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Purpose: To explore the association between race and socioeconomic status on health disparities in pediatric eye care, characterize the status of diversity within the pediatric ophthalmology workforce, and propose potential solutions to improve access to vision care, particularly for children from vulnerable populations. Methods: The major studies examining the socioeconomic and racial disparities in visual outcomes and the impact of diversity in the ophthalmology workforce were reviewed. Results: Currently, the pediatric ophthalmology workforce has limited racial diversity, and increasing the number of underrepresented in medicine providers has potential to improve access to pediatric eye care, particularly for underserved populations. Mobile eye clinics, school-based vision programs, and health literacy initiatives may engage communities to bring eye care directly to children and enhance follow-up. Conclusions: Families with lower socioeconomic status may represent a vulnerable population facing significant access to pediatric eye care barriers, particularly for asymptomatic pediatric eye conditions. Emphasis on strategies that directly engage communities and bring free vision care to families should be given to improve disparities in visual health outcomes. Ophthalmologists and pediatric ophthalmologists should be aware of the current racial underrepresentation within the pediatric ophthalmology workforce, and the importance of workforce diversity in accelerating physician–patient concordance and access to eye care. [J Pediatr Ophthalmol Strabismus. 2024;61(3):172–178.] [ABSTRACT FROM AUTHOR]

The article focuses on the Vitreo-Retina Society of the Philippines (VRSP), detailing its role in providing specialized eye care, improving medical practice standards, and influencing healthcare policies. Topics include the announcement of Manila as the host city for the 18th Congress of the Asia-Pacific Vitreo-Retina Society in 2025 and the significance of this event in advancing knowledge exchange and collaboration in the field of retina care.

The article discusses the economic and workforce issues in pediatric ophthalmology and their impact on eye care. The participants, who come from both private and academic practices, express the need for detailed and precise eye care for children, emphasizing the importance of pediatric ophthalmology as a specialty. However, they highlight challenges such as low reimbursement rates, a shortage of pediatric ophthalmologists, and the difficulty of incorporating pediatric ophthalmology into general ophthalmology practices. The article also explores strategies to address these issues, including practicing efficiently, reaching out to pediatricians, improving reimbursement rates, and leveraging the scarcity of pediatric ophthalmologists. [Extracted from the article]

Purpose: To provide a blueprint reviewing the major economic and workforce issues in pediatric ophthalmology and its effect on access to pediatric eye care, as well as potential solutions. Methods: This was a systematic review of the landmark studies examining the economic and workforce issues in pediatric ophthalmology was performed. Results: The number of residents pursuing pediatric ophthalmology fellowship has steadily declined since the early 2000s. Increasing overhead costs, low Medicaid reimbursements, practice pattern changes, and workforce shortages have all contributed to a significant crisis in access to pediatric eye care. Conclusions: Solutions to improve access to pediatric eye care involve pursuing more economical strategies within the confines of the pediatric ophthalmology practice, early exposure to the field during medical education, and enhancing residents' interest through faculty mentorship. Low reimbursements are a major driver contributing to extended appointment wait times for pediatric ophthalmology visits at major academic eye centers. Legislative changes at both the federal and state levels are needed to make appropriate increases in reimbursements, starting with states in the lowest quartile of Medicaid reimbursements. [J Pediatr Ophthalmol Strabismus. 2023;60(5):323–329.] [ABSTRACT FROM AUTHOR]

Purpose: To identify new patient, follow-up, and surgery appointment wait times for children seeking care at academic eye centers/children's hospitals (AEC/CHs) in the setting of very low Medicaid reimbursements and workforce issues in pediatric ophthalmology. Methods: Each state in the United States with AEC/CHs was contacted by phone or email. Using a standardized script, the authors inquired about approximate wait times for non-emergency new patient, follow-up, and surgery appointment times, as well as percentage of patients insured by Medicaid seen at the AEC/CH. Medicaid reimbursements for new patient visits, follow-up visits, sensorimotor examinations, and one-muscle strabismus surgery were examined for each state. Results: The mean percentage of children enrolled in Medicaid across the United States was 38.0%. Appointment and Medicaid inquiry calls were conducted across 41 states. Mean wait times across the United States for new patient, follow-up, and surgery appointments were 3.9, 3.4, and 2.7 months, respectively. Mean percentage of patients insured by Medicaid at AEC/CHs was 57.1%. High Medicaid-insured states offered longer wait times for new patient appointments than low Medicaid-insured states (4.4 versus 3.5 months; P =.20). The lowest Medicaid reimbursements for new patient visit, follow-up visit, sensorimotor examination, and one-muscle strabismus surgery occurred in Illinois, California, Ohio, and Michigan, respectively. Conclusions: Across the United States, states with higher percentages of patients insured by Medicaid exhibited longer new patient appointment wait times, suggesting that challenges related to Medicaid reimbursements directly contribute to disparities in access to pediatric eye care. [J Pediatr Ophthalmol Strabismus. 2023;60(3):170–177.] [ABSTRACT FROM AUTHOR]

Purpose: To report the clinical presentations, neuroimaging findings, and surgical outcomes in patients with acute acquired non-accommodative comitant esotropia (AACE). Methods: A retrospective review of records of all patients diagnosed as having AACE between January 2011 and December 2019 across three tertiary eye care centers was done. Cases with AACE onset after age 1 year were included. Patients were divided into two groups based on age of onset of esotropia: childhood (16 years or younger) and adult (older than 16 years). Surgical success was defined as postoperative horizontal deviation of 8 prism diopters (PD) or less at the last follow-up visit. Results: A total of 338 patients (220 males and 119 females; mean age at presentation: 12.60 ± 9.8 years) met the study criteria. The mean age at onset of esotropia in the childhood and adult onset groups was 3.61 ± 1.1 and 26.6 ± 8.7 years, respectively. There were significantly more individuals with myopia (30%) in the adult onset group compared to the childhood onset group (6%) (P =.004). Thirty-seven (16%) had positive neuroimaging findings (16.4% adult onset vs 9.4% childhood onset). A total of 148 (44%) patients underwent surgery for esotropia, and the overall success rate was 73%. Mean preoperative esotropia was comparable in either group (P =.20), but surgical success was better in the adult onset group (75.6% vs 66.3% in the childhood onset group). Mean duration of follow-up postoperatively was 13.6 ± 12 months. Conclusions: Two-thirds of the patients had childhood onset of AACE. Intracranial pathology was found in 1 of 6 patients. Surgical success was better in the adult onset group, which was not influenced by preoperative esotropia, neuroimaging findings, or refractive status, but was dependent on age at onset of esotropia and duration between onset and intervention. [J Pediatr Ophthalmol Strabismus. 2023;60(3):218–225.] [ABSTRACT FROM AUTHOR]

Purpose: To discuss the economic downturn of pediatric ophthalmology in the setting of an alarming decline in the number of residents pursuing pediatric ophthalmology and its impact on limiting access to eye care. Methods: Survey studies and articles examining the recent economic impact of reimbursement cuts and practice pattern changes in pediatric ophthalmology were reviewed. Population data from the 2020 U.S. Census Bureau and the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) were analyzed to illustrate provider-to-population relationships by state. Results: Survey studies demonstrated a deteriorating economic situation marked by progression in reimbursement cuts, reductions in pediatric ophthalmologists accepting Medicaid patients, and dwindling numbers of residents pursuing pediatric ophthalmology fellowships. Provider-to-population relationships revealed that pediatric ophthalmologists are not evenly distributed to meet population demand, and that many states are suffering from a shortage of pediatric ophthalmologists. Furthermore, many states with high percentages of Medicaid coverage simultaneously have lower AAPOS members/million person ratios. Conclusions: The simple economic principles of supply and demand reveal a crisis in access to pediatric eye and adult strabismus care. The economic downtown and change in practice patterns may produce rippling effects outside pediatric ophthalmology in fields such as pediatrics and comprehensive ophthalmology. An interdisciplinary effort among health care providers and governmental officials is needed to revive the field of pediatric ophthalmology and improve access to eye care. [J Pediatr Ophthalmol Strabismus. 2023;60(1):18–24.] [ABSTRACT FROM AUTHOR]

Purpose: To create a survey that assesses the economic factors impacting the viability of pediatric ophthalmology between January 2021 and July 2022. Methods: A 12-question survey was distributed to United States–based pediatric ophthalmologists on the American Association for Pediatric Ophthalmology and Strabismus discussion board and various social media fora. Demographic, economic, and workforce pattern data were collected and analyzed. Results: A total of 243 pediatric ophthalmologists completed the survey. One hundred seven (44.0%) respondents reported a surgical revenue decrease between 10% and 25%, 117 (48.1%) a clinical revenue decrease of less than 10%, 111 (45.6%) an overall income decrease of less than 10%, and 127 (52.2%) an overhead cost increase between 10% and 25%. Seventy-two (29.6%) respondents reported subsidizing income with pursuits outside of pediatric ophthalmology, 27 (11.1%) stopped operating due to reimbursement cuts, 75 (30.8%) limited the number of Medicaid or other public funded patients, 16 (6.5%) retired in the past 3 years, and 92 (37.8%) would not recommend a resident pursue a pediatric ophthalmology fellowship. Conclusions: There is a potential upheaval in the field of pediatric ophthalmology marked by increasing levels of disillusionment among current providers, a progressive decline in the number of trainees pursuing fellowship programs, and workforce issues suggestive of diversification of practice patterns outside of pediatric ophthalmology. The current economic crisis, in conjunction with these complex workforce issues, is and will continue to create a shortage of practicing pediatric ophthalmologists, seriously limiting access to pediatric and adult strabismus eye care. [J Pediatr Ophthalmol Strabismus. 2022;59(6):362–368.] [ABSTRACT FROM AUTHOR]

Purpose: To quantify the accessibility of eye care providers from photoscreening centers within the vision screening region in relation to population density and median household income. Methods: Driving times between vision screening locations and eye care centers were mapped and analyzed using OpenStreetMap software (Open Street Map Foundation). U.S. Census Bureau data of population density and median household income were linked with screening centers using ArcGIS Online (Esri) to determine correlations with driving times. Results: A total of 290 driving times for 145 photo-screening centers, 147 optometrists, and 7 pediatric ophthalmologists were calculated and mapped. Median driving times from a photoscreening center to the nearest optometrist and ophthalmologist were 4.74 and 25.10 minutes, respectively, with 90% of the screening centers residing within 12.46 and 67.19 minutes of the nearest optometrist and ophthalmologist, respectively. Driving times to optometrists are far less than times to pediatric ophthalmologists due to the greater number of optometrists. Decreasing driving times with increasing population and median household income indicate the concentration of optometrists and pediatric ophthalmologists within urbanized areas. Conclusions: Most photoscreening centers reside within 5 and 70 minutes of the nearest optometrist and pediatric ophthalmologist, respectively. Driving times indicate the region's greater accessibility to optometrists than to pediatric ophthalmologists. Eye care centers tend to be localized within urbanized areas with higher population densities and higher median household incomes. [J Pediatr Ophthalmol Strabismus. 2022;59(6):369–374.] [ABSTRACT FROM AUTHOR]

The article discusses the issue of low-income families not seeking preventative healthcare, leading to undiagnosed and untreated eye disorders in children. It highlights the importance of eye mobile units, such as the University of California Irvine Eye Mobile for Children program and the Eagles Eye Care Mobile Unit in Philadelphia, in identifying and treating these conditions. The article suggests that these mobile units are a valuable strategy to overcome the lack of access to pediatric eye care caused by a shortage of pediatric ophthalmologists in the United States. [Extracted from the article]

Purpose: To identify and describe the clinical profile at presentation in patients diagnosed as having Leber's hereditary optic neuropathy with primary and secondary mutations and correlate with treatment. Methods: A review of electronic medical records from January 2016 to December 2020 for proven cases of Leber's hereditary optic neuropathy was conducted. A total of 157 patients with clinically suspected Leber's hereditary optic neuropathy (143 males and 14 females) underwent genetic testing and 55 were found to have a mutation for Leber's hereditary optic neuropathy. Data of 55 consecutive patients were retrieved and analyzed for their clinical profile, investigations, mutations identified, treatment, and outcome. Results: All 55 patients were male, and the mean age was 23.80 ± 9.90 years (range: 9 to 53 years). The median duration of symptoms before the first physician examination was 6 months. The mean duration between the first hospital visit and genetically proven diagnosis of Leber's hereditary optic neuropathy was 9.03 ± 19.61 months (median: 2 months). More than half of the patients (n = 32; 58.2%) presented with severe to profound vision impairment in the better eye and 72.7% (n = 40) in the worse eye. Bilateral temporal disc pallor was more frequent in 38.2% (n = 21) and 36.4% (n = 20) had bilateral optic atrophy. Primary single mutations were detected in 61.81% (n = 34) and secondary mutations were detected in 38.2% (n = 21). The most common mutation was G11778A. One novel secondary mutation (A13615C) was identified in the cohort. Idebenone was used for treatment in 15 patients, and half of them (n = 8) showed an improvement in vision at 2 to 7 months of follow-up. Conclusions: The current cohort is the largest study to date in an Indian population that has analyzed the clinical presentations and mutations of Leber's hereditary optic neuropathy. G11778A was the most common primary mutation and several secondary mutations were identified. A delay in referral, inadequate compliance, and cost of care contributed to the outcomes. [J Pediatr Ophthalmol Strabismus. 2022;59(5):344–349.] [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the demographic details, clinical presentation, and surgical outcomes in patients presenting with strabismus following orbital wall fractures. Methods: A retrospective review was conducted over a 6-year period on 347 consecutive patients with strabismus who presented after orbital wall fractures. The patients were evaluated for their demographic data, clinical presentation, and profiles, management, complications, and outcomes of strabismus. Results: Strabismus following orbital wall fractures was noted in 347 patients: 87.03% were men (n = 302) and 12.97% were women (n = 45). Fracture of the orbital floor in isolation or in combination with other walls was more frequently noted in 72.3% of patients (n = 251). The resultant strabismus included paralytic, restrictive, or both etiologies. Exotropia was noted most frequently in 25.65% of patients (n = 89), followed by exotropia with hypotropia in 20.75% of patients (n = 72). Ten percent of patients with strabismus (n = 34), who were observed for at least 6 months after injury, underwent surgical correction for strabismus. Preoperative diplopia was observed in 79.41% of patients (n = 27) and persisted after strabismus surgery in 15% of patients (n = 6). A successful outcome regarding the postoperative angle of deviation of 10 prism diopters or less horizontal and/or 5 prism diopters or less of vertical deviation with elimination of diplopia was observed in 41.17% of patients. Conclusions: Strabismus following orbital wall fractures is complex and requires a tailored strategy. The current study found the orbital floor to be more frequently involved in orbital wall fractures. However, the resultant strabismus was a combination of paralytic and restrictive etiologies. [J Pediatr Ophthalmol Strabismus. 2022;59(3):172–179.] [ABSTRACT FROM AUTHOR]

This article discusses the challenges faced by financially disadvantaged and underrepresented minority groups in accessing pediatric eye care. The author shares their personal experience growing up in a low-income neighborhood and highlights the lack of continuity of care and preventive care in such communities. The article also addresses the disparities in the prevalence and treatment options for underrepresented racial minority groups. The lack of diversity among ophthalmologists is identified as a contributing factor to the disparities in eye health. The article suggests community outreach programs and improved screening programs as potential solutions to improve access to pediatric eye care for these populations. [Extracted from the article]

Purpose: To compare visual acuity outcomes and loss to follow-up after initiation of treatment for unilateral amblyopia in children from different socioeconomic backgrounds. Methods: Medical records of children diagnosed as having unilateral amblyopia at an initial encounter between 2015 and 2018 were reviewed. Medicaid and private insurance were used as proxies for socioeconomic status (SES). Data points were collected at the patients' initial, follow-up, and final visits. Visual acuity improvement was the primary outcome variable in patients with at least one follow-up appointment. In a separate analysis, failure to attend a single follow-up appointment was examined for associations with SES, race, sex, and distance traveled to appointments. Results: Seventy-three patients met the inclusion criteria; of these, 28 had Medicaid and 45 had private insurance. Visual acuity improved by 2.86 lines in the Medicaid group and 2.98 lines in the private insurance group (P =.84). Number of missed appointments and distance traveled did not correlate with visual acuity improvement. In the loss to follow-up subanalysis, 40 of 141 (28.4%) patients with Medicaid and 11 of 107 (10.3%) patients with private insurance failed to attend a single follow-up visit (P =.001). No association was found between loss to follow-up and race, sex, or distance traveled. Conclusions: Visual acuity outcomes of treatment for amblyopia did not differ between patients with Medicaid and patients with private insurance who followed up. However, patients with Medicaid were much more likely to be immediately lost to follow-up. Measures should be taken by eye care providers and pediatricians to increase follow-up in patients from low SES populations. [J Pediatr Ophthalmol Strabismus. 2022;59(2):110–117.] [ABSTRACT FROM AUTHOR]

Purpose: To report surgical outcomes of patients with exotropic Duane retraction syndrome. Methods: A retrospective review of the medical records from patients with exotropic Duane retraction syndrome who underwent strabismus surgery and had at least 2 months of postoperative follow-up was conducted. Surgical success was defined as a postoperative horizontal deviation within 8 prism diopters (PD), abnormal head posture (AHP) less than 5 degrees, and a two-step decrease in overshoots. Results: Seventy-three patients with exotropic Duane retraction syndrome (38, 52% male, mean age 14 ± 7.9 years) met the study criteria. Unilateral type 3 Duane retraction syndrome was seen in 56 (77%) patients and type 1 in 14 (19%) patients. The mean follow-up period was 22 weeks (range: 8 to 209 weeks). Unilateral and bilateral lateral rectus recession were performed in 48 (65%) and 25 (34%) patients, respectively. In addition to recession, a lateral rectus Y-splitting was performed in 42 (56%) patients. Five patients underwent differential medial rectus and (larger) lateral rectus recession to alleviate severe globe retraction. The mean primary position reduced from 23 PD (CI: 19.6 to 26 PD) preoperatively to 9 PD (CI: 7.02 to 11.02 PD) postoperatively (Seventy-three patients with exotropic Duane retraction syndrome (38, 52% male, mean age 14 ± 7.9 years) met the study criteria. Unilateral type 3 Duane retraction syndrome was seen in 56 (77%) patients and type 1 in 14 (19%) patients. The mean follow-up period was 22 weeks (range: 8 to 209 weeks). Unilateral and bilateral lateral rectus recession were performed in 48 (65%) and 25 (34%) patients, respectively. In addition to recession, a lateral rectus Y-splitting was performed in 42 (56%) patients. Five patients underwent differential medial rectus and (larger) lateral rectus recession to alleviate severe globe retraction. The mean primary position reduced from 23 PD (CI: 19.6 to 26 PD) preoperatively to 9 PD (CI: 7.02 to 11.02 PD) postoperatively (P <.0001). Postoperatively 50% of patients were orthotropic in the primary position. Surgical success for primary position deviation, AHP, and overshoots were achieved in 74%, 81%, and 71% of patients, respectively. Conclusions: In the current study, type 3 Duane retraction syndrome was the most common subtype necessitating surgery for exotropic Duane retraction syndrome. Good surgical outcomes were obtained for various indications. Unilateral or bilateral lateral rectus recession was successful in improving motor alignment and AHP. The addition of lateral rectus Y-splitting corrected overshoots greater than grade 2 in most patients with exotropic Duane retraction syndrome. [[J Pediatr Ophthalmol Strabismus. 2021;58(1):9–16.] [ABSTRACT FROM AUTHOR]

Purpose: To examine the clinical profile of sympathetic ophthalmia among the pediatric age group. Methods: Retrospective review of patients 18 years and younger with sympathetic ophthalmia seen in a tertiary eye care center between 1997 and 2017. Results: Of 20 patients included in the study, 70% were male. The most common inciting event for sympathetic ophthalmia was trauma (85%), followed by vitreoretinal surgery (15%). All patients were treated with systemic steroids. Seventeen patients received additional corticosteroid-sparing immunosuppressive agents, and 4 patients (20%) required more than one immunosuppressive agent. Azathioprine was the most commonly used corticosteroid-sparing immunosuppressive agent. The most common complications were cataract (50%) and ocular hypertension (30%). The mean presenting best corrected visual acuity in the sympathizing eye was 1.15 ± 0.99 logarithm of the minimum angle of resolution (logMAR), which improved to 0.54 ± 1.00 logMAR following treatment. Visual outcome was good (6/12 or better) in 70% of the sympathizing eyes, and 3 of the exciting eyes in the current study had good visual outcomes after the treatment. Conclusions: Prompt and effective management with corticosteroid-sparing immunosuppressive therapy in children with sympathetic ophthalmia allows favorable control of the disease and retention of good visual acuity. [[J Pediatr Ophthalmol Strabismus. 2020;57(3):154–158.] [ABSTRACT FROM AUTHOR]

Purpose: To investigate the potential of a mobile ophthalmic unit in the schoolyard to improve the follow-up rate for children who have failed an optometric in-school screening program. Previously, the optometric program made referrals to the center and only 53% of students attended the desired ophthalmology consultation. Methods: This was a cohort study of students conducted in elementary school lots in socioeconomically disadvantaged communities. The mobile ophthalmic unit visited schools where students with parental consent who needed examination had been identified by an in-school optometric vision care program. Results: A total of 132 students were referred by the optometric program, of whom 95 (72%) had complete signed consent forms. Eighty-two patients (62%, confidence interval: 54% to 70%) were successfully seen by the mobile unit. Compared to the historical rate of successful completion of ophthalmology consultation (53%), a statistically significant improvement in follow-up was noted (P = .036). On a Likert scale of 1 to 5, the mean school nurse satisfaction rating was 4.8. Conclusions: The findings demonstrate the potential impact of mobile eye clinics at schools in connecting children with ophthalmic care. [ABSTRACT FROM AUTHOR]

Purpose: The Philadelphia Eagle Eye Mobile (EEM) provides optometric vision care to children who fail a vision screening performed by nurses at schools in low-income areas. Methods: Data for children seen on the EEM between 2006 and 2008 for whom school nurse feedback was available regarding glasses wear at 1-,4-, and 12-month intervals served as the study population. Optometric findings and glasses prescriptions at initial examination were recorded in the EEM database. The ophthalmic records for children referred for pediatric ophthalmology consultation at our institution were reviewed and those who did not attend were counted. Results: A random subset of 689 students at 28 different schools at which follow-up forms were distributed to the school nurses regarding glasses wear was studied. This represents 10.8% of 6,365 children screened at 131 public schools visited by the EEM during that period. False-positive rates of school nurse screening averaged 16.11% (0% to 44%) for 689 children from 28 schools. Glasses compliance was 71 % at 12 months and correlated to higher prescriptions. Only 53% of children attended their pediatric ophthalmology referral. Conclusions: Nurse training to reduce false-positive screening and strategies to improve attendance at arranged pediatric ophthalmologist consultations are recommended. The EEM effectively gets glasses to students where needed and use rates are satisfactory. [ABSTRACT FROM AUTHOR]

Purpose: Evidence-based medicine requires primary results from randomized controlled trials and high-quality observational studies; however, in pediatric medicine it can be difficult to enroll sufficient numbers of children to reach sample sizes required for statistical significance. The experience of clinicians and researchers with the practicalities of recruitment has not been explored, but could potentially inform best practice and lead to the development of successful research networks. Perceived barriers and facilitators to recruitment in child eye health in the United Kingdom, where adoption of trials and studies onto a central database has created a register of high quality projects, were investigated. Methods: Studies and trials in child eye health from the United Kingdom Clinical Research Network portfolio database were identified and the named researchers contacted. Based on a validated tool, an electronic survey was created to ask about recruitment experience to identify facilitators and barriers. Results: There were 46 trials and studies recruiting children, and 51 completed questionnaires from researchers were received. Children's eye research activity is mainly based at tertiary referral centers. Although most studies recruit to target, many researchers report difficulties. Availability of dedicated research teams in clinics and good communication between research team, clinical team, and families are strong facilitators. Administrative difficulties and the burden of research to clinical teams and families are strong barriers. Conclusions: Support for investigators in the form of dedicated research and administrative staff and good communication enhance recruitment to studies in child eye health. [ABSTRACT FROM AUTHOR]

PURPOSE: A novel wavefront sensor has been developed. It follows the same principle of the Shack-Hartmann wavefront sensor in that it is based on slope information. However, it has a different symmetry, which may offer benefits in terms of application. METHODS: The new wavefront sensor consists of a set of donut-shaped acrylic lenses with a charge coupled device located at the focal plane. From detection of shift in the radial direction, radial slopes are computed for 2880 points. Theoretical computations for higher order aberrations and lower order aberrations were implemented for the Shack-Hartmann wavefront sensor and the new wavefront sensor, and practical measurements were conducted on several sphere-cylinder trial lenses. RESULTS: The overall mean value of root mean square error (RMSE) (in microns) for theoretical computations was 0.03 for the Shack-Hartmann wavefront sensor and 0.02 for the new wavefront sensor. The mean value of RMSE for lower order aberrations (1-5) was 0.01 and 0.00003, and for higher order aberrations was 0.02 and 0.02, for the Shack-Hartmann and new wavefront sensors, respectively. For practical measurements (sphere, cylinder, axis), the standard deviation was 0.04 diopters (D), 0.04 D, and 4° for the new wavefront sensor and 0.02 D, 0.02 D, and 5° for the Shack-Hartmann wavefront sensor. CONCLUSIONS: Precision of the new wavefront sensor when measuring astigmatic and spherical surfaces is compatible with the Shack-Hartmann wavefront sensor. Centration with this new sensor is an absolute process using the center of the entrance pupil, which is where the line of site passes. This wavefront sensor, similar to the Shack-Hartmann sensor, does not eliminate the possibility of tilt. For more conclusive and statistically valid data, in vivo measurements are needed. [ABSTRACT FROM AUTHOR]

PURPOSE: To determine the safety, efficacy, and stability of intrastromal corneal rings 10 years after placement for myopia. METHODS: Ten eyes with myopia treated with the placement of 360° complete intrastromal corneal rings with the ends sutured together were evaluated at 10-year follow-up for the following: uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction spherical equivalent (MRSE), induced manifest refractive cylinder, keratometry readings, slit-lamp findings, and ultrasound central pachymetry. Ten-year data were compared to 1-year results to assess visual stability over time. RESULTS: No statistically significant difference was noted between UCVA at 1 year and 10 years. At the 10-year examination, 90% of patients had BSCVA ≥20/25 and 100% had BSCVA ≥20/30. There was no statistically significant difference between MRSE at 1 year and 10 years. At the 10-year examination, induced manifest refractive cylinder was >1.00 diopter (D) in 0% of eyes and ≥0.25 D in 60% of eyes. There was no statistically significant difference between mean central keratometric power at 1-year follow-up compared with 10-year follow-up. No statistically significant difference was noted in central corneal thickness between 1 and 10 years in the eyes studied. CONCLUSIONS: Intrastromal corneal rings are an effective and stable method of correcting mild myopia based on optic parameters. [ABSTRACT FROM AUTHOR]

PURPOSE: To measure the imprecision of microkeratome cuts, preoperative corneal pachymetry, and laser ablation depth and develop a statistical model to describe the probability of the residual stromal bed thickness (RST) after myopic LASIK being significantly thinner than predicted. METHODS: Preoperative corneal thickness, flap thickness, ablation depth, and RST were measured in 36 eyes by a prototype three-dimensional very high-frequency (VHF) 50 MHz digital ultrasound scanning device (<1.2 µm precision), precursor to the commercially available Artemis 2. All eyes had undergone LASIK with the Moria LSK-One microkeratome and the NIDEK EC-5000 excimer laser. Based on the statistically combined uncertainty (standard deviation) and bias (accuracy to intended value) of corneal thickness measurement, flap thickness, and ablation depth, a continuous probability function was devised describing the chance of obtaining an actual RST less than a specified "cut-off." The model was applied using the data collected from the cohort of eyes. The model was also applied using published flap thickness statistics on a series of microkeratomes. RESULTS: Precision (standard deviation) was 0.74 µm for VHF digital ultrasound measurement of pachymetry, 30.3 µm for Moria LSK-One flap thickness, and 11.2 µm for NIDEK EC-5000 ablation depth. Assuming negligible laser ablation depth bias, the model found the probability that the actual RST will be <200 µm given a target RST of 250 µm is 7.56% with the Moria LSK-One. The model applied to published flap statistics revealed a range of probabilities of leaving <200 µm given a target RST of 250 µm from <0.01% to 33.6%. CONCLUSIONS: The choice of microkeratome, laser, and pachymeter has a significant impact on the variation of the depth of keratectomy and thus on the risk of ectasia. This model together with high-precision microkeratomes, preoperative pachymetry, and knowledge of laser ablation precision would enable surgeons to determine the specific imprecision of RST prediction for individual LASIK cases and minimize the risk of ectasia. [ABSTRACT FROM AUTHOR]

PURPOSE: To report our experience treating eye trauma after LASIK refractive surgery. METHODS: Nine eyes of eight patients (one woman and seven men) were treated for ocular trauma: blunt trauma (n=5), sharp instrument trauma (n=2,) and trauma from inflation of automobile air bags during a traffic accident (n=2). The time from LASIK varied between 3 months and 6 years. All patients were hospitalized as a result of severe decrease in visual acuity and pain. RESULTS: Seven of nine LASIK flaps had some degree of dislocation and were lifted, irrigated, and repositioned. Two flaps were edematous without dislocation. Intensive topical steroids and antibiotics were used in all patients up to 3 weeks after trauma. Three months after trauma, five eyes regained their pre-trauma visual acuity (between 20/20 and 20/40), and three eyes lost one line of best spectacle-corrected visual acuity. CONCLUSIONS: Trauma occurring several months or years after LASIK may cause flap injury. Adequate and prompt treatment usually is successful. [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate the refractive and visual outcomes of hyperopic LASIK using Esiris/Schwind technology. METHODS: This retrospective non-comparative observational study included 106 eyes (65 patients) operated with the Esiris/Schwind laser for hyperopia. Eyes were divided into two groups: group 1, ≤ + 3.99 diopters (D) and group 2, ≥ + 4.0 D (up to + 7.0 D). Visual outcome for distance and near uncorrected (UCVA) and best spectacle-corrected visual acuities (BSCVA) (decimal values), cycloplegic refraction, keratometry (K), pachymetry, and complications were evaluated. RESULTS: In group 1, mean UCVA was 0.4±0.1 preoperatively and 0.8±0.2 6 months postoperatively. Mean BSCVA was 0.9±0.1 preoperatively and 0.9±0.1 6 months postoperatively. Safety index was 1.1 and efficacy index was 0.97. Mean spherical equivalent refraction was +2.33±0.9 D preoperatively and +0.3±0.3 D 6 months postoperatively. Mean K reading was 43.7±1.1 D preoperatively and 45.0±1.6 D 6 months postoperatively. In group 2, mean UCVA was 0.3±0.1 preoperatively and 0.8±0.2 6 months postoperatively. Mean BSCVA was 0.9±0.1 preoperatively and 0.9±0.1 6 months postoperatively. Safety index was 0.98 and efficacy index was 0.92. Mean spherical equivalent refraction was +5.1±0.9 D preoperatively and +0.4±0.5 D 6 months postoperatively. Mean K reading was +43.1±1.6 D preoperatively and 46.0±1.4 D 6 months postoperatively. Forty-six (90.2%) of 51 eyes in group 1 and 47 (85.5%) of 55 eyes in group 2 were within ±0.5 D of emmetropia. At 6-month follow-up, 40 (78%) of 51 eyes in group 1 had UCVA of 20/20 compared to 41 (75%) of 51 eyes in group 2. One (2%) of 51 eyes in group 1 and 4 (7.3%) of 55 eyes in group 2 lost ≤2 lines of BSCVA. No eye lost >2 lines of BSCVA. CONCLUSIONS: Hyperopic LASIK with Esiris/Schwind technology is effective and safe in the correction of hyperopia up to +7.0 D. Although a slight statistical significance was found for low hyperopia, visual and refractive results obtained in high hyperopia were encouraging. [ABSTRACT FROM AUTHOR]

PURPOSE: To compare the pneumatonometer and the Tono-Pen XL in a closed ex-vivo system in human eye bank eyes at high intraocular pressures (IOP) and evaluate the validity of high IOP measurements with the Barraquer tonometer. METHODS: Intraocular pressure was monitored by cannulation of the anterior chamber and vitreous cavity in eight human cadaver eyes (mean donor age: 77.3±4.9 years, range: 72 to 84 years). Intraocular pressure measurements were taken at 50, 65, and 90 mmHg with the Tono-Pen XL and pneumatonometer. Intraocular pressure was raised to 110 mmHg and then the eyes were deflated slowly until they reached 50 mmHg. Pressure readings with the Barraquer tonometer were recorded when the corneal tonometer interface reached the inner and outer rings. RESULTS: The Tono-Pen XL underestimated IOP, a tendency that was more evident at higher IOP. In contrast, the pneumatonometer was more accurate and reliable at IOP of 50 and 65 mmHg but its readings underestimated IOP at 90 mmHg. The Barraquer tonometer used in this experiment accurately estimated high IOP. A variability of 5.9 mmHg and 5.8 mmHg were recorded for the inner and outer ring, respectively. CONCLUSIONS: The Tono-pen XL is an inadequate instrument to assess pressures normally encountered during LASIK flap creation in an ex vivo model using human cadaver eyes. The pneumatonometer and the Barraquer tonometer are accurate instruments at high IOP; however, the pneumatonometer underestimated pressures around 90 mmHg. [ABSTRACT FROM AUTHOR]

PURPOSE: To compare a new ablation algorithm termed the optimized aspheric transition zone (OATz) with the conventional laser ablation profile for correction of myopic astigmatism. METHODS: LASIK using OATz profile #6 or using conventional ablation profile was performed on 98 eyes of 53 patients (OATz #6 group) and 111 eyes of 66 patients (control #6 group), respectively. Further, LASIK using OATz profile #5 or using the conventional ablation profile was performed on 109 eyes of 58 patients (OATz #5 group) and 109 eyes of 75 patients (control #5 group), respectively. The effective optical zone, uncorrected visual acuity, manifest refraction, aberrations, contrast sensitivity, and patient satisfaction at 3 months postoperatively were compared between the OATz #6 and control #6 groups and between the OATz #5 and control #5 groups. RESULTS: The effective optical zones in the OATz #6 group (6.45±0.29 mm) or OATz #5 group (6.40±0.21 mm) were significantly larger than those in the control #6 group (6.33±0.27 mm) or control #5 group (6.26±0.25 mm) (P<.01), respectively. Uncorrected visual acuity and manifest refraction were similar in all groups. The changes in contrast sensitivity were significant and favored the OATz #6 (P<.01) and OATz #5 groups (P<.05). The patient satisfaction survey found no statistical difference at 3 months postoperatively. CONCLUSIONS: Patients treated with the OATz profiles had better visual quality as measured by contrast sensitivity and also had larger effective optical zones as compared with those treated by the conventional ablation profile. [ABSTRACT FROM AUTHOR]

PURPOSE: To evaluate the visual and refractive outcome of LASIK in myopic patients with a known history of dermatological keloid scar. METHODS: This retrospective case series included 10 eyes of 5 white patients with a known history of dermatological keloids. All patients had low to moderate myopia with no corneal or limbal keloid. All underwent uneventful bilateral LASIK. Postoperatively, visual outcomes, refractive outcomes, and complications were evaluated. Minimum 1-year follow-up was indicated for all patients in this study. RESULTS: Mean preoperative uncorrected visual acuity (UCVA) was 20/320 and 1 year postoperative was 20/20. Mean preoperative best spectacle-corrected visual acuity (BSCVA) was 20/25 and 1 year postoperative was 20/20. The mean preoperative spherical equivalent refraction was -5.00±2.6 diopters (D) and +0.1±0.2 D 1 year postoperative. The safety index was 1.02 and the efficacy index was 1.02. None of the eyes included in this study underwent retreatment for correction of residual error or regression up to 1 year postoperatively. No sight-threatening complications were reported. No patient reported postoperative haze, severe dry eye syndrome, or flap-related problems. CONCLUSIONS: LASIK is a safe, effective, and predictable technique for correcting low and moderate myopia in patients with dermatological keloids. [ABSTRACT FROM AUTHOR]

PURPOSE: To describe our clinical experience in wavefront-guided LASIK enhancements using the WaveLight ALLEGRETTO system (WaveLight Technologie AG, Erlangen, Germany) for symptomatic eyes previously treated with standard LASIK. METHODS: Twenty-six eyes of 20 patients with residual myopia, hyperopia, or mixed astigmatism and/or night vision symptoms after primary standard LASIK were considered for wavefront-guided customized retreatment using the WaveLight ALLEGRETTO WAVE 200 Hz excimer laser system (model 106). Preoperative best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity, topography with the ALLEGRETTO Topolyzer, wavefront analysis using the ALLEGRETTO WAVE Tscherning Analyzer, and contrast sensitivity were compared to postoperative (enhancement) measurements. RESULTS: Twenty-two of the original 26 eyes underwent wavefront-guided enhancement, 4 were excluded because they did not meet wavefront-guided treatment inclusion guidelines of this study. Mean follow-up was 8 months (range: 6 to 13 months, standard deviation [SD] 2). All patients were within -0.50 diopters (manifest refraction) of intended postoperative refraction. The mean preoperative BSCVA improved from 20/25 (SD -0.12) to 20/18 (SD ±0.1) postoperatively. All patients gained at least one line of BSCVA, and a maximum of three lines. There was no loss of BSCVA in any patient. The total amount of high order aberrations (RMSH) decreased from an average of 1.04 (SD ±0.22) to 0.46 (SD ±0.14) µm. Patients also had a mean improvement in low contrast sensitivity of 59%. CONCLUSIONS: Based on this small series, customized wavefront-guided enhancements using the WaveLight ALLEGRETTO system in patients who underwent previous LASIK appear to be safe and effective in correcting residual refractive error, reducing high order aberrations, and improving visual symptoms when reliable and reproducible measurements are achieved. [ABSTRACT FROM AUTHOR]

PURPOSE: To report the history and clinical presentation of a 23-year-old man who developed delayed onset lamellar keratitis in his right eye 2 weeks after uneventful LASIK for correction of myopia. METHODS: Initial clinical presentation suggested an infectious etiology, which led to therapeutic elevation of the LASIK flap and further microbiologic investigation with bacterial cultures. RESULTS: Bacterial cultures revealed Bacillus megaterium, which was sensitive to all antibiotics against which it was tested. Twenty-four hours after initiating aggressive topical and oral antibiotic therapy, symptomatic relief occurred in the affected eye. The patient's uncorrected final visual acuity at 1-year follow-up was 20/15 in the right eye, and the stromal bed developed a faint peripheral non-visually significant scar. CONCLUSIONS: This case is an unusual presentation and course for microbial keratitis following LASIK, which occurred despite aseptic technique and fluoroquinolone antibiotic prophylaxis. Following refractive surgery one should be prepared to culture the lamellar interface in cases of suspected microbial keratitis and begin aggressive antibiotic therapy. [ABSTRACT FROM AUTHOR]

PURPOSE: To study the effect of varying four parameters on the refractive change induced by the LASIK flap. METHODS: Using a variety of patient-specific data such as topography, pachymetry, and axial length, a finite element model is built. The model is used in a non-linear finite element analysis to determine the response and change in optical power of the cornea as a function of a material property of the cornea (corneal elasticity), flap diameter and thickness, and intraocular pressure. RESULTS: The central flattening or hyperopic shift occurred atop the flap in all four of the simulated eyes tested with the creation of the LASIK flap. Of the four parameters tested, modulus of elasticity (Young's modulus) had the most profound effect on the results of hyperopic shift, varying from <0.5 diopters (D) in the least elastic (stiffest) cornea to >2.0 D of hyperopic shift in the most elastic cornea. The depth of the lenticular cut was the second-most significant parameter tested varying from 0.24 D at 100 microns to 1.25 D at 275 microns of depth. Varying intraocular pressure demonstrated less difference, and varying corneal flap diameter demonstrated the least difference in induced refractive change on the model. The hyperopic shift was noted to be greater in hyperopic than in myopic eyes (simulated) tested. CONCLUSIONS: Three-dimensional finite element analysis modeling of actual patient data could lead to a better understanding of the biomechanical response of corneal tissue to the lenticular flap creation and potentially for ablation patterns produced by the excimer laser. Understanding these biomechanical responses may lead to greater predictability and improvement of visual outcomes. [ABSTRACT FROM AUTHOR]

PURPOSE: To evaluate higher order aberrations and contrast sensitivity after LASIK, implantation of the Verisyse phakic intraocular lens (IOL), and refractive lens exchange with the Array multifocal IOL. METHODS: In a prospective, non-randomized case series, LASIK was performed in 20 eyes with the Technolas 217z excimer laser (Bausch & Lomb, Rochester, NY), a Verisyse phakic IOL (AMO Inc, Santa Ana, Calif) was implanted in 11 eyes, and refractive lens exchange with implantation of a multifocal IOL (Array IOL, AMO Inc) was performed in 12 eyes. Wavefront error (Zywave aberrometer; Bausch & Lomb) at two pupil sizes (4 and 6 mm) and photopic contrast sensitivity (CVS-1000) was measured preoperatively and 2 months postoperatively in all eyes. RESULTS: Photopic contrast sensitivity remained unchanged in the LASIK and the Verisyse groups, and decrease was significant in the Array group at three cycles per degree only. Higher order aberrations with a 4-mm pupil were increased in the Array group only. With a 6-mm pupil, they were increased in all groups. Comparing groups, surgically induced higher order aberrations were highest after refractive lens exchange with the Array multifocal IOL and lowest after implantation of the Verisyse IOL. CONCLUSIONS: Laser in situ keratomileusis, the Verisyse IOL, and the Array IOL increase higher order aberrations at large pupil sizes, but no increase occurs at small pupil sizes with LASIK or the Verisyse IOL. Contrast sensitivity in photopic conditions is normal with LASIK and the Verisyse IOL, but slightly reduced with the Array IOL due to the multifocal optic. [ABSTRACT FROM AUTHOR]

PURPOSE: To study the quality of the flap obtained with two different heads, disposable and nondisposable, and two different speeds, low and high, using the same Moria M2 microkeratome (Moria, Antony, France). METHODS: In a prospective randomized study, 51 consecutive eyes (28 patients) underwent myopic LASIK (-4.39±2.15 diopters). The eyes were randomly assigned to four groups related to cutting head model (disposable and nondisposable) and cut speed (low and high). In all cases, the intended cut was 160 µm and the same M2 unit was used. During surgery, superficial measurements of the flap and the surgeon's opinion about the quality of the cut were recorded. One month after LASIK, the cut depth, interface particle density, and transparency of the cornea (confocal wound healing opacity index) were measured with a confocal microscope. RESULTS: Flaps performed with a disposable cutting head and high speed were statistically significantly larger than the flaps created in the other groups (Kruskal-Wallis test; P=.041). No statistical differences were noted in cut depth, number of particles, and wound healing opacity index. The surgeon's opinion parameters were similar in all groups. CONCLUSIONS: The Moria M2 microkeratome is safe and provided reproducible results, regardless of cutting head and speed. Disposable and nondisposable head models were similar in their outcome in the quality control model used in this study. [ABSTRACT FROM AUTHOR]

PURPOSE: To determine the new corneal effective index of refraction (rN) following LASIK to be used for accurate keratometry reading (K-reading). METHODS: A total of 332 eyes that underwent myopic LASIK were divided into two groups (group A [n=137] and group B [n=195]). In each group, patients were divided into four subgroups according to the amount of spherical equivalent refraction of myopic LASIK ablation (subgroup 1 [<-4.0 D], subgroup 2 [-4.0 to < -8.0 D], subgroup 3 [-8.0 to -12.0 D], and subgroup 4 [>-12.0 D]). In each subgroup of group A, K-reading was measured by the clinical history method and the new corneal effective index (rN) was determined using paraxial formula: (K-reading= (rN-1)/Ra), where Ra is the radius of curvature of the anterior corneal surface. In group B, the anterior radius of curvature of the cornea was determined by automated K-reading, and K-reading was measured in each subgroup using the new effective index in paraxial formula, clinical history method, and automated K-reading. RESULTS: In group A, the new effective index of refraction was 1.3355, 1.3286, 1.3237, and 1.3172 in the four subgroups, respectively. In group B, the mean K-reading measurements using rN in paraxial formula, clinical history method, and automated K-reading were: 40.33±1.68 D, 40.33±1.67 D, and 40.54±1.69 D, respectively, in subgroup 1; 37.96±1.26 D, 38.03±1.38 D, and 38.98±1.28 D, respectively, in subgroup 2; 35.77±1.75 D, 35.84±1.85 D, and 37.29±1.83 D, respectively, in subgroup 3; and 34.03±1.49 D, 34.15±1.84 D, and 36.21±1.59 D, respectively, in subgroup 4. In all subgroups of group B, the results of K-reading obtained using the new effective index of refraction were statistically similar to the results obtained by clinical history method (P>.05). Automated K-reading statistically overestimated the K-reading values in subgroups 2, 3, and 4 of group B (P<.001). CONCLUSIONS: The use of the new corneal effective index of refraction allows for an accurate derivation of K-reading from the anterior radius of curvature. [ABSTRACT FROM AUTHOR]

PURPOSE: To study the effect of lubricant eye drop instillation on ocular wavefront aberrations. METHODS: The wavefront aberrations of the entire optical path of 30 eyes of 15 patients before and following instillation of lubricant eye drops (Bion Tears; Alcon Laboratories Inc, Ft Worth, Tex) were obtained over a 6-mm pupil using a Hartmann-Shack wavefront sensor (WaveScan; VISX Inc, Santa Clara, Calif). Additional computation of root-mean-square (RMS) errors of higher order aberrations from third to sixth order were done using Zernike Tool Software (VISX Inc). Main outcome measures include the mean changes of total higher order aberrations RMS, higher order aberrations, and point spread function (PSF) of the higher order aberrations. RESULTS: The mean changes of total higher order aberrations following instillation of lubricant eye drops on the right eyes were -0.07 µm (95% confidence interval [CI], -0.11 to -0.03) and -0.03 µm on the left eyes (95% CI, -0.07 to 0.01). Significant mean changes were noted for coma and trefoil aberrations with a magnitude of -0.08 µm (95% CI, -0.12 to -0.03) and -0.09 (95% CI, -0.13 to -0.05), respectively, as well as a mean change of the PSF of the higher order aberrations (-0.05 diopters, 95% CI, -0.08 to -0.02) on the right eyes. Although no significant changes in these parameters were demonstrated on the left eyes, a similar trend of changes was observed. [ABSTRACT FROM AUTHOR]

PURPOSE: To present a case of successful treatment of high myopic astigmatism after a perforating injury with significant corneal laceration and pupil ectopia using excimer LASIK. METHODS: A 30-year-old man presented for treatment of high myopic astigmatism in his right eye resulting from perforating ocular trauma, which occurred 8 years prior to presentation. The corneoscleral wound repair was performed with posterior chamber intraocular lens implantation. Uncorrected visual acuity (UCVA) in the right eye was counting fingers at 1 m, best corrected to 20/30 with --7.00 +5.00 x 110. Visual acuity in the left eye was 20/20 with --1.5 D. The patient was unable to tolerate spectacles and contact lenses because of asthenopia and high astigmatism, respectively. As an alternative, LASIK with the Allegretto Wave excimer laser was performed. RESULTS: Three months postoperatively, UCVA was 20/25 in the right eye and 20/15 in the left eye. CONCLUSIONS: This case indicates that LASIK can be a useful surgical method for correcting high myopic astigmatism resulting from ocular trauma with significant corneoscleral laceration. [ABSTRACT FROM AUTHOR]

PURPOSE: To compare ablation centration after bilateral sequential and simultaneous myopic LASIK. METHODS: A retrospective randomized case series was performed of 670 eyes of 335 consecutive patients who had undergone either bilateral sequential (group 1) or simultaneous (group 2) myopic LASIK between July 2000 and July 2001 at the China Medical University Hospital, Taichung, Taiwan. The ablation centrations of the first and second eyes in the two groups were compared 3 months postoperatively. RESULTS: Of 670 eyes, 274 eyes (137 patients) comprised the sequential group and 396 eyes (198 patients) comprised the simultaneous group. Three months postoperatively, 220 eyes of 110 patients (80%) in the sequential group and 236 eyes of 118 patients (60%) in the simultaneous group provided topographic data for centration analysis. For the first eyes, mean decentration was 0.39±0.26 mm in the sequential group and 0.41±0.19 mm in the simultaneous group (P=.30). For the second eyes, mean decentration was 0.28±0.23 mm in the sequential group and 0.30±0.21 mm in the simultaneous group (P=.36). Decentration in the second eyes significantly improved in both groups (group 1, P=.02; group 2, P<.01). The mean distance between the first and second eyes was 0.31±0.25 mm in the sequential group and 0.32±0.18 mm in the simultaneous group (P=.33). The difference of ablation center angles between the first and second eyes was 43.2±48.37° in the sequential group and 45.1±50.8° in the simultaneous group (P=.42). CONCLUSIONS: Simultaneous bilateral LASIK is comparable to sequential surgery in ablation centration. [ABSTRACT FROM AUTHOR]

PURPOSE: To retrospectively compare the irregularity of the corneal surfaces of 14 patients after LASIK in 1 eye and placement of intrastromal corneal ring segments (ICRS) in the other eye. METHODS: In a within-patient comparison, Orbscan corneal topography was used to retrospectively compare the corneal surface irregularity of LASIK-treated and ICRS-treated eyes at an outpatient tertiary-care ophthalmology clinic in Sao Paulo, Brazil. For the anterior corneal surface, irregularity measurements were compared for both the central and peripheral areas of the cornea. The differences between each group were analyzed for statistical significance. RESULTS: The corneal surfaces of eyes treated with ICRS were found to be more irregular than the corneal surfaces of eyes treated with LASIK, the mean irregularity being 1.91 for LASIK-treated eyes and 3.12 for ICRS-treated eyes in the anterior corneal surface and 0.51 for LASIK-treated eyes and 0.87 for ICRS-treated eyes in the posterior corneal surface. A statistically significant difference was noted only in the posterior surfaces. CONCLUSIONS: When measured with Orbscan topography, ICRS-treated eyes show more corneal surface irregularity than LASIK-treated eyes. The difference in outcome for the two types of treatment may be due to the mechanical effect of the ICRS on the shape of the cornea. [ABSTRACT FROM AUTHOR]

PURPOSE: To investigate whether the property of the surface of a fluid film to smooth irregularities in the underlying surface will cause the tear film to partially erase the effect of higher order corrections ablated onto a corneal surface during wavefront-guided refractive surgical correction. METHODS: Coating flow theory shows that the film surface initially replicates the underlying surface. An iteration method is given to allow calculations to be made of the tear fluid flow and resulting surface change during the time between blinks. A new experimental technique is introduced using a corneal topographer and live video imaging to observe changes in tear surface curvature as the tear film flows. RESULTS: Tear flow changes in an eye with a high amount of aberration due to an unsuccessful LASIK procedure are simulated to show that while tear fluid occurs and causes changes in the tear/air surface, the change when expressed in terms of unwanted aberrations is below that which would cause any image degradation. Results of the live video technique on a cornea with an irregular surface 4 days after photorefractive keratectomy show that irregularities in the tear film surface immediately after a blink are not smoothed to any extent in the time before the next blink. CONCLUSIONS: Tear film flow following initial film formation by a blink can be demonstrated by computer simulation and observed with live corneal topography video. Tear film dynamics will not erase the effects of ablative corrections for higher order aberrations. [ABSTRACT FROM AUTHOR]

PURPOSE: To analyze the effect of a yellow filter on contrast sensitivity and disability glare under mesopic and photopic luminance conditions in laser in situ keratomileusis (LASIK) patients and control subjects. METHODS: Contrast sensitivity with and without glare was determined in 27 patients who had undergone LASIK at least 1 year previously and in 30 control subjects. Tests were performed with and without a coated yellow filter (X-482 nm cut-off) using the Mesotest II or Mesoptometer II (Oculus, Wetzlar, Germany) under mesopic conditions, and the Contrast Glaretester 1000 (Takagi, Seiko Co Ltd, Nagano, Japan) under photopic conditions. RESULTS: Under mesopic conditions, log contrast sensitivity without glare decreased by 0.14 log units in the LASIK group. When the yellow filter was used, this variable showed a significant increase of 0.04 log units and the proportion of patients able to discriminate the mesopic contrast limit of 1:5 rose from 70% to 78%. With glare, the yellow filter also improved contrast sensitivity in LASIK patients, but not significantly. Under photopic conditions, no statistical differences were observed between results obtained with and without the yellow filter in the LASIK group or between the LASIK and control group without glare. CONCLUSIONS: Mesopic contrast sensitivity without glare was worse in LASIK patients and increased significantly with the yellow filter. The filter had no effect under photopic conditions. No disability glare differences were noted between the LASIK and control groups or between the LASIK without and with filter groups under mesopic and photopic conditions. [ABSTRACT FROM AUTHOR]

Background: Approximately 5% of preschool-age children suffer from amblyopia. Many of them have high or unequal hyperopia. Amblyogenic risk factors frequently can be detected by photoscreening. Methods: Free photoscreening was offered to Alaskan children ages 1 to 5 from urban and rural screening hubs. Screened images were mailed to the Alaska Blind Child Discovery coordinating center for physician photoscreen interpretation, specifically seeking latent or anisometropic hyperopia. Parents and screeners then were mailed results and information about amblyopia. Follow-up examination data were tallied, and a cost-consequence analysis was developed for various vision screening paradigms and eye care. Results: From 1996 through 2003, a total of 13,255 screenings were performed with a positive interpretation rate of 4.7%. Penetrance of screening was 22% in urban and 44% in rural communities. Positive predictive value was estimated to be more than 90%. Average cost to screen and inform an Alaskan preschooler was approximately $10.67, and cost to detect amblyogenic risk factors by photoscreening in an Alaskan was approximately $206. Compared to American Academy of Pediatrics (AAP) 1995 guidelines, implementing photoscreening added 9%, while mandating complete prekindergarten examination added 49% to overall eye care. Conclusions: MTI photoscreening achieved high community penetrance and high positive predictive value for latent hyperopia and other amblyogenic factors. When follow-up costs are considered, adding photoscreening to current AAP guidelines may add $112 per child over 10 years, but probably would assist in the reduction of amblyopia. Penetrance of urban photoscreening likely will remain low unless pediatric vision screening guidelines and reimbursement are revised. [ABSTRACT FROM AUTHOR]

PURPOSE: To confirm that enhancements after primary laser in situ keratomileusis (LASIK) are effective in dealing with residual refractive errors, and to determine if any variables prior to or during the primary LASIK procedure predisposed eyes to require subsequent enhancement. METHODS: A retrospective study of eyes undergoing primary LASIK with the VISX S2 or S3 laser and Hansatome microkeratome between January 1, 2000 and January 1, 2002 was done. Of the 393 eyes of 207 patients, 58 eyes (14%) underwent enhancement within a 16-month window of the primary procedure. Statistical comparisons were made between enhanced (n=37) and non-enhanced (n=148) patients, and enhanced (n=48) and nonenhanced (n=303) eyes, treated for myopia only. RESULTS: In comparing the primary LASIK parameters of enhanced to non-enhanced eyes in myopic patients, no significant difference was found in right vs left eye, season of the primary treatment, preoperative astigmatism, pachymetry, or amount of attempted astigmatism correction. A multivariate logistic regression analysis revealed that male gender, patient age over 45 years, and a history of recent rigid contact lens use within 6 months of primary LASIK were significantly associated with the need for enhancement. CONCLUSION: Enhancements were an effective way of dealing with residual refractive errors after primary LASIK. Age greater than 45 years or a history of recent rigid contact lens use were significantly associated with the need for enhancement in patients with myopia or myopic astigmatism. [ABSTRACT FROM AUTHOR]

Provides information on the Corneal Navigator neural network-based software developed by Nidek Technologies for the topographic analysis of corneal states. Features of the software; Significance of the software to the field of eye care and surgery; Advantages of using the software.

PURPOSE: To identify evidence-based, best practice strategies for managing the ocular surface and tear film before, during, and after laser in situ keratomileusis (LASIK). METHODS: After a comprehensive review of relevant published literature, evidence-based recommendations for best practice management strategies are presented. RESULTS: Symptoms of ocular irritation and signs of dysfunction of the integrated lacrimal gland/ocular surface functional gland unit are common before and after LASIK. The status of the ocular surface and tear film before LASIK can impact surgical outcomes in terms of potential complications during and after surgery, refractive outcome, optical quality, patient satisfaction, and the severity and duration of dry eye after LASIK. Before LASIK, the health of the ocular surface should be optimized and patients selected appropriately. Dry eye before surgery and female gender are risk factors for developing chronic dry eye after LASIK. Management of the ocular surface during LASIK can minimize ocular surface damage and the risk of adverse outcomes. Long-term management of the tear film and ocular surface after LASIK can reduce the severity and duration of dry eye symptoms and signs. CONCLUSIONS: Strategies to manage the integrated ocular surface/lacrimal gland functional unit before, during, and after LASIK can optimize outcomes. As problems with the ocular surface and tear film are relatively common, attention should focus on the use and improvement of evidence-based management strategies. [ABSTRACT FROM AUTHOR]

PURPOSE: With the advent of wavefront-guided custom abalation we not only try to reach a target of 20/20 vision, but strive for improvement in what has always been most important--the quality of this vision. METHODS AND RESULTS: Insights are presented, based on clinical experience at Durrie Vision with our first 100 commercial CustomCornea eyes. We highlight key points for preparing a clinical practice for this new technology, such as staff training, marketing, and pricing. We discuss technical aspects such as patient selection and target adjustment as they relate to the Alcon LADARWave system. CONCLUSION: In our practice we have thus far had clinical success with CustomCornea; patient acceptance has been high, and by closely monitoring our first few patients we were able to reduce the number of future enhancements. [ABSTRACT FROM AUTHOR]

PURPOSE: To evaluate the clinical results of Alcon LADARVision4000 wavefront-guided customized treatment of eyes with myopia and/or astigmatism, and clinically significant visual symptoms related to the presence of higher order aberrations. METHODS: Seven consecutive abnormal eyes from seven patients underwent wavefront-guided CustomCornea (1 PRK, 6 enhancements after previous LASIK) to correct low and higher order aberrations, using the Alcon LADARVision4000 platform. Eyes were examined at 1 to 3 months after treatment; the longest follow-up examination was used for analysis. Uncorrected and best spectacle-corrected visual acuity, manifest refractive spherical equivalent error, and subjective visual symptoms were measured, as well as wavefront measurement of higher order aberrations. RESULTS: All seven eyes had an improvement in UCVA. One eye gained 2 lines of BSCVA, four eyes gained 1 line, and no eye lost any lines. Manifest refractive spherical equivalent error was slightly hyperopic in all eyes (+0.12 to +1.50 D). All eyes showed a reduction in pre-existing higher order aberrations, ranging between 1% and 48%. Spherical aberration was reduced most (mean 38% reduction), coma was reduced by a mean 14%, and all other terms were reduced by a mean 17% compared to preoperative values. Subjectively, all patients noticed a reduction in their pre-existing visual symptoms and reported visual performance comparable to their fellow asymptomatic eye. Overall, the treatment was considered very satisfactory by patients in terms of visual quality gain. CONCLUSION: Wavefront-guided custom ablation with Alcon's LADARVision4000 was effective in reducing higher order aberrations and related visual symptoms in this preliminary small series. Longer follow-up on more eyes is necessary to assess the accuracy of the algorithm in the correction of defocus, which resulted in a slight overcorrection in this study. [ABSTRACT FROM AUTHOR]

PURPOSE: To determine if videokeratography-based pupil measurements are an accurate method of estimating pupil size under mesopic conditions. METHODS: Sixty patients who had a preoperative work-up for refractive surgery participated in the study. A single observer obtained detailed pupil measurements with the Colvard pupillometer under standardized lighting conditions. The same observer recorded pupil size measurements obtained automatically when corneal topographic analysis was performed with Humphrey videokeratography. RESULTS: The Colvard pupillometry low light group was statistically different (P<.0001) from the Humphrey videokeratography automatic pupil measurement group. We calculated the value at which the Humphrey pupil measurements can accurately predict which patients would have pupil diameters ≥6.5 mm under low mesopic conditions. By adding a constant of 2.6 mm to the Humphrey videokeratography pupil measurement, 100% of patients with a pupil diameter ≥6.5 mm under low mesopic conditions were detected (sensitivity 100%). However, the ability to correctly reject those patients who do not have pupil diameters >6.5 mm under low mesopic conditions was lower at 55% (specificity). CONCLUSION: Videokeratography units can be used as a rapid, simple, and accurate method of predicting pupil size under mesopic conditions for potential refractive surgery patients and can provide a permanent record of pupil size. Care should be taken when relying on topography pupil sizes and more accurate measurements of mesopic and scotopic pupil sizes should be obtained. [ABSTRACT FROM AUTHOR]