Smartphone and custom-made software to assess the effect of botulinum toxin in essential blepharospasm: Initial results.

BACKGROUND AND PURPOSE: It is challenging to assess essential blepharospasm (EB) patients objectively because they exhibit chaotic patterns of abnormal eyelid movements. Previously employed objective approaches used systems with low levels of accuracy systems or were too complex to be applied in routine clinical practice. We aimed to develop a practical tool using a smartphone camera and custom-made software to objectively assess the therapeutic effects of botulinum toxin in blepharospasm patients. METHODS: Thirty-four patients with EB were evaluated before and 15 days after receiving onabotulinumtoxinA injections. The control group was composed of 19 age-matched healthy individuals. A smartphone (iPhone 6 S; Apple) was used to record spontaneous eyelid movements for 3 min, after which eyelid movement frequency was analysed using custom-made software. RESULTS: Before treatment, eyelid movement frequency was significantly higher in the EB group (21.55 ± 13.30 movements/min) compared to the control group (8.26 ± 8.89 eyelid movements/min; p < 0.001). The frequency of spontaneous eyelid movements was significantly reduced after treatment in the EB patients (8.46 ± 6.32 eyelid movements/min; p < 0.001). After treatment, no statistically significant difference in eyelid movement rate was observed between the EB patients and the control group (p = 0.32). CONCLUSIONS: Assessment of the spontaneous eyelid movements obtained with the smartphone camera and analysed with the custom-made software enabled us to objectively measure the therapeutic effects of botulinum toxin in patients with blepharospasm. Further refinement of this system could enable customized and fine adjustments to botulinum toxin doses based on each patient's needs.

Ocular Surface Metrics in Blepharospasm Patients After Treatment With Botulinum Toxin Injections.

PURPOSE: The purpose of this study was to assess blepharospasm patients regarding the effect of botulinum toxin in ocular surface parameters. METHODS: A prospective study was performed in blepharospasm patients treated with onabotulinumtoxinA. A smartphone (iPhone 6S, Apple) and custom-made software were used to record the eyelid movements for 3 minutes in a standardized manner. Optical coherence tomography of the tear meniscus was used to assess the tear meniscus area. Tear break-up time and the Ocular Surface Disease Index questionnaire were also evaluated. Patients were assessed before and 15 days after botulinum toxin injections. RESULTS: Forty eyes of 20 patients were evaluated. The frequency of the spontaneous eyelid movements was significantly reduced after treatment (23.18 ± 12.85 movements/min vs. 9.29 ± 6.87 movements/min; p < 0.0001). Significant increases in the tear meniscus area (0.020 ± 0.015 mm 2 vs. 0.057 ± 0.104 mm 2 ; p = 0.01) and in break-up time (4.2 ± 1.2 seconds vs. 5.1 ± 1.3 seconds; p = 0.03) were observed 15 days after treatment. A significant reduction in the Ocular Surface Disease Index (59.05 ± 19.04 vs. 21.2 ± 19.5; p < 0.0001) was also observed. CONCLUSION: Significant changes in the tear meniscus area, break-up time, and Ocular Surface Disease Index after treatment reflect the effect of botulinum toxin on the lacrimal pump and in the improvement of dry eye symptoms. Reduction of eyelid spasms after treatment in blepharospasm patients was demonstrated using a smartphone and custom-made software. Thus, beyond relieving eyelid spasms, botulinum toxin injections were associated with subjective and objective improvement of dry eye parameters in patients with blepharospasm.

Eye clinic attendance at the olympic and paralympic games Rio 2016 and its correlation to the WHO indicators on eye health.

OBJECTIVES: To evaluate athletes' frequency of attendance at the eye clinic during the Olympic and Paralympic Games Rio 2016 and to correlate it to WHO core indicators on progress in ophthalmology care in a country. METHODS: Frequencies of athletes' attendance at the eye clinic were calculated for each country. Countries were classified according to the World Bank income levels in high, upper-middle, low-middle or low-income country. Data on ophthalmology care for each country were derived from the International Agency for the Prevention of Blindness atlas. Data were analysed in view of WHO indicators for each country: visual impairment prevalence considering presenting visual acuity <6/18 to ≥3/60 in the better vision eye; number of ophthalmologists per million people and the cataract surgical rate per year, per million population. RESULTS: The athletes' overall frequency of attendance in the eye clinic was 6.47%. Frequencies of attendance for high, upper-middle, low-middle or low-income country were 1.97%, 9.66%, 16.54% and 22.43%, respectively. A positive correlation was observed between the athletes' attendance frequency of a country and its visual impairment prevalence (r=0.2290, p=0.0017). A negative correlation was observed between the athletes' attendance frequency of a country and its eye health workforce (r=-0.2152, p=0.0026). CONCLUSION: Countries with highest athletes' frequencies of attendance were those that face barriers to eye care provision. These results reinforce the importance of the eye clinic service during the Olympic and Paralympic Games proving access to specialised care to athletes and members of delegation.

Outcomes of different concentrations of human amniotic fluid in a keratoconjunctivitis sicca-induced mouse model.

To compare the effects of different concentrations of topical human amniotic fluid (HAF) in a mouse model of dry eye, forty C57BL/6 mice were divided into 4 treatment groups: 20 % HAF, 50 % HAF, 100 % HAF, and isotonic salt solution (control). Dry eye was induced by an injection of botulinum toxin B into the lacrimal gland. Tear production, ocular surface fluorescein staining, and blink rate were evaluated in each mouse at 5 time points during a 4-week period. Goblet cell density was assessed in stained histological sections. Regarding tear production, 20, 50, and 100 % HAF groups were all different from the control group (P < 0.001) at week 1. However, there were no statistically significant differences between the 20, 50, and 100 % HAF groups. At week 2, 20, 50, and 100 % HAF groups had significant improvement in staining score and were significantly different from the control group (P = 0.047, P = 0.005, and P = 0.001, respectively). No difference in spontaneous blink rate was observed between groups, at any time point. Goblet cell density was significantly decreased in the control group compared to the HAF treatment groups. All tested concentrations of topical HAF were effective and superior than the control in this keratoconjunctivitis sicca-induced mouse model. Further studies are needed to evaluate the effects of HAF on the human ocular surface.

Does microperimetry have a prognostic value in central serous chorioretinopathy?

PURPOSE: To investigate the relationship between retinal sensitivity and persistence of subretinal fluid and then to analyze microperimetry as a prognostic predictor of acute central serous chorioretinopathy. METHODS: A prospective observational study. Fourteen eyes of 14 patients presenting with first episode acute central serous chorioretinopathy were enrolled and underwent ocular examination, spectral domain optical coherence tomography, and MAIA microperimetry were performed. After three months of follow-up, without any treatment, visual acuity and spectral domain optical coherence tomography macular thickness assessments and microperimetry were repeated. The main outcome was to find a relation between initial macular sensitivity and persistence of subretinal fluid. A receiver operating characteristic curve was plotted to indicate the best macular sensitivity cutoff point that would be able to predict whether a patient with acute central serous chorioretinopathy would progress to the chronic form. According to the cutoff, we calculated the sensitivity, specificity, and positive and negative predictive values for macular sensitivity as a method to predict persistence of subretinal fluid. RESULTS: On the basis of the receiver operating characteristic curve, a cutoff of 20 dB macular sensitivity was obtained, as the best balance between sensitivity and specificity to predict chronicity. Using this cutoff, the method had a sensitivity of 71% and specificity of 100% with a positive predictive value of 100% and negative predictive value of 78%. Furthermore, it was found that eyes with acute central serous chorioretinopathy and microperimetry of less than 20 dB had a relative risk of 4.5 to develop subretinal fluid persistence. CONCLUSION: Microperimetry with a cutoff of 20 dB may be a useful test to predict the persistence of subretinal fluid, allowing the ophthalmologist to use treatment tools earlier, preventing extracellular damage and visual impairment.

New Device for the Correction of Aphakia Without Capsular Support.

PURPOSE: This study describes a prototype developed for aphakia without capsular support (AWCS) and its proof of concept. METHODS: This descriptive study used a 3D software to create and analyze virtual prototypes before manufacturing. A nylon-6/nylon-6.6 copolymer filament and a 3D printer were used for prototyping. A device implantation technique was developed using a 23-gauge hypodermic needle. Two opposing markings, 2 mm posterior to the limbus, were made to determine the location of the scleral punctures and the final position of the device. After adequate centralization and positioning of the device, its haptics were cut and cauterized to generate thermal modeling of the extremity and allow the thickening of the tips (flange), serving as an anchoring mechanism to the sclera. The efficacy and adequacy of the technique and device were then evaluated. RESULTS: Vitreous tissue extrusion was not observed during the sclerotomy. The device was well fixed to the sclera; however, adequate IOL stability and centralization still needed to be achieved. The surgeon evaluated the adequacy of all the other devices' characteristics. CONCLUSIONS: The development of a technology prototype for correcting AWCS was possible. Although the proposed prototype met most of the established concept guidelines, the stability of the IOL position remains challenging.

Comparative outcomes of mechanical and transepithelial PRK on the same excimer laser: A contralateral eye study.

PURPOSE: Compare refractive results between mechanical PRK (mPRK) and transepithelial PRK (tPRK) with WaveLight Allegretto EX500 excimer laser system (Alcon Laboratories, Fort Worth, TX, USA). SETTING: Department of Ophthalmology of the Federal University of Sao Paulo, Brazil. DESIGN: Prospective and randomized study. METHODS: In 151 eyes of 73 patients with astigmatism and myopia, both eyes had similar refraction before surgery, with a maximum of 15-µm difference in ablation who underwent mPRK in one eye and tPRK in the contralateral eye. The mean age of the patients in this study was 31.45 ± 6.97 years (range, 22 to 54 years). RESULTS: A comparison was made with all variables between the two groups, and we found that UDVA and SE were worse in the tPRK group at six months than in the mPRK group. In the mPRK group, there was a higher frequency in the +/- 0.50 range and a lower frequency in the +/- 1.50 range. In the tPRK group, however, there was a lower frequency in the +/- 0.50 range and a higher frequency in the +/- 1.50 range. Concerning gain or loss of lines of sight, there was no association between the two groups (chi-square test, p = 0.887). CONCLUSION: Both mPRK and tPRK appear to have similar safety. However, mPRK was associated with significantly better UDVA and SE six months post-operatively.

Vision-Related Quality of Life in Patients With Keratoconus With Enantiomorphic Topography After Bilateral Intrastromal Corneal Ring Implantation.

PURPOSE: The aim of this study was to evaluate the quality of life (QOL) after intrastromal ring implantation in patients with keratoconus. METHODS: This was a prospective, randomized, interventional study. We analyzed 60 eyes of 30 patients aged 16 to 35 years who were treated at the Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil. The Visual Function Questionnaire (VFQ-25) and Short-Form 36 Questionnaire (SF-36) were used before intracorneal ring segment (ICRS) implantation and at 3, 6, and 12 months after surgical intervention. RESULTS: The mean corrected visual acuity improved from a mean of 0.32 ± 0.2 logMAR (20/40) preoperatively to 0.14 ± 0.11 logMAR (20/25) 1 year postoperatively ( P = 0.001). The mean spherical equivalent varied from -7.24 ± 3.47 preoperatively to -4.13 ± 2.41 postoperatively ( P = 0.001). The overall composite score for the VFQ-25 improved from 55.1 preoperatively to 80.4 1 postoperatively ( P = 0.001). SF-36 showed statistically significant improvement in all scores. When analyzing the correlation between visual acuity and VFQ composite score, a significant correlation was found between both variables (Pearson correlation coefficient of -0.40, P = 0.001). CONCLUSIONS: Patients with keratoconus had increased psychological symptoms and lower QOL and improved psychosocial criteria associated with corneal remodeling and decreased visual dependence on others after surgery. Extrapolation of these data to the whole keratoconus population suggests that ICRS implantation could improve QOL in these patients.

Optimization of intraocular lens constant improves refractive outcomes in combined endothelial keratoplasty and cataract surgery.

PURPOSE: To evaluate the accuracy of intraocular lens (IOL) power calculations with A-constant optimization in Descemet's stripping automated endothelial keratoplasty (DSAEK) combined with cataract extraction and intraocular lens implantation (DSAEK triple procedure). DESIGN: Retrospective case series. PARTICIPANTS: Thirty eyes of 22 patients with Fuchs' endothelial dystrophy who underwent the DSAEK triple procedure performed by a single surgeon. METHODS: Prediction errors were calculated retrospectively for consecutive DSAEK triple procedures. These prediction errors then were used to determine an IOL constant for this cohort of patients. The new optimized IOL constant subsequently was compared with the manufacturer's IOL constant, allowing evaluation and quantification of refractive benefits of optimization. MAIN OUTCOMES MEASURES: The error in diopters (D) of the predicted refraction with the manufacturer's and optimized IOL constants. RESULTS: Optimization of the A constant decreased the mean absolute error (MAE) from 1.09 ± 0.63 D (range, 0.12-2.41 D) to 0.61 ± 0.4 D (range, 0-1.58 D; P = 0.004). Comparing the intended and final postoperative refractions calculated with the original manufacturer's constant and the optimized constant, 20% versus 43% of all eyes were in the less than 0.5-D range and 50% versus 83% of all eyes were in the less than 1.0-D range of the target refraction. Furthermore, optimization decreased the number of eyes that were more than 1.0 D from the target refraction from 50% to 17%. CONCLUSIONS: Optimization of the IOL constant showed significantly improved accuracy of predicted postoperative refraction compared with the manufacturer's IOL constant, which may help improve the postoperative refractive outcomes in patients undergoing the DSAEK triple procedure.

Assessment of fungal viability after long-wave ultraviolet light irradiation combined with riboflavin administration.

BACKGROUND: Corneal collagen cross-linking (CXL), a technique that combines riboflavin administration with long-wave ultraviolet light irradiation, was primarily developed to increase the biomechanical strength of collagen fibrils of the cornea to avoid the progression of keratoconus. Recently, this method has been proposed to treat selected cases of infectious keratitis. METHODS: To test the protocol used for progressive keratoconus in infectious keratitis, Candida albicans, and Fusarium solani, strains were exposed to irradiation using a wavelength of 365 nm at a power density of 3 mW/cm(2) for 30 min in the presence of riboflavin photosensitizer. All experiments were performed in triplicate. Qualitative and quantitative measurements of fungal viability used plate cultures and an automated trypan blue dye exclusion method respectively. Fungal cell diameter was also assessed in all groups. Statistical analyses were performed using the triplicate values of each experimental condition. RESULTS: Experimental findings of photodynamic therapy applied to the cell inactivation of both yeasts and filamentous fungi were compared with control groups. Qualitative results were corroborated with quantitative findings which showed no statistical significance between challenged samples (experimental groups) and the control group (p-value = 1). In comparison with a control group of live cells, statistical significance was observed when riboflavin solution alone had an effect on the morphologic size of filamentous fungi, while ultraviolet light irradiation alone showed a slight decrease in the cell structure of C. albicans. CONCLUSIONS: The impact of long-wave ultraviolet combined with riboflavin photosensitizer showed no antifungal effect on C. albicans and F. solani. The significant decrease in cell morphology of both filamentous fungi and yeasts submitted to photosensitizing riboflavin and exposure to ultraviolet light, respectively, may be promising in the development and standardization of alternatives for fungal cell inactivation, because of their minimal cytotoxic effects on the corneal surface. The methodological improvement in the preparation and application of individual chemical compounds, such as riboflavin, or physical systems, such as a long-wave light source, as antifungal agents may also assist in establishing promising therapeutic procedures for keratomycosis.

The 18-Month Outcomes of a Contralateral, Randomized, Prospective Clinical Trial Comparing Photorefractive Keratectomy and SMILE for Myopia.

PURPOSE: To compare clinical outcomes and patient satisfaction of photorefractive keratectomy (PRK) and small incision lenticule extraction (SMILE) for myopia. METHODS: This contralateral, randomized, prospective clinical trial included 86 eyes of 43 patients diagnosed as having spherical equivalent (SE) from -1.00 to -8.00 diopters (D). One eye of each patient was randomly allocated to receive either PRK with 0.02% mitomycin C or SMILE. Visual acuity measurement, slit-lamp microscopy, manifest and cycloplegic refraction, Scheimpflug corneal tomography, contrast sensitivity assessment, ocular wavefront aberrometry, and a satisfaction questionnaire were performed preoperatively and during an 18-month follow-up. RESULTS: Forty-three eyes of each group completed the study. After 18 months of follow-up, eyes treated with PRK and SMILE showed comparable results regarding uncorrected distance visual acuity (-0.12 ± 0.07 and -0.25 ± 0.09, respectively), safety, efficacy, contrast sensitivity, and ocular wavefront aberrometry. For predictability, eyes treated with PRK had a statistically lower residual spherical equivalent when compared with eyes treated with SMILE. Residual astigmatism of 0.50 D or less was achieved in 95% of the PRK group and 81% of the SMILE group. At the 1-month follow-up visit, the PRK group presented worse evaluation in relation to vision and foreign body sensation when compared to the SMILE group. CONCLUSIONS: Both PRK and SMILE presented as safe and effective strategies for treating myopia with comparative clinical results. Eyes treated with PRK showed lower spherical equivalent and residual astigmatism. In the first month, eyes treated with SMILE showed less foreign body sensation and faster visual recovery. [J Refract Surg. 2023;39(3):180-186.].

Measurement of the visual axis through two different methods: quantification and differences for measuring chord µ.

PURPOSE: To compare the differences between the apparent and actual chord µ. METHODS: In this prospective, comparative, non-randomized, and non-interventional study, imaging examinations using Pentacam and the HD Analyzer were performed in the same room under the same scotopic conditions. The inclusion criteria were patients aged 21-71 years, able to provide informed consent, myopia up to 4D, and anterior topographic astigmatism up to 1D. Patients using contact lenses, those with previous eye diseases or surgeries, corneal opacities, corneal tomographic changes, or suspected keratoconus were excluded. RESULTS: Altogether, 116 eyes of 58 patients were analyzed. The patients' mean age was 30.69 (±7.85) years. In the correlation analyses, Pearson's correlation coefficient of 0.647 indicates a moderate positive linear relationship between apparent and actual chord µ. The mean actual and apparent chord µ were 226.21 ± 128.53 and 278.66 ± 123.90 µm, respectively, with a mean difference of 52.45 µm (p=0.01). The analysis of mean pupillary diameter resulted in 5.76 mm using the HD Analyzer and 3.31 mm using the Pentacam. CONCLUSIONS: We found a correlation between the two measurement devices, and even though we found considerable differences, both can be used in daily practice. Given their differences, we should respect their peculiarities as well.

Spectrophotometric Analysis of Different Polymethyl Methacrylate Filters and their Importance in the Implantation of Corneal Rings.

PURPOSE: This study evaluated the luminous behavior applied to materials used in intraocular surgeries. METHODS: Discs of the different products were delivered in 19.00 mm × 3.00 mm. Each sample was fixed on support keeping it perpendicular to the spectrophotometer beam. Later, their analyses were carried out in the air/PMMA ratio. The graphs of individual profiles of the measurements along the length were constructed according to each of the filters from the spectrophotometric analysis. In addition, descriptive statistics of transmittance and absorbance for each wavelength presented were correlated for each filter. RESULTS: It is possible to observe that the minimum absorption measure was found in the Red Filter, especially in the blue and green light spectrum. CONCLUSION: Using filters in PMMA materials appears to improve visual quality in corneal implants, especially the red filter, due to greater absorbance of light leading to fewer light scattering phenomena through corneal rings. However, further studies comparing the effects of different filters on Intracorneal rings should be carried out to elucidate this field of study.

Ten-year follow-up of corneal cross-linking and refractive surface ablation in patients with asymmetric corneal topography.

Purpose: Compare the safety and efficacy of wavefront-guided photorefractive keratotomy (PRK) 6 months after cross-linking (CXL) to wavefront-guided PRK alone for refractive correction in patients with bilateral asymmetric corneal topography. Methods: Prospective randomized clinical trial with 16 patients (32 eyes). CXL with subsequent PRK after 6 months in one eye, and PRK alone was performed in contralateral eyes. The follow-up was 10 years. We analyzed visual outcomes, Scheimpflug topography, and corneal haze evaluation. Results: Eyes in the PRK group showed better results than in the CXL + PRK group. Mean postoperative CDVA was 0.044 logmar (SD, 0.073) in the PRK group and 0.1 logmar (SD, 0.21) in the CXL + PRK group, the mean sphere was + 0.21 (SD, 0.6) D in the PRK group and 0.87 (SD, 2.3) D in the CXL + PRK group, and mean SE was -0.35 (SD, 0.65) D in the PRK group and 0.62 (SD, 2.32) D in the CXL + PRK group. In one patient, a steepening of 2.5 D and a thinning of 17 µm occurred in PRK alone group. Two patients in the CXL + PRK group presented corneal haze. The overall complication rate was 18,75% (haze and ectasia). Conclusion: Non-simultaneous CXL and PRK procedures yielded good refractive results, but worse than those obtained with PRK alone. Although one patient in the PRK group developed corneal ectasia, the CXL + PRK group had a higher loss of vision lines, indicating less safety.

Impact of pterygium on central corneal thickness measured by optical coherence tomography in older adults.

PURPOSE: To measure the central corneal thickness (CCT) using anterior segment optical coherence tomography (AS-OCT) in older adults with and without pterygium from the Brazilian Amazon Region Eye Survey (BARES). METHODS: BARES is a population-based epidemiological cross-sectional study conducted in Parintins city. Participants were residents ≥45 years of age identified through a door-to-door interview. Eligible participants were invited for a comprehensive eye exam. Pterygium occurrence and severity were assessed by ophthalmologists through slit-lamp examination considering its location (nasal or/and temporal) and severity (lesion with extension <3 mm, ≥3 mm not reaching the pupillary margin or ≥3 mm reaching the pupillary margin). CCTs were obtained and measurements from the more severely affected eye were included. Images were analyzed offline by masked observers. RESULTS: A total of 671 subjects, 533 (79.4%) with pterygium in at least one eye and 138 (20.6%) without pterygium in either eye, were examined. The mean CCT evaluated by multiple linear regression and adjusted for demographic variables and pterygium severity was 521 ± 34 µm (median = 521; range = 304-665). Decreased CCT was significantly associated with age and pterygium severity. Individuals aged 65-74 years had CCT 7 µm thinner than those aged 45-54 years (p = 0.044), individuals aged 75 years and older had CCT 15 µm thinner than those aged 45-54 years (p = 0.001), and eyes with severe pterygium had CCT 33 µm thinner than eyes without pterygium (p < 0.001). CONCLUSIONS: The CCT analysis in this population-based sample shows that a thinner cornea is associated with pterygium severity and older age.

Ocular manifestations of monkeypox: a case report.

Monkeypox disease is a viral zoonosis with symptoms similar to those seen in the past in smallpox (variola), although clinically less severe. Following the eradication of smallpox in 1980 and the subsequent cessation of smallpox vaccination, monkeypox has emerged as the most important orthopoxvirus from a public health standpoint. Monkeypox virus occurs primarily in central and western Africa, often in tropical forests, and has increasingly manifested in urban areas. Animal hosts include various rodents and nonhuman primates. We report the case of a patient with monkeypox disease who developed ocular complaints (eye discomfort and conjunctivitis) and had detectable conjunctival lesions on biomicroscopy and fluorescein testing. Its ophthalmological manifestations are still poorly known.

Pain response and symptoms in photorefractive keratectomy: mechanical de-epithelization compared with transepithelial ablation.

PURPOSE: To compare postoperative pain and discomfort between mechanical and transepithelial photorefractive keratectomies. METHODS: This prospective comparative study included 190 eyes of 95 patients with hyperopia (up to +4.00 D), astigmatism (up to -5.00 D), and myopia (up to -8.00 D) who underwent mechanical photorefractive keratectomy in one eye and transepithelial photorefractive keratectomy in the contralateral eye using Wavelight Allegretto EX500 excimer laser. The patients were unaware of the side treated with each technique. The interval between operations in the same patient was 15-30 days. Both eyes had similar refraction before surgery, with a maximum of 15-µm difference in ablation. Postoperative questionnaires were administered on days 1 and 7 to assess the patients' level of discomfort (0=no discomfort to 5=extreme discomfort) with the following symptoms: pain, burning sensation, itchiness, tearing, photophobia, eye redness, foreign body sensation, and eyelid swelling. Patients were also asked about which method they preferred. RESULTS: The sample consisted of 61 women (64.21%) and 34 men (35.79%). The mean (SD) patient age was 31.66 (6.69) years (range, 22-54 years). On postoperative day 1, the patients reported significantly less discomfort in terms of pain (1.9 ± 1.74 vs 2.5 ± 1.83; p=0.017), burning sensation (1.8 ± 1.56 vs 2.5 ± 1.68; p=0.004), tearing (2.3 ± 1.71 vs 3.1 ± 1.69; p=0.001), and foreign body sensation (1.9 ± 1.77 vs 2.5 ± 1.86; p=0.024) in the eye that received mechanical photorefractive keratectomy than in the eye that received transepithelial photorefractive keratectomy. No significant differences were found between the mechanical and transepithelial photorefractive keratectomies on postoperative day 7. Fifty-nine patients (62.10%) preferred mechanical photorefractive keratectomy, while 32 (33.68%) preferred transepithelial photorefractive keratectomy. Four patients (4.22%) expressed no preference. CONCLUSIONS: Our results showed that pain scores were significantly lower in the mechanical photorefractive keratectomy-treated eyes than in the transepithelial photorefractive keratectomy-treated eyes on postoperative day 1, which may have provided greater patient comfort after surgery and led patients to prefer the mechanical photorefractive keratectomy technique.

Prevalence of ocular findings regardless of visual acuity status in older adults from the Brazilian Amazon Region.

Recently, it has been recommended that population-based studies report not only frequencies of vision impairment and blindness but also any ocular abnormalities that might lead an individual to seek for eyecare services. The current study aimed to determine prevalence of ocular findings regardless of visual acuity (VA) status in older adults from the Brazilian Amazon Region. Disturbances were grouped into: Eyelids; Anterior Segment; Posterior Segment; Increased intraocular pressure; and Overall Globe. The presence of an ocular finding was considered positive when any abnormality was noted, regardless of VA. Refractive errors were not considered. A total 2384 eligible persons were enumerated and 2041 (85.6%) examined. The prevalence of ocular disturbances in either eye was 87.0% and was associated with male gender, older age, lower education, and rural residence. Overall, main findings were pterygium, cataract, and pinguecula, occurring in 58.8%, 45.4% and 17.4%, respectively. Among individuals with 20/20 VA in both eyes, the most frequent findings were pterygium, pinguecula, and glaucoma cupping, occurring in 47.4%, 31.2% and 6.5%, respectively. The high prevalence of ocular findings observed in this population reinforces that different conditions might not immediately decrease VA but can indicate risk and/or discomfort symptoms and should be considered when planning public health ophthalmic services.

Pentacam Scheimpflug evaluation of corneal volume after LASIK.

PURPOSE: To assess the change in corneal volume and laser ablation volume over time after LASIK using a rotating Scheimpflug camera. METHODS: Twenty-six patients (49 eyes) underwent LASIK. Pentacam Scheimpflug measurements were performed pre- and postoperatively at 1, 3, 7, 15, and 30 days. Central corneal thickness, total corneal volume (10-mm diameter), and partial corneal volumes (3, 5, and 7 mm) based on the apex of the cornea, were measured. Main outcome measures were differences between pre- and postoperative volume measurements of total and partial corneal regions, volume changes over time postoperatively, and comparison between laser ablation volume and corneal volume. RESULTS: A strong linear relationship was noted between spherical equivalent refraction and laser ablation volume (r = -0.931, P < .0001). Furthermore, 30 days after LASIK, a strong linear relationship was noted between planned thickness and achieved thickness (r = 0.9457, P < .001). Corneal volumes for 3-, 5-, and 7-mm diameter regions significantly decreased over time postoperatively (one-way analysis of variance, P < .05). CONCLUSIONS: Alterations in corneal volume correlated with laser ablation volume when the diameter of the region considered was 3, 5, or 7 mm from the corneal apex.

Effect of amniotic membrane transplantation on corneal healing and proteoglycan expression in an experimental model of limbal deficiency in rabbits.

PURPOSE: Amniotic membrane transplantation (AMT) has been used as a graft or as a dressing in ocular surface reconstruction, facilitating epithelization, maintaining normal epithelial phenotype, and reducing inflammation, vascularization, and scarring. The corneal transparency is due, at least in part, to the arrangement in orthogonal lamellae of collagen fibrils, surrounded by proteoglycans (PGs). These PGs regulate fibrilogenesis, the matrix assembly, and ultimately the corneal transparency. The purpose of the present study was to investigate the effects of AMT upon the corneal PGs after severe limbal injury. METHODS: Experiments were performed on the right corneas of 22 New Zealand female albino rabbits, and their left corneas were used as matched controls. These animals were divided into 3 groups: G1 (n=10): total peritomy and keratolimbectomy, followed by application of 0.5 M NaOH; G2 (n=10): submitted to the same trauma as G1, and treated by AMT; G3: no trauma, only AMT (n=2). The right corneas of G2 and G3 were covered by DMSO4 cryopreserved human amniotic membrane, fixed by interrupted 9-0 mononylon sutures, with its stromal face toward the ocular surface. After 7 or 30 days, the corneas were removed and PGs were extracted. RESULTS: Normal corneas contained approximately 9 mg of PGs per gram of dry tissue. AMT on intact cornea (G3) did not cause any changes in the concentration of PGs. In contrast, injured corneas contained much less PGs, both on the seventh and on the 30th day posttrauma. The PG concentration was even lower in injured corneas treated by AMT. This decrease was due almost exclusively to dermatan sulfate PGs, and the structure of dermatan sulfate was also modified, indicating changes in the biosynthesis patterns. CONCLUSIONS: Although beneficial effects have been observed on clinical observation and concentration of soluble proteins after AMT, the normal PG composition of cornea was not attained, even 30 days postinjury, indicating that the normal ocular surface reconstruction, if possible, is a long-term process.