefit was demonstrated in our primary outcome for using steroids in combination with antibiotic therapy in treatment of corneal ulcers. This study suggests that the early addition of steroids to the antibiotic treatment of corneal ulcers does not seem to be harmful when employed in a closely monitored clinical setting.

Correlation between refractive error, corneal power, and thickness in a large population with a wide range of ametropia.

PURPOSE: To determine the correlations between mean keratometry (KM), central corneal thicknesses (CCT), and cycloplegic spherical equivalent (SE) in patients with a wide range of ametropia. METHODS: Retrospective analysis of the excimer laser surgery database at the University of Ottawa Eye Institute between 1993 and 2008 was performed. This study included 3395 eyes from 1858 subjects. The refractive error ranged from +6.75 to -14.00 D. CCT was obtained either by ultrasound pachymetry or anterior segment tomography. Keratometry was determined using an autokeratorefractometer. RESULTS: In the myopic group, the SE was observed to be inversely proportional to the KM (correlation coefficient, -0.18; P < 0.01). The KM and CCT were also inversely proportional (-0.11; P < 0.01). In hyperopes, a correlation between the cycloplegic SE and KM was also found (-0.25; P < 0.01), but the CCT did not correlate with either of these metrics. A direct correlation for the myopic group was found between KM and the difference in power of the principal meridians (keratometric astigmatism [KA]) (0.08; P < 0.01). This relationship was not observed for the hyperopic group. Within the myopic group the SE correlated with the refractive astigmatism (RA) (-0.04; P = 0 0.04). In all groups, a strong correlation was observed between RA and KA (0.78; P < 0.01). CONCLUSIONS: In the myopia group, the KM showed close correspondence with KA and an inverse relationship with SE and CCT. In hyperopes, an inverse correlation between the KM and SE was found, but no correlation with CCT was evident.

Effects of advanced surface ablations and intralase femtosecond LASIK on higher order aberrations and visual acuity outcome.

BACKGROUND/AIMS: To study the changes in wavefront (ocular) and corneal higher order aberrations (HOAs) and visual acuity (VA) outcome following wavefront-guided advanced surface ablation (ASA) techniques and intralase femtosecond LASIK (iLASIK) in myopia treatment. METHODS: Ocular aberration and corneal topography of 240 eyes in the ASA techniques (this was equally divided into a flap-on group where the epithelial flap was preserved and reapplied to the photoablated stromal bed and a flap-off group when the epithelial flap was discarded during the procedure), and 138 eyes in the iLASIK group were obtained before and 3 months following treatment. The correlation of aberrations with best spectacle-corrected visual acuity was analyzed. RESULTS: At 3 months, there was statistically significant (P < 0.001) surgically induced increase in spherical aberration (SA) in each of the techniques for both ocular and corneal analysis. iLASIK induced significantly less ocular and corneal HOAs (P < 0.001). The mean manifest refractive spherical equivalent was closer to attempted correction compared to other groups (P < 0.001). Eighty-three eyes (70%) of flap-on, 80 (67%) flap-off and 94 eyes (68%) in the iLASIK group achieved 20/20 uncorrected VA. Fifteen eyes (11%) accomplished 20/12.5 or better in iLASIK compared to 4 (3%) for flap-on and 7 (6%) for flap-off ASA group. Only the flap-off treatment showed a consistent correlation between the corrected aberrations and visual performance. CONCLUSION: At 3 months, all procedures resulted in a significant increase in HOAs and SA. All had comparable 20/20 VA and 11% of iLASIK patients achieved 20/12.5 or better level.