Prevalence and Associations of Central-Peripheral Rivalry-Type Diplopia in Patients With Epiretinal Membrane

An Update on Dragged-Fovea Diplopia Syndrome

Dragged-fovea diplopia syndrome (DFDS) is a type of binocular double vision caused by a displacement of the fovea in one or both eyes due to retinal disorders including epiretinal membranes or other maculopathies. DFDS induces diplopia through a mismatch between peripheral motor fusion and central (foveal) fusion. It can be diagnosed by utilizing the Lights on - Lights off test. While there is no cure, there are treatments for DFDS including monocular occlusion or blurring (tape, lenses, IOL), Bangerter filter, and Fresnel prisms. While this syndrome has been identified in the literature by multiple names including central-peripheral Rivalry (CPR)-type diplopia, macular diplopia, and foveal displacement syndrome, this article works to summarize the current known characteristics, diagnostic tests, and treatment for this syndrome.

Characteristics and type of strabismus associated to macular diplopia. Treatment outcomes

OBJECTIVE

To study the clinical characteristics of macular diplopia, treatment, and outcome.

METHODS

Retrospective descriptive study of cases referred to the ocular motility section of a tertiary hospital with diplopia, diagnosed with macular diplopia between 2022-23. The etiology of the macular pathology and the type of associated strabismus were recorded. The result was considered good if the diplopia improved or was eliminated with the medical or surgical treatment. Follow-up time from the onset of diplopia until data collection was recorded.

RESULTS

a total of 19 cases comprised the sample (63.2% women), mean age: 67.16 years. Amblyopia (21.1%), high myopia (47.4%), epirretinal membrane (ERM) (36.8%), neovascular membrane (26.3%), macular hole (10.5%), and lamellar (15.8%), and age macular degeneration (5.3%) were registered. The 47.4% had vertical diplopia, horizontal: 5.3 and 47.4% mixed. The mean horizontal deviation was: 7.3 PD (prism diopters) and vertical: 6.22 PD. Ocular extorsion was observed in 26.3%, and intorsion: 5.3%. Torticollis was present in 15.8%. The treatment consisted of strabismus surgery + Botox (15.8%), strabismus surgery (47.4%), medical treatment with Fresnel prims or Scotch cellophane (36.8%). A 68.4% presented a good result at the end of the study. The mean follow-up was 55.58 months.

CONCLUSIONS

Misregistration of macular photoreceptors is the most common cause of binocular diplopia in patients with ERM or other macular pathologies. Most complains of vertical or mixed diplopia. Sensorimotor evaluation of these patients should be thorough. Early diagnosis prevents unnecessary prescription of prism glasses. Surgical and/or medical treatment achieves good results in most cases.

Binocular visual function improvement after pars plana vitrectomy for epiretinal membrane

PURPOSE

To report binocular visual function changes after pars plana vitrectomy for epiretinal membrane (ERM) and the related outcomes.

METHODS

Twenty-three eyes of 23 patients operated on for ERM were included in a retrospective study. Clinical data, best-corrected visual acuity (BCVA), contrast sensitivity and binocular visual function were assessed pre- and 1 and 3 months post-operatively. Binocular visual function assessment included the evaluation of fusional amplitudes (i.e., vergences) by the synoptophore, far distance stereopsis using polarized glasses and near stereopsis using Randot and TNO tests. Central macular thickness (CMT) was measured on Spectral Domain - Optical Coherence Tomography.

RESULTS

Mean age of the patients was 67 years. Mean BCVA and contrast sensitivity significantly improved post-operatively at one (p = 0.0006 and p = 0.0022, respectively) and 3 months (p < 0.0001 and p < 0.0001, respectively), while CMT significantly decreased after 1-3 months (p < 0.0001 and p < 0.0001, respectively). Fusional amplitudes improved after 3 months (p < 0.0001). Far distance and near stereopsis significantly improved after 3 months (p < 0.0001 and p = 0.0007 for Randot test, and p < 0.0001 for TNO test, respectively).

CONCLUSIONS

Pars plana vitrectomy for ERM surgery leads to an improvement of monocular and binocular visual functions (i.e., binocular fusion, near and far distance stereopsis), within 3 months post-operatively.

Retinal misregistration and effect of surgery on its improvement in patients with epiretinal membrane

PURPOSE

To evaluate the prevalence of retinal misregistration, that is, misalignment of retinal elements that affect central and peripheral fusion, and the effect of surgery in patients with epiretinal membrane (ERM).

METHODS

This prospective interventional case-series was performed on 32 patients with symptomatic ERM with the complaint of binocular diplopia or decreased visual acuity. After the diagnosis of ERM, optotype frame, synoptophore, and lights on-off tests were used to evaluate retinal misregistration. Patients with severe symptoms underwent surgery and were followed for 3 months.

RESULTS

Of the 32 patients, 6 (19%) had preoperative diplopia. Optotype frame, synoptophore, and lights on-off tests had positive results in 20 (63%), 19 (63%), and 11 (34%) cases, respectively. Of the 6 diplopia cases, 5 showed positive results in all 3 tests and 1 was positive on optotype frame and synoptophore testing. Of the 26 cases without diplopia, 15 (58%) showed positive results in at least one test, including 6 (23%) in all three tests, 6 (23%) in two tests, and 3 (12%) in only one test. Ten patients underwent surgery. Postoperatively, all patients had negative lights on-off test, but optotype frame and synoptophore tests were negative in eight patients (80%). Two cases (20%) had postoperative diplopia, including 1 case with postoperative new-onset diplopia.

CONCLUSIONS

The prevalence of retinal misregistration was higher than the rate of diplopia. Surgery improved diplopia and results of tests of retinal misregistration.

Binocular Interference vs Diplopia in Patients With Epiretinal Membrane

Importance

Patients with epiretinal membrane (ERM) sometimes close 1 eye for improved vision, but associations have not been rigorously studied.

Objective

To evaluate associations with monocular eye closure in patients with ERM, and to report binocular interference (closing 1 eye to improve visual quality).

Design, Setting, and Participants

Retrospective medical record review of an adult strabismus clinic at a tertiary referral center. Patients with ERM referred from retina clinicians between June 2010 and October 2019 who completed the Adult Strabismus (AS)-20 questionnaire, including the question: "I cover or close one eye to see things better." Two groups were identified: (1) patients reporting eye closure sometimes or more, and (2) patients reporting no eye closure (as control patients).

Main Outcomes and Measures

Frequencies of (1) central-peripheral rivalry (CPR)-type diplopia (dragged fovea diplopia); (2) binocular interference (monocular eye closure but no diplopia or strabismus); and (3) other, associated with monocular eye closure. Visual acuity, metamorphopsia, aniseikonia, and AS-20 quality of life domain scores (self-perception, interactions, reading function, and general function) compared between binocular interference, CPR-type diplopia, and control patients.

Results

A total of 124 patients with ERM (58 of 124 were women [47%]; mean [SD] age, 70 [9] years) reported monocular eye closure. Associations were binocular interference in 36 (29%; 95% CI, 21%-38%), CPR-type diplopia in 34 (27%; 95% CI, 20%-36%), and other (primarily strabismus) in 54 (44%). Compared with control patients with ERM (n = 11), patients with ERM and binocular interference had worse quality of life on AS-20 reading function (95 vs 62; mean difference, 22 points; 95% CI, 7-27 points; P = .007) and general function (89 vs 68; mean difference, 23 points; 95% CI, 13-34 points; P = .01) domains. Compared with CPR-type diplopia, patients with binocular interference had poorer worst-eye visual acuity (median 0.50 vs 0.30 logMAR [20/63 vs 20/40]; mean difference, 0.13 logMAR; 95% CI, 0.00-0.25 logMAR [20/20 to 20/35]; P = .03), and a larger interocular difference (0.46 vs 0.19 logMAR [20/58 vs 20/30]; mean difference, 0.15 logMAR; 95% CI, 0.03-0.28 logMAR [20/21 to 20/38]; P = .004).

Conclusions and Relevance

Study findings suggest that binocular interference, manifesting as monocular eye closure (without diplopia or strabismus), is a distinct entity affecting quality of life in patients with epiretinal membrane.

Evolving trends in strabismus following retinal surgery: is there still a role for botulinum toxin?

Purpose Ocular motility disturbances following retinal detachment surgery are well documented, resulting in ocular misalignment and disabling diplopia. Interestingly, there has been a downward trend over the last decade across the United Kingdom with the evolution of refined vitrectomy techniques and instrumentation. We aim to report our updated experience on factors influencing botulinum toxin outcomes in view of the trend toward vitrectomy. Methods The Moorfields strabismus service carried out a follow-up retrospective study of all subjects that received botulinum toxin for retinal surgery-related strabismus at our center over an eleven-year period. All new onset constant or intermittent strabismus following retinal detachment surgery were included. Botulinum toxin response was stratified to good and poor. Results 32 patients fulfilled our criteria, with a mean follow-up of 20 months. The majority were vitrectomised eyes (62%), presented with diplopia (60%) and exotropia (66%). All isolated and combined vertical deviations (18%) were noted among cryobuckled eyes only. Baseline largest mean horizontal deviation was 49 and 51 prism diopters (PD) among the good and poor responders, respectively. A statistically and clinically significant reduction in the horizontal angle of deviation was noted among the good (p < .0001) responders, requiring a mean of six injections, in comparison to the poor responders (p = .03). Of the good responders, five patients (16%) with decompensated phorias regained fusion control. A small number of complications (15%) were noted, the most marked being intractable diplopia in a good responder (3%) with failure to fuse. Conclusions Botulinum toxin is a useful treatment modality, particularly when surgical options are limited. It can restore binocularity in patients with preexisting fusion potential. Ocular cosmesis can be achieved but requires ongoing injections. Barriers to fusion restoration include multiple retinal surgeries, persistent macula pathology and central-peripheral retinal rivalry. This highlights the need for rigorous baseline macula assessment to allow a tailored approach when considering botulinum toxin therapy for strabismus.

Test-retest reliability of the revised diplopia questionnaire

PURPOSE

To evaluate misclassification of diplopia "success" when using a standardized diplopia questionnaire (DQ), and to report test-retest reliability of the DQ.

METHODS

We retrospectively identified a cohort of 100 patients with stable strabismus (<5^Δ change in prism and alternate cover test measurements at distance and near), stable visual acuity, no change in treatment, and no clinical evidence of change, with completed DQ at two consecutive office visits (median, 71 days apart; range, 5-350 days). To evaluate the rate of misclassification of "success" and "not success," we compared the second to the first administration of the DQ using two established definitions of success: (1) "rarely" or "never" for straight ahead distance and (2) "rarely" or "never" for straight-ahead distance and reading. For DQ test-retest variability, 95% limits of agreement (LOA) and intraclass correlation coefficients (ICC) were calculated on DQ scores (0-100 scale).

RESULTS

When defining success as rarely or never diplopic for distance, misclassification occurred in 12 (12%) of 100 (95% CI, 6%-20%). When defining success as rarely or never diplopic for distance and reading, misclassification occurred in 14 (14%) of 100 (95% CI, 8%-22%). The 95% LOA for the DQ score were 35.2 points, and ICC was 0.85 (95% CI, 0.79-0.90).

CONCLUSIONS

We have quantified misclassification and test-retest variability when using the DQ dichotomously or as a continuous measure, equipping the clinician to better interpret DQ outcome data in practice and research.

Treatment for Central-Peripheral Rivalry-Type Diplopia ("Dragged-Fovea Diplopia Syndrome")

PURPOSE

To report the effectiveness of treatments for central-peripheral rivalry (CPR)-type diplopia due to retinal misregistration.

DESIGN

Retrospective, interventional case series.

METHODS

Fifty adults with retinal misregistration and CPR-type diplopia (minimum frequency of "sometimes" at distance and/or for reading) caused by epiretinal membrane (n = 44) or other retinal disorders (n = 6) were enrolled in this study, conducted at adult strabismus clinics, Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, a tertiary medical center. Treatments included Bangerter filter, adhesive tape, Fresnel prism, clear prism (incorporated into glasses or loose prism in the office), iseikonic manipulation (using iseikonic lenses or contact lenses), a MIN lens, or epiretinal membrane (ERM) peeling (alone or in any combination). Not all patients underwent all of these treatments.

RESULTS

Main outcome measurements were diplopia frequency, evaluated using the Diplopia Questionnaire. Success was defined as "never" or "rarely" diplopic for distance and reading, using the Diplopia Questionnaire, at an outcome examination as close as possible to 6 months. Overall, 17 of 50 patients (34%; 95% confidence interval [CI], 21%-49%) were classified as successful. Fresnel prism was successful in 4 of 7 patients (57%; 95% CI, 18%-90%); Bangerter filter in 4 of 28 patients (14%; 95% CI, 4%-33%); ERM peeling in 8 of 18 patients (44%; 95% CI, 22%-69%); and iseikonic manipulation in 1 of 23 patients (using a contact lens; 4%; 95% CI, 0%-22%).

CONCLUSIONS

CPR-type diplopia may be relieved in some patients using nonsurgical treatment options consisting of Fresnel prism or Bangerter filter. ERM peeling was surprisingly successful and should be considered.

IOL-Induced Extreme Blur to Alleviate Intractable Diplopia Secondary to Dragged-Fovea Diplopia Syndrome

A 73-year-old male presented with one year of intractable binocular diplopia and metamorphopsia in the right eye. He was unable to maintain fusion with prismatic correction, refused cosmetically noticeable forms of occlusion, and was not an occlusive contact lens candidate due to chronic neuropathy affecting his hands. The patient underwent cataract surgery with placement of a high plus intraocular lens to induce extreme blur. The uncomplicated procedure was successful in eliminating his diplopia. Cataract extraction with a high minus refractive target is an option for treating intractable diplopia associated with dragged-fovea diplopia syndrome.

New Onset vs Resolution of Central-Peripheral Rivalry-Type Diplopia in Patients Undergoing Epiretinal Membrane Peeling

Importance

The peeling of an epiretinal membrane (ERM) is commonly performed for poor visual acuity and/or metamorphopsia, but to our knowledge, its influence on central-peripheral rivalry (CPR)-type diplopia has not been rigorously studied.

Objective

To evaluate the occurrence of either resolution or new-onset CPR-type diplopia in patients undergoing ERM peeling.

Design, Setting, and Participants

This prospective cohort study was conducted from July 2014 to April 2018 at a tertiary referral medical center and included 33 adults with ERM who were undergoing peeling surgery with planned preoperative to postoperative analysis.

Interventions

A standardized diplopia questionnaire completed before undergoing and 6 months following ERM peeling.

Main Outcomes and Measures

For patients with CPR-type diplopia before ERM peeling (rated "sometimes" or more for distance straight ahead or reading using the diplopia questionnaire), we calculated the proportion with resolution of diplopia postpeel ("never" for distance straight ahead and reading on the diplopia questionnaire) and compared clinical characteristics between those with resolution and those without. For patients with no diplopia prepeeling ("never" for distance straight ahead and reading on the diplopia questionnaire), we calculated the proportion with new-onset CPR-type diplopia postoperatively and compared clinical characteristics between those with new-onset diplopia and those who remained without diplopia.

Results

Of 33 patients (median age, 67 years [range, 51-87 years]; 18 men [55%]), 12 (36%) had CPR-type diplopia preoperatively and 21 (64%) did not have diplopia preoperatively. Six months postoperatively, 4 of 12 patients with diplopia (33%; 95% CI, 10%-65%) had resolution of diplopia, and 4 of 21 patients without diplopia (19%; 95% CI, 5%-42%) had new-onset diplopia. Better postoperative operated-eye visual acuity appeared somewhat associated with new-onset diplopia postoperatively (mean [SD] visual acuity, 0.08 [0.10] logMAR; approximately 20/25 vs 0.34 [0.33] logMAR; approximately 20/40; difference, -0.27; 95% CI, -0.62 to 0.09; P = .07), as did greater postoperative aniseikonia (14% [5%] vs 6% [4%]; difference, 8%; 95% CI, 2%-13%; P = .04).

Conclusions and Relevance

These data suggest that epiretinal membrane peeling may result in resolution of diplopia in some patients but new-onset diplopia in others. These findings may be valuable when counseling patients regarding the risks of new-onset diplopia.