Prevalence of Sagging Eye Syndrome in Adults with Binocular Diplopia

[Differential diagnosis of vertical strabismus in the elderly]

Due to the demographic changes, the number of older patients in ophthalmological practices and clinics, including those with diplopia, is increasing. Some of the patients report not only horizontally shifted double images but also or only vertically shifted double images. Vertical double vision often causes significant diagnostic problems for ophthalmologists. The underlying condition could urgently require further neurological, neuroradiological and/or internal medical diagnostics (e.g., skew deviation, 4th nerve palsy, myasthenia, Graves' orbitopathy, orbital floor fracture, orbital mass, 3rd nerve palsy) but the cause of diplopia could also be a condition in which overdiagnosis should be avoided (e.g., sagging eye syndrome, the prevalence of which significantly increases with increasing age; decompensated strabismus due to inferior oblique muscle overaction, myopia-associated vertical tropia). For some diseases early diagnosis is important for a better prognosis, e.g., tumor diagnosis, Graves' disease and stroke. This article presents an overview of the most common and most important differential diagnoses of vertical tropia in patients over 50 years of age.

Doses of medial rectus muscle recessions for divergence insufficiency-type esotropia

We evaluated whether doses of bilateral medial rectus recessions greater than Parks's tables yielded superior outcomes for adult-onset divergence insufficiency. Forty-two patients underwent bilateral medial rectus recessions. Dose was analyzed as the average total per muscle (surgery + suture adjustment if performed) and compared with the standard dose tables (based on preoperative distance esodeviation), as difference between dose performed and dose indicated by Parks's tables. Each participant was classified as having received either Parks's dose (within 0.5 mm) or a dose greater than Parks's dose. Success was defined as "rarely" or "never" diplopia in distance straight-ahead gaze and reading. For patients classified as success, the mean difference between actual surgical dose performed and Parks's dose was calculated. Success was 91% (29/32) in those receiving greater than Parks's dose versus 67% (6/9) with Parks's dose (difference = 24%; 95% CI, -5% to 60%). The mean surgical dose was 1.0 mm greater than Parks's tables for the 35 successes (at 10 weeks) versus 0.7 mm greater for the 6 failures (difference = 0.4 mm; 95% CI, -0.2 to 0.9). For medial rectus recessions in adult-onset divergence insufficiency-type esotropia, a surgical dose 1 mm greater than Parks's tables, for each muscle, is a reasonable strategy.

Comparison of head tilt test between sagging eye syndrome and acquired unilateral trochlear nerve palsy

PURPOSE

To investigate the distinction between sagging eye syndrome (SES group) and acquired unilateral trochlear nerve palsy (Trochlear group) in the Bielschowsky head tilt test (BHTT).

METHODS

Fifteen patients in the SES group (mean age 74.6 ± 5.2 years) and 14 patients in the Trochlear group (55.2 ± 15.9 years) visited the Department of Ophthalmology, Hyogo Medical University Hospital between November 2016 and October 2022 for treatment of their diplopia. Eye position was measured with the alternate prism cover test, and values for fixation of the dominant eye, or unaffected eye, were used. Cyclodeviation was measured with the synoptophore and the Glaucoma Module Premium Edition of the SPECTRALIS optical coherence tomography. In the BHTT, eye position was measured in three head postures: primary position (PP), head tilt to the side with hypertropia (Hyper), and head tilt to the side with hypotropia (Hypo). The differences in vertical deviation between PP and Hyper (Hyper - PP), PP and Hypo (PP - Hypo) and Hyper - Hypo were measured and compared.

RESULTS

Vertical deviation in primary position was 7.3 ± 4.5 PD in the SES group and significantly larger (17.1 ± 8.4 PD) in the Trochlear group (p = 0.002). The vertical deviation in Hyper was significantly larger in the Trochlear group with 7.7 ± 4.7 PD and 22.1 ± 9.4 PD, respectively (p < 0.001), whereas the that in Hypo was not significantly different between the two groups with 6.5 ± 3.4 PD and 8.4 ± 6.6 PD, respectively (p = 0.725). The SES group showed no significant difference according to the 3 head postures (p = 0.311), while the Trochlear group showed a significantly different with smaller mean values in vertical deviation in Hypo (p < 0.001). The difference in the vertical deviation for the 3 head postures was the largest in Hyper - Hypo (1.7 ± 2.1 PD and 13.6 ± 7.1 PD, respectively), and the accuracy of SES was at the cutoff value of 6 PD, and it was considered not to be SES if the value was 6PD or higher. The accuracy of SES determination was 100% sensitivity and 100% specificity, and the area under the curve was 1.0.

CONCLUSION

The difference in Hyper - Hypo in the BHTT may be the most useful index in differentiating SES from acquired unilateral trochlear nerve palsy; if the difference was more than 6 PD, the probability of SES was very low.

Biomechanics Explains Variability of Response of Small Hypertropia to Graded Vertical Rectus Tenotomy

PURPOSE

Small angle hypertropia in sagging eye syndrome is conveniently treated by graded vertical rectus tenotomy, yet an adjustable technique under topical anesthesia has been recommended because of variability of effect. We performed graded tenotomy in an experimental model to elucidate the reason for variability of response to this surgical procedure.

DESIGN

Experimental study.

METHODS

Thirty-two fresh bovine rectus musculotendon specimens were prepared including continuity with insertional sclera, and extending for a total 40 mm length to the proximal muscle bellies, and trimmed to 16 mm width. Specimens were anchored by the clamps at the scleral insertion and muscle belly ends within a physiological chamber. After preconditioning and elongation to 10% strain was imposed by a linear motor, tensile force was allowed to stabilize at a plateau state. Then 25%, 50%, 75%, 90%, and 100% marginal tenotomies were performed progressively as remnant forces were measured.

RESULTS

Tendon thickness averaged 0.29 ± 0.05 mm and width 19.71 ± 2.25 mm. On average, remnant force decreased linearly (R2 = 0.985) from 4.23 ± 1.34, 2.76 ± 0.88, 1.70 ± 0.73, 1.01 ± 0.49, 0.39 ± 0.10, and 0 N, at 0%, 25%, 50%, 75%, 90%, and 100% tenotomy. However, there was marked individual variability in effect among specimens, with coefficients of variation of 32%, 32%, 43%, 49%, and 27%, respectively.

CONCLUSION

On average, there is a linear relationship between graded rectus tenotomy and percentage force reduction, but the effect among individual tendons is large, paralleling the reported variation in surgical effect. This explains and implies continued advisability of adjustable technique in this procedure.

Age-related nonparalytic hypertropia: Clinical features

PURPOSE

Age-related nonparalytic hypertropia (ARNH) is reported to be involved in sagging eye syndrome, where excyclotorsion is large and the lower eye is more extorted. The primary aim of this study was to describe the clinical profiles of patients with ARNH. The secondary aim was to compare cyclotorsion in patients with ARNH with that in normal individuals.

METHODS

Inclusion criteria for ARNH were insidious onset of diplopia at distance after 50 years of age, nonparalytic hyperdeviation and follow-up >6 months. Objective cyclotorsion was measured as the disc-to-fovea angle (DFA) on fundus photographs obtained from two groups: 75 patients with ARNH (age, 74.1 ± 7.9 years) and 75 sex- and age-matched normal controls (73.9 ± 8.1 years).

RESULTS

The hypertropia angle was 4.6 ± 2.8 prism dioptres. One patient also experienced diplopia at near-gaze. DFA in ARNH (right/left eye; 11.0 ± 4.8°/11.6 ± 3.9°) was larger than that of the control (6.6 ± 3.7°/9.2 ± 3.5°) (p < 0.0001). The DFA in the non-dominant eye (12.5 ± 4.1°) was larger than that in the dominant eye (10.2 ± 4.3°) (p = 0.0003). The lower eye did not have the larger DFA in 29 patients.

CONCLUSION

The angle of hyperdeviation in patients with ARNH was small. The DFA in the ARNH group was larger than that in the normal group. The lower eye was not the eye with a larger DFA in 39% of ARNH, inconsistent with sagging eye syndrome. Decreased phoria adaptation (fusional ability) may trigger diplopia in patients with ARNH.

Magnetic resonance imaging findings of high myopic strabismus with sagging eye-like symptoms, heavy eye syndrome, and non-highly myopic eyes with sagging eye syndrome

INTRODUCTION

Progressive esotropia accompanied by restricted abduction and supraduction due to high myopia is known as esotropia fixus with high myopia or heavy eye syndrome (HES). Some conditions, such as sagging eye syndrome (SES), show esotropia for distance or cyclovertical strabismus with no abduction limitations despite highly myopic eyes. We evaluated the magnetic resonance imaging (MRI) findings and clinical features of HES, high myopia with SES-like symptoms (highly myopic SES), and SES.

METHODS

We reviewed all patients diagnosed with HES, highly myopic SES, and SES who underwent MRI of the orbits and brain over 6 years. To quantitatively assess the orbital anatomy, we compared the conditions of the superior rectus muscle (SR), lateral rectus muscle (LR), and inferior rectus muscle (IR) using orbital MRI among the three groups.

RESULTS

Among the 14 patients (27 eyes) with high myopia, 5 (9 eyes) had HES, and 9 (18 eyes) had highly myopic SES. Eleven patients (22 eyes) with SES were also compared with these 14 patients. The mean axial length was 29.6 ± 1.0 mm in participants with HES, 29.0 ± 1.5 mm in those with HES-SES, and 23.7 ± 0.9 mm in those with SES. The average distance esotropia was 48.0 ± 19.9Δprism, 4.6 ± 1.5Δprism, and 6.1 ± 4.6Δprism for participants with HES, highly myopic SES and SES, respectively. The average distance hypertropia was 5.3 ± 5.9Δprism in participants with highly myopic SES and 4.8 ± 2.7Δprism in those with SES. The mean vertical angle of the LR was 32.6 ± 10.8°, 18.1 ± 5.4°, and 14.6 ± 6.8°; the mean tilting angle of the LR was 31.6 ± 9.2°, 15.9 ± 6.0°, and 13.8 ± 5.9°; and the mean displacement angle between the LR and SR was 152.3 ± 16.7°, 125.0 ± 7.1°, and 112.5 ± 7.5° for participants with HES, highly myopic SES and SES, respectively. The LR-SR displacement angle in HES-SES was significantly larger than in SES (p < .001) but the vertical and tilting angles were not. Also, the IR shift showed no significant difference with HES-SES and HES (5.8 ± 1.4 mm and 5.3 ± 1.2 mm) but not with SES (4.0 ± 0.8 mm) (p < .0001).

DISCUSSION

SES-like symptoms can develop in highly myopic eyes; however, MRI showed that the state of the LR muscle in highly myopic SES deviated almost similarly to that in SES; however, the eyeball was more dislocated than in SES. This may be useful in deciding the appropriate operative procedure.

Supraequatorial displacement with lateral rectus myopexy for treatment of myopic sagging/heavy eye

PURPOSE

To describe the outcome of the patients diagnosed of sagging/heavy eye associated to myopia, that were operated on with the supra-equatorial displacement with LR myopexy.

METHODS

A retrospective study of 9 cases between 2017-2023. The following data were analyzed: horizontal and vertical deviation, diplopia, amblyopia, ductions, ocular torsion, sensorial test, macular pathology, and the orbital magnetic resonance. Treatment was considered Successful if the diplopia was improved or eliminated and a final vertical deviation (VD) ≤5 prism diopters (PD).

RESULTS

The mean age (SD) was: 62.11 (4.6) years (100% women). A total of 88.88% presented diplopia. The mean preoperative hypotropia was: 11.33 PD (SD 3.16), and the mean final VD 3.44 PD (SD 3.05). After surgery, the hypotropia was overcorrected in one case, under corrected in 5, and orthophoria was achieved in another three. The technique was associated with surgery of another rectus muscle in 4 subjects. The mean follow-up time after surgery was 34 months (SD 34.62). Six of the 9 patients improved with a vertical deviation ≤5 PD. In 3 patients, the diplopia was eliminated, while in 5 it remained intermittent (three with macular pathology).

CONCLUSION

Supra-equatorial displacement with LR myopexy for treatment of myopic sagging/heavy eye, is a therapeutic option if hypotropia is less than 12 PD or the Yokoyama technique is not indicated. A good result was obtained in most cases, although diplopia could only be totally suppressed in three, and another five remained intermittent.

Diplopia in the Younger Adult (≤65 Years Old) Compared With Older Adult (>65 Years Old) Population-Presentation, Progression, and Outcome

BACKGROUND

Despite the impact of new-onset diplopia on the quality of life, there are few studies concerning new-onset diplopia in seniors. This study aimed to describe the epidemiology, etiology, prognosis, and outcome of different treatments in the older adults compared with younger adult patients presenting with new-onset binocular diplopia.

METHODS

A retrospective chart review of patients ≥18 YO with new-onset binocular diplopia presenting between 2010 and 2021. Data collected included age at presentation, gender, duration of time since diplopia onset, imaging results, known trigger, etiology, treatment, and follow-up.

RESULTS

Two hundred ten patients were included. Of them, 75 patients were ≤65 YO (35.7%, the "younger adult group") and 135 > 65 YO (64.3%, the "older adults group"). The common etiology in both groups was neurogenic (54.7% ≤ 65 vs 62.2% >65, P = 0.29). Cranial nerve palsies were more commonly microvascular in the older adults (96.0% vs 74.1%, P = 0.005), whereas tumor-related cranial nerve palsies were more frequent in younger adults (14.81% vs 2.04%, P = 0.03). A restrictive etiology was observed in 20% of younger adult compared with 11.1% of older adults group (P = 0.08). Sagging eye syndrome (SES) was the second most common etiology in the older adults group at 11.9%, compared with 1.3% in the younger adult group (P = 0.01). Decompensated phoria/tropia appeared in 16% of younger adult group compared with 11.9% of older adults (P = 0.4), with an obvious trigger (mostly cataract surgery) in the latter (80% older adults vs 20% younger adults, P = 0.019). Positive imaging findings were found in 46.7% of patients ≤65 compared with 25.3% of >65 (P = 0.01) and complete spontaneous resolution of diplopia was noted in 32.1% of the older adults compared with 11.8% of younger adults (P = 0.003).

CONCLUSIONS

Neurogenic diplopia was the most common etiology for both groups, but is more prominent in the older adults. Noticeable findings in the older adults were SES diagnosis, identification of triggers for impaired fusion/diplopia, and a paucity of positive findings in imaging results. It is important to know these differences not only for managing seniors better, but also to minimize symptoms of binocular diplopia after lens-related procedures.

Association of preoperative sensory monofixation with surgical failure in adult-onset divergence insufficiency-type esotropia

We investigated the frequency of sensory monofixation in patients with adult-onset divergence insufficiency esotropia and whether preoperative sensory monofixation was associated with surgical failure. Twenty-five patients with esotropia greater at distance than near who underwent bilateral medial rectus recessions were included. Near stereoacuity was measured preoperatively and 8 weeks postoperatively using the Randot Preschool test. Patients with best-corrected visual acuity worse than 0.3 logMAR in either eye or preoperative diplopia "rarely" or "never" in straight-ahead gaze at distance were excluded to minimize the inclusion of decompensated childhood strabismus. Sensory monofixation was defined as stereoacuity of 200 arcsec or worse and bifixation as 40 or 60 arcsec. Surgical failure was defined as esodeviation of >4Δ or exodeviation of >10Δ at distance or near, assessed 8 weeks (range, 6-17 weeks) postoperatively. We calculated the frequency of monofixation and surgical failure rates among patients with preoperative monofixation and those with preoperative bifixation. Preoperatively, sensory monofixation was common in divergence insufficiency-type esotropia (16 of 25 [64%]; 95% CI, 45%-83%). None of those with preoperative sensory monofixation had surgical failure, which does not support an association of surgical failure with preoperative monofixation.

Demographic and clinical characteristics of age-related distance esotropia

BACKGROUND

Age-related distance esotropia (ARDE), is an acquired, small, comitant esodeviation that is greater at distance than at near. It occurs in older adult patients without a history of neurological event or prior strabismus. It has been observed more frequently in White adults than in other racial groups. The purpose of this study was to assess the demographic and clinical characteristics of patients with ARDE presenting at a tertiary neuro-ophthalmology clinic.

METHODS

In this retrospective study, ICD-9/10 (ICD-9 378.85 and ICD-10 H51.8) codes were used to identify all patients with ARDE from 2005 to 2020 seen in a single tertiary neuro-ophthalmology clinic. ARDE was defined as esotropia greater at distance than near with associated clinical signs of adnexal tissue laxity. Patients with history or findings compatible with other etiologies of strabismus, such as thyroid eye disease, neuromuscular disorders, sensory deviations, sudden onset of diplopia, and high myopia, as well as those with prior strabismus surgery, were excluded.

RESULTS

A total of 89 patients (59 females [66%]) met inclusion criteria. Mean patient age was 76.6 years. All patients were White except for a single patient of African descent. Mean follow-up time was 25.2 months. Mean esodeviation at distance on presentation was 6.6Δ. Of the 87 patients electing nonsurgical treatment, 80 achieved remission of diplopia symptoms with prism therapy alone. Of the 89 patients, 59 had no neuroimaging.

CONCLUSIONS

ARDE in our neuro-ophthalmology clinic population was diagnosed almost exclusively in older White adults. Prism therapy was effective for a majority of our patients.

Analysis of Facial Features of Patients With Sagging Eye Syndrome and Intermittent Exotropia Compared to Controls

PURPOSE

To compare the facial features of patients with sagging eye syndrome (SES) and other ophthalmic diseases, and to evaluate the diagnostic usefulness of facial features for SES.

DESIGN

Retrospective cross-section study.

METHODS

We evaluated frontal facial photographs of patients >60 years of age with SES and intermittent exotropia (IXT), and control patients who visited the ophthalmology outpatient clinics of 2 institutions between June 2020 and December 2021. Three ophthalmologists evaluated each eye for sunken upper eyelid, blepharoptosis, and baggy lower eyelid, using a scoring scale. The average scores for each parameter among the 3 groups were analyzed. Patients with glaucoma, visual acuity <16/20, SES with a vertical strabismus angle of ≥6 Δ, IXT that could not be maintained in the phoria position during photography, a history of previous oculoplastic or ophthalmic surgery, and use prostaglandin analogs for cosmetic purposes were excluded.

RESULTS

A total of 86 patients were included: 23 with SES, 28 with IXT, and 35 in the control group. All were Japanese. In all, 45 patients were male and 41 were female. The mean age was 72.7 ± 7.4 years. The sunken upper eyelid scores were significantly higher in the SES group than in the control and IXT groups (P < .001), whereas the baggy lower eyelid scores were significantly higher in the IXT group than in the control group (P < .05).

CONCLUSIONS

Age-related orbital connective tissue degeneration may manifest as SES in the upper eyelid and as IXT in the lower eyelid.

Masquerading Superior Oblique Palsy

PURPOSE

We evaluated patients with hypertropia compatible with a diagnosis of superior oblique (SO) palsy to ascertain whether the 3-step test (3ST) can distinguish SO atrophy characteristic of trochlear nerve pathology from masquerading conditions.

DESIGN

Prospective cross-sectional study.

METHODS

In an academic practice, we performed quasi-coronal plane, surface coil magnetic resonance imaging in 83 patients clinically diagnosed with SO palsy. We evaluated alignment, SO cross-sectional area, SO contractility, and rectus muscle pulley positions.

RESULTS

A total of 57 patients with mean age 39 years (SD = 21 years) had unilateral SO palsy manifested by SO atrophy (22 congenital and 35 acquired). There was normal SO size in 26 patients with an average age of 39 years (SD =16 years) considered masquerades (8 congenital and 18 acquired). Maximum palsied SO cross-section averaged 9.5 ± 3.8 mm2, less than 18.4 ± 3.9 mm2 contralaterally (P < 10-24). In masquerades, maximum hypertropic SO cross-section was 20.7 ± 3.1 mm2, which was not different from the hypotropic SO or the contralesional muscle in SO palsy. Head tilt testing in masquerades was indistinguishable from SO palsy. In SO palsy, central hypertropia averaged 13.2 ± 9.4Δ, increasing to 21.1 ± 14.0Δ in ipsilateral tilt, and decreasing to 4.3 ± 5.3Δ in contralateral tilt. In masquerades, central hypertropia averaged 13.1 ± 8.7Δ, and was 17.7 ± 11.1Δ in ipsilateral and decreasing to 4.9 ± 5.1Δ in contralateral tilt. Upright hypertropia was larger at 17.7 ± 9.9Δ in congenital than 12.0 ± 8.4Δ in acquired SO palsy (P = 0025) but was indistinguishable from congenital masquerades. Contractile change in SO cross-section was bilaterally similar in masquerades. Relevant coordinates of rectus pulleys were similar bilaterally in masquerades.

CONCLUSIONS

The 3ST pattern characteristic of unilateral SO palsy may be mimicked in all respects by masquerades.

Evaluation and Management of Divergence Insufficiency-Type Esotropia

Divergence insufficiency-type ET is a common cause of distance diplopia in elderly adults. A recent prospective multicenter data collection study has provided additional guidance on management. Either base-out prism glasses or strabismus surgery were found to have high success rates, based on patient report of diplopia, and health-related quality-of-life domain scores. It was concluded that either prism or surgery were reasonable initial treatment strategies. Although allocation bias precluded formal comparison of prism versus surgery (evident in baseline differences between groups), there were hints that surgery may yield superior outcomes. For surgery, the most common approach was bilateral medial rectus recession, which was highly successful when assessed 10 weeks and 12 months postoperatively. It was unclear whether adjustable sutures were helpful, but in the vast majority of adjustable cases, additional recession at the time of adjustment was performed, suggesting that larger than standard surgical doses are needed.

Visual disorders and mal de debarquement syndrome: a potential comorbidity questionnaire-based study

Aim: Mal de debarquement syndrome (MdDS) is a neurological condition characterized by a constant sensation of self-motion; onset may be motion-triggered (MT) or non-motion-triggered/spontaneous (NMT/SO). People with MdDS experience similar symptoms to those with vertical heterophoria, a subset of binocular visual dysfunction. Hence, we aimed to explore potential visual symptom overlaps. Methods: MdDS patients (n = 196) and controls (n = 197) completed a visual health questionnaire. Results: Compared with controls, the MdDS group demonstrated higher visual disorder scores and visual complaints. NMT/SO participants reported unique visual symptoms and a higher prevalence of mild traumatic brain injury. Conclusion: Our findings suggest visual disorders may coexist with MdDS, particularly the NMT/SO subtype. The difference in visual dysfunction frequency and medical histories between subtypes, warrants further investigation into differing pathophysiological mechanisms.

Can Binocular Alignment Distinguish Hypertropia in Sagging Eye Syndrome From Superior Oblique Palsy?

Purpose

Although the three-step test (3ST) is typically used to diagnose superior oblique palsy (SOP), sagging eye syndrome (SES) has clinical similarities. We sought to determine if alignment measurements can distinguish unilateral SOP from hypertropia in SES.

Methods

We studied hypertropic subjects who underwent surface-coil magnetic resonance imaging (MRI) demonstrating either SO cross-section reduction indicative of congenital or acquired palsy (SOP group) or lateral rectus muscle sag (SES group). Alignment was measured by Hess screen and prism-cover testing. Multiple supervised machine learning methods were employed to evaluate diagnostic accuracy. Rectus pulley coordinates were determined in SES cases fulfilling the 3ST.

Results

Twenty-three subjects had unilateral SOP manifested by SO atrophy. Eighteen others had normal SO size but MRI findings of SES. Maximum cross-section of the palsied SO was much smaller than contralaterally and in SES (P < 2 × 10-5). Inferior oblique cross-sections were similar in SOP and SES. In both SOP and SES, hypertropia increased in contralateral and decreased in ipsilateral gaze and was greater in ipsilateral than contralateral head tilt. In SES, nine subjects (50%) fulfilled the 3ST and had greater infraplacement of the lateral than medial rectus pulleys in the hypotropic orbit. Supervised machine learning of alignment data distinguished the diagnoses with areas under the receiver operating curves up to 0.93, representing excellent yet imperfect differential diagnosis.

Conclusions

Because the 3ST is often positive in SES, clinical alignment patterns may confound SES with unilateral SOP, particularly acquired SOP. Machine learning substantially but imperfectly improves classification accuracy.

Comparison of subjective cyclofusion ranges and objective ocular torsion in normal participants according to age

PURPOSE

To investigate the relationship between subjective cyclofusion ranges and objective ocular torsion in normal participants according to age.

METHODS

This cross-sectional study included 120 participants aged ≥ 20 years with no ocular diseases. The subjective cyclofusion ranges were measured centrifugally and centripetally in the direction of excyclotorsion and incyclotorsion, respectively, concurrently with rotational diplopia production by rotation using synoptophore. Disc fovea angle (DFA) was defined as the angle formed by two lines: a line passing through the center of the optic nerve papilla and fovea and a horizontal line passing through the center of gravity of the optic papilla using fundus photographs.

RESULTS

The participants were aged 49.1 ± 17.7 years. The total cyclofusion centrifugal (sum of extorsion and intorsion) and centripetal ranges were 10.9 ± 2.2° and 7.2 ± 1.8°, respectively, both of which decreased in participants in their 60 s and 70 s (p < 0.01). The DFA was - 7.0 ± 3.4° in the right eye (- : excyclo, + : incyclo) and - 8.0 ± 3.2° in the left, which was associated with age (p < 0.001). The correlation between the DFA and centrifugal (r =  - 0.13, p = 0.16) and centripetal (r =  - 0.002, p = 0.99) cyclofusion ranges of extorsion was not significantly different. The centrifugal (r = 0.37, p < 0.001) and centripetal (r = 0.40, p < 0.001) cyclofusion ranges of intorsion were positively correlated.

CONCLUSION

Subjective cyclofusion ranges decreased in both extorsion and intorsion in the elderly. Objective ocular torsion showed excyclotorsion with age. When strabismus surgery is performed in elderly patients with torsional strabismus, the decrease in subjective cyclofusion ranges should be considered.

Objective excyclotorsion in age-related distance esotropia

Age-related distance esotropia (ARDE) is thought to be caused by sagging eye syndrome. Sagging of the lateral rectus derives from the naturally occurring aging process and induces excyclotorsion of the eye. To date, no study has compared the cyclodeviation in ARDE with that in the age-matched individuals without strabismus. This study aimed to measure the objective cyclotorsion on fundus photographs of ARDE patients and compare the findings with those for normal age-matched individuals. Objective cyclotorsion was measured by determining the disc-to-fovea angle (DFA) on fundus photographs, which were obtained from two groups: 38 consecutive patients with ARDE (age, 74.1 ± 7.9 years), 76 normal age-matched controls (age, 73.9 ± 8.1 years). DFA in ARDE patients was not different from that in the control group (Welch's t-test: ARDE vs Control, right eye; 7.7° ± 2.9° vs 6.8° ± 3.9°, p = .18. Left eye; 10.0° ± 4.5° vs 9.4° ± 3.6°, p = .54. Sum of both eyes; 17.6° ± 5.8° vs 16.2° ± 4.7°, p = .21). These findings suggest sagging of the lateral rectus is not the sole cause of ARDE. Another aging-related factor, such as decreased phoria adaptation, might also be responsible for ARDE.

Prevalence and clinical features of sagging eye syndrome in Korean patients

Purpose

To retrospectively analyze the relative frequency and describe the clinical features of sagging eye syndrome in Korean patients from a single center.

Methods

We retrospectively analyzed the medical records of patients with diplopia, aged over 40 years, who visited Chosun University Hospital from January 2018 to December 2020. The relative frequency of sagging eye syndrome was examined by classifying the cause of diplopia. Clinical features, such as age, sex, strabismus type, angle of deviation, treatment method, and prognosis were evaluated.

Results

A total of 128 patients were identified, of which 23 (18%) were diagnosed with sagging eye syndrome, including 12 male patients (52.2%) and 11 female patients (47.9%). Their mean age was 74.6 ± 7.6 years (range, 61–89 years), and all patients were over 60 years. Among the 62 patients with diplopia and age over 60 years, the relative frequency of sagging eye syndrome was 23 (37.1%), the highest among all age groups. Among the 23 patients with sagging eye syndrome, nine patients (39.1%) had only distance esotropia, with a mean distance esotropia value of 10.1 ± 8.6 prism diopters (PD) (range, 4–25 PD) at the first visit; nine patients (39.1%) had a combination of esotropia and vertical strabismus, with a mean esotropia value of 6.2 ± 4.8 PD (range, 2–12 PD) and a vertical angle of 4.7± 3.2 PD (range, 2–10 PD); and five patients (21.7%) had only vertical strabismus, with an average vertical strabismus angle of 3.3 ± 1.6 PD (range, 4–8 PD). Furthermore, 17 out of 23 patients (73.9%) used prism glasses, in whom the symptoms of diplopia disappeared. Finally, only three patients (13.0%) underwent surgery.

Conclusions

Sagging eye syndrome in Korean patients was identified in those over 60 years with a similar male-to-female ratio. Moreover, nonsurgical treatments, such as prism glasses, largely helped relieve the symptoms of sagging eye syndrome.

Increasing incidence and risk factors for divergence insufficiency esotropia

PURPOSE

To document the increasing incidence of divergence insufficiency (DI) esotropia and to identify risk factors for DI.

METHODS

All patients with a diagnosis of esotropia seen by one provider (DLG) over 41 years were identified from the medical record. Patients with onset of strabismus before age 10 years or with prior strabismus surgery were excluded. Cases of esotropia associated with thyroid eye disease, scleral buckles, trauma, neurological diseases, or atypical misalignment were included but not labeled as DI regardless of the distance versus near deviation. The remaining patients, whatever the original diagnosis, were retrospectively categorized as having, or not having, DI, using a uniform criterion: distance esotropia ≥5^Δ more than near esotropia.

RESULTS

The percentage of DI patients among acquired esotropia patients increased significantly between the first and second half of the 41-year period, from 11.8% to 29.4% (P < 0.001). Multivariate logistic regression identified advancing age and the use of progressive addition lenses as risk factors for the development of DI.

CONCLUSIONS

The incidence of DI is increasing. DI's association with age and progressive addition lenses may help us to understand its etiology and to decrease the prevalence of this condition in the future.

A prospective study of treatments for adult-onset divergence insufficiency-type esotropia

PURPOSE

To describe 10-week and 12-month outcomes following treatment for divergence insufficiency-type esotropia in adults.

METHODS

In this prospective observational study, 110 adults with divergence insufficiency-type esotropia, with a distance esodeviation measuring 2^Δ to 30^Δ and at least 25% larger at distance than near, and binocular diplopia present at least "sometimes" at distance, were enrolled at 28 sites when initiating new treatment. Surgery, prism, or divergence exercises/therapy were chosen at the investigator's discretion. Diplopia was assessed at enrollment and at 10-week and 12-month outcome examinations using a standardized diplopia questionnaire (DQ). Success was defined as DQ responses of "rarely" or "never" when looking straight ahead in the distance, with no alternative treatment initiated.

RESULTS

Of the 110 participants, 32 (29%) were prescribed base-out prism; none had received prior treatment for esotropia. Success criteria were met by 22 of 30 at 10 weeks (73%; 95% CI, 54%-88%) and by 16 of 26 at 12 months (62%; 95% CI, 41%-80%). For the 76 (68%) who underwent strabismus surgery (82% of whom had been previously treated with prism), success criteria were met by 69 of 74 at 10 weeks (93%; 95% CI, 85%-98%) and by 57 of 72 at 12 months (79%; 95% CI, 68%-88%).

CONCLUSIONS

In this study cohort, both base-out prism as initial therapy and strabismus surgery (usually following prism) were successful in treating diplopia for most adults with divergence insufficiency-type esotropia when assessed during the first year of follow-up.

Sagging eye syndrome

The pulley is the functional origin of the extraocular muscles and prevents their dislocation from the muscle cone. The pulley degenerates with age and may progress to cause the sagging eye syndrome (SES). Divergence paralysis, a type of distance esotropia, occurs when the lateral rectus muscle pulley and lateral rectus-superior rectus (LR-SR) band show degenerated symmetry OU. Cyclovertical strabismus of a small angle occurs when the lateral rectus muscle pulley and LR-SR band show degenerated asymmetry OU. Patients with SES have distinctive features, such as baggy eyelids, deep superior sulcus deformity, and aponeurotic ptosis. SES is the leading cause of non-paralytic diplopia, and its rate increases with age, with 60% of the patients being women. One-third of the cases of SES are distance esotropia of 9Δ on average, and two-third of the cases are small-angle hypertropia of 4Δ on average. Diplopia is cured with surgery, and each case needs to be differentiated from the heavy eye syndrome for diagnosis and treatment.

Quantification of Cover Test Prior and Post Pyridostigmine in Diagnosis of Myasthenia Gravis

Objective: To assess the value of measuring diplopia before and after pyridostigmine intake to differentiate myasthenia gravis from sagging eye syndrome.To establish a threshold for a positive response to pyridostigmine in the diagnosis of myasthenia gravis.Methods: 15 patients with myasthenia gravis and 15 with sagging eye syndrome diplopia were evaluated. Diplopia was measured in five positions (upgaze, downgaze, right gaze, left gaze, and primary position). After baseline measurements, the patient received a single dose (60 mg) of pyridostigmine. After 60 minutes the prism measure was performed again in five positions. Horizontal deviation, vertical deviation at distance was compared before and after a single dose of pyridostigmine in each gaze. Ocular deviations were compared between the two groups to identify the threshold with the highest sensitivity and specificity.Results: Differences between pretest deviations and posttest deviations in any gaze were found to be statistically significant only in the MG group. The optimum threshold for a positive response to pyridostigmine was a reduction of 2 prism diopters in any component in any gaze. Sensitivity for the detection of myasthenia diplopia was 80.00% and specificity was 86.67%.Conclusions: Our results suggest that measuring diplopia with prisms before and after pyridostigmine administration can help to detect patients with suspected myasthenia.

Characterization of the position of the extraocular muscles and orbit in acquired esotropia both at distance and near using orbital magnetic resonance imaging

PURPOSE

Age-related distance esotropia (ARDE) involves acquired esotropia at distance and phoria at near. However, distance-independent esotropia (DIE) exists esotropia both at distance and near. Thus, we examined the orbital magnetic resonance imaging (MRI) findings for DIE to assess differences in its characteristics.

METHODS

This study was a retrospective case-control study. We evaluated the efficacy of the standard coronal MRI in patients with acquired esotropia and control patients with optic neuritis. Cases with strabismus in the control group were excluded. DIE was defined as having esotropia both at distance and near, and an angle of more than 10 prism diopters at near. The condition of the lateral rectus-superior rectus band, position of rectus muscles, and the volume ratio of the globe to the whole orbit (G/WO) were examined.

RESULTS

The DIE group consisted of 12 eyes of 6 patients (77.3±7.7 years); ARDE group, 38 eyes of 19 patients (73.1±6.8 years); and control group, 34 eyes of 17 patients (70.9±4.3 years). The ratio of abnormality of the lateral rectus-superior rectus bands was higher in the DIE and ARDE groups than in the control group (p<0.01). The vertical angle of the lateral rectus deviated downwards in the control (-7.5±5.1°), ARDE (-12.2±9.1°), and DIE groups (-18.8±5.7°) (p<0.05). The tilting angle of the lateral rectus was tilted temporally in the control (-12.2±9.1°), ARDE (-20.0±8.6°) and DIE groups (-28.6±5.4°) (p<0.01). G/WO was higher in the DIE (0.28±0.01) and ARDE groups (0.27±0.02) compared to the control (0.25±0.03) group (p<0.01).

CONCLUSION

In comparison with the ARDE and control groups, the DIE group presented with abnormalities of the lateral rectus-superior rectus band, malposition of the lateral rectus, and differences in the G/WO. The DIE group showed a more severe form of ARDE.

Functional Anatomy of Muscle Mechanisms: Compensating Vertical Heterophoria

PURPOSE

Magnetic resonance imaging (MRI) of extraocular muscle function was used to evaluate the role of newly recognized mechanisms underlying compensation of large heterophoria by vertical fusional vergence (VFV).

DESIGN

Prospective case series.

METHODS

At one academic center, 8 adults with large hyperphoria and supernormal VFV underwent MRI during monocular and binocular fixation of a centered, near target. Contractility of the rectus and superior oblique (SO) extraocular muscles in hypertropic and hypotropic eyes was determined from changes in posterior partial volume (PPV).

RESULTS

Five of 8 patients could sustain binocular fusion in the scanner. In those patients, VFV corrected approximately 5-degree misalignment, approximately 5-fold greater than normal VFV. Vertical strabismus was compensated mainly by significant contractility of the lateral more than the medial compartment of the inferior rectus (IR) in both eyes (P < .005). The superior rectus (SR) and inferior oblique muscles had no significant contractile contribution, although the hypotropic SO relaxed significantly. The IR lateral compartment and SR medial compartment significantly co-relaxed when binocular fusion was attained from monocular target fixation (P < .01).

CONCLUSIONS

Although VFV protects patients from small muscle imbalances over the lifespan, even enhanced VFV may be inadequate to avert diplopia. Compensation of hyperphoria by VFV is accomplished mainly by IR muscle relaxation in the hypotropic eye, principally in its selectively innervated lateral compartment, whereas the SO contributes little. Fusion involves compartmentally selective co-relaxation in hypotropic eye vertical rectus muscles. Taken together, these overall findings suggest a physiologic basis to prefer therapeutic surgical weakening of the medial IR in the hypotropic eye.

Shape analysis of rectus extraocular muscles with age and axial length using anterior segment optical coherence tomography

Purpose

This study aimed to evaluate the shape of the extraocular muscles (EOMs) in normal subjects using the en-face images of anterior segment optical coherence tomography (AS-OCT). The EOM insertion and the direction of the muscle fibers were investigated.

Subjects and methods

A total of 97 healthy normal subjects (194 eyes) at Okayama University Hospital (age, 47.1±21.5 years; range, 8–79 years) participated in the study. A series of 256 tomographic images of the rectus EOMs were captured using the C-scan function of the AS-OCT (CASIA2, TOMEY Co., Japan), and the images were converted to en-face images in multi-TIFF format. The anterior chamber angle to EOM insertion distance (AID) and the angle of the muscle fibers from the insertion site (angle of muscles) were measured from the images. The correlations of AID and angle of muscles with age and axial length were investigated and evaluated.

Results

AID and angle of muscles were significantly correlated with age or axial length in some EOMs. The AIDs of medial rectus (MR) (P = 0.000) and superior rectus (SR) (P = 0.005) shortened with age. The AIDs of MR (P = 0.001) and inferior rectus (IR) (P = 0.035) elongated with axial length, whereas lateral rectus (LR) (P = 0.013) shortened. The angles of MR (P = 0.001) and LR (P = 0.000) were found to have a more downward direction toward the posterior in older subjects.

Conclusion

En-face images can be created by AS-OCT, and the shape of the EOMs in normal subjects using these image measurements was available. With the ability to assess the EOMs, AID and angle of muscles are expected give useful information for treating and diagnosing strabismus-related diseases.

Differential Diagnosis of Acquired Esotropia in the Elderly

AIM

To provide an overview of the differential diagnoses of acquired esotropia that occur in the elderly and to facilitate their differentiation in everyday clinical practice.

METHODS

The data of all patients who presented in our outpatient university department for strabology and neuroophthalmology from March 2014 to October 2015 due to esotropia with diplopia with onset after age 50 were evaluated retrospectively. Exclusion criteria were a known strabismus before the age of 50 and/or vertical deviations in the primary position. Anamnestic characteristics, accompanying findings and orthoptic parameters, were analysed.

RESULTS

85 patients were included in the study, 42 of them female and 43 male. The following diagnoses were made: abducens nerve palsy (n = 34, 3 of them both sides), esotropia due to myopia magna (n = 12), esotropia with accompanying neurological symptoms (n = 6) and other etiology (n = 5). In 4 cases, the diagnosis was still unclear at the end of the study. In 24 patients, none of the above diagnoses existed and the diagnosis of "sagging eye syndrome" (ETSAG) was made. The abducens nerve palsy typically showed a sudden onset of double vision, slowed abduction saccades and asymmetrical abduction ability. With unilateral abducens nerve palsy, the esotropia increased continuously from the view to the unaffected side through the primary position to the view to the affected side. Patients with ETSAG and myopia-associated esotropia, on the other hand, reported a gradual onset of double vision, showed normal abduction saccades and a slightly reduced abduction ability. The squint angle often increased slightly to both sides. Esotropia with accompanying neurological symptoms was rare and was seen in various underlying diseases.

CONCLUSIONS

The kind of onset of the double vision, the quality of the saccades, the incomitance pattern and the ability to abduct are important parameters for the etiological assignment of an esotropia in the elderly. The characteristics of the individual diagnoses are described and differential diagnostic aspects are discussed.

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.

Standard coronal orbital magnetic resonance imaging is an effective technique for diagnosing sagging eye syndrome

PURPOSE

The aim of this study was to determine the importance and efficacy of the standard coronal magnetic resonance imaging (MRI) analysis method for the correct clinical diagnosis of the sagging eye syndrome.

METHODS

This retrospective study evaluated the standard coronal MRI efficacy by comparing the positions of the orbital pulleys and extraocular muscles in patients with sagging eye syndrome as well as controls. The participants included 50 patients with sagging eye syndrome (aged 73.3 ± 6.7 years) and 17 age-matched control patients (aged 70.9 ± 4.3 years) that presented optic neuritis. The participants were classified into groups of age-related distance esotropia and cyclo-vertical strabismus. Lateral rectus-superior rectus band condition, lateral rectus vertical angle, lateral rectus tilting angle, and superior rectus-lateral rectus displacement angle were examined.

RESULTS

The lateral rectus-superior rectus band was more frequently disordered in the two groups than that in the control. The lateral rectus vertical and tilt angle examinations exhibited a significant difference in the age-related distance esotropia [(- 13.3 ± 10.9°, p < 0.05) and (- 24.1 ± 9.5°, p < 0.01)] and cyclo-vertical strabismus [(- 11.9 ± 6.9°, p < 0.05) and (- 20.8 ± 9.3°, p < 0.01)] groups compared with those in the control group [(- 7.5 ± 5.1°) and (- 12.2 ± 9.1°)]. The superior rectus-lateral rectus displacement angle did not present a significant difference between the patients and control groups.

CONCLUSIONS

Patients with sagging eye syndrome exhibited disordered orbital pulley and extraocular muscle malposition, as determined by standard coronal magnetic resonance imaging, indicating the effectiveness of the procedure for diagnosing sagging eye syndrome.