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Journal Highlights
New Findings from Ophthalmology, AJO and Archives

 
 

Atropine: Weekend Dosing Similar to Daily Results for Moderate Amblyopia

Intraoperative Sub-Tenon’s Triamcinolone Supresses Postcataract Inflammation

A Description of the Ocular Manifestations of Dengue Fever

Guidelines for Detecting Progression of Glaucoma in Visual Fields

Intravitreal Triamcinolone Effective in Treatment of Intractable Diabetic Macular Edema

The Effect of Lens Edge Design vs. Anterior Capsule Overlap on Posterior Capsule Opacification

Quality of Life in Keratoconus

Vitreous Presentation During Cataract Surgery—What’s the Impact on VA at One Year?

An Analysis of Melanoma Cell Type in Uveal Melanoma Following Treatment Failure

Clinical Significance of Central Corneal Thickness in the Management of Glaucoma

Topical Gatifloxacin in the Treatment of Mycobacterium chelonae Keratitis

Ten-Year Results of Anterior Chamber Fixation of the Posterior Chamber IOL

Orbital Venous Malformations: Current Multidisciplinary Treatment Approach

Trabeculotomy Is Effective Long-Term Treatment for Developmental Glaucoma

Zinc Binding to Rhodopsin in Retinitis Pigmentosa

Primary Care Physicians’ Referral Patterns to Specialists

Dietary Glycemic Load and Age-Related Cataract

Identifying Bacterial Cause in Infectious Conjunctivitis

Previews

Atropine: Weekend Dosing Similar to Daily Results for Moderate Amblyopia
November’s Ophthalmology

Findings from a study by The Pediatric Eye Disease Investigator Group indicate that weekend atropine appears to be as effective as daily atropine in treating children between the ages of 3 and 7 who have moderate amblyopia in the range of 20/40 to 20/80. This prospective 30-site clinical trial included 168 children under the age of 7 with moderate amblyopia who were randomized either to daily atropine or to weekend atropine for four months. Those who partially responded continued on their specific treatment regimen until no further improvement was noted.

Results showed that at four months, improvement of baseline visual acuity averaged 2.3 lines in each group. Additionally, there was no difference between partial responder groups in the improvement achieved beyond the four-month outcome. The authors conclude since the magnitude of improvement was similar to that previously reported for two- or six-hours-per-day patching, weekend atropine treatment may serve as another treatment alternative to consider for children with moderate amblyopia.

Intraoperative Sub-Tenon’s Triamcinolone Supresses Postcataract Inflammation
November’s Ophthalmology

Cognizant of the sustained anti-inflammatory effects associated with the use of triamcinolone acetonide (Kenalog) in the ophthalmic setting, Paganelli et al. embarked on a study to determine its therapeutic use for controlling postcataract surgery inflammation as an alternative to postoperative steroid drops.

In a randomized study of 100 patients undergoing phacoemulsification and implantation of an intraocular posterior chamber lens, the investigators found that a single intraoperative sub-Tenon 40-milligram triamcinolone acetonide injection had a clinically equivalent therapeutic response to conventional 1 percent prednisolone eyedrops in controlling postoperative ocular inflammation. Additionally, on the third, seventh, 14th and 28th postoperative days, a significantly lower IOP was noted in the triamcinolone group than in the prednisolone group. Triamcinolone was also found to be as safe as prednisolone in terms of adverse effects, changes in visual acuity, IOP and biomicroscopic and ophthalmoscopic variables.

The authors conclude that intraoperative 40-mg triamcinolone acetonide sub-Tenon injections, with the technique’s technical simplicity, lack of complications and low cost, merit additional investigation.

A Description of the Ocular Manifestations of Dengue Fever
November’s Ophthalmology

Dengue fever is a viral infection transmitted through the bite of an infected female Aedes aegypti/albopictus mosquito. In this paper, Lim et al. focus on the ocular manifestations of the disease, presenting a retrospective case series of five females and one male with a sudden decrease in vision six to seven days after initial manifestations of dengue fever. Presenting BCVA ranged from 20/30 to counting fingers, with ocular involvement bilateral but asymmetric in five cases and unilateral in one case.

Fundus findings included small intraretinal, whitish lesions with localized retinal and retinal pigment epithelium disturbance, small dot hemorrhages and vascular sheathing around the macula and in the papillomacular bundle. The authors found diffuse hyperfluorescence of indocyanine green at the outer choroidal layers with or without silhouetting of the choroidal vessels. They recommend that ophthalmologists be aware of ocular manifestations of dengue infection, given the recent increase in incidence and geographic distribution of the disease.

Guidelines for Detecting Progression of Glaucoma in Visual Fields
November’s Ophthalmology

One challenge in managing glaucoma is the need to confirm visual field changes because of long-term fluctuation in automated perimetry results. What is the minimum worsening of visual field and the minimum number of six-month visits required to establish true glaucomatous deterioration?

The Advanced Glaucoma Intervention Study (AGIS) investigators attempted to answer these questions with long-term follow-up data based on 12,746 visual field test results from 752 eyes of 565 participants who had at least two consecutive six-month visual field tests after enrollment. Of these eyes, 737 had at least three consecutive six-month visual field tests after enrollment. Visual field tests were quantified with the AGIS visual field defect score and the Humphrey Field Analyzer mean deviation using a follow-up period of eight to 13 years. For most glaucoma patients, a modest worsening of the visual field, two units of AGIS visual field defect score or two decibels of mean deviation, confirmed by a single test after six months, indicated glaucomatous visual field progression.

Intravitreal Triamcinolone Effective in Treatment of Intractable Diabetic Macular Edema
November’s Ophthalmology

Sutter et al. have found that intravitreal triamcinolone results in a significant short-term improvement of visual acuity in eyes with impaired vision resulting from persistent diabetic macular edema.

The researchers studied 43 patients, with 34 eyes randomized to treatment and 35 to placebo; 65 of the 69 eyes completed the three-month study visit. Treatment eyes received 0.1 milliliter of triamcinolone acetonide (Kenalog) injected through the pars plana. Fifty-five percent of treated eyes gained five or more letters of BCVA, compared with 16 percent of eyes treated with placebo. Macular edema was reduced by one or more grades in 75 percent of treated eyes vs. 16 percent of untreated eyes. Adverse events included infectious endophthalmitis in one treated eye.

The authors conclude that short-term intravitreal triamcinolone appears effective and relatively safe for macular edema in patients who have failed laser treatment. While longer-term safety and efficacy studies are necessary, they suggest ophthalmologists consider intravitreal triamcinolone in one eye of patients with intractable diabetic macular edema.

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Ophthalmology previews are written by Lori Baker Schena and edited by John Kerrison, MD.


Reviews

The Effect of Lens Edge Design vs. Anterior Capsule Overlap on Posterior Capsule Opacification
American Journal of Ophthalmology
October’s issue

The effect of lens edge design vs. the effect of anterior capsule overlap with the IOL on posterior capsule opacification has been debated for years.

Smith et al. performed a retrospective cohort clinical study of patients (259 eyes) who underwent uncomplicated cataract surgery and at least one year of follow-up after surgical placement of a silicone or hydrophobic acrylic lens. Digital retroillumination photographs were taken to ascertain PCO, anterior capsular opacification, previous YAG capsulotomy and degree of anterior capsule overlap on the IOL optic. Of those digital images, 148 (74 silicone and 74 acrylic) were measurable for both anterior capsule overlap and PCO.

Results showed decreased incidence of PCO was associated with complete 360 degree overlap of the anterior capsule on the IOL (P < 0.001). A significant negative correlation was found between the degree of anterior capsule overlap and PCO (P < 0.001). Evaluation of PCO and YAG capsulotomy rates were similar whether lenses were acrylic or silicone. Minimal anterior capsule overlap may also be associated with PCO prevention.

Implanting a lens with complete anterior capsule overlap on the IOL was found to significantly reduce PCO; this advantage appeared to be greater than that afforded by a truncated, sharp edge IOL design.

Quality of Life in Keratoconus
American Journal of Ophthalmology
October’s issue

Since keratoconus is a chronic, noninflammatory disease of the cornea with onset in early adulthood in otherwise healthy individuals, there are important financial and social health concerns.

Kymes at al. report on the vision-related quality of life of patients in the Collaborative Longitudinal Evaluation of Keratoconus Study. In this cross-sectional study, the NEI-Visual Function Questionnaire was administered to 1,166 CLEK Study patients at their first annual follow-up examination. Associations between clinical and demographic factors and NEI-VFQ scale scores were evaluated.

Binocular entrance visual acuity worse than 20/40 was associated with lower quality of life scores on all scales except those scales for General Health and Ocular Pain. A steep keratometric reading > 52 D was associated with lower scores on the Mental Health, Role Difficulty, Driving, Dependency and Ocular Pain scales. Scores for all scales were comparable to scores for AMD patients with category 3 and category 4 of the disease. The only exceptions were for the General Health scale, which was better than for AMD patients, and Ocular Pain, which was worse than for AMD patients.

Keratoconus is a disease of relatively low prevalence that rarely results in blindness, but because it affects young adults, the magnitude of its public health impact is disproportionate to its prevalence and clinical severity.

Vitreous Presentation During Cataract Surgery—What’s the Impact on VA at One Year?
American Journal of Ophthalmology
October’s issue

Vitreous loss is one of the most common complications of cataract surgery. Collins et al. tried to determine the effects that vitreous presentation during extracapsular cataract surgery has on patients’ one-year
postoperative vision.

This prospective, long-term, clinical trial took place at 19 Veterans Affairs medical centers. Patients who had vitreous presentation during cataract surgery and received a posterior chamber IOL (230 patients) were prospectively compared with a 5 percent random sample of cataract surgery patients without vitreous presentation (521 patients). BCVA at one year was obtained by a masked, certified examiner.

In patients with 20/40 or better BCVA at one year, there was no statistical difference between the percent of patients with vitreous presentation-PC IOL (90 percent) and those without vitreous presentation (95 percent).

There were significantly more vitreous presentation-PC IOL patients than nonvitreous-presentation patients with BCVA of 20/50 or worse at some time during the first postoperative year (22 percent vs. 11 percent; P = 0.0003). At one year, there were significantly fewer vitreous presentation-PC IOL patients than nonvitreous-presentation patients with BCVA of 20/20 or better (28 percent vs. 39 percent; P = 0.013), and significantly more with cystoid macular edema (11 percent vs. 4 percent; P = 0.0002), retinal detachment (4 percent vs. 0.2 percent; P = 0.0002), and uveitis (3 percent vs. 0.6 percent; P = 0.012). The patients without vitreous presentation rated their vision as very good or excellent significantly more often than the vitreous presentation patients (71 percent vs. 58 percent; P = 0.025).

The authors conclude that vitreous presentation during extracapsular cataract surgery leads to somewhat worse overall outcomes in patients, although the majority of patients with vitreous presentation do reasonably well.

An Analysis of Melanoma Cell Type in Uveal Melanoma Following Treatment Failure
American Journal of Ophthalmology
October’s issue

It is not always clear why therapy for uveal melanoma fails. Char et al. tried to determine whether an increase (or progression) in the degree of malignancy according to cytologic or histopathologic criteria corresponded with failure of intraocular melanoma control.

This was a retrospective case control study from a single institution in California. Uveal melanoma patients had either fine-needle aspiration biopsy followed by irradiation and later enucleation or an eyewall resection followed by enucleation. The classification was based on serial histology or cytopathologyand histology, reanalyzed in a masked manner. The main outcome measures were change in the predominant tumor cell type, local tumor control and metastases.

There was no significant correlation between a change in melanoma cell type and failure to control intraocular melanoma. Similarly, the latency between treatment and enucleation was actually less (but not statistically so) in tumors that showed no increase in melanoma malignancy cell type compared with those that had a more malignant cell type on serial examination.

The authors conclude that there was no correlation between a change to more malignant cell type and local control failure in patients treated either with radiation or eyewall resection for uveal melanoma.

Clinical Significance of Central Corneal Thickness in the Management of Glaucoma
Archives of Ophthalmology
2004;122(9):1270–1275

Does determination of central corneal thickness have an effect on the clinical management of patients with glaucoma and glaucoma suspects? Shih et al. evaluated this question in a cross-sectional retrospective study of 188 consecutive patients with diagnoses of glaucoma and glaucoma suspects.

After obtaining both mean ultrasound pachymetry and Goldmann applanation tonometry measurements, IOPs were corrected using linear and mathematical (Orssengo-Pye) algorithms. Measurement-significant outcomes (defined as IOP adjustments of 1.5 mmHg or greater) with the linear correction scale and Orssengo-Pye algorithm were observed in 105 (55.9 percent) and 119 (63.3 percent) patients, respectively. In addition, outcomes-significant results (IOP adjustments of 3 mmHg or greater) were obtained in 36 (20.2 percent) and 80 (42.6 percent) patients, respectively. Based on these IOP adjustments, changes in glaucoma medical therapy and in recommendations for glaucoma laser and incisional surgeries were observed.

In summary, pachymetry-measured central corneal thickness has a significant effect on the clinical management of patients with glaucoma and glaucoma suspects.

Topical Gatifloxacin in the Treatment of Mycobacterium chelonae Keratitis
Archives of Ophthalmology
2004;122(8):1166–1169

Nontuberculous mycobacteria are slowly replicating organisms that are increasingly frequent opportunistic corneal pathogens. Often recalcitrant to conventional anitibiotics, they typically require multiple agents and a protracted treatment course. Hyon et al. compared antibacterial efficacy of topical gatifloxacin 0.3 percent (Zymar); ciprofloxacin 0.3 percent (Ciloxan); a combination therapy with clarithromycin (10 milligrams/milliliter) plus amikacin (50 mg/ml); and triple-combination therapy with gatifloxacin 0.3 percent, amikacin (50 mg/ml) and clarithromycin (10 mg/ml) against M. chelonae keratitis in a rabbit model.

In this in vivo study, M. chelonae keratitis was induced by intrastromal injection with 106 colony-forming units (CFU) of M. chelonae. Antibacterial efficacy was determined by counting CFU from bacterial culture of the cornea following hourly administration of topical antibiotics for 12 hours.

Therapy with gatifloxacin 0.3 percent was more effective than ciprofloxacin alone (P < 0.001), and it demonstrated synergy by enhancing the efficacy of amikacin plus clarithromycin (P < 0.001). Newer generation 8-methoxy fluoroquinolones may provide an alternative treatment, alone or in combination with other agents, in therapy of keratitis due to M. chelonae.

Ten-Year Results of Anterior Chamber Fixation of the Posterior Chamber IOL
Archives of Ophthalmology
2004;122(8):1112–1116

For 21 aphakic eyes without capsular support, Hara and Hara implanted conventional J-loop posterior chamber IOLs into the anterior chamber. All loops positioned at scleral spur and pupil remained round. Most eyes had received Binkhorst four-loop IOLs and were explanted later due to severe cell loss.

At 17 months’ follow-up the results showed average corneal endothelial cell loss was 4.9 percent. However, at 10 years’ follow-up, average corneal cell loss was 30.9 percent, and six eyes developed bullous keratopathy.

In summary, although this procedure is simple, it is not recommended for secondary implantation into  aphakic eyes.

Orbital Venous Malformations: Current Multidisciplinary Treatment Approach
American Journal of Ophthalmology
2004;122(8):1151–1158

In a 38-year retrospective review of 22 patients, Arat et al. evaluated the clinical, radiologic and histopathologic features, treatment and outcome of a series of orbital venous flow malformations (OVMs) with the aim of delineating a more systematic approach for management.

They report that 18 patients showed clinical or radiological evidence of distensibility. All three patients with deep nondistensible OVM presented with a sudden onset of proptosis and pain or diplopia secondary to thrombosis or hemorrhage. There were 17 patients who required treatment. All four nondistensible lesions were treated by surgical excision. A variety of techniques were used to treat distensible OVM including CO2 laser ablation, percutaneous ethanol sclerotherapy, embolization with Guglielmi detachable coils (GDC) after surgical exposure and surgical excision. Of the 14 patients with follow-up, eight had complete resolution and six patients showed marked improvement of the symptoms and signs.

In summary, if intervention is indicated, less invasive methods such as CO2 laser ablation and percutaneous ethanol sclerotherapy for superficial and combined lesions and endovascular treatment by GDC embolization for deep lesions should be considered before proceeding with more invasive procedures.

Trabeculotomy Is Effective Long-Term Treatment for Developmental Glaucoma
American Journal of Clinical Nutrition
2004;122:1122–1128

Ikeda et al. performed a retrospective study of trabeculotomy for developmental glaucoma to elucidate long-term outcome of this treatment.

At the final visit after surgery, the mean IOP of eyes with primary developmental glaucoma (n = 112) was 15.6 mmHg and one hundred eyes (89 percent) were defined as achieving success with a mean follow-up period of 9.5 years.

The mean IOP of eyes with secondary developmental glaucoma (n = 37) was 16.7 mmHg at the final visit.

Visual acuities were 20/40 or better in 60 percent of eyes examined (n = 131). Visual fields were classified as normal or almost normal in 45 percent of eyes.

In summary, trabeculotomy for developmental glaucoma is effective over a long time and visual function of the eyes with proper treatment is fairly good.

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American Journal of Ophthalmology reviews are edited by Thomas J. Liesegang, MD. Archives summaries are edited by the lead authors.


Roundup of Other Journals

Zinc Binding to Rhodopsin in Retinitis Pigmentosa
Journal of Biological Chemistry
2004;279:35932–35941

In a laboratory study to establish the biologic plausibility of zinc deficiency in retinitis pigmentosa, Stojanovic et al. examine the critical biochemical and structural relevance of zinc ions in rhodopsin (a light receptor protein in the eye) to determine whether zinc deficiency can lead to rhodopsin dysfunction. They based their hypothesis on mounting evidence that has demonstrated the gain or loss of zinc binding to the progression of such severe protein misfolding disorders as Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis.

The researchers identified a high-affinity zinc coordination site within the transmembrane domain of rhodopsin and demonstrated that this zinc coordination is critical for rhodopsin folding, 11-cis-retinal binding and the stability of the chromophore-receptor interaction (defects observed in retinitis pigmentosa). They also found a cluster of retinitis pigmentosa mutations localized around this zinc-binding site. The authors conclude that a pharmacological approach that improves zinc binding to rhodopsin within the transmembrane domain may represent an effective treatment option in select retinitis pigmentosa mutations.

Primary Care Physicians’ Referral Patterns to Specialists
Annals of Family Medicine
2004;2:245–252

Kinchen et al. shed light on how primary care physicians choose specialists when referring patients for specialty care, comparing survey results by physicians’ race and sex. The researchers mailed a 17-item questionnaire to 1,252 primary care physicians including equal numbers of black female, black male, white female and white male physicians. The overall response rate was 59.1 percent.

The medical skill of the specialist rated across the board as the factor of greatest importance when considering a patient referral. Also of major importance were appointment timeliness, previous experience with the specialist, quality of specialist communication, efforts to return the patient to the primary physician and good patient-specialist rapport. Compared with black physicians, white physicians were more likely to rate previous experience with the specialist and board certification as important. White physicians were less likely than black physicians to rate patient convenience as a major consideration. Female physicians were more likely than male physicians to rate the patient’s insurance status with the specialist as a major importance factor. The authors conclude that a better understanding of these preferences may help clarify primary care physicians’ expectations of specialists and improve the referral process.

Dietary Glycemic Load and Age-Related Cataract
American Journal of Clinical Nutrition
2004;80:489–495

The great carbohydrate debate has entered the realm of ophthalmology with a study looking at the possible link between consumption of high dietary glycemic loads and an increased risk of age-related cataract. Schaumberg et al. followed two cohorts—71,919 women and 39,926 men aged 45 or older who had no previous diagnosis of cataract, diabetes mellitus or cancer—for 14 years and 12 years, respectively, for occurrence of cataract extraction. They calculated dietary glycemic load from food-frequency questionnaires and used pooled logistic regression models to estimate the association with incident cataract extraction.

The data demonstrated that, after adjusting for age, smoking, body mass index, caloric intake, dietary lutein and zeaxanthin levels and alcohol consumption, the risk of cataract extraction was not greater among those with the highest dietary glycemic loads. The authors conclude that although a higher dietary glycemic load has been shown to induce hyperglycemia and increased concentrations of the inflammatory biomarker C-reactive protein, it is not a risk factor for cataract.

Identifying Bacterial Cause in Infectious Conjunctivitis
British Medical Journal
2004;329:206–210

Rietveld et al. propose an efficient set of diagnostic indicators to help identify a bacterial origin of acute infectious conjunctivitis and thus allow primary care physicians to efficiently identify patients who might benefit most from antibiotic treatment. The cohort study involved 184 adults presenting with a red eye and either (muco)purulent discharge or glued eyelid(s). None wore contact lenses.

The prevalence of bacterial culture– positive conjunctivitis was 32 percent, with Streptococcus pneumoniae being the most common (47 percent). Logistical regression analysis showed optimal diagnostic discrimination for the combination of presence or absence of early morning glued eye(s), itch and a history of conjunctivitis. The first of these indicators increased the likelihood of a bacterial cause, whereas the other two decreased it. The investigators concluded that physicians can help determine if a patient’s conjunctivitis is bacterial by asking (possibly by telephone) about early morning glued eyes, itch and history of infectious conjunctivitis.

Through this approach, the number of prescriptions for topical ocular antibiotics could be considerably reduced.

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Roundup is written by Lori Baker Schena and was edited this month by Brian A. Francis, MD.