43 research outputs found
Objective Quantification of Posterior Capsule Opacification after Cataract Surgery, with Optical Coherence Tomography
PURPOSE: To evaluate posterior capsule opacification (PCO) in humans after
cataract surgery with intraocular lens (IOL) implantation, by using optical
coherence tomography (OCT-1). METHODS: Sixty-six eyes with PCO and 20 eyes with a
normal posterior capsule were analyzed. A 3-mm-long horizontal scan of the
posterior capsule was obtained. Measurements at three points and their average
were recorded. Intraoperator and interoperator reliabilities were assessed.
Investigated was peak intensity (PI) and posterior capsule thickening (PCT), with
PCT indicating the distance between two reflectivity spikes, with an approximate
axial resolution of 10 microm. Results were compared with visual acuity (VA) and
PCO type. RESULTS: Intraoperator reliability was 0.59 and 0.97 for average PI and
PCT, respectively. The interoperator concordance correlation coefficient was 0.70
and 0.82 for average PI and PCT, respectively. Median (interquartile range)
intensities of the reflectivity spike were 16.88 (dB) (range, 12.88-20.41) and
11.9 (8.58-14.28), respectively, in the PCO and control eyes (P = 0.001). PCT was
found in PCO eyes (median: 86.13 microm; range, 46.33-115.33), whereas no second
spike appeared in control eyes (P = 0.001). The area under the receiver operating
characteristic curve of the average PCT for differentiating pearl-type from
fibrosis-type PCO was 0.87 (P = 0.001). For a cutoff point of 55.3 microm, the
sensitivity was 97.5%, and the specificity was 69%. Worse VA correlated
significantly only with larger PCT (r(o) = 0.66; P = 0.01). CONCLUSIONS: OCT-1
appears useful to quantitate PCO. In addition, this system seems to discriminate
between different types of PCO. PCT may be a previously unrecognized factor in VA
degradation
Medición de presión intraocular con el tonómetro Proview®
Purpose: To evaluate a new ocular tonometer (Proview®) which functions by visualizing a phosphene after putting pressure on the upper eyelid. To ascertain its accuracy and reproducibility with respect to the Goldmann tonometer (GT).
Methods: A study on both eyes of 110 non-selected patients was performed. One measurement with GT and three subsequent measurements with Proview® were taken by the same investigator. The number of failed attempts to visualize the phosphene was recorded. We evaluated each eye separately to observe the possible learning effect.
Results: The intraocular pressure (IOP) mean with Proview® is 5 mm Hg higher than the GT (p0.05).
Conclusions: The Proview® tonometer showed low accuracy and reproducibility in comparison with the GT. This tonometer requires a long learning process before phosphene visualization. The results demonstrated that this tonometer is not clinically useful, except in patients with serious corneal diseases which make measurement with GT very difficul
Manifestaciones corneales en las enfermedades sistémicas
Systemic diseases affecting the cornea have a wide
range of manifestations. The detailed study of all
pathologies that cause corneal alteration is
unapproachable, so we have centered our interest in
the most prevalent or characteristic of them. In this
paper we have divided these pathologies in sections to
facilitate their study. Pulmonar and conective tissue
(like colagen, rheumatologic and idiopathic inflamatory
diseases), dermatologic, cardiovascular, hematologic,
digestive and hepatopancreatic diseases with corneal
alteration are described. Endocrine and metabolic
diseases, malnutrition and carential states are also
studied, as well as some otorhinolaryngologic and
genetic diseases that affect the cornea. Finally, a brie
Variabilidad en la presentación del Síndrome de Brown-McLean
Case report: We report two aphakic patients with Brown-McLean syndrome.
Discussion: One patient was affected by Marfan syndrome, after having undergone lens subluxation surgery and aphakia 23 years previously. The other patient was aphakic due to cataract surgery with complications three years before. Our cases demonstrate that this syndrome can show a variety of clinical characteristics, but peripheral corneal edema is always present. A full understanding of the clinical signs of presentation is of great importance in order to detect this syndrom
Comparison of dynamic contour tonometry (Pascal®) with pneumotonometry and Goldmann tonometry
To compare the intraocular pressure measurements as defined by the
Pascal tonometer, the Goldmann tonometer and the pneumotonometer. METHODS: This
was an observational clinical study, which included two hundred and five randomly
selected subjects recruited from the Ophthalmology Department. The intraocular
pressure measurements were performed with each tonometry technique in a
randomized order. RESULTS: The Pascal's intraocular pressure measurement was
significantly higher than that measured by the other two tonometers (p<0.05). The
quality data of Pascal was: optimum in 27.3% (56 of 205 patients), acceptable in
42% (86 of 205 patients) and unacceptable in 23.4% (48 of 205 patients). In 7.3%
(15 of 205 patients) it was impossible to obtain any measurement using Pascal. A
weak correlation coefficient between the Pascal and the Goldmann, and between
Pascal and the pneumotonometer was found. The Bland-Altman method of measurement
using these tonometers showed a high degree of discordance. CONCLUSION: As
reported by others authors, the Pascal's intraocular pressure measurement is
higher than that of the Goldmann tonometer. The measurement differs from 0.7 to
4.4 mmHg. In corneas with pathology, it is very difficult or even unacceptable to
measure the intraocular pressure using the Pascal tonometer
Amniotic membrane transplantation with fibrin glue as treatment of refractory conjunctivochalasis
Case report: A 63-year-old man with bilateral conjunctivochalasis
presented with tearing, irritation,
foreign body sensation and a delayed fluorescein
clearance test. After no symptomatic improvement
with topical treatment, surgery was carried out,
with amniotic membrane transplantation and fibrin
sealant.
Discussion: Conjunctivochalasis is a frequent
disorder that shares symptoms with dry eye syndrome.
When there is no response to topical treatment,
surgical treatment is needed. The surgical technique
described by Tseng, and based on amniotic membrane
transplantation without suture, resulted in a
very useful response, due to less inflammation and
a rapid resolution and improvement of symptom
Oftalmopatía tiroidea: determinación de parámetros de actividad clínica de la oftalmopatía tiroidea como factor pronóstico de respuesta al tratamiento inmunosupresor
Objective: To determine the usefulness of the clinical, biochemical and thyroid imaging parameters in patients with thyroid-associated ophthalmopathy, in predicting their response to immunosuppressive treatment.
Methods: This retrospective study of 16 patients with thyroid ophthalmopathy considered a number of variables including sex, age, thyroid hormone levels, treatment of the thyroid dysfunction, clinical activity score (CAS), severity (NOSPECS) of the ophthalmopathy, signs in standardized A-mode ultrasonography, in CAT and/or NMR, and previously used treatments and their effectiveness.
Results: The average age of the patients was 50.81 (S.D: 11.89) years; there were 5 males (31.3%) and 11 females (68.8%). The ophthalmopathy was classified as active in 10/16 patients (62.5%) and inactive in 6/16 (37.5%); and as moderate in 9/16 (56.25%) and severe in 7/16 (43.75%) according to the severity defined in NOSPECS. Ultrasonography was diagnostic in 100% of the cases.
The severity decreased significantly (p ≤ 0.05), however the clinical activity decrease did not reach significance (p=0.38) during immunosuppressive therapy. Better results were obtained during treatment of patients with a higher CAS (p=0.04) and in those with more severe ophthalmopathy (p=0.02). There was a tendency for the patients with higher levels of TSI to respond better to the treatment (p=0.06).
Conclusions: The CAS is the best parameter to quantify the activity of the disease and predicting the response to treatment. The higher the CAS and the more severe the ophthalmopathy, the better the response to treatment. No association existed between thyroid function and the activity or severity of the ophthalmopathy; or the effectiveness of treatmen
Comparation of the new rebound tonometer IOPen and the Goldmann tonometer, and their relationship to corneal properties
Purpose To compare the intraocular pressures
(IOPs) obtained with the IOPen rebound
tonometer, Goldmann applanation tonometer
(GAT) and the ocular response analyzer (ORA)
and investigate the effects of corneal
biomechanical properties on IOPen
measurements.
Methods A total of 198 normal eyes were
included in this cross-sectional and
randomized study. Three measurements were
taken using IOPen. Agreement between
tonometers was calculated using the Bland
and Altman limits of agreement (LoA)
analysis.
Results The median IOPen IOP was 3mmHg
below the GAT (Po0.001), 3mmHg below
the ORA IOP similar to Goldmann (IOPg),
and 3mmHg below the ORA IOP corrected
using corneal parameters (IOPcc)(Po0.01).
The LoA width between the IOPen and GAT
IOPs varied between 13.92 (mean IOPen IOP)
and 15.99mmHg (third IOPen measurement).
The central corneal thickness (CCT) was
unrelated to IOPen measurements (P40.05).
Corneal hysteresis (CH) and corneal rigidity
factor (CRF) were correlated with IOPen
and GAT.
Conclusions IOPen underestimated the IOP
compared with GAT and ORA. The effect of
measurement quality or measurement order on
IOPen was low. CCT did not affect the IOPen,
but the CH and CRF did. The LoA width
between the IOPen and GAT IOPs was higher
than between the ORA IOPg or ORA IOPcc
and GAT IOPs
Cirrus high-definition optical coherence tomography compared with Stratus optical coherence tomography in glaucoma diagnosis
To compare the retinal nerve fiber layer (RNFL) evaluation using Cirrus
optical coherence tomography (OCT) and Stratus OCT in glaucoma diagnosis.
METHODS: One hundred thirty normal and 86 patients with glaucoma were included in
this prospective study. The signal strengths of the OCTs were evaluated. The
sensitivities and specificities of global RNFL average thickness were compared in
the four quadrants and in each clock hour sector. Receiver operating
characteristic (ROC) curves, areas under the ROC (AUC), and the likelihood ratio
(LR) were plotted for RNFL thickness. Agreement between the OCTs was calculated
by using the Bland-Altman method and kappa (kappa) coefficient. RESULTS:
Twenty-three percent of all cases examined with Stratus OCT and 1.9% examined
with Cirrus OCT had a signal strength below 6 (P = 0.01). In cases with signal
strengths > or =6, the mean signal strength was higher with Cirrus OCT than with
Stratus OCT (P = 0.01). The RNFL measurements by Cirrus were thicker than those
of Stratus OCT (P < 0.05). The AUCs were 0.829 for Stratus and 0.837 for Cirrus
OCT (P = 0.706) for global RNFL average. LRs were similar in both OCTs in global
RNFL classification but varied in quadrants. The widths of the limits of
agreement varied between 42.16 and 97.79 microm. There was almost perfect
agreement (kappa = 0.82) in the average RNFL classification. CONCLUSIONS: Cirrus
OCT has better scan quality than Stratus OCT, especially in glaucomatous eyes. In
cases with good-quality scans, the sensitivity and specificity, and AUCs were
similar. The best agreement was in the global average RNFL classification. The
widths of limits of agreements exceed the limits of resolution of the OCTs
Regeneración de la superficie ocular: stem cells/células madre y técnicas reconstructivas Regeneration of the ocular
La córnea es un tejido transparente constituido
microscópicamente por 5 capas bien diferenciadas. El
epitelio corneal es esencial para la transparencia corneal
y se encuentra en continua renovación a lo largo
de la vida a partir de la población de células madre limbocorneales.
La localización de estas células madre
limbocorneales parece residir en las capas basales del
epitelio limbocorneal, de vital importancia para mantener
el microambiente de estas células madre limbocorneales,
que depende de una variedad de factores
intrínsecos y extrínsecos. La insuficiencia límbica se
produce cuando ocurre una pérdida parcial o total de
estas células madre limbocorneales. Este cuadro lleva
a una opacificación corneal con la consiguiente pérdida
de visión. En estos casos, el trasplante corneal
supone únicamente un reemplazo temporal del epitelio
corneal; es necesario llevar a cabo un tratamiento
previo con trasplante de limbo autólogo o alogénico,
que permita regenerar la población de células limbocorneales
dañadas. Para disminuir el riesgo que supone
el trasplante de limbo en el ojo donante, se han propuesto
técnicas de cultivo de células limbocorneales a
partir de pequeñas biopsias limbocorneales