[Comparative analyses between clinical refraction and automatic refraction obtained through a wave front sensor]

PURPOSE

To evaluate and compare refractive errors obtained through clinical subjective and automatized wavefront refraction analyses in eyes under cycloplegia.

METHODS

Prospective study of 147 patients, 279 eyes, undergoing preoperative examination for refractive surgery. Clinical subjective refraction was performed first followed by wavefront refraction. Results on astigmatism obtained from refraction were decomposed in power vectors for statistical analyses. Data were first analyzed in one eye and then in both eyes.

RESULTS

The mean difference between clinical subjective refraction and automatized wavefront refraction on cycloplegic eyes was of -0.19 SD combined with -0.06 CD in the 15 degrees axis for data in one eye, and -0.17 SD combined with -0.05 CD in the 3 masculine axis for data in both eyes of the same patient.

CONCLUSION

In the present study clinical subjective refraction and automatized wavefront refraction under cycloplegia had similar numerical values.

[Anterior ocular segment study with the Scheimpflug rotational camera in refractive surgery candidates]

PURPOSE

To analyze the anterior segment of refractive surgery candidates and establish the variability pattern in this population regarding corneal volume, anterior chamber volume and depth and corneal thickness, using the noncontact three dimensional analyzer Pentacam.

METHODS

A retrospective study of 297 eyes of 149 patients was conducted using Pentacam. According to the spherical equivalent value two groups were created, myopia (n=242 eyes) and hyperopia (n=55 eyes), to analyze the variables of corneal volume, anterior chamber volume and depth and corneal thickness.

RESULTS

The mean values of the myopia group were: corneal total volume 59.37 +/- 3.51 mm(3), corneal volume at 3 mm 3.87 +/- 0.23 mm(3), at 5 mm 11.31 +/- 0.67 mm(3), and at 7 mm 24.30 +/- 1.43 mm(3), anterior chamber volume 198.74 +/- 32.40 mm(3), anterior chamber depth 3.19 +/- 0.28 mm and corneal thickness 533.33 +/- 33.47 mm. In the hyperopia group, the mean total corneal volume was 60.77 +/- 3.31 mm(3), corneal volume at 3 mm from the apex was 4.01 +/- 0.20 mm(3), at 5 mm was 11.73 +/- 0.58 mm(3), and at 7 mm was 25.09 +/- 1.21 mm(3), the anterior chamber volume was 146.61 +/- 32.86 mm(3), the anterior chamber depth was 2.76 +/- 0.38 mm and the corneal thickness was 550.52 +/- 29.49 mm. The difference between the groups was significant for all variables (p<0.05).

CONCLUSION

We observed in this study that patients with myopia had lesser mean corneal volume and pachymetry, and greater anterior chamber depth and volume compared with hyperopic patients.

Effect of corneal thickness on the agreement between ultrasound and Orbscan II pachymetry

PURPOSE

To study the agreement between ultrasound (US) and Orbscan II (Bausch & Lomb) measurements with different ranges of central thickness in normal corneas.

SETTING

Noor Ophthalmology Research Center, Tehran, Iran.

METHODS

The central corneal thickness was measured first by the Orbscan II and then with a US pachymeter in 177 right eyes. Data were compared in 3 thickness groups: less than 500 microm, 500 to 600 microm, and more than 600 microm. In all cases, uncorrected Orbscan II data were used. For each range, a correction factor was calculated through regression analysis, which was then used in a new set of analyses. To study the agreement between the 2 methods, the 95% limits of agreement (LoA) and intraclass correlations coefficients (ICC) were determined.

RESULTS

The mean interdevice difference was 2.7 +/- 16.9 (SD) in the less than 500 microm group (P = .365), 21.3 +/- 3.1 in the 500 to 600 microm group (P = .0001), and 27.2 +/- 20.9 in the more than 600 microm group (P = .0001). No clinically acceptable LoA were found in any group. The application of regression equations to the Orbscan II readings improved the agreement in the less than 500 microm group better than the other 2 groups. The ICC was 0.76, 0.61, and 0.43 in the less than 500 microm, 500 to 600 microm, and more than 600 microm groups, respectively.

CONCLUSIONS

The Orbscan corneal thickness readings had relatively lower validity than US measurements. The 2 devices should not be used interchangeably, especially when the validity of the measurement is vital. In patient screening for corneal surgery, it is advisable to recheck corneal thickness with a US pachymeter.

Screening for diabetic retinopathy in primary care with a mobile fundal camera--evaluation of a South African pilot project

BACKGROUND AND AIMS

In South Africa diabetes makes a significant contribution to the burden of disease. Diabetic retinopathy is a leading cause of adult blindness, and screening can reduce the incidence. This project aimed to implement and evaluate a new service for retinal screening that uses a non-mydriatic mobile fundal camera in primary care. This is the first time such a service has been evaluated in an African primary care context.

METHODS

The service was implemented as an operational research study at three community health centres and data were collected to evaluate the operational issues, screening, reporting and referral of patients.

RESULTS

Out of 400 patients screened 84% had a significantly reduced visual acuity, 63% had retinopathy (22% severe nonproliferative, 6% proliferative and 15% maculopathy), 2% of eyes could not be screened and 14% of patients required dilatation. Referral was necessary in 27% of cases for cataracts, in 7% for laser treatment and in 4% for other specialist services. Repeat photography was needed in 8% and urgent follow-up in 12%. A SWOT analysis of the pilot project was completed and recommendations were made on how to integrate it into the district health system.

CONCLUSION

Screening with a fundal camera improved the quality of care for diabetic patients and is feasible in the South African public sector, primary care setting. A single technician should be able to photograph almost 10,000 patients a year.

New microscopic pushbroom hyperspectral imaging system for application in diabetic retinopathy research

To aid ophthalmologists in determining the pathogenesis of diabetic retinopathy and in evaluating the effects of medication, a microscopic pushbroom hyperspectral imaging system is developed. 40 healthy Wistar rats of half gender are selected in this study. They are divided into three groups (six rats failed to be models). 10 normal rats as the normal control group, 12 diabetic rats without any treatment as the model control group, and another 12 diabetic rats treated with LCVS1001 as the LCVS1001 group. The microscopic hyperspectral image of each retina section is collected and processed. Some typical spectrum curves between 400 and 800 nm of the outer nuclear layer are extracted, and images at various wavelengths are analyzed. The results show that a small trough appears near 522.2 nm in the typical spectrum curve of the model control group, and the transmittance of it is higher than that of the normal control group. In addition, the spectrum of the LCVS1001 group changes gradually to the normal spectrum after treatment with LCVS1001. Our findings indicate that LCVS1001 has some therapeutic effect on the diabetic retinopathy of rats, and the microscopic pushbroom hyperspectral imaging system can be used to study the pathogenesis of diabetic retinopathy.

Central corneal thickness measurement with Pentacam, Orbscan II, and ultrasound devices before and after laser refractive surgery for myopia

PURPOSE

To determine the agreement in central corneal thickness (CCT) measurements between the gold standard method of ultrasound (US) pachymetry (UP-1000, Nidek) and 2 noncontact systems based on Scheimpflug imaging (Pentacam, Oculus) and scanning-slit topography (Orbscan II, Bausch & Lomb) in myopic eyes before and after laser refractive surgery.

SETTING

Noor Vision Correction Center, Tehran, Iran.

METHODS

In this prospective study, 30 consecutive patients having refractive surgery for myopia were enrolled. All 60 eyes were examined with the 3 devices preoperatively and 6 weeks after surgery; the US measurements were performed last. The Pentacam and Orbscan II CCT readings were compared with the US readings. Both the original and corrected Orbscan II readings were used in the analyses.

RESULTS

The mean CCT readings with US, Pentacam, and Orbscan II were, respectively, 555 microm, 548 microm, and 580 microm before surgery and 478 microm, 468 microm, and 474 microm after surgery. Preoperatively, the 95% limits of agreement (LoA) with US were -31 microm and +19 microm for the Pentacam device and -5 microm and +57 microm for the Orbscan II device. Postoperatively, the LoA were -40 microm and +19 microm and -51 microm and +50 microm, respectively. Corrected Orbscan II measurements gave 95% LoA of -48 microm and +6 microm before surgery and -85 microm and +5 microm after surgery.

CONCLUSIONS

Refractive surgery had a modest effect on the agreement between Pentacam readings and US measurements. With Orbscan II, the 95% LoA width nearly doubled after surgery. Although the Pentacam seems to show better agreement than Orbscan II, especially after refractive surgery, it is not advisable to use the 3 devices interchangeably in every clinical situation.

Application of special computer programs for diagnostics and treatment of amblyopia

Under amblyopia one ought to understand a variety by origin forms of reduction of vision the reason for which are functional disorders of the visual analyzer with no changes in the fundus of the eye and without any organic affections of the visual pathways and centers. At the present time, the pathophysiological mechanisms of amblyopia remain a puzzle. Diagnostics and adequate treatment of amblyopia remains so far a topical problem in clinical ophthalmology. The objective of our investigation was to estimate functional state of the visual system and efficiency of treatment of amblyopia of varying degree by means of special computer programs. Clinical researches were based on the analysis of results of 317 patients (410 eyes) with anisometropic (120 patients-120 eyes), disbinocular (127 patients-150 eyes) and refractive (70 patients-140 eyes) amblyopias of different degrees at the age from 5 to 17 with visual acuity from 0.05 up to 0.5 on the amblyopic eye, with the symptoms of functional disturbance: decrease in achromatic and color spatial contrast sensitivity in the domain of high and middle frequencies; decrease in contrast sensitivity of on-off channels of the retinal cone system; normal sensitivity to saturated colors; decrease in color sensitivity to unsaturated, red and green colors; dramatic changes in color (red and green) sensitivity in the paracentral zone (5 degrees -10 degrees ) of the retina and 20 healthy children-40 eyes. In addition to routine ophthalmologic methods we also used the special computer programs for diagnostics and adequate treatment of amblyopia: "ZEBRA"; "OFF-ON"; "eYe" ("Shooting-gallery", "Chase", "Crosses","Spiders"); "Contour"; "MEKO" ("KONSTR", "UFO", "SHOW"). Statistical analysis of results was performed with statistical method "ANOVA". Diagnostical computer methods enable quantitative estimation of the functional state of different channels of the visual system (based on the data of spatial contrast, light, color and contrast sensitivity); pathophysiologically substantiated computer methods for the treatment of amblyopia and restoration of binocular function are characterized by a high efficiency according to all accepted criteria for the evaluation of the functional state of the visual system; the patients thanks to the game character and diversity of exercises show interest in the treatment; the methods mentioned above may be actively applied in clinical practice.

Multimodal imaging in macular diagnostics: combined OCT-SLO improves therapeutical monitoring

BACKGROUND

Digital imaging methods are a centrepiece for diagnosis and management of macular disease. A recently developed imaging device is composed of simultaneous confocal scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT). By means of clinical samples the benefit of this technique concerning diagnostic and therapeutic follow-up will be assessed.

METHODS

The combined OCT-SLO-System (Ophthalmic Technologies Inc., Toronto, Canada) allows for confocal en-face fundus imaging and high resolution OCT scanning at the same time. OCT images are obtained from transversal line scans. One light source and the identical scanning rate yield a pixel-to-pixel correspondence of images. Three-dimensional thickness maps are derived from C-scan stacking.

RESULTS

We followed-up patients with cystoid macular edema, pigment epithelium detachment, macular hole, venous branch occlusion, and vitreoretinal tractions during their course of therapy. The new imaging method illustrates the reduction of cystoid volume, e.g. after intravitreal injections of either angiostatic drugs or steroids. C-scans are used for appreciation of lesion diameters, visualisation of pathologies involving the vitreoretinal interface, and quantification of retinal thickness change.

CONCLUSION

The combined OCT-SLO system creates both topographic and tomographic images of the retina. New therapeutic options can be followed-up closely by observing changes in lesion thickness and cyst volumes. For clinical use further studies are needed.

Ocular dominance diagnosis and its influence in monovision

PURPOSE

To analyze the response of normal emmetropic subjects to different ocular dominance tests and to analyze the influence of this response in surgically induced monovision.

DESIGN

A prospective study of diagnostic accuracy was carried out to analyze the different tests to determine ocular dominance, without a gold standard test.

METHODS

Nine different tests were carried out in a group of 51 emmetropic subjects to determine both motor and sensory ocular dominance. For analysis, patients were divided into two groups according to age. Normal ophthalmologic examination results were the inclusion requirement, with normal binocular vision and good stereoacuity.

RESULTS

A significant percentage of uncertain or ambiguous results in all tests performed was found, except in the hole-in-card and kaleidoscope tests. When the tests were compared, two by two, the correlation or equivalence found was low and was much lower if tests were compared three by three.

CONCLUSIONS

No clear ocular dominance was found in most studied subjects; instead, there must be a constant alternating balance between both eyes in most emmetropic persons, but not in those with pathologic features. This fact would explain the great variability both between and within different kinds of tests. Also, it would establish that the monovision technique is well tolerated in most patients, with unsuccessful results only in those patients with strong or clear dominance. Consequently, it seems appropriate to evaluate patient's dominance before monovision surgery to exclude those individuals with clear dominance.

Clinical characteristics of eyes demonstrating atypical patterns in scanning laser polarimetry

PURPOSE

To characterize which clinical features are associated with the occurrence of atypical birefringence patterns (ABP) occasionally seen with scanning laser polarimetry (SLP).

METHODS

Sixty-one subjects, including glaucoma patients, glaucoma suspects, and normal subjects, underwent a full clinical examination, standard visual field (VF) test, and a GDx-VCC SLP examination. One eye was selected from each patient. The magnitude of ABP was determined in two independent ways: using a support vector machine analysis (typical scan score (TSS)) and by a masked experienced observer. We assessed whether the magnitude of ABP was correlated with age, gender, the refractive state of the eye, corneal polarization axis and magnitude, GDx global parameters (TSNIT and NFI), and the VF status, as evident from glaucoma hemifield test (GHT), mean deviation (MD), and the pattern standard deviation (PSD).

RESULTS

Of the 61 study eyes, 27 (44%) showed an ABP, based on a TSS cutoff (<82.5). A very high correlation was found between the TSS score and the masked experienced observer score (r(2)=0.80; P<0.001). The following clinical parameters were found, on bivariate analysis, to be significantly correlated with the presence of an ABP: age (r(2)=0.086; P=0.02); corneal polarization magnitude (r(2)=0.069; P=0.04); TSNIT (r(2)=0.16; P<0.001).

CONCLUSION

The presence and magnitude of ABP did not seem to be closely correlated with most clinical parameters. A low, but statistically significant, correlation was found for age and corneal polarization magnitude (r(2)=0.086 and 0.069, respectively). A low-medium correlation was found for TSNIT (r(2)=0.16); however, we speculate that this might represent a confounding effect, rather than an underlying association. We conclude that none of the clinical parameters investigated in this study appears to be strongly correlated with the presence of an ABP on SLP scans performed using the commercially available GDx-VCC.

Can the Bruckner test be used as a rapid screening test to detect significant refractive errors in children?

PURPOSE

To assess the suitability of Brückner test as a screening test to detect significant refractive errors in children.

MATERIALS AND METHODS

A pediatric ophthalmologist prospectively observed the size and location of pupillary crescent on Brückner test as hyperopic, myopic or astigmatic. This was compared with the cycloplegic refraction. Detailed ophthalmic examination was done for all. Sensitivity, specificity, positive predictive value and negative predictive value of Brückner test were determined for the defined cutoff levels of ametropia.

RESULTS

Ninety-six subjects were examined. Mean age was 8.6 years (range 1 to 16 years). Brückner test could be completed for all; the time taken to complete this test was 10 seconds per subject. The ophthalmologist identified 131 eyes as ametropic, 61 as emmetropic. The Brückner test had sensitivity 91%, specificity 72.8%, positive predictive value 85.5% and negative predictive value 83.6%. Of 10 false negatives four had compound hypermetropic astigmatism and three had myopia.

CONCLUSIONS

Brückner test can be used to rapidly screen the children for significant refractive errors. The potential benefits from such use may be maximized if programs use the test with lower crescent measurement cutoffs, a crescent measurement ruler and a distance fixation target.

Requirements for discrete actuator and segmented wavefront correctors for aberration compensation in two large populations of human eyes

Numerous types of wavefront correctors have been employed in adaptive optics (AO) systems for correcting the ocular wavefront aberration. While all have improved image quality, none have yielded diffraction-limited imaging for large pupils (>/=6 mm), where the aberrations are most severe and the benefit of AO the greatest. To this end, we modeled the performance of discrete actuator, segmented piston-only, and segmented piston/tip/tilt wavefront correctors in conjunction with wavefront aberrations measured on normal human eyes in two large populations. The wavefront error was found to be as large as 53 microm, depending heavily on the pupil diameter (2-7.5 mm) and the particular refractive state. The required actuator number for diffraction-limited imaging was determined for three pupil sizes (4.5, 6, and 7.5 mm), three second-order aberration states, and four imaging wavelengths (0.4, 0.6, 0.8, and 1.0 microm). The number across the pupil varied from only a few actuators in the discrete case to greater than 100 for the piston-only corrector. The results presented will help guide the development of wavefront correctors for the next generation of ophthalmic instrumentation.

Holographic multivergence target for subjective measurement of the astigmatic error of the human eye

In subjective refraction the spherical and cylindrical errors of the human eye are measured. Recently, we reported a technique by which the spherical error can be measured in one step using a hologram [K. V. Avudainayagam and C. S. Avudainayagam, Opt. Lett.28, 123 (2003)]. We have now developed a holographic target consisting of sunburst patterns to measure the astigmatic error of the human eye as well. Apart from being simple, quick, and low cost, holography offers the advantage of being an open field refraction system that is devoid of the problem of proximal accommodation. We describe the holographic target, its working principles, the measurement procedure, and the initial results obtained.

[Aging effect on peripheral anterior chamber depth in male and female subjects investigated by scanning peripheral anterior chamber depth analyzer]

PURPOSE

To investigate the distribution of anterior chamber depth (ACD), the influence of age and sex on ACD, and the frequency of eyes with a shallow anterior chamber, the scanning peripheral anterior chamber (SPAC) depth analyzer was used in measuring these parameters in subjects visiting a health screening center.

METHODS

Paramedical staff measured the ACD of 285 subjects (250 eyes of 141 men, 264 eyes of 144 women) who visited the health screening center between October 31 and December 22, 2005. Based on the data provided by SPAC, the following parameters were determined : distribution of ACD from the central region to the peripheral region, distribution of the grades of ACD, frequency of suspected or possible angle-closure eyes, and number of measurable points.

RESULTS

ACD decreased with age, and peripheral ACDs of subjects 60 years of age or older were significantly shallower than those of subjects younger than 60, both in men and in women. The ACD tended to be shallower in women than in men in each generation. The high risk of angle closure among women was estimated as 1.6%, and possible angle closure was considered likely for 1.9% of women. Among men, 0.8% were considered vulnerable to possible angle closure. Women 50 years of age or older were at greater risk.

CONCLUSIONS

The decrease with age in peripheral ACD was shown quantitatively in both men and women. Eyes at risk for angle closure were more frequent in women 50 years of age or older.

Development of an instrument for measurement of light scattering at the corneal epithelial basement membrane in diabetic patients

PURPOSE

Diabetic complications are associated with abnormality of the basement membranes. We have developed a light-scattering detection system (LSDS) specifically for measurement of light scattering at the corneal epithelial basement membrane, and have determined the reproducibility and clinical significance of the results obtained by the LSDS in diabetic patients.

METHODS

Thirty nondiabetic controls and 40 diabetic subjects participated in the study. Light scattering at the corneal epithelial basement membrane was measured with the LSDS.

RESULTS

The measurement of light scattering at the corneal basement membrane was found to be reproducible. The LSDS index (mean +/- SD) was 28.1 +/- 4.8 in controls, 35.7 +/- 6.3 in mild diabetic retinopathy subjects, and 42.7 +/- 8.6 in severe diabetic retinopathy subjects. This demonstrated that the LSDS index at the corneal basement membrane is proportional to the extent of diabetic retinopathy.

CONCLUSIONS

Measurement of light scattering at the corneal epithelial basement membrane is possible with the LSDS, is relatively easy to perform, and is reproducible. The LSDS may prove suitable for the early detection of diabetic ocular complications.

Comparison of central corneal thickness measurements by visante anterior segment optical coherence tomography with ultrasound pachymetry

PURPOSE

To compare the measurement of the central corneal thickness (CCT) by Visante (Carl Zeiss Meditec, Dublin, California, USA) anterior segment optical coherence tomography (AS-OCT) with ultrasound pachymetry.

DESIGN

Population-based, cross-sectional study.

METHODS

Participants were part of a population-based study of 3280 Malay subjects aged 40 to 80 years in Singapore. Ultrasound pachmetry of CCT was performed on all participants and approximately 10% underwent further evaluation with AS-OCT.

RESULTS

Two hundred and eighty-five consecutive subjects were included, with a mean age of 57.9 (+/- 10.8) years. CCT as measured by ultrasound pachymetry was highly correlated with the equivalent AS-OCT reading (The Pearson correlation coefficient = 0.93, P < .001). However, Bland-Altman analysis showed that CCT as measured by ultrasound pachymetry was significantly higher by 16.5 +/- 11.7 microm (limits of agreement -6.1 to 39.1, P < .001).

CONCLUSIONS

CCT measured by Visante AS-OCT was highly correlated with that from ultrasound pachymetry. However, CCT readings by Visante AS-OCT were consistently less than that of ultrasound pachymetry.

Clinical Ocular Wavefront Analyzers

PURPOSE

To provide a summary of the methods used by clinical wavefront analyzers and their historical, current, and future applications.

METHODS

Review of the literature and authors' experience with the various devices.

RESULTS

A wide range of clinical wavefront aberrometers, which use different principles, are available to clinicians and researchers.

CONCLUSIONS

Applications of wavefront analyzers in vision sciences range from assessment of refractive error, refractive surgery planning, evaluation of outcomes, optimization of contact lenses and IOL designs, evaluation of pathology relating to optical performance of the eye, and evaluation of accommodation alterations.

Exophthalmometric values in a normal Turkish population living in the northeastern part of Turkey

BACKGROUND

Exophthalmometry is a simple examination procedure used for the early diagnosis of many of the orbital pathologies. The exophthalmometric measures tend to vary with age, sex, and race. Therefore, a lot of investigators conducted researches to determine the minimum, maximum, and normal values of exophthalmometric measures in their populations.

OBJECTIVE

We planned this study to gather data about the normal exophthalmometric measures in our population.

DESIGN

In this study, 240 male and 240 female subjects with age ranging from 3 to 80 years were included. The results of measures from both the eyes were evaluated for the study subjects. The protrusions of both the eyes were measured simultaneously in daylight via Hertel exophthalmometry.

RESULTS

The minimum and maximum measures of Hertel exophthalmometry for the male subjects were found to be 8 and 20 mm, respectively, with the mean being 13.49 +/- 2.6 mm. No statistically significant difference existed either between the eyes or between the age groups for the male subjects. The minimum and maximum measures of Hertel exophthalmometry for the female subjects were 8 and 19 mm, respectively, with the mean being 13.39 +/- 2.6 mm. Similar to the males, no statistically significant difference existed either between the eyes or between the age groups for the females. When the results of Hertel measurements for male and female subjects were compared, no significant difference could be found.

CONCLUSIONS

As it provides results of exophthalmometry for the Turkish population, our study is important. However, larger, nationwide, and multisite studies examining more subjects may provide more valuable data about the Turkish population.

A simple confocal fibre-optic laser method for intraocular lens power measurement

PURPOSE

To develop novel confocal fibre-optic laser method (CFOLM) for accurate and objective measuring of the dioptric power of both positive and negative intraocular lenses (IOLs).

METHODS

The CFOLM principle of operation is based on a simple apertureless single-mode fibre laser confocal design. The key element is a single-mode fibre coupler that serves simultaneously as a point light source (3-5 microm fibre diameter) used for the formation of a collimated Gaussian beam, and as a confocal point receiver that is highly sensitive to spatial displacements of the focused backreflectance laser emission. The basic CFOLM systems include IOL testing set-ups for the measurement of both positive and negative IOLs.

RESULTS

The CFOLM designs provide high accuracy (

CONCLUSIONS

The presented IOL power testing method offers a simple, accurate, objective, quick, and relatively inexpensive approach for dioptric power measurement of positive and negative IOLs. It provides an independent source of IOL power measurement data and information for evaluating the effectiveness and safety of novel IOL products.

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Key Words

• intraocular lens dioptric power
• confocal fibre-optic laser method
• single-mode fibre coupler

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MESH Headings

• Diagnostic Techniques, Ophthalmological/instrumentation
• Equipment Design
• Fiber Optic Technology/methods
• Humans
• Lasers
• Lenses, Intraocular
• Optics and Photonics

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Grants

• FD999999 Intramural FDA HHS

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