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Ultrasound Biomicroscopy (UBM) of Ciliary Processes in
Uveitis
E.Saavedra, D.Socci da Costa, L.Sculley, C.Y. Lowder. Cole Eye
Institute, The Cleveland Clinic Foundation, Cleveland, OH.
Purpose: To determine the effect of duration, severity, and
location of uveitis on the length of ciliary processes.
Methods: Ultrasound biomicroscopy (UBM) of ciliary processes
was obtained in superior, temporal, nasal, and inferior quadrants in 91 uveitic
eyes and 16 normal eyes. The five longest ciliary processes measured in microns
from each quadrant were analyzed with regards to duration (acute, chronic, and
recurrent), severity (aggressive, moderate, and mild), and location (anterior,
intermediate, posterior, and diffuse) of uveitis.
Results: Ciliary processes measurements were as follows. Duration:
inferior (chronic, 356.33; acute, 423.96; normal, 534.64; P = 0.004); nasal
(chronic, 434.69; acute, 457.46; normal, 565.33; P = 0.017); temporal (chronic,
467.75; acute, 487.75; normal, 582.48; P = 0.015); and superior (chronic,
498.70; acute, 549.97; normal, 581.17; P = 0.127). Severity: inferior
(aggressive, 334.38; moderate, 392.59; mild, 429.50; normal, 523.23; P =
0.007); nasal (aggressive, 413.79; moderate, 465.99; mild, 444.98; normal,
562.74; P = 0.018); temporal (aggressive, 429.52; moderate, 509.47; mild,
492.55; normal, 577.48; P = 0.007); and superior (aggressive, 480.44; moderate,
558.62; mild, 480.08; normal, 568.33; P = 0.146). Location: inferior
(diffuse, 338.57; intermediate, 533.00; anterior, 421.18; normal, 530.81; P =
0.003), nasal (diffuse, 423.04; intermediate, 502.90; anterior, 464.67; normal,
565.47; P = 0.024), temporal (diffuse, 441.29; intermediate, 558.00; anterior,
516.77, normal, 584.99; P = 0.007), and superior (diffuse, 489.25;
intermediate, 561.60; anterior, 545.46; normal, 578.05; P = 0.190).
Conclusions: Significant differences in ciliary process
lengths were found between eyes with and without uveitis. Greatest damage to
ciliary processes was found in eyes with chronic, aggressive, and diffuse
uveitis. Superior quadrant ciliary processes were least susceptible to damage.
Information on ciliary processes may be used to guide management of patients
with uveitis.
Expression of Soluble Fas Ligand in the Cornea Inhibits
Lipopolysaccharide Induced Keratitis
V.L. Perez1, M.Gregory2, A.Marshak-Rothstein3,
B.Ksander2. 1Cole Eye Institute Cleveland Clinic
Foundation, Cleveland, OH; 2Schepens Eye Research Institute, Boston,
MA; 3Boston University School of Medicine, Boston, MA.
Purpose: We have previously shown that the selective expression
of soluble Fas Ligand (sFasL) in the cornea does not induce inflammation and
blocks the activation of neutrophils. We hypothesize that sFasL effectively
blocks the development of innate immunity and therefore will prevent
destructive corneal inflammation associated with keratitis. To test this we
examined the effects of sFasL in a model of lipopolysaccharide (LPS) induced
keratitis.
Methods: sFasL was expressed in the corneal
stroma of C57BL/6 mice by adenoviral transduction, using intra-stromal
injection of adenoviral vectors. The adenoviral vector contained a gene
encoding the soluble-only form of FasL and a GFP marker gene, both under the
control of a CMV promoter. Gene expression was confirmed by measuring GFP expression
in the cornea with fluorescent microscopy and by western blot. To induce
keratitis, LPS intrastromal injections (4ug) were performed 24 hrs after gene
transduction and corneal inflammation was monitored by slit-lamp examination
and histological analysis.
Results: Intra-stromal injection of sFasL or
control vector alone resulted in GFP expression for 30 days, without any
evidence of inflammation. Intra-stromal injection of LPS into corneas
transduced with the control adenoviral vector developed keratitis at 3-5 days,
followed by corneal scarring and neovascularization after 10 days. By contrast,
corneal expression of sFasL effectively prevented LPS induced corneal
keratitis, scaring, and neovascularization. Histological analysis of corneas
with LPS induced keratitis revealed a vigorous infiltration of neutrophils,
which was reduced in corneas treated with sFasL.
Conclusion: Corneas expressing sFasL are
protected against LPS induced inflammation and scarring. This is the first
demonstration of the role of sFasL in regulating in vivo innate immune
responses in a model of inflammation induced by LPS signaling. Furthermore, it
suggests the potential use of sFasL in treating neutrophil mediated keratitis.
Real Time Imaging of Bone Marrow-Derived Inflammatory Cell Migration into
the Cornea During Lipopolysaccharide Induced Keratitis
M.I. Roche1, A.Hsia2, L.Van Parijs1, V.L.
Perez2. 1Center for Cancer Research, MIT, Cambridge,
MA; 2Cole Eye Institute Cleveland Clinic Foundation, Cleveland, OH.
Purpose: To establish an in vivo technique to visualize in
real time the migration of bone marrow derived inflammatory cells into the
cornea during the induction of keratitis.
Methods: GFP bone marrow chimera mice were
generated to trace the migration of inflammatory cells into the cornea. Bone
marrow-derived stem cells were first harvested from the tibia and fibula of
mice treated with 5-FU. After expansion in vitro, bone marrow stem cells
were infected with a retroviral vector expressing GFP. GFP positive transfected
cells were then transplanted into a lethally irradiated mouse and
reconstitution was confirmed by flow cytometry. Keratitis was induced by
intrastromal injection of LPS (2ug) in the cornea of GFP chimera mice.
Migration pattern of GFP cells into the cornea was evaluated at different time
points by in vivo real time imaging, using fluorescent microscopy and
digital camera with time lapse software. Immunohistochemical analysis was done ex-vivo
to identify infiltrating GFP positive inflammatory cells.
Results: GFP positive cells were detected in
the peripheral blood, thymus, spleen and bone marrow of GFP bone marrow chimera
mice by flow cytometry. Bone marrow-derived GFP cells were present in the
corneal limbus prior to treatment. In vivo microscopy showed migration
of GFP positive cells from the limbus into the cornea as early as 30 minutes
after intrastromal LPS injection. Time lapse analysis revealed a dynamic and
random pattern of GFP positive cells migrating from limbus to limbus across the
cornea. Immunohistochemical staining of corneal specimens demonstrated the
presence of neutrophils and macrophages in the cornea.
Conclusion: Real time visualization of
inflammatory cells migration into the cornea can be accomplished in GFP chimera
mice using time lapse in vivo imaging. Bone marrow-derived inflammatory
cells reside in the limbus and rapidly migrate across the cornea in response to
LPS. We believe that real-time imaging in the cornea is a novel technique that
will enhance the understanding of mechanisms involved in the recruitment of
neutrophils and macrophages into sites of inflammation.
Graded Approach to Orbital Decompression for Dysthyroid
Orbitopathy
S.T. O'Connor, J.D. Perry. Cole Eye Institute, Cleveland Clinic
Foundation, Cleveland, OH.
Purpose: To report a graded technique for dysthyroid orbital
decompression and the resulting intermediate-term changes in proptosis. The
ability to access the inferior wall for decompression through a transcaruncular
technique is also described.
Methods: Retrospective case series. Charts of 27 consecutive
patients (48 eyes) were reviewed for changes in proptosis and strabismus
following different types of orbital decompression surgery.
Results: Follow-up ranged from 6 to 37 months. Three wall orbital
decompression through a lateral and transcaruncular approach was performed in
15 eyes and produced the greatest amount of proptosis reduction. The
transcaruncular approach offered easy access to the medial and inferior-medial
walls for orbital decompression but generally resulted in less proptosis
reduction. Lateral orbital decompression with removal of intraconal fat also
yielded less proptosis reduction.
Conclusions: A graded approach to orbital decompression for
dysthyroid orbitopathy leads to fairly predictable proptosis reduction. While
many surgeons use the transcaruncular approach to easily access the medial
wall, this approach may also be used to access the inferior wall for orbital
decompression.
Exposed Porous Orbital Implants Treated with Simultaneous Secondary Implant
and Dermis Fat Graft
J.D. Perry. Ophthalmology, Cole Eye Institute/The Cleveland, Cleveland,
OH.
Purpose: To describe a technique of simultaneous secondary
implantation and dermis fat graft placement for treatment of exposed porous
implants with significant overlying conjunctival and Tenon’s insufficiency.
Methods: Retrospective review of two
consecutive cases. Charts were reviewed for type and size of initial implant,
surgical therapy prior to presentation, preoperative findings, operative
report, and postoperative course after simultaneous secondary implantation and
dermis fat graft placement.
Results: Two patients underwent simultaneous
dermis fat graft placement and secondary implantation. Each patient underwent
placement of an acrylic sphere within the muscle cone. The anterior aspects of
the rectus muscles were sutured over the implant to act as the host bed for the
dermis fat graft. Both patients tolerated a new prosthesis well, with adequate
motility and cosmetic appearance.
Conclusions: Simultaneous secondary
implantation and dermis fat graft placement may adequately address avascular
porous implant exposure with significant conjunctival insufficiency.
Argpyrimidine Modification of Heat Shock Protein 27 in
the Human Lens
T.Oya-Ito1, S.Padival1, A.K. Padival2, D.G.
Smith1, J.W. Crabb3, R.H. Nagaraj1. 1Ophthalmology,
Case Western Reserve University, Cleveland, OH; 2Medicine, Veterans
Affairs Medical Center/Case Western Reserve University, Cleveland, OH; 3Cole
Eye Institute, Cleveland Clinic Foundation, Cleveland, OH.
Purpose: Argpyrimidine is a blue fluorescent product generated by
the reaction of methylglyoxal with arginine residues in proteins and
accumulates in relatively large amounts in brunescent cataractous lenses
(Padayatti et al, IOVS, 42:1299-1304, 2001). Here we investigate argpyrimidine
formation in a human lens epithelial cell line and in whole lenses.
Methods: Cytosolic proteins of the human lens
epithelial cells (HLE B-3 from Dr. Usha Andley, St. Louis, MO) were subjected
to 2-D Western analysis using a monoclonal antibody to argpyrimidine.
Water-soluble human lens proteins from a young (22 years) and an aged lens (66
years) were also probed by 2-D Western analyses with antibodies to heat shock
protein 27 (Hsp27) or to phospho-Hsp27 (ser 82), or to argpyrimidine.
Immunohistochemical studies were carried out with the same antibodies.
Immunoreactive gel components were excised, digested in situ with trypsin and
identified by LC MS/MS.
Results: Human lens epithelial cells exhibited
three strongly immunoreactive 2-D gel spots with the anti-argpyrimidine
antibody. The major component was identified as Hsp27. Minor, more acidic spots
may be phospho-Hsp27s. 2-D Western analysis of human lens proteins showed that
most of the argpyrimidine immunoreaction was with proteins that also reacted
with antibodies to Hsp27 or to phospho-Hsp27. Immunoprecipitation of
water-soluble human lens proteins with anti-argpyrimidine antibody followed by
Western analyses with anti-Hsp27 antibody confirmed that argpyrimidine
formation occurs on Hsp27 in vivo. Immunohistochemical studies in the human
lens revealed that the immunoreactivity for argpyrimidine and Hsp27 occur
mostly in the outer cortical layers and epithelial cells. Immunofluorescence
studies in the human lens epithelial cells showed Hsp27 throughout the
cytoplasm but argpyrimidine mostly in the nucleus and in the perinuclear
region.
Conclusions: Hsp27 appears to be
preferentially modified by methylglyoxal in epithelial cells and in fiber cells
of the human lens. The functional consequences of this argpyrimidine
modification are under investigation.
Chest Computerized Tomography in the Evaluation of
Uveitis
S.Chang, C.Y. Lowder, P.K. Kaiser, M.A. Meziane, T.W. Rice, D.M.
Meisler. Cole Eye Institute, The Cleveland Clinic Foundation, Cleveland,
OH.
Purpose: Computerized tomography (CT) of the chest was valuable
in the evaluation of elderly women with uveitis. We further examined the
utility of chest CT in patients with intraocular inflammation of undetermined
etiology regardless of age and gender.
Methods: Prospective case series. Chest CT was performed on all
patients with intraocular inflammation without definitive cause between January
2002 and December 2002.
Results: 42 patients (14 males, 28 females), ages 13-88 (median,
54.5 yrs) were included. All patients underwent a battery of diagnostic
laboratory studies and chest CT. Chest CT in 16 of 42 (38%) patients was
positive for parenchymal, mediastinal, and/or hilar adenopathy. Eight of 16
(50%) were women (41-88 yrs; median, 61.5 yrs) and 8 (50%) were men (26-79 yrs;
median, 51 yrs). Eleven of 16 patients with positive CT underwent
mediastinoscopy. Non-necrotizing granulomas were present in 8 patients (6
females, 2 males). Necrotizing granulomas were found in 2 patients and benign
anthracotic lymph node in 1 patient. In 6 additional patients, chest CT
revealed breast mass (1), postinflammatory change (1), interstitial fibrosis
(1), axillary lymphadenopathy (1), pleural mass (1), and subcutaneous nodule (1).
Conclusions: Chest CT is useful in the evaluation of uveitis.
Modified Transconjunctival Technique for Repair of Lower
Eyelid Involutional Entropion
E.Baylin, J.D. Perry. Cole Eye Institute, The Cleveland Clinic
Foundation, Cleveland, OH.
Purpose: To evaluate the efficacy of a modified transconjunctival
approach to repair lower eyelid entropion.
Methods: A retrospective noncomparative case series of patients
undergoing repair of involutional entropion from 5/00 through 3/02. Surgery
addressed all 3 anatomic factors underlying their entropion. Lateral canthal
resuspension addressed horizontal laxity, extirpation of the orbicularis with
monopolar cautery addressed preseptal override, and reinsertion of the
retractors addressed retractor disinsertion.
Results: Twenty-six patients (30 eyelids) underwent repair of
lower lid involutional entropion through a transconjunctival approach.
Follow-up ranged from 6 months to 3 years. Transconjunctival repair resulted in
resolution of entropion in 30/30 eyelids. There were no recurrences during the
follow-up period.
Conclusions: Modified transconjunctival lower eyelid entropion
repair is efficacious and safe with a low rate of recurrence. The
transconjunctival approach addresses all major anatomic factors related to involutional
entropion. The rate of recurrence compares favorably with the external
approaches and avoids violation of the orbital septum.
An Undescribed Autosomal Recessive Form of Strabismus with Features of Duane
Syndrome and Congenital Fibrosis of the Extraocular Muscles
E.I. Traboulsi. Pediatric Ophthalmology, Cleveland Clinic Foundation,
Cleveland, OH.
Purpose:To report a family with a previously undescribed form of
congenital strabismus.
Methods: Clinical examination and surgery on four affected members
of a family comprised of four affected siblings, four unaffected siblings and
consanguineous parents.
Results: Two brothers and two sisters (ages 4 - 17 years) had
congenital bilateral esotropia. The clinical manifestations were identical in
all four patients. There was no ptosis. Abduction was severely limited
bilaterally. Vertical ocular movements were normal. There was adduction of the
eye that attempted abduction on lateral gaze. Visual acuity was very good in
all patients, reflecting probable alternating fixation. Forced duction testing
under general anesthesia revealed severe limitation to abduction and very tight
medial rectus muscles in all patients. Bilateral medial rectus recession
resulted in good ocular alignment in primary position of gaze without any
alteration of the abnormal ocular movement pattern.
Conclusions: This family appears to have an undescribed autosomal
recessive form of an ocular motility disorder that shares features of Duane
syndrome and congenital fibrosis of the extraocular muscles. Genetic mapping
and candidate gene analysis studies are under way.
The Prevalance of Glaucoma in a Population-Based Sample of Elderly Saudis
S.D. Smith1, I.Al-Jadaan2, M.H. Jabak2,
A.Al-Rajhi2, A.Al-Saif2. 1Cole Eye
Institute, Cleveland Clinic Foundation, Cleveland, OH; 2King Khaled
Eye Specialist Hospital, Riyadh, Saudi Arabia.
Purpose: To determine the prevalence of glaucoma by mechanistic
subtype in a population-based sample of elderly Saudis, age 60 years and older.
Methods: A population-based sample of 785 Saudi citizens age 60
years and older was selected from a census maintained through community health
centers near Al-Kharj, Saudia Arabia. Comprehensive ophthalmic examination was
performed for each subject, including gonioscopy. Patients in whom suspicion of
glaucoma was present were sent for visual field testing with the Dicon LD400 40
point threshold-related suprathreshold screening exam with quantification of
missed points. Final classification of glaucoma status was made by two trained
glaucoma specialists. Each reviewed the results of the clinical examination and
visual field testing, and classified subjects as normal, possible, probable, or
definite glaucoma. For purposes of classification, glaucoma was defined as the
presence of glaucomatous optic nerve damage with visual field loss. The level
of IOP was not a criterion for the diagnosis of glaucoma. In addition to
assigning a category of diagnostic certainty, the glaucoma experts assigned a
glaucoma mechanism for each eye. Disagreements in classification were
reconciled by joint review of study charts when necessary.
Results: A total of 565 (72.0%) subjects agreed to participate. Each
decade of increasing age was associated with an odds ratio for having probable
or definite glaucoma of 1.49 (95% CI [1.05, 2.12], p=0.03). The median IOP of
subjects with glaucoma was 27 mm Hg, compared to 17 mm Hg among the remaining
subjects (p=0.0001) The most common glaucoma subtypes were primary narrow-angle
and primary open-angle glaucoma, with prevalence of 3.9% (95% CI [2.5,5.8]) and
3.7% (95% CI [2.3,5.6]), respectively. Among subjects without probable or
definite glaucoma, the presence of occludable angles 19.0% (95% CI[15.6,22.7]).
Conclusions: In this population, primary narrow-angle glaucoma is
common, with prevalence approaching that reported in east Asian populations.
Primary open-angle is also common, with prevalence intermediate to that
reported in other racial groups of comparable age. The high prevalence of
primary narrow-angle glaucoma and occludable angles in Saudi Arabia indicates
the need to develop effective methods of population-based screening and
prevention in that region.
High-Speed Optical Coherence Tomography of Anterior Segment Surgical Anatomy
and Pathology
D.Huang1, M.R. Chalita1, Y.Li2, C.Y.
Lowder1, D.M. Meisler1, A.M. Rollins2, J.A.
Izatt3. 1Cole Eye Institute, Cleveland Clinic
Foundation, Cleveland, OH; 2Biomedical Engineering, Case Western
Reserve University, Cleveland, OH; 3Biomedical Engineering, Duke
University, Durham, NC.
Purpose: To use a high-speed corneal and anterior segment optical
coherence tomography (CAS-OCT) system to image ocular pathologies and surgical
anatomy.
Methods: A high-speed (4000 a-scan/sec) wide-field (16 mm)
CAS-OCT system was developed. It uses a longer wavelength (1.3 microns)
compared to retinal OCT systems (0.8 microns). OCT scans were performed on 11
eyes with anatomic features of interest.
Results: OCT of post-surgical cornea (LASIK, penetrating
keratoplasty), trabeculectomy bleb, anterior chamber intraocular lens (IOL),
iris masses and cataract were obtained. Full-thickness imaging of sclera, angle
and iris was possible. No appreciable motion artifact was noted at 8
frames/sec. The entire LASIK flap could be fully visualized. In keratectasia,
OCT showed relative corneal thinning in the area of steepening. Causative
factor such as inadequate residual posterior stromal thickness and excessive
flap thickness could be quantitatively assessed. The longer 1.3-micron
wavelength allowed the angle recesses to be visualized. The recess-to-recess
anterior chamber width could be directly measured, along with other parameters
such as the anterior chamber depth and crystalline lens vault. In
trabeculectomy images, the sclerotomy site could be visualized as well as the
whole bleb anatomy. The anterior chamber IOL were seen and the footplates
position were recorded. Iris and ciliary body masses could be precisely
delineated and accurately measured.
Conclusions: The CAS-OCT prototype allowed non-contact visualization
and measurement of corneal and anterior segment pathologies and surgical
anatomy. The high speed allows quantitative measurements of relevant biometric
dimensions. The longer wavelength (1.3-micron) allows greater penetration
through highly scattering tissue such as limbus and sclera.
Anterior Chamber Width Measurement by Optical Coherence
Tomography
J.A. Goldsmith1, Y.Li1, M.R. Chalita1,
V.Westfall2A, C.Patel2A, A.M. Rollins2B,
J.Izatt3, D.Huang1. 1Ophthalmology, Cole
Eye Institute/Cleveland Clinic, Cleveland, OH; ABiomedical
Engineering, BDepartment of Medicine, 2Case Western
Reserve University, Cleveland, OH; 3Biomedical Engineering, Duke
University, Durham, NC.
Purpose: Measurement of anterior chamber (AC) width with optical
coherence tomography (OCT).
Methods: A high-speed, wide-field 1.3-micron
wavelength OCT system was developed. OCT AC scans were made on 40 normal eyes
(20 subjects). White-to-white corneal diameter was measured with a corneal
ruler.
Results: AC width averaged 12.5 mm (±0.47 mm
SD, 11.5 to 13.5 range) and reproducibility was 0.11 mm. AC width-corneal
diameter difference averaged 0.75 mm (±0.44 mm SD, range - 0.31 to + 1.84 mm).
Conclusions: AC width is not accurately
predicted by external corneal diameter. OCT can precisely measure AC dimension
to improve AC-IOL sizing.
Automated Anterior Chamber Biometry with High-speed
Optical Coherence Tomography
Y.Li1, M.R. Chalita2, J.Goldsmith2,
V.Westphal1, B.A. Bower1, R.Shekhar2, A.M.
Rollins1, J.A. Izatt3, D.Huang2. 1Case
Western Reserve Univ, Cleveland, OH; 2Cleveland Clinic Foundation,
Cleveland, OH; 3Duke University, Durham, NC.
Purpose: Accurate sizing of angle-supported anterior chamber
intraocular lens (AC-IOL) is crucial in preventing complications. To accurate
measure AC width and other dimensions, we developed a high-speed optical
coherence tomography (OCT) system and automated image processing.
Methods: The OCT prototype operated at 1.3 micron wavelength and
was capable of 8 images/sec at 500 axial scans/image. Scan dimensions are 16mm
wide and 6mm deep (in air). The OCT scanner was adapted to a slit-lamp with
video camera. Horizontal cross-sectional OCT images of the anterior segment was
obtained. Each of the 40 eyes from 20 healthy volunteers was scanned 3 times. A
computer algorithm was developed to measure angle-to-angle AC width, AC depth,
and lens vault. These measurements were also obtained manually by 3
ophthalmologist using computer calipers on screen displays of OCT images.
Results: The computer algorithm successfully measured AC diameter
and AC depth from all 120 OCT images. The difference between computer and human
measurements was 0.13+/-0.14 mm (mean +/- SD) for AC width, 0.04+/-0.04 mm for
AC depth, and 0.08+/-0.06mm for lens vault. The image-to-image reproducibility
of computer measurements (pooled SD) is 0.11 mm for AC width, 0.04mm for AC
depth, and 0.07mm for lens vault. The image-to-image reproducibility of human
measurement was 0.13 mm for AC width, 0.05 mm for AC depth, and 0.06mm for lens
vault. The agreement between the human raters (inter-rater SD by analysis of
variance) is 0.30 mm for AC width, 0.05 mm for AC depth, and 0.08mm for lens
vault.
Conclusion: Due to its longer wavelength, the OCT system was able
to penetrate and image the angles. The speed was sufficient high for
reproducible AC width measurement. The automated computer algorithm agrees well
with human raters. The use of a computer measurement algorithm avoids the
relatively large disagreement between human raters for AC width. The use of OCT
to directly measure AC width may improve the fitting of AC-IOL and avoid
complications such as IOL dislocation and pupil ovalization.
Decreasing Wavefront Aberrations of Irregular Optics
Resulting from Corneal Laceration
P.A. Kusy, M.D. Toabe, H.A. Harris, D.W. Barnhart. Cole Eye
Institute, Cleveland, OH.
Purpose: Analysis of aberrations present in a distorted cornea
via laceration injury, and possible correction methods to increase visual
acuity.
Methods: Fitting contact lenses of different optical designs and
evaluation of their effectivity on improvement of best visual acuity.
Results: Variables in BVA dependent upon contact lens design.
Conclusions: Visual acuity affected by corneal lacerations can be
improved by neutralization of irregular optics by the lacrimal lens formation
allowed by the Orion XL-Therapeutic Contact Lens design. Wavefront analysis can
assist in determining the source and degree of corneal aberrations.
Inhibition of Nitric Oxide Synthesis in Corneas in
Corneal Storage Media
D.M. Meisler1A, T.Koeck1B, J.T. Connor1C,
K.S. Aulak1B, B.H. Jeng1A, J.G. Hollyfield1A,
D.J. Stuehr1B. ACole Eye Instititute, BDepartment
of Immunology, CDepartment of Biostatistics and Epidemiology, 1Cleveland
Clinic Foundation, Cleveland, OH.
Purpose: To determine if nitric oxide synthesis by human corneas
can be inhibited during corneal storage.
Methods: 1.0 mM of monomethyl-L-arginine
(LMMA), a nitric oxide synthase inhibitor, was added to four chambers of
Optisol GS corneal storage media, each containing a viable human corneal
button. Each chamber was sampled (0.4 ml) for baseline measurements and at
one-day intervals for 21 days. Four chambers of Optisol GS corneal storage
media, each containing companion corneas to the corneas exposed to LMMA served
as controls and were sampled in tandem with the LMMA-containing chambers. An
unused vial of Optisol GS corneal storage media served as a background media
control. The total amount of nitrate and nitrite (stable breakdown products of
nitric oxide) in each sample was determined using a spectrophotometric method
based on the Greiss reaction. A polynomial random coefficients model, fitting
Concentration on linear, quadratic, cubic, and square-roots terms times time in
Days, was fit. The derivative of the fitted equation was also investigated to
estimate rates of accumulation over time.
Results: Data from the daily sampling of
LMMA-containing media showed a statistically marked reduction in the rate of
accumulation of nitrate and nitrite concentrations, as compared to controls
(p<0.01), up until Day 10 when the rates became and remained equivalent.
There was a marked reduction in the levels of nitrate and nitrite accumulation
in the study chambers as compared to control chambers for each time point
during the course of the study (p<0.01, e.g. 1.03 μM 95% CI 0.92-1.16
μM at 10 days). There was also a substantial delay (3 days) in the rise of
nitrate and nitrite concentration in the study group. Accumulation rates were
more than 0.15 μM/day higher for the first three days in the media without
LMMA. No nitrate and nitrite were detected in the background media control
sample.
Conclusions: The progressive increase in
nitrate and nitrite accumulation in corneal storage media can be delayed and
blunted by the addition of a nitric oxide synthase inhibitor. Given the toxic
free radical properties of nitric oxide, corneas in storage awaiting
transplantation may benefit from having a nitric oxide synthase inhibitor added
to storage media.
Improvment in Stereoacuity Is Less than Expected After Treatment of
Anisometric Amblyopia in Children Without Strabismus
B.I. Riemann1, C.D. Riemann MD2, S.Crowe COT3,
E.I. Traboulsi MD3. 1Strabismus, Cincinnati Eye
Institute/ Cole Eye Institute, Cincinnati, OH; 2Retina, Cincinnati
Eye Institute, Cincinnati, OH; 3Pediatric Ophthalmology, Cole Eye
Institute, Cleveland, OH.
Purpose: To determine the relationship between stereoacuity (SA)
and visual acuity (VA) in children with anisometropic amblyopia (AA).
Methods: SA and VA were retrospectively analyzed before and after
amblyopia treatment in 44 children with AA.
Results: SA improved from 200 to 152 degrees of stereo arc (p<
0.005) and VA in amblyopic eyes improved from 0.3 ± 0.2 to 0.5 ± 0.3
(p<0.0000001) after amblyopia treatment. The improvement in SA was markedly
less than expected given the improvement in VA. (p<0.005) using both
internal and historic controls.
Conclusions: The modest improvement in SA in the setting of a
larger improvement in VA suggests the existence of “stereoscopic amblyopia” as
an entity which is distinct from and less responsive to treatment than
amblyopia of VA in orthotropic children with AA.
The Portal Color Sort Test - A New Touch Screen
Computerized Test of Color Discrimination
A.Melamud, E.Simpson, E.I. Traboulsi. Cole Eye Institute, Cleveland
Clinic Foundation, Cleveland, OH.
Purpose: To introduce the Portal Color Sort Test (PCST), a
computer-based test of color vision, and to compare it to the
Farnsworth-Munsell (FM) 100 Hue test (FMHHT) in normal subjects. The FMHHT is a
widely accepted instrument for the testing of color discrimination. Its
advantage over other psychophysical tests of color discrimination is its
ability to distinguish trichromats into categories (superior, average, and
poor). Its disadvantages include the need for special ambient illumination and
the length of time it takes for its completion. The touch screen computer-based
Portal Color Sort Test (PCST) has a design similar to the FM 100-Hue but
consists of only 36 color plates in 4 sets of 9 plates. The test is based on
the accuracy with which an individual arranges each set of 9 plates on a
computer screen from one shade of one color to another shade of another color.
Methods: 10 subjects with presumed
"normal" trichromatic vision and without known eye disease have been
recruited to date. Each subject underwent a series of color vision tests that
included the 15 plate Ishihara test, the D-15 FM test, the FM-100 hue test and
the PCST under rigorous standardized conditions and as recommended by the respective
manufacturers. The PCST was administered twice; once at the beginning and once
at the end of the session. Tests were recorded and scored according to the
manufacturers' instructions.
Results: Of the ten trichromats tested, 3
received "Superior" scores (<20) on the FMHHT and received a score
of 0 (no error) on the PCST. 7 subjects tested "Average" (score =
20-100) on the FMHHT and had error scores of 0 to 12 (average 5.57) on the
PCST. On repeated administration of the PCST, all but one of these 7 subjects
received a perfect score of 0. The one subject who had a score of 4 on his
second attempt had the highest error score of 12 on the first attempt, and the
second highest error score on the FMHHT; he probably has poorer color
discrimination than the rest of subjects in the FMHHT "Average"
category. The average time to complete the FMHHT was 14 minutes. The average
time to complete the PCST was 3 minutes.
Conclusions: Our preliminary results indicate
that the PCST allows an approximately 4 – 5 times faster testing of color
discrimination than the FMHHT. Subjects who have excellent color discrimination
ability on the FMHHT have perfect scores on the PCST; those with average color
discrimination ability on FMHHT have error scores of 0-12 on the PCST. Additional
data is currently being collected to define the range of scores in the
different categories of color discrimination abilities on the PSCT, including
patients with known color vision defects.
Light Induced Protein Modifications and Lipid Oxidation Products in Rat
Retina
K.Renganathan1A, M.Sun1B, R.Darrow2, L.Shan1B,
X.Gu1A, R.G. Salomon3, S.Hazen1B,
D.Organisciak2, J.W. Crabb1A. AOphthalmology,
Cole Eye Institute, BLerner Research Institute, 1Cleveland
Clinic Foundation, Cleveland, OH; 2Department of Biochemistry and
Molecular Biology, Wright State University, Dayton, OH; 3Department
of Chemistry, Case Western Reserve University, Cleveland, OH.
Purpose: To better understand the mechanisms of oxidative damage
in retinal pathology, we have sought the identity of lipid oxidation products
and protein adducts in rat retina after in vivo exposure to damaging
light
Methods: Albino rats maintained in a dark environment for 2
months were exposed to intense green light (1500 lux) for 1 or 4 hours and
sacrificed immediately following light treatment. Retinas were isolated and
immediately protected with antioxidants. Lipids were extracted with
chloroform/methanol and analyzed by LC MS. Proteins were extracted with
SDS-PAGE sample buffer and analyzed by Western blotting.
Results: Lipid oxidation products in rat retina from
docosahexaenoyl phosphatidylcholine (DHA-PC), arachidonoyl (AA)-PC, and
linoleyl (LA)-PC were more abundant after 4 h of light exposure than after 1h
or no light. Anti-carboxyethylpyrrole, anti-argpyrimidine and
anti-nitrotyrosine immunreactivities were significantly greater after 4h light
exposure compared with control animals maintained in the dark. Anti-opsin
immunoreactivity was also significantly greater after light treatment.
Conclusions: Current results are consistent with our recent
observation that light modulates protein nitration in rat retina (2002 Mol.
& Cell. Proteomics 1, 293). Intense light also generates lipid
oxidation products in rat retina in vivo that result in oxidative
protein modifications such as carboxyethylpyrrole from DHA containing lipids.
Argpyrimidine, derived from methylglyoxal, appears to be another protein
modification induced by light. The apparent increase in opsin after light may
be due to modifications that increase the solubility and extractability of this
integral membrane protein. These findings justify further consideration of
lipid oxidation products and protein modifications as mediators in the
light-induced biochemical sequel leading to photoreceptor cell death.
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