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Grand Rounds 29 Feb 2016 Overminus spectacles as a treatment for IXT. Jonathan M. Holmes. CME Record of Attendance Ophthalmology Grand Conference– February 29. Text JAHJUC to (507) 200-3010 to record your attendance today. 48 Hours to Text Attendance
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Grand Rounds 29 Feb 2016Overminus spectacles as a treatment for IXT Jonathan M. Holmes
CME Record of Attendance Ophthalmology Grand Conference– February 29 Text JAHJUCto (507) 200-3010 to record your attendance today. 48 Hours to Text Attendance For questions, contact Elaine Eckheart (eckheart.elaine@mayo.edu) • Only Residents and Fellows still need to swipe to comply with accreditation requirements for conference attendance. • Residents and Fellows (who are not Board certified) do not need to obtain CME credits. • Faculty who want to obtain CME credits must text the unique code for each conference.
AccreditationMayo Clinic College of Medicine is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Mayo Clinic College of Medicine designates this live activity for a maximum of 0.75 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. CME Objectives1) Identify/summarize/describe concepts related to clinical eye care2) Apply new knowledge to relevant clinical situations. As a provider accredited by ACCME, Mayo Clinic College of Medicine, (Mayo School of CPD) must ensure balance, independence, objectivity and scientific rigor in its educational activities. Course Director(s), Planning Committee Members, Faculty, and all others who are in a position to control the content of this educational activity are required to disclose all relevant financial relationships with any commercial interest related to the subject matter of the educational activity. Safeguards against commercial bias have been put in place. Faculty also will disclose any off label and/or investigational use of pharmaceuticals or instruments discussed in their presentation. Disclosure of this information will be published in course materials so those participants in the activity may formulate their own judgments regarding the presentation. Listed below are individuals with control of the content of this program who have disclosed… Relevant financial relationship(s) with industry: Raymond Iezzi, M.D. is a consultant to Alcon, Alimera, Vergent No relevant financial relationship(s) with industry: Dept. of Ophthalmology Planning Committee includes members of the Education Committee: Drs. Sophie Bakri, Sanjay Patel, Keith Baratz, Andrew J. Barkmeier, Elizabeth Bradley, William Brown, John Chen, Amir Khan, Sunil Khanna, Leo Maguire, Michael Mahr, Brian Mohney, Wendy Smith, Linda Mrozek, Kari Sczepanski.
DISCLOSURE Jonathan M. Holmes Relevant Financial Relationship(s) None (only grant funding from NIH) Off Label Usage None
Presentation Learning Objectives • To understand the current evidence-base for the use of overminus spectacles as a treatment for intermittent exotropia • To identify factors that might predispose to successful treatment of intermittent exotropia with overminus spectacles
Question 1 Control of intermittent exotropia should be assessed with: • Standardized timing of the tropic phase • Prism and alternate cover test • Near stereoacuity • Standardized assessment on the synoptophore
Question 2 The current evidence suggests • Overminus may be more effective when control is moderate • Overminus may be more effective when control is poor • There is no relationship between the effectiveness of overminus and level of control • Overminus is ineffective as a treatment for intermittent exotropia
Index Case 5 year-old boy Hx - “left eye wanders particularly when tired or at end of day” VA 20/20 20/20 Full ductions D 25 X(T) comitant N 25 X(T) SLE Fundus Normal Cret +0.50 R +0.50 L
Diagnosis – Intermittent Exotropia One of the most common strabismus disorders of childhood Other Accommodative ET (28%) Sensory XT (3%) XT assoc with CNS (4%) Acquired Non-accomm ET (10%) CI XT (5%) Up to 1% of children under 11y in Olmsted CO MN ET assoc with CNS (7%) Intermittent Exotropia (17%) Sensory ET (4%) Paralytic ET (4%) Congen ET (5%)
IXT treatment options • Observe • Alternate patching e.g. 3hrs/day (? Anti-suppression therapy) • Convergence exercises • Surgery
Another non-surgical treatment option • Overminus spectacles e.g. adding -2.50 sphere to each spectacle lens • E.g. Cret -1.00 sph R -1.00 sph L • Overminus Rx -3.50 sph R -3.50 sph L • E.g. Cret +1.00 sph R +1.00 sph L • Overminus Rx -1.50 sph R -1.50 sph L
Theoretical underpinnings • Overminus stimulates accommodation which then stimulates convergence (therefore high AC/A ratio may be beneficial) • Fusional vergence stimulates accommodation (we have a CA/A ratio) accommodation blurs distance VA requiring overminusfor clarity
Previous studies of “Overminus” • Small case series • Differing amounts of overminus (-0.50 to -5.00) • Differing methods of prescription (fixed versus titrated to control of IXT) • No control groups • No standardized outcome assessment • No masking of outcome assessment
Intermittent Exotropia Study 3(IXT3) A Pilot Randomized Clinical Trial of Overminus Spectacle Therapy for Intermittent Exotropia
Study Objectives To assess initial short-term response to overminus treatment
What is the question ? Is overminus treatment more effective than non-overminus treatment in the management of childhood intermittent exotropia?
Candidate 1o Outcome measures • Angle of deviation? • No – 2 cases can have same angle but very different • Stereoacuity? • No – stereoacuity often preserved • Control? • Yes - that is what others see
“Control” ? • Proportion of the time the eyes are manifestly exotropic • Ease of recovery when dissociated
“Control” ? • Proportion of the time the eyes are manifestly exotropic • Ease of recovery when dissociated
Mohney/Holmes office control score Phoric Tropic Mohney BG, Holmes JM. An office-based scale for assessing control in intermittent exotropia. Strabismus 2006;14:147-50.
30 second observation Constant exotropia – Grade 5 Exotropia > 50% of 30 seconds before dissociation – Grade 4 Exotropia < 50% of 30 seconds before dissociation – Grade 3 Score distance and near fixation separately
Three 10-second periods of dissociation first R, then L, then the eye that deviated longest – estimate how many seconds it takes to recover Grade by the worst of 3 trials (R, L, then worst) >5 seconds – grade 2 1-5 seconds - grade 1 <1 second – grade 0 (pure phoria)
Patient 1 Patient 10 5 Patient 13 Tropic 4 3 2 Phoric 1 0 8:00 -10:30 10:31-13:00 13:01-15:30 15:31-18:00 But……control can be variable Distance control over the course of day 46% showed variable control ( >1 level) during a single day Controlscore Assessment time
Multiple assessments of control Early am Late pm Late am Early pm Single Double Triple Mean of one or two or three measures (single, double, triple) Compared to 1. Day mean (of 12 measures) 2. Subsequent day mean (of 12 measures) Triple measures (mean of 3) were most representative of the patient
Current recommendations for assessing control – 3 assessments 30 sec observation 5 - constant Visit 4 ->50% 3 - <50% Mean of three assessments For Distance For Near 3 10-sec covers 2 - >5 secs 1 - 1-5 secs 0 - phoria
Refining the question in terms of the chosen primary outcome measure
Study Objectives To assess initial short-term response to overminus treatment Compare: • Study group mean of distance IXT control scores (primary outcome)* • Proportion of patients with improvement >=1 point in distance IXT control score* • Adverse symptoms, near VA, & compliance *The distance IXT control score is the mean of 3 controltestsat the visit.
Major Eligibility Criteria • Age: 3 to <7 years • IXT • Distance control score ≥ 2 (mean of 3) • Near control score ≠ 5 (mean of 3) • ≥ 15∆ exoat distance by PACT • Near deviation does not exceed distance deviation by >10 ∆ on PACT
Major Eligibility Criteria (cont.) • No previous strabismus surgery • No previous substantial overminus (>=1.00D) • No non-surgical treatment for IXT within past 6 months (other than refractive correction) • SE in both eyes between +1.00 and -6.00 inclusive • No ADHD drugs or other drugs known to affect accommodation • Wearing appropriate correction for ≥1wk if refractive error meets certain criteria
Study Flow Chart Enrollment Randomization Observation GROUP (non-overminus spectacles or no spectacles) Overminus GROUP Spectacles with full CR plus 2.50D overminus 2-WEEK PHONE CALL (FROM SITE) 8-WEEK Primary outcome exam (masked exam)
Study Treatment & Sample Size 58 patients enrolled at 21 sites We planned 50 patients, knowing that we would have 88% power to detect a 0.75 pt difference with a SD of 0.926 (1-sided test with alpha of 0.05) 58 patients enrolled and randomized (1:1) to: • Observation (N=31) • Non-overminus spectacles or no spectacles (if correction not needed) • Overminus (N=27) • Spectacles with 2.50D overminus
Baseline: XT Control at Distance N/A N/A Distance Exotropia Control Score (mean of 3 testings)
Baseline: XT Control at Near Near Exotropia Control Score (mean of 3 testings)
Baseline: PACT at Distance N/A Magnitude of Exodeviation by PACT at Distance (∆) Note: PACT at distance had to be at least 15 PD for eligibility.
Baseline: PACT at Near Magnitude of Exodeviation by PACT at Near (∆)
Baseline Stereoacuity at Near Baseline Near Stereoacuity (arcsec)
Treatment Compliance Weeks of Overminus Spectacle Wear Possible
Weeks Overminus Patients Had Overminus Spectacles Mean = 7 weeks Range = 4 -11 weeks Weeks Between Spectacle Receipt and 8-Week Visit
Compliance with Overminus* *Based on parental report and discussion with investigator.
8-week Mean Distance Control Difference = -0.75 (-1.42 to -0.07) P = 0.03 for one-sided test Observation (N=31) Overminus (N=27)
8-week: Mean Distance Control Difference = -0.75 (-1.42 to -0.07) P = 0.03 for one-sided test 8-wk Distance Control Score (mean of 3 testings)
8-week Change in Distance Control Worse Mean change = -0.4 Mean change = -1.2 N/A N/A N/A N/A Better Percentage of Patients
8-week Distance Control Treatment Response (≥ 1 point improvement) Difference = 20% (-6% to 45%) P = 0.07 for one-sided test
Improvement in controlby level of baseline control Does improvement depend on baseline control?
8-week Mean Change in Distance Control According to Baseline Control