Anterior approach ptosis surgery: comparison of absorbable polyglactin sutures and non-absorbable polyester sutures. Does Vicryl stand the test of time?

PURPOSE: To determine whether the long-term success of ptosis surgery is influenced by the use of absorbable or non-absorbable sutures to advance the levator aponeurosis onto the tarsal plate. METHODS: Multi-centre retrospective comparative study of re-operation rates in primary anterior approach ptosis surgery using absorbable polyglactin sutures (Vicryl) and non-absorbable polyester sutures (Ethibond). The Medisoft audit tool was used to identify all patients who underwent primary ptosis surgery for aponeurotic ptosis, performed by five oculoplastic consultants within a 7-year period, across two NHS Ophthalmology departments. The electronic patient records were reviewed for each patient. Basic demographics, suture material, and post-operative complications were recorded. All patients requiring repeat surgery between the study dates and the present day were recorded, allowing a minimum postoperative period of 3 years and 10 months. Re-operation rates in surgery using absorbable Vicryl sutures and non-absorbable Ethibond sutures were compared using Fisher's exact test. RESULTS: Four hundred and fifty-five operations in 330 patients were performed within the study period that met the inclusion and exclusion criteria. Fifty-seven percent of the patients were female, with an average age of 68.8 years. One hundred and sixty-nine operations in 128 patients were performed using absorbable Vicryl sutures. Of these, 22 (13.0%) required repeat operations. Two hundred and eighty-six operations in 202 patients were performed using non-absorbable Ethibond sutures. Of these, 17 (5.9%) required repeat operations. The two-tailed P-value was 0.0143. CONCLUSION: The use of non-absorbable Ethibond sutures to advance the levator aponeurosis onto the tarsal plate in primary ptosis surgery is associated with improved long-term success and reduced need for secondary surgery.

Incidence, risk factors and management of intractable diplopia.

AIMS: There is a paucity of literature concerning intractable diplopia. The aims of this study were to determine the incidence of intractable diplopia in the UK, identify the causes and any associated risk factors, establish how cases are managed and if the treatment is successful and tolerated. METHODS: A 1-year prospective observational study was undertaken via the British Ophthalmological Surveillance Unit (BOSU). This involved implementation of a reporting mechanism, which then triggered distribution of an incident questionnaire to explore clinical details concerning each case and a follow-up questionnaire 6 months later to explore how the case had been managed. RESULTS: The incidence of intractable diplopia was 53 cases per year. The most common preceding events were strabismus surgery (32%), no known preceding event, that is,spontaneous (25%), severe head trauma (8%), cataract surgery (6%) and vitrectomy (6%). In the at-risk age group of 7 years and above, the incidence of intractable diplopia following strabismus surgery is 1 in 494 (95% CI; 1 in 296 to 790) cases. A total of nine different treatments were used in the management, with many patients receiving between two and four different methods. The overall success rate was poor, but most effective were opaque intraocular lenses (IOLs) (86%) and opaque contact lenses (50%). CONCLUSION: Intractable diplopia is a relatively rare but important condition. The main risk factor is a pre-existing strabismus, and careful counselling is needed when planning surgical correction in patients with no demonstrable binocular function. Treatment success of intractable diplopia is high when using opaque IOLs, although with additional risk, but is often disappointing via other methods where it can be difficult to eradicate the diplopia successfully.

Pre-operative experiences and post-operative benefits of ptosis surgery: A qualitative study.

This qualitative study sought to explore the experiences of patients who had undergone successful ptosis correction surgery. Participants were recruited from Bristol Eye Hospital. Nine participants were interviewed using a semi-structured interview schedule and open ended questions. Data were analysed using inductive thematic analysis. Four major themes were identified from patient accounts. Patients described the psychosocial and functional difficulties they experienced living with ptosis, and the subsequent benefits of surgery. Patients reported experiencing appearance related anxiety pre-operatively due to their condition and engaging in behaviours to avoid social encounters. Gender differences were noted in the internalization of perceived negative reactions from others, with men describing fewer adverse impacts. Patients described perceived barriers to seeking surgery including a lack of awareness of ptosis as a treatable condition, the perception that being concerned with their appearance could be seen as vain and the view that ptosis surgery is synonymous with cosmetic surgery. Following successful surgery patients outlined positive impacts on their vision, appearance and psychosocial well-being after successful surgery. This qualitative study highlights the complexities of the factors and processes contributing to the psychosocial impacts of ptosis and the potential benefits of surgery and/or psychosocial support. An increased awareness amongst people with ptosis of the potential positive impacts of surgery and an enhanced understanding of the reasons why patients may not seek treatment amongst health care professionals are likely to benefit this often overlooked patient group.

Why can't my child see 3D television?

A child encountering difficulty in watching three-dimensional (3D) stereoscopic displays could have an underlying ocular disorder. It is therefore valuable to understand the differential diagnoses and so conduct an appropriate clinical assessment to address concerns about poor 3D vision.

The psychosocial impact of ptosis as a symptom of Myasthenia Gravis: a qualitative study.

The aim of this qualitative study was to investigate the psychosocial impact of ptosis as a symptom of Myasthenia Gravis (MG). Participants were recruited from a MG patient group on Facebook. 166 participants answered a series of open ended questions examining the impact of ptosis, and responses were analysed using Inductive Thematic Analysis, which revealed four main themes. The first highlighted the extent to which ptosis impacted negatively on psychosocial functioning. The second related to ways in which ptosis can be framed in a positive way, eg, as a believable symptom. The final two themes revealed the complex inter-relationships between functional and appearance-related impacts, and a desire from many participants for health care professionals to provide more support directly related to their ptosis. This study suggests that ptosis impacts in ways not currently recognized in literature and practice.

Levator function revisited: a two-phase assessment of lid movement to better identify levator-superior rectus synkinesis.

AIM: To assess a two-phase method of recording levator function in order to facilitate the identification of patients with ptosis who have a synkinesis between the levator and superior rectus muscles. METHODS: 40 consecutive patients who attended oculoplastic clinics with ptosis and 22 patients with normal lid function were recruited. In each subject, levator function was recorded by the conventional method, measuring total upper eyelid excursion between the extremes of down-gaze and up-gaze. Levator function was also assessed using our novel two-phase approach in which upper-eyelid excursion is measured separately between down-gaze and primary position (Phase 1), and between primary position and up-gaze (Phase 2). RESULTS: In normal patients and most of the patients with ptosis, the majority of lid movement and hence levator function occurs between down-gaze and the primary position (Phase1). In those patients with ptosis and levator-superior rectus synkinesis, a higher proportion of lid movement occurred on up-gaze (Phase2). CONCLUSION: The two-phase measurement of lid movement highlights levator function in differing gaze positions and facilitates the identification of those patients with levator-superior rectus synkinesis.

Duration of conjunctival redness following adult strabismus surgery.

PURPOSE: To determine the duration of postoperative conjunctival injection following strabismus surgery and to assess how this is affected by previous extraocular muscle surgery. This would improve preoperative counseling of strabismus patients. METHODS: Subjective evaluation of conjunctival redness based on patient questionnaire response. RESULTS: Fifty-three patients returned completed questionnaires. A total of 93 muscles were operated on. Of these, 46 had not undergone previous operations; 47 had. Previously unoperated eyes remained red for a median duration of 9.5 weeks; reoperated eyes remained red for a median of 11 weeks. Of the 93 muscles, 50 were sutured with adjustable sutures. These remained red for a median duration of 11 weeks. Muscles tied with nonadjustable sutures remained red for a median of 10 weeks. CONCLUSIONS: In both previously unoperated and reoperated eyes, conjunctival redness resolved in approximately 10 weeks; adjustable sutures did not alter the duration of redness significantly.

Disparity tuning of binocular facilitation and suppression after normal versus abnormal visual development.

PURPOSE: To study the pattern of facilitatory and suppressive binocular interactions in stereodeficient patients with strabismus and in healthy controls. METHODS: Visual evoked potentials were recorded in response to a Vernier onset/offset pattern presented to one eye, either monocularly or paired dichoptically with a straight vertical square-wave grating, which, when fused with the target in the other eye, gave rise to a percept of a series of bands appearing in depth from an otherwise uniform plane or with a grating that contained offsets that produced a standing disparity and the appearance of a constantly segmented image, portions of which moved in depth. RESULTS: Participants with normal stereopsis showed facilitative and suppressive binocular interactions that depended on which dichoptic target was presented. Patients with longstanding, constant strabismus lacked normal facilitative binocular interactions. The response to a normally facilitative stimulus was reduced below the monocular level when it was presented to the dominant eye of patients without anisometropia, consistent with classical strabismic suppression of the nondominant eye. The dominant eye of strabismic patients without anisometropia retained suppressive input from crossed but not uncrossed disparity stimuli presented to the nondominant eye. CONCLUSIONS: Abnormal disparity processing can be detected with the dichoptic VEP method we describe. Our results suggest that suppression in stereoblind, nonamblyopic observers is determined by a binocular mechanism responsive to disparity. In some cases, the sign of the disparity is important, and this suggests a mechanism that can explain diplopia in patients made exotropic after surgery for esotropia.

Releasable conjunctival suture for adjustable suture surgery.

BACKGROUND: Adjustable sutures are widely used in adult strabismus surgery, with a second procedure performed to close the conjunctiva irrespective of whether adjustment is required. We describe a technique where the conjunctiva is closed using a buried releasable suture, eliminating the second procedure if adjustment is deemed unnecessary. METHOD: The conjunctiva is closed using a 6/0 absorbable polyglactin 910 releasable suture. It is tied in a bow, like the muscle sutures, and tucked under the conjunctiva. If adjustment is not required, the eye does not need to be touched because the conjunctiva is secured by the suture. If adjustment is required, it is easy to untie the conjunctival suture, allowing good exposure to the underlying muscle sutures. RESULTS: In our prospective series of 30 patients, we found our technique effective and patient friendly. Patients had at least 3 months of follow-up with no significant complications. CONCLUSIONS: This technique is acceptable, accessible, and time saving for both surgeons and patients. It is especially useful for anxious patients and adolescents, for whom postoperative manipulation can be difficult, and for cases where the probability of adjustment is low.

A VEP measure of the binocular fusion of horizontal and vertical disparities.

PURPOSE: Because of the lateral separation of the orbits, the retinal images differ in the two eyes. These differences are reconciled into a single image through sensory and motor fusional mechanisms. This study demonstrates electrophysiologically the effects that normal horizontal and vertical fusional processes have on the processing of monocular position signals. METHODS: VEPs were recorded in 16 healthy adults in response to a vernier onset-offset target presented to one eye. The vernier offsets appeared and disappeared at 2 Hz and were introduced into bar targets that were oriented either vertically (horizontal offsets) or horizontally (vertical offsets). The magnitude of the offsets was varied over the range of 0.5 to 10 arc min. VEP amplitude was measured as a function of the size of the dynamic offset under monocular viewing conditions and in the presence of two different static targets presented to the other eye. One of the static targets matched the dynamic test, except that it had no vernier offsets. The other static target, the static pedestal, matched the dynamic test, but contained a set of static vernier offsets in locations corresponding to the locations of the dynamic offsets presented to the other eye. RESULTS: VEP amplitude was a monotonically increasing function of vernier offset size under monocular viewing conditions. The addition of the static target without offsets in the other eye resulted in an increased amplitude VEP response. The addition of the static target with vernier offsets resulted in a decrease in VEP amplitude for both horizontal and vertical disparities. CONCLUSIONS: The normal process of fusion results in a single visual direction. To obtain a single visual direction, the visual system must synthesize a binocular visual direction that differs from the monocular components. One of the conditions (the static pedestal with offsets) produces binocular visual direction shifts that degrade the appearance of vernier onset-offset, and reduce VEP amplitude for both horizontal and vertical disparities. This characteristic evoked response marker is a promising tool for measuring binocular fusion objectively in patients with strabismus.

The effect of ocular dominance on visual field testing.

PURPOSE: During standard automated perimetry (SAP), some patients experience visual disturbances in the tested eye while the other eye is covered with an opaque occluder. It is possible that a binocular interaction producing an inhibitory response in the nonoccluded eye, such as rivalry or Ganzfeld blankout, may be the causative factor, particularly when the dominant eye is occluded. The objective of this experiment was to determine whether subjective visual disturbances occurring during conventional perimetric test conditions were related to ocular dominance and to investigate the effect of these disturbances on measurements made during threshold visual field analysis. METHOD: Ocular dominance was determined by questioning and objective testing on 55 normal subjects. Each subject underwent program 24-2 Full Threshold SAP on a Humphrey Field Analyzer, and an opaque black patch was used to occlude the nontested eye. After testing, patients were asked to report symptoms of visual disturbance characteristic of rivalry or blankout, and the relationship between ocular dominance and visual disturbances was investigated. To determine whether symptoms of rivalry or blankout had affected visual field quantification, comparisons of short-term fluctuation, mean deviation, and false-negative errors were performed between eyes with and without visual disturbances. RESULTS: A total of 24 of 55 subjects reported visual disturbances consistent with rivalry or blankout (44%). Sixteen subjects complained of the phenomenon in one eye, and eight complained of the phenomenon in both eyes. Of the 16 experiencing disturbances in one eye only, nine cases occurred during occlusion of the dominant eye. The association between ocular dominance and visual disturbances was not found to be significant (p > 0.10). No significant differences in short-term fluctuation (p = 0.78), mean deviation (p = 0.64), or false-negative errors (p = 0.10) were found between eyes with and without visual disturbances. CONCLUSIONS: Patients undergoing standard automated perimetry with opaque patch occlusion of the nontested eye often experience visual disturbances consistent with rivalry or blankout, although these disturbances do not cause increased within-test variability or reduced sensitivity as quantified by visual field global indices. In terms of summary visual field indices, ocular dominance does not appear to affect visual field test results.