• Cyclosporine 0.1 Percent Emulsion Twice Daily Safe and Well-Tolerated in Dry Eye Patients
• Myopic and Hyperopic LASIK Have Different Patterns of Higher-Order Aberration Induction
• Low Rate of Malignant Transformation of a Choroidal Nevus in U.S. White Population
• Graduated Pneumatic Retinopexy for Internal Retinal Detachment Following Failed Scleral Buckle
• Phase 2 Pegaptanib Trial Shows Visual Acuity Gain in Patients With Diabetic Macular Edema
• Deep Lamellar Endothelial Keratoplasty an Alternative in Patients With Endothelial Dysfunction
• Endocanalicular Laser Dacryocystorhinostomy an Incision-Sparing Approach for Duct Obstruction
• Posterior Sub-Tenon’s Capsule Triamcinolone Acetonide Injection for Diffuse Diabetic Macular Edema
• Treatment of Patients in Glaucoma Population Varies Widely
• Fully Automated Molecular Assay Rapidly Diagnoses Adenoviral Keratoconjunctivitis
American Journal of Ophthalmology:
• Positron Emission Tomography/ Computed Tomography Staging of Metastatic Choroidal Melanoma
• Comparison Between Accommodative and Monofocal IOLs
• Survival Analysis of Conjunctival Limbal Graft and Amniotic Membrane Transplantation
• Randomized Clinical Trial of LASIK With Two Different Lasers
• Cosmetic Significance of External Dacryocystorhinostomy Scars
• Central Retinal Artery Occlusion: Visual Outcome
• Macular Hole Development in Fellow Eyes of Patients With Unilateral Macular Hole
• The Association Between Hypermetropia and Essential Hypertension
Roundup of Other Journals:
• Increasing Dose and Frequency of Interferon Beta-1a in Patients With Relapsing Multiple Sclerosis
• Monocular Autorefraction as Pediatric Eye Screening Tool
• New Application of Optical Coherence Tomography to Assess Central Corneal Thickness
• Echographic Examination With New-Generation Contrast Agent in Choroidal Malignant Melanoma
Cyclosporine 0.1 Percent Emulsion Twice Daily Safe and Well-Tolerated in Dry Eye Patients
Barber et al. have found that during a one- to three-year period, cyclosporine 0.1 percent ophthalmic emulsion is safe, well-tolerated and not associated with systemic side effects.
This nonrandomized trial was an extension of two ophthalmic cyclosporine Phase 3 clinical trials. Four hundred twelve patients who previously dosed for six to 12 months with cyclosporine 0.05 percent or 0.1 percent in prior Phase 3 trials instilled ophthalmic cyclosporine 0.1 percent twice daily into both eyes for up to three consecutive 12-month extension periods. During the first 12-month extended period, treatment resulted in modest improvements in the dry eye disease. This was an expected result, according to the authors, because participants had been treated with cyclosporine emulsion prior to the study.
No serious treatment-related adverse events occurred during the trial, and 95.2 percent of the participants said they would continue cyclosporine therapy; 97.9 percent said they would recommend it to other dry eye patients. The investigators conclude these results support the existing favorable safety and tolerability profile for cyclosporine 0.05 percent ophthalmic emulsion.
Myopic and Hyperopic LASIK Have Different Patterns of Higher-Order Aberration Induction
In a retrospective comparative case series of 100 eyes (50 myopes and 50 hyperopes) of 59 patients, Kohnen et al. compared the change in anterior corneal higher-order (3rd–5th order) aberrations induced by myopic and hyperopic LASIK.
The researchers found that myopic LASIK induced positive spherical aberrations and positive secondary astigmatism, while hyperopic LASIK induced negative spherical aberrations and negative secondary astigmatism. Additionally, hyperopes showed a greater change in total higher order aberrations, with coma-like aberrations being more pronounced in hyperopic treatments. Third and 5th order aberrations showed a more pronounced increase in the hyperopic group, while 4th order aberrations increased with myopic treatments and decreased with hyperopic ones.
The authors theorize the higher coma induction in hyperopic LASIK procedures is due to the steeper gradients of the hyperopic ablation profiles inducing more spherical aberrations. They conclude that different patterns of higher order aberration induction in myopic and hyperopic LASIK provide key information in developing future aberration-optimized algorithms.
Low Rate of Malignant Transformation of a Choroidal Nevus in U.S. White Population
Assuming that all melanomas arise from preexisting nevi, published data indicate there is a low rate—one in 8,845—of malignant transformation of a choroidal nevus in the American white population.
Singh et al. conducted a literature review to determine the annual rate of malignant transformation of a choroidal nevus. At the time of the review, an estimated 8,864,625 individuals in the United States had a choroidal nevus. The number of individuals with choroidal melanoma in the corresponding age- and race-matched population was estimated to range from 989 to 1008. The authors cautioned that this estimated risk applies only to relatively small choroidal melanocytic lesions, and the risk may be higher for “suspicious nevi.”
Based on these findings, the investigators recommend that patients with choroidal nevi (less than 6 millimeters and flat to minimal elevation) should only be followed periodically as part of the preventive eye care recommendations of the American Academy of Ophthalmology. They also call for an observational study for better epidemiological characterization of choroidal nevi.
Graduated Pneumatic Retinopexy for Internal Retinal Detachment Following Failed Scleral Buckle
Ahmad M. Mansour describes a graduated pneumatic retinopexy positioning approach to manage retinal detachment from inferior retinal breaks following failed scleral buckling surgery. His retrospective review involved 17 eyes of 17 patients in whom an internal tamponade was achieved by 10-degree Trendelenburg, 10-degree neck hyperextension, 10-degree ocular supraduction, and a large intravitreal gas bubble. This positioning was assumed most of the time for the first 48 hours, followed by part-time positioning for one week.
The procedure was well-tolerated, with the retina settling initially within 72 hours in all patients. Retinal attachment was maintained in 15 of 17 (88.2 percent) patients, who were followed for a mean of 2.8 years (range 0.1 to 11.5 years). Two patients redetached after five days and four months, respectively, and six patients required antiglaucoma medications.
Mansour observed good patient compliance, including in obese patients. He concludes that graduated pneumatic retinopexy offers a relatively simple alternative for inferior retinal detachment after failed scleral buckle.
Phase 2 Pegaptanib Trial Shows Visual Acuity Gain in Patients With Diabetic Macular Edema
Results from a Phase 2 trial of pegaptanib sodium injection, an anti-vascular endothelial growth factor aptamer, suggest an overall visual acuity gain as well as reduced risk of visual acuity loss in patients with diabetic macular edema.
The Macugen Diabetic Retinopathy Study Group conducted a randomized, double-masked, multicenter (24 sites), dose-ranging, controlled trial with 172 patients who were randomized to one of four treatment arms: 0.3 milligrams, 1 mg or 3 mg pegaptanib or sham injection.
All pegaptanib doses were well-tolerated, and the outcomes appeared to favor the 0.3-mg dose in terms of mean visual acuity, greater decrease in retinal thickness and reduced need for focal/ grid laser intervention.
No serious systemic adverse events were reported, although endophthalmitis occurred in one in 652 injections. The authors have planned prospective clinical trials to confirm observations of pegaptanib safety, efficacy and patient tolerance.
Deep Lamellar Endothelial Keratoplasty an Alternative in Patients With Endothelial Dysfunction
Six-month results from a large prospective study indicate that deep lamellar endothelial keratoplasty (DLEK)—an endothelial replacement surgery that eliminates surface corneal incisions or sutures—is a reasonable alternative to penetrating keratoplasty in patients with endothelial dysfunction who need transplant surgery.
Terry et al. performed DLEK surgery on 98 eyes with corneal edema from Fuchs’ dystrophy and pseudophakia. Of these patients, 36 eyes received a 9-millimeter scleral access incision and 62 eyes received a 5-mm scleral access incision. A 7.5- to 8.0-mm posterior lamellar disc of donor tissue was placed through the pocket. Six months after surgery, all 98 DLEK corneas were clear with grafts healing in good position.
The surgery resulted in a BCVA of 20/46. It also minimized astigmatism and provided a healthy donor endothelial cell count and function. The authors conclude that while DLEK appears to be a viable alternative, a multicenter randomized clinical trial should be done to confirm these findings.
Endocanalicular Laser Dacryocystorhinostomy an Incision-Sparing Approach for Duct Obstruction
Hong et al. conducted a retrospective review of 108 patients who underwent 118 consecutive endocanalicular laser dacryocystorhinostomy (ECL DCR) surgeries. A 73.6 percent success rate was achieved in the 102 initial ECL DCR surgeries; 27 of the surgeries were considered failures due to recurrent epiphora, discharge or reflux on nasolacrimal irrigation. Some of the failed patients underwent successful repeat procedures, increasing the overall success rate to 81.5 percent. In addition, the success rate of this technique as a repeat procedure after previous external, endonasal or ECL DCRs was 87.5 percent.
The authors credit the 800-micrometer, conical, infrared-coated, fiber-optic tip as a key to this procedure because the shape and coating confine the laser energy to the tip. They conclude that while neither ECL DCR nor any other endoscopic technique has matched the success rate of external DCR, technological advances—as well the absence
of a facial incision—will likely bring incision-sparing approaches to the
forefront of lacrimal surgery.
Posterior Sub-Tenon’s Capsule Triamcinolone Acetonide Injection for Diffuse Diabetic Macular Edema
The increasingly routine use of sub-Tenon’s capsule (SBT) triamcinolone acetonide (TA) to treat various inflammatory eye diseases prompted Cardillo et al. to investigate its therapeutic response and ocular tolerance for diffuse diabetic macular edema.
In this prospective study, one eye of 12 patients randomly received a single 4-milligram TA intravitreal (IVT) injection, and the fellow eye received a 40-mg TA posterior SBT injection. Quantitative measurements of retinal thickness showed a reduction from baseline exceeding 56 percent (IVT TA) at the one-month follow-up visit and 29 percent (SBT TA) at the three-month follow-up visit. At one and three months, IVT TA injected eyes had thinner central macular thickness measurements compared with SBT TA injected eyes. The mean reduction in macular thickness was 15 percent (IVT TA) and 16 percent (SBT TA) at six months.
The authors conclude that while the study does not necessarily support the use of corticosteroids for these patients, the approaches may be equally well tolerated with short-term performance favoring IVT TA.
Treatment of Patients in Glaucoma Population Varies Widely
Using billing records from a large, U.S., managed care organization, Friedman et al. documented a wide variation in treatment among individuals in a population of glaucoma and glaucoma-suspect patients.
After reviewing data from 35,754 diagnosed suspects, 5,265 diagnosed glaucoma patients and 2,633 individuals coded as having cupping of the optic disc, they found that women were more frequently identified as diagnosed suspects or diagnosed glaucoma patients, but were 24 percent less likely to be treated than men. In addition, younger people appeared to be treated less frequently than older ones. Disparities were also seen in treatment by region, with the Northeast having lower treatment rates than other regions of the country.
Monitoring of glaucoma also varied: individuals initially diagnosed by an optometrist were less likely to undergo a follow-up visit, a visual field test or optic nerve head imaging. The authors assert that understanding the sources of these variations will help to determine how to arrive at better management
Fully Automated Molecular Assay Rapidly Diagnoses Adenoviral Keratoconjunctivitis
Koidl et al. have found that a new molecular assay based on automated nucleic acid extraction and real- time polymerase chain reaction (PCR) can rapidly diagnose adenoviral keratoconjunctivitis.
The MagNA Pure Compact System is a new technology for automated extraction of nucleic acids. It uses silica beads that bind nucleic acids to their surfaces and transfer them through various steps of the extraction process within one hour.
The LightCycler instrument allows high-speed thermal cycling and online real-time fluorescence monitoring. When clinical specimens were tested, 15 of 52 conjunctival smears were found to be positive for human adenovirus DNA. Identical results were found when compared with the reference test kit.
The authors conclude that while this new molecular assay may not replace culture completely, it can easily be added to existing molecular protocols in routine diagnostic laboratories to detect different viruses producing ocular infections.
Positron Emission Tomography/ Computed Tomography Staging of Metastatic Choroidal Melanoma
American Journal of Ophthalmology
Kurli et al. evaluated whole-body positron emission tomography/ computed radiographic tomography (PET/CT) in the staging of 20 patients with metastatic choroidal melanoma. Biopsies were performed to confirm the presence of metastatic disease.
Of the 20 patients who underwent PET/CT, 18 were imaged because of abnormal clinical, hematologic or radiographic screening during the course of follow-up after plaque brachytherapy or enucleation. Two were imaged before treatment of their primary tumor. PET/ CT revealed or confirmed metastatic melanoma in 8 (40 percent) of these
20 patients. The mean time from initial diagnosis to metastasis was 47 months (range 0 to 154). The most common sites for metastases were the liver (100 percent), bone (50 percent), lung (25 percent), lymph nodes (25 percent) and subcutaneous tissue (25 percent). Cardiac, brain, thyroid and posterior abdominal wall lesions (12.5 percent) were also noted. Six patients (75 percent) had multiple organ involvement. PET/CT imaging also detected benign lesions of the bone and lymph nodes in three patients (15 percent). All patients had hepatic metastases, and liver enzyme assays were abnormal in only one (12.5 percent) of eight patients.
The authors conclude that PET/CT imaging is a sensitive tool for the detection and localization of hepatic and extrahepatic (particularly osseous) metastatic choroidal melanoma.
Comparison Between Accommodative and Monofocal IOLs
Archives of Ophthalmology
Heatley et al. examined the near visual performance of an accommodative IOL when compared with a standard monofocal IOL in a randomized fellow eye study.
Thirty patients (60 eyes) with bilateral cataracts but otherwise normal eyes were randomized to receive either the 1CU accommodative IOL (HumanOptics) in their first eye or the Acrysof MA30 monofocal IOL (Alcon). The alternative lens was then implanted in the second eye four to six weeks later. At all follow-up visits, a full assessment was made of distance, near and reading visual performance, and accommodative amplitude.
Data are available for all patients at six months and for 20 patients at one year. At six months, no difference was found in distance-corrected acuity between the two IOLs. Of the 1CU eyes, nine patients (30 percent) could read J6 or better at a reading speed of 80 words/minute or better. In these nine patients, the mean difference in the amplitude of accommodation between the two eyes was 0.71 D.
The authors conclude that no measurable variable was able to distinguish eyes that developed functional reading vision from those that did not. The accommodative IOL appears to produce improved near vision in some eyes, but it does not work in all eyes. In eyes where there is apparent accommodation, there is a discrepancy between subjective reading performance and the modest measured increase of accommodative amplitude.
Survival Analysis of Conjunctival Limbal Graft and Amniotic Membrane Transplantation
American Journal of Ophthalmology
Santos et al. evaluated the survival of conjunctival limbal grafts and amniotic membrane transplantation (AMT) for total limbal stem cell deficiency (LSCD) in a prospective, noncomparative and interventional case series. They also looked at the influence of several parameters on surgical outcome.
Thirty-three eyes of 31 patients with total LSCD underwent conjunctival limbal grafts and AMT. Only those eyes with LSCD secondary to chemical burn or Stevens-Johnson syndrome were included. Ten eyes (30 percent) underwent conjunctival limbal autograft
and 23 (70 percent) underwent conjunctival limbal allograft from living HLA-matched donor.
Graft survival was seen in 13 eyes (40 percent) at one year and in 11 eyes (33.3 percent) at two years, with a cumulative survival of 33 percent after a mean follow-up time of 33 months. Increase in postoperative visual acuity was observed in 20 eyes (60.6 percent) during this period. Negative impact on graft survival was observed for patients with Stevens-Johnson syndrome, dry eye, keratinization, eyelid abnormalities and allogeneic conjunctival limbal transplantation (independently of HLA compatibility) (P <0 .05). Preoperative dry eye was the most important negative prognostic parameter for surgical outcome (P < 0.001).
Conjunctival limbal grafts associated with AMT are useful for restoring corneal epithelium phenotype in eyes with total LSCD. However, the cumulative survival declines substantially over a two-year period.
Randomized Clinical Trial of LASIK With Two Different Lasers
American Journal of Ophthalmology
Twa et al. compared optical quality, visual function, corneal shape, ocular wavefront aberrations and patient-reported symptoms and satisfaction after LASIK in a prospective, randomized clinical trial.
Sixty eyes of 30 patients with low to moderate myopia were randomized to receive LASIK in one eye with the Technolas 217A (Bausch & Lomb); the other eye was treated with the Visx S3. Patients were followed up for six months after surgery. The primary outcome measure was BCVA.
At six months, the mean best-spectacle corrected high contrast visual acuity was similar between the two treatment groups. Uncorrected visual acuity differences were also not significant. The difference in residual spherical equivalent subjective refractive error between treatment groups was –0.15 D. Spherical aberration increased in both groups after treatment, and the change in root mean square ocular wavefront error was greater in the Visx group.
After LASIK, corneal curvature was steeper in the midperipheral region among Visx treated eyes. There were no patient-reported differences in satisfaction between eyes.
There were no significant differences in visual acuity or refractive outcomes attributed to either laser under any of the conditions measured. There was also no significant difference in patient-reported symptoms, satisfaction with treatment or eye preference associated with either laser.
Additional study is needed to establish the importance of differences in higher-order optical aberrations and corneal shape that was observed in these two treatment groups.
Cosmetic Significance of External Dacryocystorhinostomy Scars
American Journal of Ophthalmology
Internal dacryocystorhinostomy (DCR) is becoming a popular alternative to the external DCR. Sharma et al. evaluated the significance of the surgical scar of external dacryocystorhinostomy as assessed by the patients with a cross-sectional, questionnaire-based study.
Two hundred ninety-seven external DCRs were performed in 263 patients. Structured questionnaires were sent to patients requesting them to assess the visibility of scarring and the significance of the scar to them on a scale of one (least) to five (greatest). The average age of patients was 67.9 years (72 percent female, 28 percent male). Ninety-six percent of the patients were white and of Australian/Western European descent.
Sixty-one of 296 scars (20.6 percent) were felt to be visible by patients, and 31 of those scars (10.5 percent) were rated >1, or cosmetically important. The average age of patients who did not see a visible scar was higher than for patients who did.
A significantly higher proportion of female patients complained of marked scarring (>1 on a scale of 1 to 5). A significantly higher proportion of patients who complained of discomfort during suture removal also complained of a marked scar.
The authors concluded that, in view of the low percentage of patients who complained of marked scarring, scarring should not be the main ground for deciding the approach to DCR surgery, particularly in older patients. They cautioned that the results are valid for the population that was studied and may be different for different racial backgrounds.
Central Retinal Artery Occlusion: Visual Outcome
American Journal of Ophthalmology
Hayreh et al. systematically investigated the natural history of visual outcome in central retinal artery occlusion (CRAO) in a cohort study.
At entry, 244 patients (260 eyes) with CRAO (seen consecutively from 1973 to 2000) had a detailed ocular and medical history and ocular evaluation. CRAO eyes were classified into four categories: nonarteritic (NA) CRAO (171 eyes), NA-CRAO with cilioretinal artery sparing (35), transient NA-CRAO (41) and arteritic CRAO (13).
Within seven days of onset of CRAO, initial visual acuity differed among the four CRAO types (P < 0.0001). In eyes with vision of counting fingers or worse, vision improved in 82 percent of eyes with transient NA-CRAO, 67 percent of eyes with NA-CRAO with cilioretinal artery sparing and 22 percent of eyes with NA-CRAO. Visual acuity improved primarily within the first seven days (P < 0.0001).
In the central 30-degree visual field, central scotoma was the most common defect. Central visual field improved in 39 percent with transient NA-CRAO, 25 percent with NA-CRAO with cilioretinal artery sparing and 21 percent with NA-CRAO.
Peripheral visual field was normal in 62.9 percent of eyes with transient NA-CRAO and 22.1 percent in those with NA-CRAO. In 51.9 percent of eyes with NA-CRAO, the only remaining visual field was a peripheral island. Peripheral fields improved in NA-CRAO (39 percent) and in transient NA-CRAO (39 percent).
The classification of CRAO is crucial for understanding differences in visual outcome. Marked improvement in visual acuity and visual field can occur without treatment and is determined by several factors.
Macular Hole Development in Fellow Eyes of Patients With Unilateral Macular Hole
American Journal of Ophthalmology
Niwa et al. sought to determine in a retrospective, cross-sectional, observational study the incidence of developing an idiopathic full-thickness macular hole in fellow eyes that have vitreofoveal attachments and perifoveal vitreous detachment in patients with unilateral idiopathic macular hole.
The fellow eyes of 201 patients with full-thickness macular holes were examined by optical coherence tomography (OCT).
A subset of 58 fellow eyes with vitreofoveal attachments and perifoveal vitreous detachment was observed during follow-up, and the changes in the vitreofoveal attachment within 24 months from the initial OCT examination were investigated.
The vitreofoveal relationship changed in 27 of the 58 eyes.
Among the 27 eyes, three eyes developed a full-thickness macular hole, and the other 24 eyes developed a posterior vitreous detachment only over the fovea or a complete posterior vitreous detachment without macular hole formation.
The vitreofoveal relationship did not change in 31 eyes during the 24-month period.
From an analysis of the changes in the vitreoretinal relationship identified by OCT, three (11 percent) of 27 fellow eyes in patients with unilateral idiopathic macular hole developed a full-thickness macular hole.
The Association Between Hypermetropia and Essential Hypertension
American Journal of Ophthalmology
Karadayi et al. explored the relationship between the refractive state of the eye and high blood pressure in a representative population in a case-control study.
Three hundred twenty-one patients with essential hypertension (mean age 53.9 years) and 188 age-matched and sex-matched healthy control subjects (mean age 50.9 years) from the same regional health management organization were consecutively included for the study.
The refractive state of the eyes was identified objectively by an autorefractometer and retinoscopic examination, recording the autorefractometer values. Spherical equivalents between –0.50 and +0.50 D were regarded as emmetropia. Values below or above this interval were regarded as either myopia or hypermetropia. Mean spherical equivalents of the groups were compared using independent samples tests; distributions of refraction were compared with x2 tests. The mean spherical equivalent of the patients with essential hypertension was +0.88 ± 1.34 D (range –3.75 to +6.38 D), whereas the mean spherical equivalent of the control subjects was –0.26 ±1.12 D (range –5 to +3.38 D) (P < 0.0001). Whereas 61.4 percent of hypertensive patients were hypermetropic, 18.1 percent of normotensive patients were hypermetropic (P < 0.0001).
There seems to be a strong association of essential arterial hypertension with hypermetropia, which has not been previously reported. Given the findings of this study, the authors recommend that patients who have hypermetropia and have had no recent systemic examination should have their blood pressure checked.
Ophthalmology summaries are written by Lori Baker Schena and edited by John Kerrison, MD. American Journal of Ophthalmology summaries are edited by Thomas J. Liesegang, MD.
Roundup of Other Journals
Increasing Dose and Frequency of Interferon Beta-1a in Patients With Relapsing Multiple Sclerosis
Archives of Neurology
Schwid et al. have added to data indicating that in patients with multiple sclerosis, high-dose/high-frequency therapy with interferon beta-1a, 44 micrograms administered three times weekly (TIW), offers greater therapeutic benefit on relapse and in MRI measures than a lower-dose, less-frequent regimen of 30 µg administered once a week (QW).
These data are from the EVIDENCE (Evidence of Interferon Dose-Response: European North American Comparative Efficacy) study, which involved 677 MS patients at 56 centers worldwide. In this particular phase of the study, the patients who were originally randomized to interferon 30 µg QW were transitioned to the 44 µg TIW regimen. Those who were on TIW remained on that regimen. Following the transition, the annualized relapse rate decreased from 0.64 to 0.32 for patients increasing the dose, and went from 0.46 to 0.34 for those continuing the dose. Additionally, patients converting from QW to the TIW regimen had fewer active lesions on T2-weighted MRI.
These findings suggest that increasing the interferon beta-1a dose and
frequency can rapidly reduce ongoing disease activity in patients receiving low-dose weekly therapy.
Monocular Autorefraction as Pediatric Eye Screening Tool
Archives of Pediatric and Adolescent Medicine
Monocular autorefraction is a relatively new technology for vision screening that has been recommended to test young children. These devices automatically determine the refractive state of each eye but cannot directly detect amblyopia or strabismus—conditions that may or may not have associated refractive error.
Kemper et al. compared the results of a commercially available monocular autorefractor with findings from a comprehensive eye examination in children 5 years and younger who were new patients at a university-affiliated pediatric ophthalmology clinic. The researchers found that while monocular autorefraction can identify most cases of visual impairment in children aged 3 to 5 years, the low specificity in this age group suggested that the device could lead to many false-positive results.
They also found most children three years or older could be tested with monocular autorefraction, but less than half (49 percent) of children under 3 years old could be tested.
The investigators urge caution with this device, noting that monocular autorefraction has limited usefulness in children under age 3 because of the low testability rate and nonspecific results.
New Application of Optical Coherence Tomography to Assess Central Corneal Thickness
Archives of Pediatric and Adolescent Medicine
The OCT3 optical coherence tomographer (Carl Zeiss Meditec) employs a new version of a noninvasive, noncontact imaging technique that uses infrared light to obtain high-resolution cross-sectional images in vivo. The OCT3 permits tissue resolution of less than 10 micrometers.
Although the device plays a role in diagnosing optic nerve and retinal pathology, Fishman et al. studied whether the OCT3 could determine central corneal thickness in normal human corneas in vivo compared with standard ultrasound pachymetry and Orbscan.
They found that the OCT3 represented an accurate, noninvasive and reproducible technique to evaluate CCT. The OCT3 also demonstrated some advantages over pachymetry.
For example, since OCT is noninvasive and noncontact, it may prove useful when corneal epithelial disease precludes direct contact with the cornea. Also, with OCT3 the patient’s gaze can be fixated during testing, unlike ultrasound pachymetry, thereby allowing for more accurate repeated measurements.
The authors conclude that while standard OCT software adequately measures corneal thickness, a more sensitive caliber may result in additional benefits. children under age 3 because of the low testability rate and nonspecific results.
Echographic Examination With New-Generation Contrast Agent in Choroidal Malignant Melanoma
Journal of Cataract and Refractive Surgery
One of the most important criteria in diagnosing choroidal malignant melanomas when using standardized A-scan echography is the evidence of vessels inside the neoplasia.
In this study, Forte et al. have found that the use of new generation contrast agents during echographic examination can provide good resolution of choroidal malignant melanoma microcirculation.
Twenty-five patients with choroidal lesions already diagnosed with standardized echocardiography received a bolus injection of 2 milliliters of echographic contrast medium, which consisted of phospholipidic microbubbles filled with sulphur hexafluoride (Sonovue). The contrast agent was suspended in 0.9 percent physiological solution,
at a concentration of 8 micrograms/ milliliter.
In untreated malignant melanomas, the contrast agent echography revealed the presence of a dense microcirculation inside the mass. In 12 patients treated with transpupillary thermotherapy, contrast agent echographic evaluation revealed heavy regression of microcirculation after one week.
Roundup is written by Lori Baker Schena and edited by Deepak P. Edward, MD.