Inferior Rectus Muscle Y-Split for Thyroid-Related Vertical Strabismus

Incomitant hypotropia in thyroid eye disease can be difficult to manage, especially in the presence of orthotropia with fusion in down gaze and reading position. Recessing the affected ipsilateral inferior rectus muscle may result in an undesirable downgaze diplopia secondary to a hypertropia in downgaze. Various surgical techniques have been described to manage this potential complication including asymmetric recession of both inferior rectus muscles, posterior myoscleropexy operation, and the Scott recess/resect procedure of the contralateral inferior rectus. In 2004, Hoerantner et al. introduced the y-split recession of the medial rectus muscle for near esotropic deviations. The anterior portion of muscle is split and secured in a y-shaped configuration, which reduces the muscle lever arm and helps minimize incomitance and muscle slippage. Unlike the traditional Cüppers Faden, a y-split recession results in torque reduction in all gaze positions. In addition, a y-split recession does not involve scleral passes posteriorly reducing the risk of globe perforation. We report a patient with incomitant strabismus secondary to thyroid eye disease who underwent a combination of traditional recession and y-splitting recession of the contralateral inferior rectus muscle, resulting in good functional alignment in primary gaze and in the reading position.

Teprotumumab for Thyroid Eye Disease-related Strabismus

PURPOSE

To assess and quantify teprotumumab's effect on thyroid eye disease-related strabismus by change in measured horizontal and vertical deviations and change in extraocular motility.

METHODS

We reviewed a series of patients with thyroid eye disease-related strabismus treated with teprotumumab. Exclusion criteria included age under 18 years, strabismus of alternate etiology, or thyroid eye disease-related reconstructive surgery during the treatment course. Primary outcomes were absolute (prism diopters) and relative (%) differences in horizontal and vertical deviations in primary position at distance, as well as change in ductions of the more affected eye. Secondary outcomes included incidence and timing of strabismus surgery postteprotumumab.

RESULTS

Thirty-one patients were included, with mean age 63 years and thyroid eye disease duration 10 months. After teprotumumab, there was 6 prism diopters (39%) mean reduction in vertical deviation (p < 0.001), without significant change in mean horizontal deviation (p = 0.75). Supraduction, abduction, adduction, and infraduction significantly improved in the more restricted eye (p < 0.01, p < 0.01, p = 0.04, and p = 0.01, respectively). Thirty-five percent of patients underwent strabismus surgery posttreatment, at an average 10 months after last infusion.

CONCLUSIONS

Teprotumumab produced a statistically significant reduction in vertical but not horizontal strabismus angles in primary position at distance. Extraocular motility in all 4 ductions also improved. A substantial minority of patients still required strabismus surgery following teprotumumab.

Outcomes of Strabismus Surgery Following Teprotumumab Therapy

PURPOSE

To investigate the results of patients undergoing surgical treatment for strabismic diplopia in thyroid eye disease (TED) following teprotumumab.

DESIGN

Multicenter, retrospective, case series.

METHODS

We report 28 patients who underwent extraocular muscle surgery for strabismic diplopia after treatment with teprotumumab at 7 different academic centers. Elapsed time from last teprotumumab dose to the date of surgery, previous orbital decompression, primary preoperative horizontal and vertical deviation, surgical procedure, and 2-month postoperative results were collected from the patient records.

RESULTS

Sixteen (57%) patients were diplopia-free after 1 surgery. Three (11%) chose prism spectacles to correct residual diplopia, 2 (7%) used compensatory head posture to resolve diplopia, and 1 (4%) had intermittent diplopia and was functionally improved (choosing no prisms or further surgery). These were considered treatment successes. Three (11%) patients required reoperation, and all were diplopia-free after their second procedure.

CONCLUSIONS

Most patients requiring surgery for strabismic diplopia following teprotumumab achieve good outcomes with success rates comparable to series published before the availability of teprotumumab.

Dry eye disease in the young: A narrative review

Dry eye disease (DED), a multifactorial ocular disease that significantly impacts quality of life, is most commonly reported in adults. This review describes the prevalence, risk factors, diagnosis and management of DED in children. A literature search, conducted from January 2000-December 2022, identified 54 relevant publications. Using similar diagnostic criteria to those reported in adults, namely standardized questionnaires and evaluation of tear film homeostatic signs, the prevalence of DED in children ranged from 5.5% to 23.1 %. There was limited evidence for the influence of ethnicity in children, however some studies reported an effect of sex in older children. Factors independently associated with DED included digital device use, duration of digital device use, outdoor time and urban living, Rates of DED were higher in children with ocular allergy and underlying systemic diseases. Compared with similar studies in adults, the prevalence of a prior DED diagnosis or a diagnosis based on signs and symptoms was lower in children, but symptoms were commonly reported. Treatment options were similar to those in adults, including lifestyle modifications, blinking, management of lid disease and unpreserved lubricants in mild disease with escalating treatment with severity. Management requires careful exploration of symptoms, medical history and the diagnosis and management of ocular comorbidities such as allergy and anterior blepharitis. Appropriately powered population-based studies are required to understand the prevalence of and risk factors for DED in children. Development of age-appropriate thresholds for signs and symptoms of DED would support better diagnosis of disease and understanding of natural history.

AAPOS Adult Strabismus Committee's Report on the Status of Adult Strabismus Telemedicine

PURPOSE

To evaluate the utility of telemedicine in the treatment of adult patients with strabismus.

METHODS

A 27-question online survey was sent to ophthalmologists of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) Adult Strabismus Committee. The questionnaire focused on the frequency of telemedicine utilization, the benefits in the diagnosis, follow-up, and treatment of adult strabismus, and barriers of current forms of remote patient visits.

RESULTS

The survey was completed by 16 of 19 members of the committee. Most respondents (93.8%) reported 0 to 2 years of experience with telemedicine. Telemedicine was found to be useful for initial screening and follow-up of established patients with adult strabismus, mainly to reduce wait time for a subspecialist visit (46.7%). A successful telemedicine visit could be completed with a basic laptop (73.3%) or a camera (26.7%) or could be assisted by an orthoptist. Most participants agreed that common forms of adult strabismus (cranial nerve palsies, sagging eye syndrome, myogenic strabismus, and thyroid ophthalmopathy) could be examined via webcam. It was easier to analyze horizontal than vertical strabismus. Among the paralytic forms, sixth nerve palsy was the easiest one to assess. Latent forms of strabismus can be partially diagnosed and evaluated using telemedicine, but half of the respondents underlined the importance of in-person examinations in these cases. Sixty-nine percent believed that telemedicine could be a low-cost and time-efficient health service solution.

CONCLUSIONS

Most members of the AAPOS Adult Strabismus Committee consider telemedicine to be a useful supplement to the current adult strabismus practice. [J Pediatr Ophthalmol Strabismus. 2023;60(6):386-389.].

Optical Coherence Tomography Findings in Cherry-Red Spot: Implications for Understanding Pathophysiology and Visual Prognosis

PURPOSE

To report optical coherence tomography (OCT) findings of cherry-red spots from Tay-Sachs and Niemann-Pick disease.

METHODS

Consecutive patients with Tay-Sachs and Niemann-Pick disease evaluated by the pediatric transplant and cellular therapy team, for whom a handheld OCT scan was obtained, were included. Demographic information, clinical history, fundus photography, and OCT scans were reviewed. Two masked graders evaluated each of the scans.

RESULTS

The study included 3 patients with Tay-Sachs disease (5, 8, and 14 months old) and 1 patient with Niemann-Pick disease (12 months old). All patients had bilateral cherry-red spots on fundus examination. In all patients with Tay-Sachs disease, handheld OCT revealed parafoveal ganglion cell layer (GCL) thickening, increased nerve fiber layer, and GCL reflectivity, and different levels of residual normal signal GCL. The patient with Niemann-Pick disease had similar parafoveal findings, but there was a thicker residual GCL. Sedated visual evoked potentials were unrecordable in all 4 patients despite 3 of them demonstrating normal visual behavior for age. Patients with good vision had relative sparing of the GCL on OCT.

CONCLUSIONS

The cherry-red spots in lysosomal storage diseases appear as perifoveal thickening and hyperreflectivity of the GCL on OCT. In this case series, residual GCL with normal signal proved to be a better biomarker for visual function than visual evoked potentials and could be considered for future therapeutic trials. [J Pediatr Ophthalmol Strabismus. 2023;60(6):435-440.].

Anterior segment ischemia following strabismus surgery in a young adult using gender-affirming estrogen hormone therapy

Well-known risk factors for anterior segment ischemia (ASI) following strabismus surgery include ipsilateral surgery on three or more rectus muscles, older age, and vasculopathy. ASI is rarely reported in young patients following uneventful strabismus surgery on two ipsilateral rectus muscles. We report a 30-year-old transgender female on long-term estrogen therapy who underwent strabismus surgery involving recessions of both lateral rectus muscles, the right inferior rectus muscle, and the left superior rectus muscle. The left eye developed severe ASI with hypotony maculopathy that was resistant to topical medications, oral steroids, anterior chamber reformation, and intravitreal steroid injection. Following phacoemulsification with intraocular lens and capsular tension ring insertion 1 year later, intraocular pressure and hypotony maculopathy improved.

Unilateral four muscle surgery for extra-large monocular exotropia

INTRODUCTION

Recurrent exotropia is common following surgery for monocular large angle constant sensory exotropia. Surgery is usually limited to operations on the affected eye. Simultaneous oblique weakening surgery may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting forces. We report the results of simultaneous oblique muscle weakening procedures combined with ipsilateral horizontal rectus muscle surgery constant monocular exotropia greater than 35 prism diopters (PD).

METHODS

Retrospective case series of patients who underwent unilateral lateral rectus recession combined with medial rectus muscle resection and simultaneous weakening of both ipsilateral oblique muscles. Primary outcome measure was ocular alignment in primary position.

RESULTS

Twelve eyes of 12 patients were included. The mean preoperative exotropia improved from 57.9 ± 15.1 (range 35-80; median 60 PD) to 3.3 ± 5.5 (range 0-16; median 0 PD) postoperatively (p < 0.005). Two of 3 patients with a pre-existing vertical deviation had resolution of their vertical misalignment postoperatively. At the last postoperative follow up 92%% of the patients had an exodeviation of 10 PD or less (range 0-16 PD median 0 PD), and 7 (58%) measured near and distance orthotropia. Postoperative abduction measured -0.6 ± 1 (0 to -3) and adduction -0.4 ± 0.7 (0 to -2).

CONCLUSION

Weakening the ipsilateral oblique muscles may enhance the effect of the horizontal rectus muscles surgery by decreasing the abducting vectorial forces when operating for a large angle monocular exotropia. As an additional potential advantage, oblique muscle surgery may be used simultaneously to address associated vertical deviations.

A Potentially Adjustable Modification of the Nishida Procedure

For patients with a complete, chronic abducens nerve palsy and resulting abduction deficit, a transposition procedure is often the procedure of choice. One such transposition procedure involves transposing the superior rectus (SR) and inferior rectus (IR) laterally without disinserting or splitting either muscle. While effective, this procedure - like many transposition procedures - carries with it the risk of induced torsional or vertical misalignment. Here, we describe an adjustable variation of the above transposition procedure, one which potentially would allow for post-operative correction of induced vertical or torsional deviations.

Prevalence of pediatric eye disease in the optumlabs data warehouse

PURPOSE

To define the prevalence of medical eye disease diagnoses among children enrolled in commercial insurance plans in the United States and to evaluate differences among groups based on the US census region, race/ethnicity, and familial net worth.

METHODS

: Retrospective study of de-identified claims data from the OptumLab® Data Warehouse (OLDW) between 2007 and 2018. All children (<19 years) in the OLDW with coverage were studied and those with a claim for a significant eye disease (strabismus, amblyopia, nystagmus or structural eye disorders) with minimum 6-months follow-up were studied. Baseline characteristics were extracted for the calculation of eye disease prevalence, including age, sex, race/ethnicity, region of residence, and family net worth. The prevalence of each type of eye disease was calculated among all children and by baseline characteristics.

RESULTS

: 10,759,066 children met the study criteria. The presence of any significant eye diagnosis was 6.7%. Disease was diagnosed more often in whites (6.9%) than blacks (5.6%) and Hispanics (5.9%). The most common eye disease diagnosed was strabismus (3.2%) followed by amblyopia (1.5%). In the North-East region, there was a 10.6% prevalence of any significant eye disease diagnosis, whereas in the Mid-West, it was 7.4% followed by the South and West (5.9% and 5.3%, respectively) (p < .001). There was an increase in eye disease diagnoses with increasing income (5.5% in<$25,000 and 9.4% in >$500,000 household net worth groups, p > .001).

CONCLUSION

: Diagnosis of significant eye diseases is relatively common in American children. The most common medical eye disease diagnosis is strabismus. Prevalence of eye disease diagnosis from claims data varies between geographical regions and different income groups. This may reflect differences in healthcare utilization rather than true disease prevalence.

Association of Strabismus With Mood Disorders, Schizophrenia, and Anxiety Disorders Among Children

Importance

Children with strabismus have poorer functional vision and decreased quality of life than those without strabismus.

Objective

To evaluate the association between strabismus and mental illness among children.

Design, Setting, and Participants

This cross-sectional study analyzed claims data from the OptumLabs Data Warehouse, a longitudinal deidentified commercial insurance claims database, from 12 005 189 patients enrolled in the health plan between January 1, 2007, and December 31, 2017. Eligibility criteria included age younger than 19 years at the time of strabismus diagnosis, enrollment in the health plan between 2007 and 2018, and having at least 1 strabismus claim based on International Classification of Diseases, Ninth Revision, Clinical Modification and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Clinical Modification codes. Controls were children in the same database with no eye disease codes other than refractive error reported. Demographic characteristics and mental illness claims were compared. Statistical analysis was conducted from December 1, 2018, to July 31, 2021.

Main Outcomes and Measures

Presence of mental illness claims.

Results

Among the 12 005 189 patients (6 095 523 boys [50.8%]; mean [SD] age, 8.0 [5.9] years) in the study, adjusted odds ratios for the association of mental illnesses with strabismus were 2.01 (95% CI, 1.99-2.04) for anxiety disorder, 1.83 (95% CI, 1.76-1.90) for schizophrenia, 1.64 (95% CI, 1.59-1.70) for bipolar disorder, 1.61 (95% CI, 1.59-1.63) for depressive disorder, and 0.99 (95% CI, 0.97-1.02) for substance use disorder. There was a moderate association between each strabismus type (esotropia, exotropia, and hypertropia) and anxiety disorder, schizophrenia, bipolar disorder, and depressive disorder; odds ratios ranged from 1.23 (95% CI, 1.17-1.29) for the association between esotropia and bipolar disorder to 2.70 (95% CI, 2.66-2.74) for the association between exotropia and anxiety disorder.

Conclusions and Relevance

This cross-sectional study suggests that there was a moderate association between strabismus and anxiety disorder, schizophrenia, bipolar disorder, and depressive disorder but not substance use disorder. Recognizing that these associations exist should encourage mental illness screening and treatment for patients with strabismus.

Association of Mood Disorders, Substance Abuse, and Anxiety Disorders in Children and Teens With Serious Structural Eye Diseases

PURPOSE

We sought to evaluate the association between 5 eye diseases (including glaucoma, cataract, congenital optic nerve disease, congenital retinal disease, and blindness/low vision) and mental illness in a pediatric population.

DESIGN

Cross-sectional study.

METHODS

A de-identified commercial insurance claims database, OptumLabs Data Warehouse, between January 1, 2007, and December 31, 2018, was used. Children and teens less than 19 years of age at the time of eye diagnosis were included. Demographics and mental illness claims were compared, looking at the association of mental illness and eye disease claims.

RESULTS

A total of 11,832,850 children and teens were included in this study with mean age of 8.04 ± 5.94 years at the first claim. Of the patients with at least 1 of the 5 eye diseases (n = 180,297), 30.5% had glaucoma (n = 54,954), 9.5% had cataract (n = 17,214), 21.4% had congenital optic nerve disease (n = 38,555), 26.9% had congenital retinal disease (n = 48,562), and 25.9% had blindness or low vision (n = 46,778). There was a statistically significant association, after adjusting for confounding variables, between at least 1 of the 5 eye diseases and schizophrenia disorder (OR = 1.54, 95% CI = 1.48-1.61, P < .001), anxiety disorder (OR = 1.45, 95% CI = 1.43-1.48, P < .001), depressive disorder (OR = 1.27, 95% CI = 1.25-1.29, P < .001), and bipolar disorder (OR = 1.27, 95% CI = 1.21-1.31, P < .001), but a reversed association with substance use disorder (OR = 0.88, 95% CI = 0.86-0.90, P < .001).

CONCLUSIONS

We found associations between eye disease in children and teens and mental illness. Understanding these relationships may improve mental illness screening and treatment in the pediatric population.

Risk of physical injuries in children and teens with ophthalmic diagnoses in the OptumLabs Data Warehouse

BACKGROUND

To evaluate how eye diseases affect the risk of injuries (fractures, musculoskeletal, head and eye injuries) in children and teens.

METHODS

Claims from the OptumLabs Data Warehouse, a longitudinal deidentified commercial insurance claims database, were analyzed. Eligible subjects were aged <19 years at the time of their eye disease diagnosis, enrolled in the health plan between 2007 and 2018, and had >1 visit for >1 significant eye disease (strabismus, amblyopia, nystagmus, structural diseases), based on ICD9/10 codes. Controls were children in the same database who had no eye disease codes reported. Demographics and injury claims (fractures, musculoskeletal injuries, head injuries and eye injuries) were compared.

RESULTS

The overall incidence of any subsequent physical injury (even into adulthood) was 29% in eye disease patients and 23% in controls (P < 0.001). After accounting for covariates, the hazard ratio for injury with any type of eye disease was 1.14 (95% CI, 1.13-1.15), 1.17 (95% CI, 1.16-1.18), 0.97 (95% CI, 0.96-0.98), and 1.63 (95% CI, 1.60-1.66) for musculoskeletal injuries, fractures, head injuries, and eye injuries, respectively. The eye disease with the highest adjusted injury risk was nystagmus (HR = 1.26; 95% CI, 1.23-1.28), followed by optic neuritis and pseudotumor cerebri (HR = 1.25). The eye diseases with the lowest risk included amblyopia, esotropia, and glaucoma (HR ≤ 1.06).

CONCLUSIONS

There was an increased long-term risk of physical injury among children and teens with eye disease. The clinical significance of these small differences is unclear.

A 2020 Update on 20/20 X 2 Diplopia after Ocular Surgery: Strabismus Following Retinal Detachment Surgery

Persistent ocular motility and sensorial abnormalities following retinal detachment surgery are not common. Scleral buckling increases the risk of deviation in secondary gaze positions most commonly horizontal deviations. Suspect superior oblique incarceration in patients with limited downgaze. For patients with persistent strabismus, surgery is an option. Removing the exoplant may be necessary to access the extraocular muscles but the effect on alignment is minimal except in cases were the scleral buckle migrates anteriorly causing restriction. Removing the scleral buckle may increase the risk of retinal re-detachment. Hangback recessions and adjustable sutures can be safely used.

Acute Onset Variable and Progressive Trochlear Nerve Palsy and Ophthalmoparesis Secondary to Bilateral Carotid Cavernous Fistula

Purpose: To describe a patient who presented with right unilateral white-eyed posteriorly-draining carotid-cavernous fistulas (CCF) causing an isolated, acute-onset trochlear nerve palsy with atypical progression to a contralateral left red-eyed anteriorly-draining CCF associated with orbital congestion.Observation: A 74-year-old female presented with an acute onset incomitant right hypertropia consistent with the clinical diagnosis of a superior oblique palsy. Initial workup including MRI was normal. During a several-week course, she progressed to a comitant deviation. Six-weeks later she developed an episode of severe headache followed by worsening of her diplopia, reverse left hypertropia and left orbital congestive signs. CTA revealed mild opacification of the left cavernous sinus without a concomitantly present superior ophthalmic vein dilatation. A diagnostic angiogram was obtained which revealed a posterior-draining indirect CCF of the right internal carotid artery (ICA) and an anterior-draining indirect CCF of the left ICA. Transvenous Coil embolization resulted in immediate resolution of diplopia, orbital congestion, and headaches.Conclusion: Although it is atypical for a CCF - or other vascular pathology - to present with an isolated fourth nerve palsy, this case illustrates that vascular imaging should be considered in cases of acquired ocular motor paresis associated with headaches and cases with atypical progression despite normal initial cranial imaging.

The use of atropine for treatment of amblyopia using the OptumLabs Data Warehouse

Atropine and patching are standard treatments for amblyopia, but the prevalence of atropine therapy in the United States is unknown. This study used the OptumLabs Data Warehouse to evaluate pharmacy claims for topical atropine to evaluate the frequency of its treatment for amblyopia and to compare demographic factors in cohorts of amblyopic children who were and were not prescribed atropine. Overall, 55.2% of amblyopic children were prescribed atropine more than once. The children who were prescribed atropine had a higher likelihood of living in geographic regions in the South or Midwest.

Strabismus After Ahmed Glaucoma Valve Implantation

PURPOSE

Most reports of strabismus after glaucoma drainage device implantation study larger devices and rarely note the incidence of strabismus after Ahmed glaucoma valve (AGV) implantation. It is unknown if the pattern of strabismus is similar with smaller devices. We investigated characteristics of strabismus after AGV implantation.

DESIGN

Retrospective review.

METHODS

Institutional study of 732 patients at our institution undergoing AGV implantation between 2013 and 2018. Rate and characteristics of strabismus were the primary outcome; age, gender, and location of AGVs were also analyzed.

RESULTS

We identified 29 patients who developed new-onset strabismus postoperatively after initial AGV implantation, for 4% incidence of strabismus. Twenty-one (72%) of these had diplopia. AGVs were implanted superotemporally in 21, superonasally in 5, inferotemporally in 1, and inferonasally in 2. Three patients were esotropic, 11 were exotropic, 4 had hypertropia, 2 had hypotropia, and 9 patients had combined horizontal/vertical strabismus (esotropia/hypotropia [n = 1] or exotropia/hypertropias [n = 8]). Exotropia was the most common type of strabismus in both the superotemporal and superonasal (60%) AGV groups. Superotemporal AGVs were more commonly associated with ipsilateral hypertropia (43%) than superonasal AGVs. Treatments included strabismus surgery (n = 14), prisms (n = 6), or an occlusive lens (n = 1).

DISCUSSION

In the largest single-center series of patients undergoing initial AGV implantation, the overall incidence of postoperative strabismus was 4%. This is comparable to strabismus incidence following implantation of other types of glaucoma drainage devices, even larger devices. The possibility of this complication should be discussed with patients prior to surgery.

Single horizontal rectus muscle vertical augmented transposition with posterior fixation suture in management of monocular elevation deficiency

We describe successful management of three cases of acquired monocular elevation deficiency (MED) with superior transposition of the lateral rectus augmented with a posterior fixation suture with or without simultaneous inferior rectus muscle weakening. In each case, the lateral rectus muscle was transposed superiorly to the superior rectus muscle along the spiral of Tillaux, with maintained distance between the original lateral rectus muscle poles and the limbus. Augmentation was achieved with a posterior fixation suture 8 mm posterior to the muscles' insertion. At the time of lateral rectus transposition, simultaneous inferior rectus recession by 5.5 mm was performed in case 1 whereas simultaneous botulinum toxin injection was performed in case 3. With regards to all three cases, the mean age was 32 years [10-46 years] and the mean follow-up period was 10 months. The mean hypotropia was reduced from 35 prism diopters (PD) (range: 20 to 60 PD) to 4.67 PD (range: 0 to 14 PD) with a mean correction of 32.57 ± 9.34 PD after 9 months. In our experience, full-tendon-width transposition of the lateral rectus to the superior rectus with posterior fixation suture corrects primary position hypotropia in MED and does not always require simultaneous inferior rectus recession. When transposing the lateral rectus muscle along the spiral of Tillaux, the measured distance of the original muscle insertion point to the limbus must be maintained in order to prevent recession of the muscle.

Periocular infantile hemangioma masquerading as dacryocele

A 2-month-old boy developed a protuberant, blue nodule inferomedial to the left medial canthus. It was unresponsive to oral and intramuscular antibiotics. After developing difficulty breathing, he was admitted, with the diagnosis of a dacryocele, and, after an inconclusive ultrasound, underwent probing and irrigation with nasal endoscopy. Intraoperatively, the lesion appeared discontinuous with the nasolacrimal system and could not be decompressed. Postoperative magnetic resonance imaging suggested a hemangioma or possible collapsed dacryocele. Doppler ultrasound confirmed a perinasolacrimal duct hemangioma. Systemic propranolol treatment was initiated.

Post-traumatic superior oblique tendon nodule associated with acquired Brown syndrome

A 67-year-old woman presented with a left hypotropia and eye pain after a traumatic fall. She had multiple left orbital wall fractures and an acquired limitation to elevation in all gazes, worse in adduction, suggestive of Brown syndrome. During strabismus surgery, a white nodule on the superior oblique tendon was identified and excised. Histopathology of the nodule revealed densely aggregated inflamed fibrovascular and fibrocollagenous scar tissue. Superior oblique rupture with spontaneous reparative reapproximation resulting in nodular formation is uncommon. We speculate that resulting tendon shortening may have contributed to the apparent Brown syndrome in this patient.

Modified Anterior Superior Oblique Tuck: A Case Series

PURPOSE

Selection of the ideal procedure to correct symptomatic excyclotropia depends on several factors including the degree of torsion and associated vertical, horizontal and pattern deviation. Selective tuck of the anterior temporal torsional fibers of the superior oblique (SO) tendon is an alternative procedure to the classical Harada-Ito. The purpose of this study is to report its stability and results.

METHODS

Retrospective review of all consecutive patients with symptomatic excyclotorsion of at least 5º (degrees) treated by selectively splitting and tucking the anterior temporal fibers of the SO tendon. Torsion in primary position was measured using the double Maddox Rods. Patients with additional symptomatic vertical or horizontal diplopia underwent simultaneous surgery on other extraocular muscles.

RESULTS

Five patients were studied. Mean age was 60 ± 8 years (47-67). Mean postoperative follow-up was 10 ± 8 months (3-21). The mean preoperative torsion of 11º±4º (7º-15º) significantly decreased to 3º±2º (p = .03) at the first postoperative visit (16 ± 9 days) and 3 ± 2º during the last visit (P = .03). The procedure corrected 1.4º±0.9º per mm of tuck. Postoperatively no patient complained of torsion. No undesirable vertical or horizontal deviations were noted.

CONCLUSION

This technique is a simple alternative to manage symptomatic excyclotorsion, with significant and stable relief of moderate amounts of torsion and without inducing unexpected vertical or horizontal deviation.

Compartmental Strabismus

Recent reports confirm innervational compartments of select rectus extraocular muscles as well as the superior oblique.¹ Histopathological and orbital imaging studies demonstrate well defined compartmental innervation of the horizontal rectus muscles with less differentiation in the vertical rectus muscles. Acquired vertical misalignment not associated with cyclovertical muscle dysfunction has been associated with horizontal rectus muscle compartment dysfunction. Pattern and other forms of strabismus have been associated with segmental or compartmental abnormal innervation of the extraocular muscles. Taking advantage of segmental function and innervation, selective weakening and strengthening procedures have been used to treat patients with incomitant near/distance disparities, incomitant vertical and torsional strabismus, and patients with A- and V-pattern strabismus.

Comparison of Pre-Treatment vs. Post-Treatment Retinal Vessel Density in Children with Amblyopia

BACKGROUND

Prior studies have reported a lower retinal vessel density (RVD) in amblyopic vs. non-amblyopic eyes. No studies have shown if amblyopic eye RVD changes following patching therapy. We assessed for RVD differences between pre-treatment vs. post-treatment amblyopic eyes.

METHODS

Participants were included if they were <10 years old with unilateral amblyopia. All subjects were required to visit the pediatric eye clinic for examination. Exclusion criteria included: deprivation amblyopia, bilateral amblyopia, nystagmus, media opacity, intraocular inflammation, or any retinal disease. All participants underwent optical coherence tomography angiography (OCTA) before and after refraction and patching treatment. Outcomes included superficial (SCP) and deep (DCP) capillary plexus RVD.

RESULTS

12 patients (12 amblyopic eyes) were included. Mean (SD) age, gestational age (GA), birth weight (BW), and follow-up time were: 6.5 (1.7) years, 39.4 weeks (1.4 w), 3271 g (262 g), and 114 days (46d), respectively. There was a significant increase in the RVD of the DCP in 3 × 3-mm scans after treatment, specifically in the whole image (52.6 ± 5.75 vs 56.5 ± 2.48%, p = .046) and superior hemisphere regions (52.47 ± 6.17 vs 56.73 ± 2.27%, p = .048).

CONCLUSIONS

Amblyopic eye RVD potentially increases after amblyopia treatment in specific regions of the retina. Further research is required to refine this clinical parameter.

Prevalence of Sagging Eye Syndrome in Adults with Binocular Diplopia

PURPOSE

Sagging eye syndrome (SES), horizontal and/or vertical strabismus caused by orbital connective tissue degeneration, was first defined 10 years ago. This study investigated SES and other causes of acquired binocular diplopia in adults presenting to a single institution since the description of SES.

DESIGN

Retrospective observational case series.

METHODS

Medical records were reviewed of all new patients over the age of 40 who presented to the Stein Eye Institute with binocular diplopia between January 2015 and December 2018. Clinical causes of diplopia were tabulated in patients grouped by age and sex. In patients with SES, we tabulated binocular alignment, types of treatment, and surgical outcomes.

RESULTS

There were 945 patients of mean age 66.5 years, of whom 514 (54.4%) were female. The most common cause of diplopia was SES (31.4%). The 297 patients with SES were older at 71.2 years (P < 0.0001) and more predominantly female at 59.9% than other patients (52.0%; P = 0.023). The relative proportion of SES patients among all diplopic patients increased with age from 4.7% under age 50 years to 60.9% over the age of 90. Age-related distance esotropia was present in 35% and cyclovertical strabismus in 65% of cases of SES. Strabismus surgery was performed in 50% of cases of SES. Mean esotropia at distance decreased from 6.9 ± 0.7Δ preoperatively to 0.3 ± 0.3Δ postoperatively. Preoperative hypertropia decreased from 3.0 ± 0.3Δ to 0.7 ± 0.2Δ postoperatively. Surgery resolved diplopia in all cases.

CONCLUSIONS

It is important to recognize that SES is a very common cause of adult binocular diplopia.

Association of Change in Iris Vessel Density in Optical Coherence Tomography Angiography With Anterior Segment Ischemia After Strabismus Surgery

Importance

Anterior segment ischemia (ASI) is a rare but potentially serious complication of strabismus surgery. Indocyanine green angiography and fluorescein angiography have been used to reveal iris-filling defects for clinicians considering a patient's risk of ASI. However, both are limited by invasive and time-consuming nature and potential adverse effects. Recently, optic coherence tomography angiography (OCT-A) has been introduced and used to image iris vasculature in individuals without abnormalities.

Objective

To determine the use of iris OCT-A for patients undergoing strabismus surgery and who are at risk for ASI.

Design, Setting, and Participants

This prospective case series study took place in an academic center. Adults undergoing strabismus surgery on at least 1 vertical muscle were prospectively recruited. The study took place from June to November 2017, and analysis began in January 2018.

Interventions

Indocyanine green angiography and OCT-A of the iris preoperatively and 1 day postoperatively.

Main Outcomes and Measures

A masked examiner evaluated all images and determined whether any filling defects were present qualitatively (lack of perfusion) and quantitatively (for OCT-A using internal software to calculate vessel density).

Results

Ten eyes of 9 individuals (mean [SD] age, 63 [11] years) were included. Two individuals (22.2%) identified as Hispanic, and 7 (77.8%) identified as white. There were 6 women (66.7%). The mean preoperative vessel density (percentage of the area occupied by vessels) averaged for all quadrants decreased from 57% preoperatively to 55% postoperatively (mean difference, 2%; 95% CI, 0.4%-4.2%; P = .05). When comparing quadrants adjacent to operated muscles, the mean vessel density decreased from 56% to 53% (mean difference, 2.6%; 95% CI, 0.17%-4.8%; P = .02). In addition, OCT-A detected vascular filling defects in the quadrant adjacent to the operated muscle on the patients in whom they were present (n = 1, inferior rectus recession).

Conclusions and Relevance

In this preliminary study, OCT-A determined iris vessel filling defects when present. In addition, OCT-A gives qualitative vessel density values that can be compared preoperatively and postoperatively although the clinical relevance of small differences is not known. While only 10 eyes were evaluated, and as such generalizability of these findings cannot be determined, the results suggest that OCT-A may be a useful tool in the evaluation of patients undergoing strabismus surgery to determine whether a patient is at risk to develop ASI.

Severe Acquired Restrictive Strabismus Fixus in Patients with Trisomy 21

Acquired strabismus fixus is a rare form of severe esotropia described most frequently in patients with high axial myopia and infrequently associated with other conditions. Refractive errors, cataracts, and ocular motility disorders are common in patients with trisomy 21. We report two unusual cases of patients with trisomy 21 who developed severe acquired restrictive strabismus fixus. Both patients were successfully treated with medial rectus recession followed by lateral rectus and superior rectus myopexy combined with additional medial rectus weakening, including free tenotomy in one case.

Etiology and Age Modifies Subjective Visual Function After Cerebral Hemispherectomy

BACKGROUND

Cerebral hemispherectomy is typically used to treat patients with pharmacoresistant epilepsy. Visual-related outcomes are relatively unstudied in this population, aside from the knowledge that patients develop a complete homonymous hemianopia contralateral to the side of the hemispherectomy. The purpose of this study was to determine and characterize parent-reported functional visual, oculomotor, and postural changes in a large population of patients following cerebral hemispherectomy.

METHODS

An online survey was sent to parents of children who had undergone hemispherectomy for seizure control. Families were recruited by the Brain Recovery Project: Childhood Epilepsy Surgery Foundation. Parent-reported subjective visual function was assessed by the presence of peripheral field defects, ocular misalignment and anomalous head posture.

RESULTS

A total of 196 (12.5%) participants responded. Postoperative follow-up was 92±78 months (range: 1-382). Ninety-three percent of parents reported the child had difficulties with peripheral vision. Torticollis was present postoperatively in 122 (62%) patients. Strabismus was noted in 93 (49%). Fifty-five (59%) of the strabismus patients demonstrated exotropia with the majority of exotropia patients demonstrating the exo-deviated eye in the direction contralateral to the hemispherectomy (74.5%). Both torticollis and strabismus were most frequently seen immediately after surgery. Sixty-six patients (34%) underwent strabismus treatment. Patients with younger age of seizure onset, younger age of surgery, and certain epilepsy etiologies (hemimegencephaly, Sturge-Weber syndrome) were more likely to develop strabismus and torticollis.

CONCLUSIONS

Torticollis and strabismus are common after hemispherectomy and appear to be influenced by etiology and age at surgery. Preoperative discussion with parents and patients regarding those compensatory mechanisms is recommended, and postoperative ophthalmologic assessments are also encouraged.

Pathologic Study of Supernumerary Orbital Band in Type I Duane Syndrome

Background/Aims

Accessory orbital bands are relatively rare and very few reports detail histopathology. Cases in the literature describe the composition of the bands as muscular and/or fibrous. The composition of the supernumerary band lying deep in the medial rectus muscle in a patient with type I Duane syndrome was investigated.

Methods

Histochemical stains were used in conjunction with polarized light for differentiating compressed collagen from muscle. Immunohistochemistry was used for verification of the presence of muscle.

Results

Compressed collagen appeared red using Masson trichrome staining. Collagen was positively identified by illumination with polarized light on several stains including the underutilized Sirius red dye.

Conclusions

The findings of dense collagen fibers in the fibrotic band with focal striated muscle correlated with the restrictive strabismus. In concert with other cases in the literature, it is proposed that the fibrous bands are generally associated with restrictive strabismus. Bands that are muscular may or may not be associated with strabismus. Special techniques are needed to positively identify compressed collagen.

Management of surgical overcorrections following surgery for Duane syndrome with esotropia in primary position

Surgery for esotropic Duane syndrome may result in overcorrections. Managing these overcorrections can be challenging. We describe the most common over-correction scenarios and recommendations for their surgical management.

Anterior superior oblique tuck: an alternate treatment for excyclotorsion

Excyclotorsion is typically treated with surgical procedures such as the Harada-Ito, rectus muscle transposition, and inferior oblique weakening. We describe an alternative technique, the anterior superior oblique tuck. This procedure is technically simpler than the Harada-Ito and provides similar results.

Adjustable Posterior Fixation Suture Technique in Adjustable Superior Rectus Transposition

BACKGROUND

Recently, the superior rectus transposition has been widely adopted for the treatment of complete abducens palsy and Duane syndrome. This procedure is useful in that there is a decreased risk of anterior segment ischemia compared to complete vertical rectus transposition, possibly decreased incidence of postoperative-induced vertical deviations than complete vertical rectus transposition, and improvement in abduction compared to simple medial rectus recession. One difficulty with this procedure is the lack of adjustability in most patients. Our group has adopted a new technique for an adjustable posterior fixation myopexy suture for use with patients under topical anesthesia.

METHODS

The superior rectus muscle is temporally transposed to the insertion of the lateral rectus muscle. The corner of the superior rectus muscle that is placed adjacent to the lateral rectus muscle is placed on an adjustable suture. Then, a posterior fixation myopexy suture consisting of a single-armed 6-0 vicryl suture is secured between the superior and lateral rectus muscles, approximately 10 mm from the lateral rectus insertion to drag the superior rectus muscle temporally. This suture is also placed on an adjustable suture. The patient is then positioned sitting up, fixing at a target at approximately 10 feet away from the patient's head. Cover testing is utilized to determine whether any vertical deviation has been induced. If there is a vertical deviation, the posterior fixation suture may be loosened.

RESULTS

We find that this technique to be useful if an induced vertical deviation or an overcorrection occur, and is thought to be due to the reported possible complication of restriction induced by the posterior fixation suture and the transposed rectus muscle.

CONCLUSION

Our technique for performing superior rectus transposition with an adjustable posterior fixation myopexy suture may be useful to surgeons who wish to have an adjustable option as a way to decrease the risk of postoperative complications such as induced vertical deviations and overcorrections.

Increased choriocapillaris vessel density in amblyopic children: a case-control study

PURPOSE

To investigate the choriocapillaris in children with amblyopia, using optical coherence tomography angiography (OCT-A).

METHODS

Patients with amblyopia and age-matched controls were prospectively imaged using OCT-A. On OCT-A, the choriocapillaris measures 30 μm starting 31 μm posterior to the retinal pigment epithelium. The section of choriocapillaris under superficial retinal vessels was excluded from analysis to avoid shadowing or projection artifacts. The main outcome measure was choriocapillaris vessel density. Secondary outcome measures were foveal macular thickness and parafoveal macular thickness.

RESULTS

A total of 20 eyes of 16 patients with amblyopia and 25 eyes of 25 controls were included. Mean age of amblyopic subjects was 7.6 ± 3.6 years; of controls, 9.3 ± 2.2 years (P = 0.10). Mean refractive error of subjects was 4.3 ± 6.2 D; of controls, 0.0 ± 1.6 D (P = 0.004). Mean choriocapillaris vessel density was 74.8 ± 5.8 in the amblyopic group and 71.1 ± 3.6 in the control group, which was significant even after adjusting for age and refractive error (P = 0.012). There was no difference between groups in foveal macular thickness or parafoveal macular thickness; however, outer parafoveal macular thickness (the inner boundary of the inner nuclear layer to the retinal pigment epithelium outer boundary) was significantly greater in amblyopic eyes than in control eyes, even after adjusting for age and refractive error (203 ± 11 μm and 189 ± 12 μm, resp. [P = 0.014]).

CONCLUSIONS

In our study cohort, amblyopic eyes were found to have increased choriocapillaris vessel density as well as a greater outer parafoveal macular thickness, which may be due to alterations in outer retinal maturation.

Isolated Ocular Motor Nerve Palsies

Isolated cranial nerve (CN) palsies are frequently encountered by strabismologists. Management decisions for patients with isolated ocular motor nerve palsies must take into account multiple factors, including patient age, historical features, the specific CN affected, examination findings, and coexistent medical diagnoses. In general, isolated ocular motor nerve palsies in children are assessed and managed differently than adults. Furthermore, older adults with vascular risk factors may be managed differently than younger adults and children. The need for urgent neuroimaging in older adults with microvascular risk factors is under debate and requires the physician to weigh the risks and benefits of close observation with immediate testing. The presence of multiple cranial neuropathies should also raise the level of concern and indicate the need for a more urgent work-up. The following manuscript aims to provide information on common etiologies of isolated ocular motor nerve palsies and to suggest algorithms for the management of these CN palsies in children and adult.

Extraocular Muscle Damage Associated with Endoscopic Sinus Surgery: An Ophthalmology Perspective

Background

Orbital complications associated with endoscopic sinus surgery are well documented. Damage to the medial rectus muscle results in complicated strabismus and disturbing diplopia. The aim of this study was to characterize the types of extraocular muscle injury and the number of muscles involved that may complicate endoscopic sinus surgery and correlate its occurrence to factors in the surgical procedure itself.

Methods

A retrospective chart review was performed of 14 patients with strabismus after endoscopic sinus surgery. Operative notes of the surgical procedure, pathology reports of the intraoperative specimens, postoperative pattern of strabismus, the extraocular muscle involved, and the type of muscle injury characterized by orbital imaging were reviewed in each patient.

Results

In our series, not only the medial rectus muscle but also the inferior rectus and the superior oblique muscles were damaged with multiple muscles being involved in one patient. Extraocular muscle injury varied from hematoma, entrapment of muscle in the fractured orbital wall, damage to the oculomotor nerve entry zone, muscle transection, and partial or complete muscle destruction with entrapment in scar tissue. Use of the microdebrider causes extensive irreparable muscle damage.

Conclusion

Extraocular muscle damage complicating endoscopic sinus surgery can produce therapeutically challenging complicated strabismus.

Surgical success and lateral incomitance following three-muscle surgery for large-angle horizontal strabismus

PURPOSE

To evaluate motor alignment, motility, and sensorial outcomes of simultaneous three-muscle surgery for large-angle horizontal strabismus, with special attention to lateral incomitance and long-term success.

METHODS

The medical records of consecutive patients with large-angle deviations (≥30^Δ) who underwent simultaneous surgery on three horizontal muscles to correct esotropia or exotropia were reviewed retrospectively. Successful motor alignment was defined as residual deviation of ≤10^Δ and consecutive deviation in primary position of ≤4^Δ, with no induced lateral incomitance >5^Δ between lateral gazes. Sensory success was defined as an improvement in stereopsis of ≥2 octaves. Surgical procedures included a combination of recessions and resections/plications depending on surgeon preference. The majority of cases were two-muscle recessions combined with one-muscle resection or plication.

RESULTS

A total of 19 patients with exotropia and 9 patients with esotropia were included. In the esotropic group, the mean age at surgery was 48 ± 15 years and the mean preoperative deviation improved from 45.6^Δ ± 11.9^Δ to 1.5^Δ ± 1.6^Δ (P < 0.001); there was no undercorrection, recurrence or overcorrection. In the exotropic group, the mean age at surgery was 44 ± 25 years, and the mean preoperative deviation improved from 44.1^Δ ± 8.7^Δ to 5.8^Δ ± 9.6^Δ (P < 0.001), recurrence occurred in 2 (22%). Overall motor success at distance was 85%, with 1 (3.8%) unsuccessful patient due to induced incomitance. Sensory success was 44% for esotropia and 31% for exotropia. No patient lost stereopsis.

CONCLUSIONS

Patients undergoing three-muscle surgery for horizontal strabismus had good motor outcomes with low incidence of induced lateral incomitance. Motor and sensorial outcomes for esotropia were very stable.

Spectral-Domain Optical Coherence Tomographic Angiography in Children With Amblyopia

Importance

Amblyopia is the most common cause of visual impairment in childhood, with a prevalence of 1% to 4% in children in the United States. To date, no studies using noninvasive optical coherence tomographic angiography (OCTA) have measured blood flow in the retinal capillary layers in children with amblyopia.

Objective

To evaluate the retinal and microvascular features using OCTA in children (<18 years) with amblyopia.

Design, Setting, and Participants

This observational case-control study enrolled patients from September 1, 2016, through May 31, 2017, and was conducted from September 1, 2016, through June 30, 2017, at the Stein Eye Institute at UCLA (University of California, Los Angeles). Participants included 59 children (<18 years) with amblyopia and without amblyopia examined at a pediatric ophthalmology clinic or referred to the clinic by coinvestigators. All patients underwent comprehensive ophthalmological examination, including visual acuity, refraction, and ocular motility tests; anterior and posterior segment examination; and OCTA.

Main Outcomes and Measures

Reduced superficial and deep retinal capillary vessel density on OCTA.

Results

Of the 63 eyes evaluated, 13 (21%) were amblyopic and 50 (79%) were control eyes. Of the 59 patients, the mean (SD) age of patients with amblyopia was 8.0 (4.0) years and 10.3 (3.3) years for the controls; 33 patients (56%) were female; and 5 of 13 (39%) and 27 of 46 (54%) patients in the amblyopic and control groups, respectively, were identified as white. The macular vessel density of the superficial capillary plexus was lower in the amblyopic group than in the control group in both 3 × 3-mm and 6 × 6-mm scans. After adjusting for age and refractive error, the mean (SD) difference in the superficial capillary plexus in the 6 × 6-mm scan was statistically significant (49.3% [4.1] vs 51.2% [2.9]; P = .02). Macular vessel density of the deep capillary plexus in the 6 × 6-mm scans was also considerably different between groups: mean (SD) vessel density of the deep retinal capillary plexus was 54.4% (4.7%) in the amblyopia group and 60.1% (3.3%) in the control group, with a difference of 5.7% (95% CI, 3.4%-8.1%; P = .002).

Conclusions and Relevance

The study found that OCTA reveals subnormal superficial and deep retinal capillary density in the macula of patients with amblyopia. Further studies are needed to determine the clinical relevance of this finding.

Necrotizing Tenon's capsule infection in a lymphopenic Down syndrome patient following strabismus surgery

Periocular infection is a rare complication of strabismus surgery. We describe a case of necrotizing Tenon's capsule infection after uncomplicated strabismus surgery in a boy with Down syndrome and blepharitis. Pathologic diagnosis was severe acute necrotizing inflammation with Gram positive coccal forms. Resolution of infection occurred after surgical debridement and intravenous and topical antibiotics. Work-up revealed lymphopenia related to Down syndrome. Patients with Down syndrome may have risk factors for postoperative infection including blepharitis and immunologic abnormalities.

Accuracy of Diagnostic Imaging Modalities for Classifying Pediatric Eyes as Papilledema Versus Pseudopapilledema

PURPOSE

To identify the most accurate diagnostic imaging modality for classifying pediatric eyes as papilledema (PE) or pseudopapilledema (PPE).

DESIGN

Prospective observational study.

SUBJECTS

Nineteen children between the ages of 5 and 18 years were recruited. Five children (10 eyes) with PE, 11 children (19 eyes) with PPE owing to suspected buried optic disc drusen (ODD), and 3 children (6 eyes) with PPE owing to superficial ODD were included.

METHODS

All subjects underwent imaging with B-scan ultrasonography, fundus photography, autofluorescence, fluorescein angiography (FA), optical coherence tomography (OCT) of the retinal nerve fiber layer (RNFL), and volumetric OCT scans through the optic nerve head with standard spectral-domain (SD OCT) and enhanced depth imaging (EDI OCT) settings. Images were read by 3 masked neuro-ophthalmologists, and the final image interpretation was based on 2 of 3 reads. Image interpretations were compared with clinical diagnosis to calculate accuracy and misinterpretation rates of each imaging modality.

MAIN OUTCOME MEASURES

Accuracy of each imaging technique for classifying eyes as PE or PPE, and misinterpretation rates of each imaging modality for PE and PPE.

RESULTS

Fluorescein angiography had the highest accuracy (97%, 34 of 35 eyes, 95% confidence interval 92%-100%) for classifying an eye as PE or PPE. FA of eyes with PE showed leakage of the optic nerve, whereas eyes with suspected buried ODD demonstrated no hyperfluorescence, and eyes with superficial ODD showed nodular staining. Other modalities had substantial likelihood (30%-70%) of misinterpretation of PE as PPE.

CONCLUSIONS

The best imaging technique for correctly classifying pediatric eyes as PPE or PE is FA. Other imaging modalities, if used in isolation, are more likely to lead to misinterpretation of PE as PPE, which could potentially result in failure to identify a life-threatening disorder causing elevated intracranial pressure and papilledema.

Binocular Summation and Control of Intermittent Exotropia

BACKGROUND

Binocular summation (BiS), or improvement in binocular vision exceeding the better eye alone, is affected by strabismus. Being easily measured, BiS may be a useful indicator for subjective outcomes like stereopsis in strabismus. This study aims to investigate the relationship between BiS and measures of control of intermittent exotropia (IXT).

METHODS

Patients with IXT were recruited before undergoing strabismus surgery and underwent tests of binocular and monocular high- and low-contrast visual acuity, stereopsis at distance and near, and Newcastle Control Score (NCS), a score developed by incorporating home control and clinic control criteria into a control rating scale. BiS was calculated using high-contrast Early Treatment of Diabetic Retinopathy Study (ETDRS) and Sloan low-contrast acuity charts (LCA) at 2.5% and 1.25% contrast as the difference between the binocular score and that of the better eye. The relationship between BiS and measures of IXT control (NCS and distance near stereoacuity disparity) was evaluated using a correlation analysis by Spearman correlation coefficients and the Kruskal-Wallis test.

RESULTS

Thirty-four patients were included (mean [± standard deviation (SD)] age 19±16 years) having a mean (±SD) of 26±16Δ IXT at distance and 20±16Δ at near. Mean (±SD) BiS for ETDRS and Sloan LCA at 2.5% and 1.25% was 0.8±3.6, 1.9±6.0, and -2.3±7.2, respectively. The Spearman correlation coefficient of BiS and NCS was -0.53 (95% CI -0.85 to -0.25) for 2.5% LCA and -0.43 (95% CI -0.77 to -0.13) for 1.25% LCA. BiS at 2.5% LCA (P=0.006) and at 1.25% LCA (P=0.029) significantly differed between the groups based on NCS score groupings (1-3, 4-6, and 7-9), with patients who had better control scores having higher levels of BiS. BiS did not differ significantly between patients grouped according to the difference between stereoacuity measured at near versus distance.

CONCLUSION

Significantly lower low-contrast BiS in patients with higher NCS may suggest that decreased BiS is associated with less control in IXT. This finding suggests that BiS may reflect control in IXT across a population of patients with IXT.