The Doctor's Channel - Ophthalmology

Strabismus

2010-03-08T15:33:16+00:00

Joseph Demer, MD, Professor of Opthalmology and Neurology, UCLA David Geffen School of Medicine, discusses strabismus and describes mechanical causes versus neurological causes of this eye condition. If the extraocular muscles can be shown by clinical examination to be generating a normal amount of force, then causes such as thyroid opthalmopathy, eye socket trauma or a vascular lesion must be sought. Also to be considered are the ligaments around the extra-ocular muscles.

Reading:
Bosman J, ten Tusscher MP, de Jong I, Vles JS, Kingma H. The influence of eye muscle surgery on shape and relative orientation of displacement planes: Indirect evidence for neural control of 3D eye movements. Strabismus. 2002 Sep;10(3):199-209.
Dickey CF, Scott WE, Cline RA.Oblique muscle palsies fixating with the paretic eye. Surv Ophthalmol. 1988 Sep-Oct;33(2):97-107. Review.
Siepmann K, Herzau V.[Is congenital superior oblique strabismus a paretic disorder?--A magnetic resonance tomographic study] Klin Monbl Augenheilkd. 2005 May;222(5):413-8. German.

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Four clinical factors help rule out bacterial conjunctivitis in kids

2010-03-04T19:12:12+00:00

NEW YORK (Reuters Health) – Four clinical factors can help rule out bacterial conjunctivitis in children, New York City researchers say.

The four factors are: age at least 6 years, only watery discharge (or no discharge), no glued eyes in the morning, and presentation between April and November, according to Dr. James A. Meltzer and colleagues from Jacobi Medical Center in the Bronx.

Children who met all four of these criteria had more than a 90% likelihood of a negative culture for bacterial conjunctivitis, the investigators report in the March issue of the Archives of Pediatrics and Adolescent Medicine.

The researchers say the goal of their study -- which involved 368 patients ages 6 months to 17 years -- was to determine whether a low risk of bacterial conjunctivitis could be predicted based on history and physical examination findings.

They note that up to 80% of the time, conjunctivitis in children is bacterial. But since there are no guidelines to help distinguish bacterial from nonbacterial cases, most clinicians prescribe antibiotics for all cases of acute conjunctivitis, even though “bacterial resistance to antibiotic drugs is an ever-increasing problem, and there is a nationwide effort to find conditions for which antibiotic drug use can be restricted.”

The children in the study had come to the authors’ pediatric emergency department with conjunctival erythema, eye discharge, or both. Any child with eye trauma, chemical exposure, contact lens use, or antibiotic use in the last 5 days was excluded. The study group was 52.7% male and the median age was 3 years.

For each child, the treating clinician completed a checklist of signs and symptoms and collected a conjunctival swab for bacterial culture.

Roughly 35% of subjects had negative conjunctival cultures. Using the researchers’ model, children with none of the specified characteristics had an 11.8% rate of negative cultures, compared to a 76.4% rate in children with three factors and a 92.3% likelihood of negative cultures for children whose eye conditions met all four criteria.

“If these findings are validated in other populations, we may be able to limit routine antibiotic drug administration for children with acute conjunctivitis,” the authors conclude.

Reference:
Arch Pediatr Adolesc Med 2010;164:263-267.

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Benefits of early intensive insulin therapy can persist unless HbA1C levels rise

2010-03-01T17:22:21+00:00

NEW YORK (Reuters Health) - Intensive insulin therapy in type 1 diabetics reduces their risks of neuropathy and retinopathy over the long-term, according to two papers published online February 11th in Diabetes.

Both papers report data from the long-term Epidemiology of Diabetes Interventions and Complications (EDIC) study. Since the early 1990s, the EDIC researchers have followed participants in the landmark Diabetes Control and Complications Trial, which showed that intensive therapy (three or more insulin injections per day or use of a continuous pump) prevented complications more effectively than standard therapy (two injections per day).

In the follow-up study, which has lasted more than 10 years now, all of the subjects have been told to use intensive insulin therapy.

In one of the two papers in Diabetes, Dr. James W. Albers, from the University of Michigan Medical School, Ann Arbor, and colleagues used clinical and nerve conduction studies to compare rates of neuropathy in 603 former intensive-therapy and 583 former conventional-treatment subjects. Over time, both groups have achieved similar HbA1c levels.

Between the end of the original study and years 13-14 of EDIC, the prevalence of neuropathy rose from 9% to 25% in the former intensive therapy group and from 17% to 35% in the former conventional therapy group (p < 0.001). The incidence of neuropathy was also lower in the former intensive treatment group: 22% vs. 28% (p = 0.0125).

On longitudinal analysis, improved HbA1c control was directly linked to lower risks of incident and prevalent neuropathy.

In the second paper, Dr. Neil H. White, from Washington University, Saint Louis, and colleagues assessed the impact of intensive therapy in the original trial on patients' risk of retinopathy. The researchers also looked to see whether any effect on risk was mediated by the patient's age when intensive therapy started.

Among 1055 adults and 156 adolescents, during 10 years of EDIC, there was no significant difference in HbA1c levels between former intensive and conventional therapy patients, nor between adults and teens. In adults, however, former use of intensive therapy cut the risk of retinopathy by 57%, whereas in teens, no benefit of former intensive therapy was noted. Further analysis suggested a possible explanation for this finding: during long-term follow-up, teens who had been given intensive therapy had higher mean HbA1c levels than adults: 8.1% vs. 7.2%.

The current findings, the authors of both studies agree, emphasize the importance of maintaining HbA1c at as close to target values as possible. "The benefits of former intensive therapy treatment wane over time if HbA1C levels rise," Dr. White and his colleagues conclude.

Reference:
Diabetes 2010.

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Lateral eye pulley popping

2010-02-24T16:37:49+00:00

Joseph Demer, MD, Professor of Opthalmology and Neurology, UCLA David Geffen School of Medicine, discusses lateral rectus ligament dysfunction in the eye, its diagnosis and management techniques used to correct this defect.

Reading:
Patel AS, Simon JW, Lininger LL. Bilateral lateral rectus recession for consecutive exotropia. J AAPOS. 2000 Oct;4(5):291-4.
Hamlet YJ, Goldstein JH, Rosenbaum JD. Dehiscence of lateral rectus muscle following intrascleral buckling procedure. Ann Ophthalmol. 1982 Jul;14(7):694-7.
Huerva V, Mateo AJ, Espinet R. Isolated medial rectus muscle rupture after a traffic accident. Strabismus. 2008 Jan-Mar;16(1):33-7.

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Eye muscles and vision

2010-02-24T16:33:20+00:00

Joseph Demer, MD, Professor of Opthalmology and Neurology, UCLA David Geffen School of Medicine, discusses eye muscles, which are regulated by connective tissue structures called pulleys, and horizontal double vision.

Reading:
Mims JL 3rd. Further implications of probable changes in medial rectus muscle innervation after surgery for infantile esotropia. Binocul Vis Strabismus Q. 2009;24(4):228-32.
Reddy AK, Freeman CH, Paysse EA, Coats DK. A data-driven approach to the management of accommodative esotropia. Am J Ophthalmol. 2009 Sep;148(3):466-70. Epub 2009 May 23.
Magli A, Iovine A, Gagliardi V, Fimiani F, Nucci P. LASIK and PRK in refractive accommodative esotropia: a retrospective study on 20 adolescent and adult patients. Eur J Ophthalmol. 2009 Mar-Apr;19(2):188-95.

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Uveual melanoma treatment

2010-02-01T15:52:09+00:00

Miguel Materin, MD, Director of Ocular Oncology Section, Yale Eye Center, discusses uveal melanoma treatment which depends on saving the patient's life before consideration of saving the eye or restoring vision.

Reading:
Li B, Xu XL.[What else can we do for uveal melanoma] Zhonghua Yan Ke Za Zhi. 2009 Apr;45(4):289-92
Kaiserman N, Kaiserman I, Hendler K, Frenkel S, Pe'er J. Ruthenium-106 plaque brachytherapy for thick posterior uveal melanomas. Br J Ophthalmol. 2009 Jun 30

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Double vision

2010-02-01T15:20:15+00:00

Joseph Demer, MD, Professor of Opthalmology and Neurology, UCLA David Geffen School of Medicine, discusses double vision, which is not uncommon in the elderly and is traditionally attributed to neurological causes. Research now shows that it is often caused by wear and tear of the ligaments surrounding the eye sockets.

Reading:
SNYDACKER D. Diplopia in the person over 50. Geriatrics. 1959 Jun;14(6):385-90.
Serafino M, Fogagnolo P, Trivedi RH, Saunders RA, Nucci P. Torsional diplopia after orbital decompression and strabismus surgery. Eur J Ophthalmol. 2009 Oct 9.
Milea D. [Transient diplopia.] J Fr Ophtalmol. 2009 Dec;32(10):775-8.

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Surgery duration linked to infectious complications, hospital stay

2010-01-12T17:16:46+00:00

NEW YORK (Reuters Health) – New research indicates that operative times are independently and directly linked to the risk of infectious complications and the length of hospital stay.

“These data show that operative duration remains associated with increasing infectious complications in a broad spectrum of general surgery patients after adjustment for numerous patient and operative risks,” Dr. Levi D. Procter and colleagues, from the University of Kentucky College of Medicine, Lexington, note.

In a study of nearly 300,000 operations performed at 173 hospitals from 2005 to 2007, the authors found that the 30-day rate of infectious complications rose by almost 2.5% for every 30 minutes between incision and closing. The rates ranged from 3.7% for cases lasting up to an hour to 31.4% for cases that took more than 6 hours (p < 0.001), according to the report in the January issue of the Journal of the American College of Surgeons.

After adjusting for patient risk variables, type and complexity of surgery, wound class, and intraoperative transfusion, operative time was still a significant predictor of infectious complications. Compared to patients whose operation no more than an hour, those whose surgery lasted 2.1 to 2.5 hours had nearly double the risk of infectious complications, the report indicates.

This pattern was also seen in a subgroup of otherwise healthy patients who had laparoscopic cholecystectomy with a clean or clean-contaminated wound and no blood transfusion. In this subset, infections rates were 0.7% when cases lasted less than 30 minutes, 1.4% in cases lasting from 60 to 90 minutes, and 1.7% in cases longer than 90 minutes.

“Across all procedures,” hospital stays increased geometrically along with operative times, at a rate of about 6% for every 30 minutes, the authors said.

“Our data contribute to our understanding of the independent infection risk relative to operative duration across a broad range of procedures in a very large, multicenter contemporary patient population,” the researchers conclude. “Strategies to reduce operative duration can reduce infectious complications and length of stay.”

Reference:
J Am Coll Surg 2010;210:60-65.

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Graves’ Eye Disease and IGF-1

2009-12-07T17:32:05+00:00

Robert Goldberg, MD, Chief, Orbital and Opthalmic Plastic Surgery, David Geffen School of Medicine UCLA, discusses new advances on the medical and surgical sides of Graves’ Eye Disease, and in particular, the IGF antibody and its relationship to TSH.

Reading:
Matos K, Manso PG, Marback E, Furlanetto R, Alberti GN, Nosé V. Protein expression of VEGF, IGF-1 and FGF in retroocular connective tissues and clinical correlation in Graves' ophthalmopathy. Arq Bras Oftalmol. 2008 Jul-Aug;71(4):486-92.
Tsui S, Naik V, Hoa N, Hwang CJ, Afifiyan NF, Sinha Hikim A, Gianoukakis AG, Douglas RS, Smith TJ. Evidence for an association between thyroid-stimulating hormone and insulin-like growth factor 1 receptors: a tale of two antigens implicated in Graves' disease. J Immunol. 2008 Sep 15;181(6):4397-405.
Khoo TK, Bahn RS. Pathogenesis of Graves' ophthalmopathy: the role of autoantibodies. Thyroid. 2007 Oct;17(10):1013-8. Review.

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Fluoroquinolones linked to diplopia

2009-09-08T15:08:23+01:00

NEW YORK (Reuters Health) - New research suggests that fluoroquinolones may cause diplopia in some patients.

"According to World Health Organization criteria, the relationship between fluoroquinolone therapy and diplopia is 'possible'," conclude co-authors Dr. Frederick W. Fraunfelder and Dr. Frederick T. Fraunfelder from the Oregon Health and Science University, Portland.

"This causality assessment," explain the father-and-son researchers, "is based on the time relationship of drug administration and adverse drug reaction (ADR) development, the multiple positive dechallenge and rechallenge reports, and the plausible mechanism by which diplopia could occur: possible tendinitis of the extraocular muscles."

As reported in the September issue of Ophthalmology, the authors assessed the link between fluoroquinolone use and diplopia by analyzing 171 case reports from the National Registry of Drug-Induced Ocular Side Effects, World Health Organization, and Food and Drug Administration.

The reports involved 76 male patients, 91 females, and 4 patients for whom gender was not specified. The dosages varied between the different fluoroquinolones used, but usually the median dose was within the recommended range for the specific agent.

The median time from fluoroquinolone use to diplopia was 9.6 days, with a range of 1 day to 5 months. Concomitant tendinitis was seen in 17 patients. Forty-nine patients were 60 years or older, 1 subject had renal cysts, and 4 were using systemic anti-inflammatory steroids.

According to a statement from the authors, medication was discontinued in 53 patients, and diplopia resolved in all 53.

"Clinicians are encouraged to be aware of fluoroquinolone-associated diplopia and should consider stopping therapy after consultation with the prescribing physician if diplopia occurs," the authors conclude.

Also, they advise, fluoroquinolone-associated ocular effects should be reported to the National Registry of Drug-Induced Ocular Side Effects (www.eyedrugregistry.com).

Reference:
Ophthalmology 2009.

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