1,721,177 research outputs found
Surgical Correction and Outcome of Exotropia
No full textThe issue of surgical correction of exodeviations is still an open one. The article by Raiyawa et al1
entitled ‘‘Outcomes of 3 or 4 Horizontal Muscles Surgery in Large-Angle Exotropia’’ provides an
opportunity for a discussion on this topic. When and how much surgery is needed for exotropia is
still up to the decision of individual surgeons. Guidelines on these aspects, and the majority of
existing clinical aspects of strabismology, are essentially not followed.
Exodeviations are a continuum, generally originating at birth, for which the natural mechanisms of
balance between converging and diverging forces are not as effective as they should be.2 As a result, the
eyes tend to diverge, initially only occasionally and eventually more and more often. Here, anatomical
causes for divergence such as orbital anomalies are not considered. If the periods of deviation per day are
limited, no sensory adaptations develop. This means that patients experience diplopia. This condition is
identified as exophoria. Suppression with no diplopia is found in those patients in whom, already before
age 2, moments of deviation are prolonged and repeated during the day: this is defined as intermittent
exotropia. The situation may evolve from exophoria, through intermittent exotropia to constant
exotropia. Monocular eye closure, in bright light, is a distinctive element that characterizes exodeviations.
The origin of this phenomenon is still debated, although it seems to be connected with the increased strain
to motor fusion caused by high levels of illumination.
The aim of exotropia surgery is to maintain normal binocular vision, which is at risk when
periods of deviation prevail over those of control. Patients with intermittent exotropia are more at
risk, as compared with those with exophoria, in the absence of subjective symptoms. No orthoptic
treatment has been proven to be effective for exodeviations. In selected cases, surgery can be delayed
by minus lenses, which favor convergence, because more accommodation is required.
A surgical decision should be made when periods of deviation prevail over those of control,
ideally not earlier than age 6 or 7, as exodeviations tend to increase spontaneously until age 14 or 15
because of the reduction in accommodative range and widening of the orbits. Overcorrection often
aimed for in children can interrupt normal binocular vision permanently. Therefore, it should be
avoided, particularly in patients with limited fusional amplitudes.
On one hand, retention of normal binocular vision is guaranteed more in exodeviation (because
of its tendency to slow deterioration) than in esotropia. On the other hand, a cure for exotropia cannot
be achieved even with successful surgery. In fact, a relapse is common, particularly around the onset
of presbiopia. Moreover, subjective symptoms, such as asthenopia, are present in exodeviation, because
of the prolonged effort to keep the eye aligned, particularly for near vision.
Surgery for exotropia in patients with no normal binocular vision offers limited functional advantages.
Certainly, a small-angle deviation provides better distance judgments than a large-angle
strabismus. Yet, several elements are responsible for the reduced stability of postsurgical results,
such as lack of free alternation of fixation, amblyopia of the deviated eye, and previous surgery for
esotropia (secondary exotropia).
A comparison of surgical results of patients with normal binocular vision with those of patients
who lack this function, as done in the article by Raiyawa et al, can be misleading. Only motor control
is present in this second instance, and motor fusion does not contribute to maintaining a parallel
status of the eyes. Moreover, adjustable sutures should not be used in exotropic patients with normal
binocular vision because postoperative adjustment tends to cause an undercorrection for the uncontrolled
role of motor fusion.
Large-angle exotropia should ideally be corrected by operating on no more than 3 horizontal
muscles, leaving the fourth untouched for a second procedure. It is preferable, however, for deviations
not exceeding 50 prism diopters to limit surgery to 1 eye (operating on the eye less often
used for fixation). Duplication (or tuck) of the medial rectus muscle is preferable as compared with
resection: the results are the same, but the risks of inducing a vertical misplacement of the muscle and
perforation are eliminated. The final cosmetic appearance of
eyes with duplicated versus resected muscles is the same: for a
few weeks postoperatively, there is a bulky appearance of the
conjunctiva, which flattens rapidly. Finally, the amount of recession
and duplication in large-angle exotropia should range
from 6 to 8 mm. Smaller amounts are ineffective and require
operating on more muscles. Recess/resect or recess (duplication)
on 1 eye has been proven to be much more effective than
bilateral lateral rectus recession for exotropia. In extreme largeangle
deviations, the third muscle operated on should be the
contralateral medial rectus (with a duplication) in order to leave
the lateral rectus muscle free for possible future modulation.
Possible lateral incomitance induced by using too much surgery
is a negligible concern in my clinical experience.
A residual exodeviation in the presence of efficient motor
fusion is usually an acceptable end result. Aiming toward slight
overcorrection in surgery for large-angle exotropia is commonly
suggested. In principle, this can be acceptable if divergent fusional
amplitudes are well developed. Otherwise, patients can be left
with persistent postoperative esotropia. This may need further
surgery if diplopia cannot be eliminated (adults) or there is a risk
of loss of binocular vision (children).
A final comment pertains to the relationship between
refractive errors and exodeviation. Any surgical decision for
exotropia has to be made only after the total optical correction
of coexisting hyperopia. Very often, surgery can be avoided
in these cases. Real problems are due to the coexistence of
hyperopia and exotropia. Erroneously, hyperopia is often undercorrected,
thus causing asthenopia complaints, particularly after
age 20. A correct approach is the total optical correction of hyperopia
followed by surgery.
In conclusion, some suggestions for the proper handling of
exotropia have been offered here. It is hoped that in the future,
perspective studies will substitute for retrospective evaluations
of results in this and other areas of strabismology. Moreover,
patient grouping should be obtained on the basis of surgery
performed in childhood versus adulthood, and postoperative
follow-up needs to be extended to at least 10 years
of observation
ALMA OFTALMOLOGIA ECM 2010. sesto anno
No full textOrganizzazione di corsi di aggiornamento a calendario annuale ( 16 eventi per il 2010) accreditati presso il Sistema ECM della Regione Emilia Romagna per varie figure professionali e specialità mediche
ANNALS EXPRESS: Predictive Role of Tear Protein Expression in The Early Diagnosis of Sjögren's Syndrome
No full textBackground: The contribution of tear protein expression in patients with presumed diagnosis of Sjogren syndrome is underestimated. We aimed to evaluate the role of tear proteins in the Sjogren syndrome early diagnosis.
Methods: Charts from 110 patients suspected of Sjogren syndrome were analysed and the subsequent diagnosis retrieved. Subjective symptoms (ocular surface disease index, OSDI), tear film break-up time (TFBUT), Schirmer test, Jones test, tear clearance (TC), corneal (NEI score) and conjunctival staining (van Bjerstelveldt score), esthesiometry, cytology, tear protein analysis (total protein [TP] content, lysozyme-C [LYS-C], lactoferrin [LACTO], lipocalin-I [LIPOC-I] and albumin [ALB]) were analysed. The diagnostic performance with area under the curve (AUC) and odds ratio (OR) for each parameter were calculated.
Results: Thirty-five patients (31.8%) had been diagnosed as affected by Sjogren syndrome. Clinical tests showed lower diagnostic performance (OSDI > 44 [AUC 0.57], Schirmer 1/16 [0.68], Jones 2 [0.51], conjunctival staining > 2 [0.78]) compared with tear proteins (LYS-C = 15% [0.79]). LYS-C, LACTO, LIPOC-1 and ALB showed a significant association in predicting Sjogren syndrome vs. not-Sjogren syndrome dry eye (OR, respectively, 4.9, 5.5, 7.2, 6.7).
Conclusions: Tear proteins' concentrations showed a significant higher accuracy compared with the traditional ocular clinical tests for reaching Sjogren syndrome's diagnosis. In particular, LACTO and LIPOC- I provided an excellent diagnostic performance and thus could likely be considered promising biomarkers of Sjogren syndrome
ET-1 plasma levels, choroidal thickness and multifocal electroretinogram in retinitis pigmentosa
No full textAbstractAimTo assess the relationship between both photoreceptor function and choroidal thickness and endothelin-1 (ET-1) plasma levels in patients with early stage retinitis pigmentosa (RP).Main methodsWe compared 24 RP patients (14 males and 10 females), 25 to 42years of age (mean age: 34±7years) with 24 healthy controls (12 males and 12 females) aged between 28 and 45years (mean 36±6.8years). All patients underwent visual field test, electroretinogram and multifocal-electroretinogram and choroidal thickness measurement by using spectral domain optical coherence tomography.Key findingsRP patients had a visual acuity of 0.95, a mean defect of the visual field of −7.90±1.75dB, a pattern standard deviation index of 6.09±4.22dB and a b-wave ERG amplitude of 45.08±8.24μV. Notably RP subjects showed significantly increased ET-1 plasma levels and reduced choroidal thickness compared with controls: respectively, 2.143±0.258pg/ml vs. 1.219±0.236pg/ml; p<0.002 and 226.75±76.37μm vs. 303.9±39.87μm; p<0.03. Spearman's correlation test highlighted that the increase of ET-1 plasma levels was related with the decrease of choroidal thickness (r=−0.702; p<0.023) and the increase of implicit time in both ring 2 (r=−0.669; p<0.034) and ring 3 (r=−0.883; p<0.007) of mfERG.SignificanceIncreased ET-1 plasma levels may play a key role in the impairment of retinal and choroidal blood flow due to the vasoconstriction induced by ET-1. This could lead to worsening of the abiotrophic process of the macular photoreceptors
Subjective Discomfort Symptoms Are Related to Low Corneal Temperature in Patients with Evaporative Dry Eye
No full textPurpose: To measure the corneal temperature in patients with dry eye (DE) and to correlate the values with subjective discomfort symptoms. Methods: Twenty-four patients with DE (scored as DEWS severity grade 2 to 3) and 15 age-matched normal control subjects were enrolled. Subjective symptoms of discomfort were scored with an Ocular Surface Disease Index questionnaire, and a 100-mm horizontal visual analog scale (VAS) technique was used to measure symptom intensity. Schirmer I test, tear film breakup time (TFBUT), and Oxford grade scoring were performed in all subjects. Dynamic infrared noncontact thermal imaging (Tomey TG 1000) was used to measure the central corneal temperature (CCT). After training, subjects were asked to maintain their eyes forcedly open and to signal the discomfort onset time (DOT). The temperature was measured at eye opening (T 0) and every second during 10 seconds of sustained eye opening (T 10). The first discomfort sensation onset time (DOT) was also recorded. Temperature values were correlated with the clinical tests, Ocular Surface Disease Index, VAS, and DOT, and data were statistically evaluated (significance P < 0.05). Results: The corneal temperature immediately after eye opening was significantly lower in patients with DE than in controls, in correlation to the subject age, VAS, and TFBUT. A 3-phase cooling profile in patients with DE and a point of highest decrease (HD) in both groups were identified. DOT occurred earlier in patients with DE than in controls (5.9 vs. 15.9 seconds) and was strongly correlated to the VAS, TFBUT, and CCT-HD. Conclusions: Subjective sensation of discomfort occurred earlier in patients with DE than in controls, in correlation to low corneal temperatures and enhanced tear evaporation.
Accommodative spasm might influence surgical planning and outcomes in acute acquired distance esotropia in myopia
No full textIntroduction Acute acquired distance esotropia (AADE) is a poorly understood moderate-angle strabismus, affecting young adult myopes and determining bothersome diplopia. Symptoms can be intermittent in the early stages, becoming constant in long-lasting disease. Symptomatic therapy includes prism correction, while surgery is the only curative treatment. However, the latter is affected by high rate of symptoms recurrence with the frequent need for reoperation. Hypothesis We hypothesize that AADE could be caused by the increase of the accommodative demand, often secondary to a myopic overcorrection. This condition could determine an increase in induced hyperopia at near, dominated by an excess of accommodation and therefore of convergence. The latter cannot be relaxed at distance and diplopia develops. We speculate that early-stage AADE could be successfully treated by cycloplegic eye drops slowly tapered within three months. On the other hand, surgery remains the only option in long-lasting AADE. In these cases, we propose a new pre-operative assessment of esotropia by asking the patient to fix alternatively a stimulus at near and at distance in order to stimulate the accommodative convergence. This technique allows to unmask the total amount of the angle of deviation and to plan a wider bilateral medial rectus muscle recession avoiding long-term residual esotropia. Discussion Currently, AADE curative therapy is surgical regardless of onset time but it is usually affected by poor outcomes. If our hypothesis was to be confirmed, pharmacological treatment could solve early-stage AADE, avoiding any surgery. Furthermore, a wide bilateral medial rectus muscle recession, quantified on the basis of the above mentioned test for measuring the total amount of the strabismus angle, could improve outcomes eliminating the need for reoperation in long-lasting AADE
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Photorefractive keratectomy in 22 adult eyes with infantile nystagmus syndrome
No full textPurpose To analyze visual and refractive outcomes of photorefractive keratectomy (PRK) in adult patients with infantile nystagmus syndrome. Setting Ophthalmology Unit, Department of Experimental Diagnostic and Specialty Medicine, Saint Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy. Design Retrospective case series. Methods Photorefractive keratectomy was performed in both eyes of patients with infantile nystagmus syndrome under topical anesthesia using an eye-tracking excimer laser. Patient satisfaction was tested using a questionnaire. The main outcomes were a decrease in refractive error, an improvement in postoperative corrected distance visual acuity (CDVA), and an uncorrected distance visual acuity (UDVA) equal to or better than the preoperative UDVA. Results Twenty-two eyes of 11 patients with infantile nystagmus syndrome were evaluated. The mean patient age was 30.82 years (range 22 to 42 years). All eyes had simple, compound, or mixed astigmatism (mean -3.40 D; range -0.75 to -6.00 diopters [D]). The mean postoperative astigmatism (-0.70 D ± 0.81 [SD]) and spherical equivalent (-0.420 ± 0.652 D) were statistically significantly better than the preoperative values (-3.40 ± 1.31 D and -3.426 ± 3.343 D, respectively (P <.0001 and P =.0002, respectively). The mean monocular postoperative CDVA (0.24 ± 0.19 logMAR) and UDVA (0.25 ± 0.18 logMAR) were better than the mean preoperative CDVA (0.32 ± 0.28 logMAR) (P =.0045 and P =.0338, respectively). The mean binocular postoperative UDVA was better than the mean preoperative CDVA (0.15 ± 0.14 logMAR versus 0.23 ± 0.23 logMAR) (P =.05). No patient required repeat surgery. Conclusions Nystagmus patients are eligible for PRK. The results were promising; gaining a few Snellen lines in visual acuity can be very important to these patients for their daily life. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned
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