Randomized Controlled Trial of Patching versus Dichoptic Stimulation Using Virtual Reality for Amblyopia Therapy

Purpose: To compare the outcomes of patching to dichoptic stimulation using virtual reality (VR) in moderate and severe amblyopia.Methods: This study was conducted on 86 subjects with unilateral anisometropic and mixed amblyopia. The subjects were randomized to the VR or patching group. The VR group received treatment using the Vivid Vision software (Vivid Vision Inc., San Francisco, USA) with each subject receiving weekly 2 h-sessions for 10 weeks. The patching group was prescribed patching for 10 weeks. Best-corrected visual acuity (BCVA) was measured using a single crowded letter in an ETDRS chart before, after 10 weeks of treatment, and after another 10 weeks of cessation of treatment. Near stereoacuity was measured using the TNO test.Results: Forty-two patients were randomized to the patching group and 44 to the VR group. The median age of the subjects was 12.0 (range 6.0 to 37.0) years. In the VR group, mean amblyopic eye BCVA showed statistically significant improvement by 0.89 line (95% confidence interval {CI}, 0.73 to 1.35 lines; p < 0.001) after 10 weeks of therapy, and after another 10 weeks of follow-up by 1.32 lines from baseline (95% CI, 1.15 to 1.7 lines; p < 0.001). Regarding the patching group, mean BCVA showed statistically significant improvement after 10 weeks by 1.38 lines (95% CI, 0.82 to 1.8 lines; p < 0.001), and after another 10 weeks by 1 line from baseline (95% CI, 0.06-0.147; 0.6 to 1.47 lines; p < 0.001). There was no significant difference between both groups at any time-point (p values >0.05). No serious adverse events were noted. Adults and severe amblyopes in the VR group showed more significant VA improvement than their counterparts in the patching group.Conclusions: Amblyopes treated using VR dichoptic treatment demonstrated statistically significant VA improvement after 10 and 20 weeks of follow-up that is comparable to patching.

Outcome of intraocular lens exchange for the management of myopic shift in pseudophakic children

PURPOSE

To evaluate the visual outcome of intraocular lens (IOL) exchange for the management of myopic shift in pseudophakic children.

METHODS

The medical records of children who underwent IOL exchange for myopic shift were examined. The preoperative data, operative details and the postoperative outcome were analyzed.

RESULTS

Twenty-one eyes (16 patients) were identified. Mean age at cataract extraction was 20 ± 26 months (range, 2-84 months). Twelve patients (6 unilateral, 6 bilateral) had primary IOL implantation. Mean age at IOL exchange was 7.3 ± 3.2 years. Mean spherical equivalent (SE) at IOL exchange was -14 ± 5 D (range, -7 to -21 D): Mean SE at IOL exchange was -13.64 ± 4.99 D, -12 ± 1.53 D, and -15.5 ± 4.7 D in unilaterally pseudophakic cases (8 patients), in the eye that underwent unilateral IOL exchange (3 patients) in bilaterally pseudophakic cases, and in bilateral IOL exchange cases (5 patients), respectively. Mean axial length at IOL exchange was 24 ± 1.3 mm (range, 23 to 27 mm). Following IOL exchange, mean SE was reduced to -2 ± 1.8 D (range, -4 to +2.5 D). An average of three logMAR line improvement in the best-corrected visual acuity was observed in 12/16 eyes of patients for whom pre- and post-exchange visual acuity were available, while visual acuity remained unchanged in 4 eyes. Mean logMAR visual acuity improvement was 0.35 and 0.49 in unilateral and bilateral pseudophakic cases, respectively.

CONCLUSIONS

IOL exchange is a safe procedure that should be considered to improve visual rehabilitation in pseudophakic patients with myopic shift.

Convergence Excess Esotropia: Review

Convergence excess esotropia is a condition characterized by an esotropia which is greater for near fixation than for distance fixation after full hypermetropic correction with a single focus lens. Convergence excess esotropia may be classified according to the AC/A ratio into two subtypes: accommodative type and non-accommodative type. Bifocal glasses are a suitable option for the management of patients with a high AC/A ratio and for the hypoaccommodative type. However, the overall success rate with bifocals is still low even in selected patients. Surgery is often eventually needed for most patients with convergence excess esotropia. Surgical options that do not directly address the variability of the angle of deviation entail medial rectus recession with the target angle based on the distance deviation, the near deviation, an augmented formula based on an intermediate angle, or on a prism adaptation test. Surgical options that directly address the variability of the angle include partial myotomy, medial rectus muscle posterior scleral fixation with or without recession, pulley fixation, slanting recession, Y-splitting, or combined recession-resection of the medial rectus muscle. The review article summarizes the surgical outcome of these strategies and suggests an algorithm for the management of patients with convergence excess esotropia.

Palpebral Fissure Changes in the Contralateral Eye in Duane Retraction Syndrome

Duane retraction syndrome (DRS) is a congenital cranial dysinnervation disorder that is characterized by paradoxical lateral rectus muscle innervation of the affected eye by axons meant to innervate the ipsilateral medial rectus muscle, with resultant varying degrees of co-contraction. It is characterized by severe abduction deficiency, variable limitation of adduction, globe retraction with narrowing of the palpebral fissure, and oblique elevation or depression on adduction. A total of 16 patients with unilateral DRS were identified. The mean age was 13 ± 8 years (range: 6 to 28 years). There were 5 males and 11 females. The cohort included 8 patients with DRS type I, 3 patients with DRS type II, 4 patients with DRS type III, and 1 patient with synergistic divergence (DRS type IV). The mean width of the palpebral fissure in primary gaze was 9.95 ± 0.25 mm, increased in abduction to 11.11 ± 1.16 mm, and changed on adduction to 10.03 ± 1.19 mm. The mean reduction in the size of the palpebral fissure on adduction was 11.7 ± 10.2% (range: 0 to 30%). The difference in the palpebral fissure width between adduction and abduction was statistically significant (P = .0018). Of the 16 patients, 8 (50%) showed narrowing of the palpebral fissure of the contralateral eye on adduction compared to abduction of more than 10%. In this case series of unilateral Duane retraction syndrome, there was a common association between widening of the palpebral fissure of the unaffected eye and adduction of the eyes with DRS in DRS types II, III, and IV and DRS type I with upshoot or downshoot. [J Pediatr Ophthalmol Strabismus. 2023;60(3):e22-e25.].

Overcorrection after vertical muscle transposition with augmentation sutures in sixth nerve palsy

PURPOSE

To report a series of cases, who developed consecutive exodeviation after vertical muscle transposition (VRT) performed for sixth nerve palsy, describe their management and analyse their outcome.

DESIGN

Retrospective case series.

METHODS

This is an institutional study on patients who developed consecutive exotropia following VRT for sixth nerve palsy in two different centres. The age, gender, cause, and time to surgery were reviewed. Ductions, versions and angles of misalignment were analysed. In those who developed an exotropia >10 PD after surgery, a second surgery was performed. The time to the second surgery, intra-operative findings, surgical procedure and outcome were studied.

RESULTS

A total of 164 cases of VRT for sixth nerve palsy were identified. Nine patients developed consecutive exotropia >10 PD (5.5%). There were no significant differences in the characteristics of those who developed overcorrection compared to those who did not. Five patients had full-tendon muscle transposition, three patients had Hummelsheim procedure and one patient had Jensen procedure. The average angle of consecutive exotropia was 26 ± 9 Δ (range 10-40 Δ). After the second surgery, angle of exotropia decreased to 21 ± 15 PD. Seven patients still had residual exotropia ≥10Δ and the exotropia was corrected in the remaining two patients. The time to second surgery in those two patients was much shorter than the other seven patients.

CONCLUSIONS

Patients who undergo VRT should be followed up in the early post-operative period and revisiting the transposition should be done immediately in case of consecutive exotropia to avoid permanent overcorrection.

Muscle fenestration in vertical rectus muscle surgeries

PURPOSE

To evaluate the outcome of fenestration of the vertical rectus muscles in correcting vertical deviations.

MATERIAL AND METHODS

A retrospective chart review was conducted on patients who underwent fenestration surgery on the superior rectus (SR) or inferior rectus (IR) muscles. Ductions, versions, angle of deviations before and after surgery, and surgical details were analyzed. Success was defined as vertical alignment within 4 PD of orthophoria.

RESULTS

Nineteen patients were identified. The mean age of the patients was 19.3 ± 13.1 (range; 4 to 48) years. The mean follow-up was 6.5 ± 2.7 (range, 3 to 12) months. Eleven patients presented with dissociated vertical deviation (DVD), 2 patients with sensory hypertropia, and 6 patients with sensory hypotropia. Fourteen patients had concomitant horizontal muscle surgery. The mean change of the angle of deviation was 13 ± 3 (range, 8 to 20) PD after SR fenestration. and 12 ± 2 (range; 10 to 15) PD after IR fenestration. There was a significant improvement in the post operative angle of deviation in both groups (P value <0.001). Success was achieved in 10 (77%) of patients who underwent SR fenestration and in all patients underwent ir fenestration. Only one patient in the IR group developed a 1-mm lower lid retraction.

CONCLUSION

Fenestration of the vertical rectus muscles is an effective and safe method for correcting vertical deviations. We recommend increasing the amount of fenstration in DVD to further improve the outcome.

Nasal insertion of the superior oblique tendon presenting as Brown syndrome

BACKGROUND

Anomalous ocular muscle insertions are a rare cause of ocular motility disturbances.

METHODS

We report the clinical presentation and the intraoperative findings of two cases with an abnormally nasally inserted superior oblique tendons presenting with a Brown syndrome-like clinical picture.

RESULTS

Case no 1 was a 5-year-old girl presenting with a chin up position. There was bilateral limitation of elevation in adduction, -4 on the right side and -3 on the left side with +1 downshoot on adduction on either side Patient was orthotropic in down-gaze with small V-pattern exotropia. Case no 2 was a 4-year-old boy presenting with an esotropia of 35Δ that was partially corrected with his spectacles to 20Δ. Ductions showed -4 defective elevation in adduction of the right eye. Surgical exploration in both cases revealed abnormal nasal insertion of the superior oblique tendons. The line of insertion had a convexity facing superonasally. The posterior fibers were inserted 7-8 mm posterior and just nasal to the nasal border of the superior rectus insertion, while the anterior fibers were shorter and inserted 5 mm nasal and 4 mm posterior to the nasal edge of superior rectus insertion. In both cases, there was an improvement in the elevation on adduction after superior oblique lengthening.

CONCLUSIONS

Abnormal nasal insertion of the superior oblique muscle enhances the depressor effect of the muscle and can create a Brown-like picture.

Early and delayed suture adjustments after adjustable suture strabismus surgery: a randomized controlled trial

Background

Adjustable sutures increase the success rate of strabismus surgery. However, the optimal timing of postoperative suture adjustment remains controversial. This trial was aimed at comparing the surgical outcomes and pain scores of early or 2 - 4 h and delayed or 24 h postoperative suture adjustment in adult patients undergoing strabismus surgery.

Methods

An open-label, prospective, randomized, comparative interventional study was performed in consecutive adult patients scheduled for eye muscle surgery. Patients were randomized into two groups: the early group, with suture adjustment 2 - 4 h postoperatively, and the delayed group, with suture adjustment 24 h postoperatively. Subjective pain scores during the adjustment were also analyzed. The angles of misalignment at 1 and 3 months and the success rate at 3 months postoperatively were compared.

Results

Forty-five (90%) patients completed the follow-up, including 23 (92%) in the early adjustment group and 22 (88%) in the delayed adjustment group, with a mean (standard deviation) age of 25.6 (9.5) years and a male-to-female ratio of 46.7:53.3. Thirty patients (66.7%) had exotropia, and 15 (33.3%) patients had esotropia. Both groups had comparable baseline characteristics (all P > 0.05). The mean pain scores during adjustment did not differ significantly between groups (P > 0.05). The postoperative angles of alignment were comparable between the groups before suture adjustment and at the 1- and 3-month follow-ups (all P > 0.05). The success rate in the early adjustment group was slightly higher (87.0% versus 63.6%), but the difference was not statistically significant (P > 0.05). The success rate was comparable between the groups in patients with esotropia or exotropia (both P > 0.05).

Conclusions

Although the early adjustment group had a slightly higher success rate, the difference was not significant. Both groups had comparable subjective pain scores during adjustment, final motor alignment, or success rate. Future clinical trials should be performed different time intervals for postoperative suture adjustment, and subjective and objective outcomes, such as diplopia and stereopsis, should be compared between patients with a first strabismus surgery and those who underwent reoperation. This could better resolve the persistent controversy related to the optimal time for suture adjustment.

Comparison between Hummelsheim and Jensen procedures in the management of chronic sixth nerve palsy

PURPOSE

To compare the postoperative alignment, degree of improvement of abduction, and complications of the Hummelsheim procedure to the Jensen procedure in chronic sixth nerve palsy, and to calculate the dose-response of both procedures.

METHODS

A retrospective study was done on patients who either had Hummelsheim or Jensen procedure for chronic sixth nerve palsy. Demographic characteristics, details of surgical procedure, ductions, versions, and angles of misalignment before and after surgery were analyzed.

RESULTS

A total of 79 patients were identified: 38 Jensen and 41 Hummelsheim. There were no statistically significant differences in baseline characteristics of both groups. Medial rectus recession was performed in 35 patients in the Jensen group and in 30 patients in the Hummelsheim group. Success defined as orthotropia within 8 PD was achieved in 25 (66%) patients in the Jensen group and in 24 (59%) patients in the Hummelsheim group (P = 0.51). The mean improvement in the angle of deviation in the primary position was 42 ± 12 PD in the Jensen group and 42 ± 16 PD in the Hummelsheim group (P = 0.89). The mean improvement in abduction was slightly better in the Hummelsheim group (1.8 vs 1.5, P = 0.32). A new vertical deviation occurred in three patients in the Jensen group and in 4 patients in the Hummelsheim group. Anterior segment ischemia occurred in one patient in the Jensen group.

CONCLUSIONS

There was no difference in the success rate between the Hummelsheim and Jensen procedures in cases of chronic sixth nerve palsy. Strabismus surgeons can choose between the two procedures according to their preference.

Duane-minus (Duane sine retraction and Duane sine limitation): possible incomplete forms of Duane retraction syndrome

PURPOSE

To report ocular motility patterns that mimic, but do not fulfil the full clinical picture of Duane retraction syndrome (DRS) and to describe their clinical features and surgical management.

METHODS

This is a retrospective case series study conducted on patients with DRS, mimicking non-comitant exotropia or esotropia and a face turn. Patients were included only if they lacked either globe retraction on adduction (sine retraction) or limitation of adduction or abduction on ductions (sine limitation not >0.5). Any overshoots or pattern strabismus was recorded. The ocular motility and alignment, details of surgery and their surgical outcomes were analysed.

RESULTS

Twenty-one patients were identified; 13 in the sine retraction and 8 in the sine limitation group. All patients presented with a compensatory face turn. Overshoots were present in 10 (77%) and 7 patients (88%) in the sine retraction and sine limitation groups, respectively. Forced duction test showed tightness of the ipsilateral medial and the ipsilateral lateral rectus muscle in esotropic (n = 3) and exotropic patients (n = 18), respectively. Orthotropia was achieved in 82% of patients following ipsilateral medial or lateral rectus muscle recession.

CONCLUSIONS

There is a subset of patients who present with motility pattern similar to DRS but lack its complete diagnostic criteria. The presence of a face turn, overshoots on adduction or an ipsilateral tightness of the affected muscle should make one consider DRS sine retraction/sine limitation. The patients in our study responded well to lines of management similar to those of DRS.

Contralateral Surgery for the Treatment of Third Nerve Palsy with Aberrant Regeneration

PURPOSE

To report the results of contralateral recession-resection of the horizontal muscles in oculomotor nerve palsy with aberrant regeneration to correct both the strabismus and the ptosis in one procedure.

DESIGN

Retrospective case series.

METHODS

This is an institutional study on patients with oculomotor nerve palsy with aberrant innervation who had contralateral eye muscle surgery in 2 different centers. Patients were included if they have both exotropia and aberrant regeneration with a ptosis that improved on adduction. All patients had contralateral lateral rectus recession and medial rectus resection. Ductions, versions, angle of misalignment, and degree of ptosis were evaluated before surgery and at last follow-up.

RESULTS

Eleven patients were identified. The mean age at surgery was 15.0 ± 9.2 years. Five patients were male (45%). Trauma was the cause in 8 (72%) cases. The mean angle of exotropia was 42 ± 14 prism diopters. The mean degree of ptosis was 3.9 ± 1.6 mm. The mean lateral rectus recession was 8.2 ± 1.1 mm, and the mean medial rectus muscle resection was 6.7 ± 0.9 mm. The mean follow-up was 6.4 ± 2.5 months. After surgery, none of the patients had residual exotropia >10 prism diopters. The mean degree of ptosis after surgery was 0.9 ± 0.8 mm. None of the patients required further surgery for ptosis or strabismus.

CONCLUSION

Contralateral eye muscle in third nerve palsy with aberrant innervation offers the advantage of simultaneous correction of both strabismus and ptosis through a single procedure.

Pattern strabismus in consecutive esodeviation after bilateral lateral rectus muscle recession for intermittent exotropia

PURPOSE

After bilateral lateral rectus recession for intermittent exotropia, children can develop V- or A-pattern esodeviation and adopt a chin-down or chin-up position to facilitate fusion. The aim of this study was to discuss possible causes and management of this pattern.

METHODS

The medical records of children who developed consecutive esodeviation with V- or A-pattern strabismus after surgery for intermittent exotropia but with no pre- or postoperative oblique muscle dysfunction were reviewed retrospectively. Ductions, versions, angles of deviation, and fundus torsion were evaluated before and after surgery. Patient management and outcomes were analyzed.

RESULTS

A total of 37 patients were identified (mean age, 5.7 ± 1.5 years), with a mean preoperative deviation of 30.6^Δ ± 5.2^Δ; no patient had a preoperative pattern strabismus. Mean bilateral lateral rectus recession was 6.2 ± 0.9 mm. Of the 37, 34 (89%) returned postoperatively with V pattern, 2 with an A pattern, and 1 with an hourglass-like pattern. No patient showed oblique muscle dysfunction or fundus torsion. Reoperation for the consecutive deviation was performed in 19 patients, in all of whom the lateral rectus muscles were not vertically displaced. The pattern disappeared completely after reoperation and reestablishment of adequate alignment in the primary position.

CONCLUSIONS

In our patient cohort, pattern strabismus after bilateral lateral rectus recession was successfully reversed by correction of the consecutive esodeviation.

Exotropic heavy eye syndrome in unilateral high axial myopia

PURPOSE

To describe a pattern of combined exotropia and hypotropia in patients with unilateral high myopia and to suggest a surgical approach for their management.

METHODS

In this observational study of 13 patients presenting with unilateral combined exotropia and hypotropia with high axial myopia in the deviating amblyopic eye, cycloplegic refraction, visual acuity, ocular motility, and orbital imaging findings were evaluated. For patients who had undergone surgery, the intraoperative findings and their surgical outcome were also analyzed.

RESULTS

Median age at presentation was 27 ± 14.6 years. In the deviated eyes, mean spherical equivalent was -13.6 ± 9 D; mean axial length, 28.3 ± 1.7 mm. The mean preoperative horizontal and vertical angles of deviation in primary gaze were 46.5 ± 12.1^Δ (range, 25-60) and 21.1 ± 6.5^Δ (range, 15-35), respectively. All patients had a V pattern, with limitation of elevation in abduction. Magnetic resonance imaging revealed no evident displacement of the lateral rectus muscles in all cases. Six patients (46%) had surgical intervention. In 5 cases, the lateral rectus was displaced inferiorly by a mean of 2.5 mm (range, 2-4 mm) and was recessed and transposed 8 mm upward. The muscle was then fixated to the sclera with a nonabsorbable polyester suture 2-4 mm behind its new insertion. Successful surgical outcome was achieved in 5 cases (83%).

CONCLUSIONS

Combined exotropia and hypotropia associated with high myopia shows an overlap in the clinical presentation of the heavy eye syndrome. Although not evident radiologically, downward displacement of lateral rectus muscle was documented intraoperatively.

Medial transposition of a split lateral rectus muscle in synergistic divergence

Synergistic divergence is a rare congenital ocular motility disorder characterized by paradoxical abduction during attempted horizontal gaze to the contralateral side. It is generally unilateral and associated with limited adduction of the affected eye and large-angle exotropia in primary position. Various surgical techniques have been used to manage this condition, with limited success. We describe our experience using splitting and medial transposition of the lateral rectus muscle on the affected side to treat an 18-month-old girl with synergistic divergence. Postoperative improved motor alignment remained stable through 6 months' follow-up.

Outcomes and Complications Rate of Resident versus Attending Performed Eye Muscle Surgeries

Purpose: to compare the type, complications rate, and success rate of eye muscle surgeries performed by residents to those performed by attending consultants. Methods: A retrospective review was done on the charts of all children who underwent an eye muscle surgery in Cairo University Hospital during the period from January 2015 to December 2017. Preoperative data including age, sex, and type of deviation were tabulated. Details of the operative procedure including the surgeon, the type of eye muscle surgery, the number of muscles operated upon, perioperative complications, and the final ocular alignment at the end of the third month after surgery were recorded. Results: A total of 319 patients were included; 143 patients (315 muscles) in the supervised resident group and 176 patients (387 muscles) in the attending group. More vertical and oblique muscles surgeries were done by the attending consultants than by residents. Surgical success after three months was higher in the attending group (n = 126, 72%) than the resident group (n = 91, 64%). However, the difference was not statistically significant (P = .129). The perioperative complications rate was significantly higher (P = .004) in the resident group (14%) than the attending group (6%). Accidental scleral perforation was the most commonly encountered complication in the resident group (n = 6, 1.9%) followed by extruded/exposed Tenon (n = 5, 1.6%), and muscle slippage (n = 4, 1.3%). Conclusions: Success rate is similar in eye muscle surgeries performed by residents and attending consultants. However, perioperative complications are still more common among residents.

Torsional Changes After Vertical Transposition of Horizontal Recti in V-pattern Exotropia Without Oblique Dysfunction

PURPOSE

To evaluate pattern collapse and torsional changes following vertical transposition of horizontal recti in patients with V-pattern exotropia and no oblique dysfunction.

METHODS

A prospective study was performed on patients who had V-pattern exotropia and no oblique dysfunction. Lateral recti were transposed upward half-tendon width in V-pattern of 25 prism diopters (PD) or less (n = 14) and full-tendon width in V-pattern of greater than 25 PD (n = 10). Amblyopic patients had unilateral lateral rectus recession with upward transposition and medial rectus resection with downward transposition (n = 8). Ductions, versions, pattern strabismus, disc foveal angle, and astigmatic axis were analyzed before and 6 months after surgery.

RESULTS

In the 32 patients (21 females), the mean age was 8.25 ± 1.23 years. Only amblyopic patients showed preoperative fundus extorsion (mean disc foveal angle = 16.9°, P < .01). Mean pattern collapse was 13.1 ± 3.8 PD with half-tendon transposition, 35.6 ± 13.7 PD with full-tendon transposition, and 13.8 ± 7.9 PD in the unilateral group. Pattern collapse increased gradually so that pattern normalization occurred after 6 months in most patients. There was a statistically significant correlation between the preoperative V-pattern and the magnitude of pattern collapse after surgery (r = 0.80, P < .01). There were no significant changes in the mean disc foveal angle (< 0.5°) or axis of astigmatism (< 0.5°) in all three groups.

CONCLUSIONS

Vertical transposition of horizontal muscles can correct V-pattern exotropia, although the effect might not be immediate. Torsional changes are minimal. Amblyopic patients with V-pattern exotropia showed a preoperative extorsion that did not change after surgery. [J Pediatr Ophthalmol Strabismus. 2019;56(2):107-115.].

Factors associated with early and late failure after goniotomy for primary pediatric glaucoma

Purpose:

To analyze the risk factors associated with early and late failure after goniotomy for primary pediatric glaucoma.

Methods:

A retrospective study was done on infants who underwent goniotomy as the initial surgical procedure for primary pediatric glaucoma, and had a follow-up period ⩾48 months after surgery. Early and late failures were defined as intraocular pressure ⩾18 mmHg or signs of glaucoma progression before and after the end of first year, respectively.

Results:

A total of 81 eyes of 47 children were included. The mean age at the time of surgery was 6.1 ± 6.7 months, 34 children (72.3%) were bilateral. The mean follow-up was 5.9 ± 2.8 years. Of the included eyes, 41 eyes (50.6%) showed success, 25 eyes (30.9%) showed an early failure, and 15 eyes (18.5%) showed a late failure. The mean survival time was 43 months. However, only surgery before the end of the first month and positive consanguinity of the parents (P < 0.01 for both) were independent risk factors for early and late failure of goniotomy for primary pediatric glaucoma. Patients with late failure showed a statistically significant lower preoperative intraocular pressure (P = 0.02). A larger preoperative corneal diameter and a male gender were associated with higher but statistically insignificant failure rates. There were no differences in the early or late failure rates between unilateral and bilateral cases.

Conclusion:

A positive consanguinity of the parents and surgery before the end of the first month are the major predictors of failure of goniotomy.

The effect of flap thickness on corneal biomechanics after myopic laser in situ keratomileusis using the M-2 microkeratome

Purpose

The purpose of this study was to determine the effect of flap thickness on corneal biomechanics after myopic laser in situ keratomileusis (LASIK).

Methods

This is a prospective controlled non-randomized, institutional study. Patients underwent either epi-LASIK with mitomycin (advanced surface ablation [ASA]), thin-flap LASIK (90 µm head), or thick-flap LASIK (130 µm head). In ASA, the Moria Epi-K hydroseparator was used. LASIK flaps were created using the Moria M-2 mechanical microkeratome. The corneal hysteresis (CH) and corneal resistance factor (CRF) were measured preoperatively and 3 months after surgery, using the Ocular Response Analyzer^®.

Results

Ten patients (19 eyes) underwent ASA, 11 patients (16 eyes) underwent thin-flap LASIK, and 11 patients (16 eyes) underwent thick-flap LASIK. The mean preoperative CH was 10.47±0.88, 10.52±1.4, and 11.28±1.4 mmHg (p=0.043), respectively, decreasing after surgery by 1.75±1.02, 1.66±1.00, and 2.62±1.03 mmHg (p=0.017). The mean reduction of CH per micron of central corneal ablation was 0.031, 0.023, and 0.049 mmHg/µm (p=0.005). Mean preoperative CRF was 10.11±1.28, 10.34±1.87, and 10.62±1.76 mmHg (p=0.66), decreasing after surgery by 2.33±1.35, 2.77±1.03, and 2.92±1.10 mmHg (p=0.308). The mean reduction of CRF per micron of central corneal ablation was 0.039, 0.040, and 0.051 mmHg/µm (p=0.112).

Conclusion

Thick-flap LASIK caused a greater reduction of CH and CRF than thin-flap LASIK and ASA, although this was statistically significant only for CH. ASA and thin-flap LASIK were found to be biomechanically similar.

Synergistic divergence: case series and literature review

Background

To present the data of a series of patients with synergistic divergence, to propose a different modality of surgical correction and to perform a literature review of such a rare entity.

Methods

A retrospective study was performed on all patients who presented with unilateral or bilateral synergistic divergence to the Ophthalmology Department, Cairo University, during the period from January 2007 to July 2016. The demographic data, the results of sensorimotor examination, the surgical procedures performed and the ophthalmological as well as the systemic findings of all patients were collected and tabulated. PubMed was searched for patients with features of synergistic divergence.

Results

Thirteen patients with features of synergistic divergence were identified. The mean age of the patients was 8.9±10.1 years (range 1–40 years). Only one case was orthotropic in the primary position. Lateral rectus orbital wall fixation combined with 8–10 mm medial rectus resection was done in 10 patients. The mean follow-up was 6.6±7.7 months. Exotropia was significantly reduced in all patients. All patients had complete disappearance of synergistic divergence after surgery. A total of 78 patients with features of synergistic divergence were identified from PubMed. Surgery was done for 37 patients. Synergistic divergence disappeared in patients who had lateral rectus extirpation or orbital wall fixation.

Conclusion

Synergistic divergence is a challenging rare condition. We propose that lateral rectus orbital wall fixation combined with medial rectus resection both improves the alignment in primary position and eliminates the synergistic divergence in such patients.

Progression of High Anisometropia in Children

PURPOSE

To investigate the onset and rate of progression of high anisometropia in myopic children younger than 13 years.

METHODS

A retrospective study was performed on children with anisometropia younger than 13 years with myopia of more than 4.00 diopters (D) in the more ametropic eye and a difference in spherical equivalent refraction of 4.00 D between both eyes. All children had a complete ophthalmologic examination, including measurement of visual acuity and cycloplegic refraction every 3 to 6 months for at least 5 years. Change in the spherical equivalent and the cylindrical error for both eyes and changes in the difference in spherical equivalent refraction between both eyes were calculated for each patient at each visit. Linear, polynomial, logarithmic, and exponential fitting models were tested for both eyes and for the anisometropic difference between both eyes. The regression line with the greatest R² value was considered best fit.

RESULTS

Sixty-three patients fulfilled the inclusion criteria. The more ametropic eye grew in a regular fashion during the first 2 years of life, followed by a rapid decrease in the rate of growth to become almost stable after 4 years of age. The increase in myopia best fit a third-degree polynomial (cubic) model (R² = 0.98). The less ametropic eye showed only a small increase in myopia during the follow-up period. The anisometropic difference between both eyes increased gradually during the first 2 years, then remained stable.

CONCLUSIONS

High anisometropic myopia progresses rapidly in the first few years of life before becoming stable. [J Pediatr Ophthalmol Strabismus. 2017;54(5):282-286.].

Comparison between medial rectus pulley fixation and augmented recession in children with convergence excess and variable-angle infantile esotropia

PURPOSE

To compare the outcomes of medial rectus (MR) muscle pulley fixation and augmented recession in children with convergence excess esotropia and variable-angle infantile esotropia.

METHODS

This was a prospective randomized interventional study in which children with convergence excess esotropia or variable-angle infantile esotropia were randomly allocated to either augmented MR muscle recession (augmented group) or MR muscle pulley posterior fixation (pulley group). In convergence excess, the MR recession was based on the average of distance and near angles of deviation with distance correction in the augmented group, and on the distance angle of deviation in the pulley group. In variable-angle infantile esotropia, the MR recession was based on the average of the largest and smallest angles in the augmented group and on the smallest angle in the pulley group. Pre- and postoperative ductions, versions, pattern strabismus, smallest and largest angles of deviation, and angle disparity were analyzed.

RESULTS

Surgery was performed on 60 patients: 30 underwent bilateral augmented MR recession, and 30 underwent bilateral MR recession with pulley fixation. The success rate was statistically significantly higher (P = 0.037) in the pulley group (70%) than in the augmented group (40%). The postoperative smallest and largest angles and the angle disparity were statistically significantly lower in the pulley group than the augmented group (P < 0.01).

CONCLUSIONS

Medial rectus muscle pulley fixation is a useful surgical step for addressing marked variability of the angle in variable angle esotropia and convergence excess esotropia.

Surgical management of monocular elevation deficiency combined with inferior rectus restriction

PURPOSE

To evaluate the results of ipsilateral inferior rectus (IR) recession, when performed alone or in combination with contralateral superior rectus (SR) recession in patients with monocular elevation deficiency (MED) and IR tightness.

METHODS

The medical records of patients with MED and tight IR muscle were retrospectively reviewed. Patients underwent either ipsilateral IR recession alone (IR group) or combined with contralateral SR recession (IR+SR group). Pre- and postoperative ocular motility and alignment and fundus torsion were analyzed. Abnormal head posture was recorded. All patients were followed for at least 6 months.

RESULTS

A total of 23 patients were identified. Mean patient age at time of surgery was 9.8 ± 8.7 years (range, 3-45 years). Ten patients underwnet ipsilateral IR recession 5-8 mm; 13 patients, 4 mm ipsilateral IR recession combined with 5-12 mm contralateral SR recession. Both groups experienced marked improvement in ocular alignment in the primary position (P = 0.34). However, there was a statistically better ocular alignment in both upgaze (P = 0.03) and downgaze (P < 0.01) in the IR+SR group, with a lower degree of fundus intorsion (P < 0.01). An ipsilateral head tilt developed in 70% of patients in the IR group and in 54% of patients in the IR+SR group.

CONCLUSIONS

In this patient cohort, combined contralateral SR recession with ipsilateral IR recession reduced postoperative IR underaction and achieved better ocular alignment in upgaze and downgaze.

Lateral rectus recession with/without transposition in V-pattern exotropia without inferior oblique overaction

OBJECTIVE

To compare bilateral lateral rectus (BLR) recession with BLR recession combined with half-tendon upward transposition in the management of patients with V-pattern exotropia (XT; 15-20 prism diopters [PD] greater XT in upgaze than downgaze) with no or minimal inferior oblique overaction.

DESIGN

Retrospective, observational, cohort study.

PARTICIPANTS

Twenty-nine patients had BLR recession (Group A). Twenty-one patients had BLR recession combined with half-tendon upward transposition (Group B).

METHODS

A retrospective study was performed on patients with V-pattern XT with no or minimal inferior oblique overaction. Ductions, versions, pattern strabismus, stereoacuity, and degree of fundus torsion were analyzed in all patients before and after surgery. Patients were included in the study only if they achieved a minimum follow-up of 6 months.

RESULTS

Normalization of V pattern (<5Δ) was achieved in 14% in Group A and 64% in Group B (p < 0.001). Mean reduction in V pattern after surgery was 7Δ ± 6Δ in Group A and 13Δ ± 4Δ in Group B (p < 0.001). No change in fundus intorsion occurred in Group A, whereas fundus extorsion occurred in 8 patients (44%) in Group B. Orthophoria within 8Δ in the primary position was achieved in 79% in Group A and 82% in Group B (p = 1.00). There was no statistically significant difference in the postoperative stereoacuity in both groups (p = 0.67).

CONCLUSIONS

BLR with half-tendon upward transposition is much more effective than BLR recession alone in correcting V pattern.

Management of large V-pattern exotropia with minimal or no inferior oblique overaction

PURPOSE

To compare the outcomes of patients with large V-pattern exotropia and minimal inferior overaction who underwent bilateral lateral rectus recession combined with full-tendon-width upward transposition of the lateral rectus muscles or bilateral inferior oblique myectomy.

METHODS

The medical records of consecutive patients with V-pattern exotropia (at least 20(Δ) greater in upgaze than in downgaze) with minimal inferior oblique overaction who underwent either of the above procedures and who had at least 6 months' follow-up were retrospectively reviewed. Pre- and postoperative ductions, versions, pattern strabismus, stereoacuity and fundus torsion were analyzed. Success was defined as esophoria <8(Δ)/tropia ≤5(Δ) to exophoria/tropia ≤8(Δ) in primary gaze.

RESULTS

A successful outcome was achieved in 9 patients (56%) in the transposition group and 13 (72%) in the myectomy group (P = 0.48). Reduction of V pattern to <10(Δ) was achieved in 7 cases (44%) in the transposition group and 14 (78%) in the myectomy group (P = 0.04), with mean reductions of 16(Δ) ± 5(Δ) and 25(Δ) ± 5(Δ), respectively (P = 0.03). In the myectomy group, 4 patients (22%) had overcorrection with consecutive A patterns of 2(Δ)-6(Δ).

CONCLUSIONS

In patients with a V pattern exotropia and minimal inferior oblique over action, bilateral lateral rectus recessions plus bilateral inferior oblique myectomy can successfully eliminate the V pattern but the surgery may occasionally result in overcorrection with consecutive A pattern.

ICL versus Veriflex phakic IOL for treatment of moderately high myopia: randomized paired-eye comparison

PURPOSE

To compare the objective and subjective outcome of implantable collamer lenses (ICLs; Staar Surgical, Monrovia, CA) versus Veriflex lenses (AMO, Santa Ana, CA) for the correction of moderately high myopia.

METHODS

A prospective randomized comparative eye study was performed on 24 patients with bilateral myopia that ranged from -6 to -14.5 diopters (D). One eye was implanted with an ICL and the other eye was implanted with a Veriflex phakic intraocular lens (PIOL). Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), higher-order aberrations (HOAs), contrast sensitivity, patient satisfaction, central endothelial cell count, and PIOL centration were determined 6 months after surgery

RESULTS

The logMAR UDVA and CDVA improved significantly in both groups (P < .001). There was no statistically significant difference in postoperative logMAR UDVA (P = .41) or logMAR CDVA (P = .36) between the two groups. Postoperative deviation from target refraction was -0.06 ± 0.41 D in the ICL group and -0.07 ± 0.49 D in the Veriflex group (P = .15). The difference in both induced and absolute postoperative HOAs between groups was not statistically significant. The area under the log contrast sensitivity function increased significantly in both groups postoperatively. The difference in patient satisfaction between both PIOLs was not statistically significant. A higher but statistically insignificant central endothelial cell count loss occurred in the Veriflex group (P = .11).

CONCLUSION

Both ICL and Veriflex PIOLs have equally satisfactory objective and subjective visual outcomes after surgery.

Inferior oblique myectomy for upshoots mimicking inferior oblique overaction in Duane retraction syndrome

PURPOSE

To evaluate the results of inferior oblique myectomy in selected patients with Duane retraction syndrome with upshoot on adduction.

METHODS

This was a prospective, interventional study of consecutive patients with types 1, 2, or 3 Duane syndrome with isolated upshoot in adduction operated on from January 2007 to December 2011. Patients underwent inferior oblique myectomy on the side of the upshooting eye. Only patients with gradual elevation of the eye in adduction in a pattern similar to inferior oblique overaction or patients with hypertropia in the primary position were included. All patients were followed for at least 6 months. Ductions, versions, degree of upshoot, degree of fundus torsion, and pattern of strabismus were analyzed in all patients before and after surgery.

RESULTS

A total of 11 patients were included in the study. Mean patient age at time of surgery was 6.4 ± 5.2 years (range, 3-22 years). Two patients had bilateral inferior oblique myectomy and 4 had simultaneous bilateral medial rectus muscle recession to correct horizontal misalignment. Mean duration of follow-up was 8.6 months (range, 6-36 months). Of the 11 patients, 10 (91%) had complete disappearance of the upshoot at last follow-up. None of the patients developed inferior oblique underaction postoperatively. There was a statistically significant improvement of V pattern after surgery (P < 0.01). Mean vertical misalignment in primary position was 5(Δ) before surgery and 1(Δ) after (P = 0.02). Most patients had no significant fundus torsion before or after surgery.

CONCLUSIONS

Inferior oblique muscle weakening can improve upshoot in selected patients with Duane retraction syndrome without inducing inferior oblique muscle underaction.

Polypropylene vs silicone Ahmed valve with adjunctive mitomycin C in paediatric age group: a prospective controlled study

PURPOSE

To compare the results of silicone and polypropylene Ahmed glaucoma valves (AGV) implanted during the first 10 years of life.

METHODS

A prospective study was performed on 50 eyes of 33 patients with paediatric glaucoma. Eyes were matched to either polypropylene or silicone AGV. In eyes with bilateral glaucoma, one eye was implanted with polypropylene and the other eye was implanted with silicone AGV.

RESULTS

Fifty eyes of 33 children were reviewed. Twenty five eyes received a polypropylene valve, and 25 eyes received a silicone valve. Eyes implanted with silicone valves achieved a significantly lower intraocular pressure (IOP) compared with the polypropylene group at 6 months, 1 year, and 2 years postoperatively. The average survival time was significantly longer (P=0.001 by the log-rank test) for the silicone group than for the polypropylene group and the cumulative probability of survival by the log-rank test at the end of the second year was 80% (SE: 8.0, 95% confidence interval (CI): 64-96%) in the silicone group and 56% (SE: 9.8, 95% CI: 40-90%) in the polypropylene group. The difference in the number of postoperative interventions and complications between both groups was statistically insignificant.

CONCLUSION

Silicone AGVs can achieve better IOP control, and longer survival with less antiglaucoma drops compared with polypropylene valves in children younger than 10 years.

A computerized version of the Lancaster red-green test

PURPOSE

To compare results from a computerized version of the Lancaster red-green test with those of the conventional test.

METHODS

Consecutive adult patients with noncomitant strabismus were tested with the conventional Lancaster red-green test and with a computerized version of the same. The computerized test was administered by means of a 40-inch monitor at a working distance of 50 cm or a projector and screen at a working distance of 1 meter. Agreement between the measured horizontal, vertical, and torsional deviations in the conventional test and both computerized versions was evaluated with the mountain plot, Bland-Altman plot, and Deming regression analysis models.

RESULTS

A total of 82 patients were tested. Agreement of measured horizontal deviation in the conventional test was better with the projector version of the test (limits of agreement: right eye, -4.6(Δ) to 3.4(Δ); left eye, -4.9(Δ) to 3.5(Δ)) than the monitor version (limits of agreement: right eye, -10(Δ) to 4.2(Δ); left eye, -8.9(Δ) to 4.1(Δ)). The measured vertical and torsional deviation in the conventional test showed good agreement with both versions of the computerized test (limits of agreement <5(Δ) for vertical measurements and <3° for torsional measurements). Agreement was similar for right and left eyes.

CONCLUSIONS

The vertical and torsional deviations measured with both computerized versions of the test were in good agreement with those obtained with the conventional test. For measured horizontal deviations, the projector version had better agreement than the monitor version.

Clinical findings, orbital imaging, and intraoperative findings in patients with isolated inferior rectus muscle paresis or underaction

PURPOSE

To present the clinical findings, orbital imaging, and intraoperative findings of patients with inferior rectus muscle underaction and to determine whether specific findings can help discern the underlying cause.

METHODS

A retrospective observational study was performed on patients presenting with isolated inferior rectus muscle underaction between January 2007 and October 2011. Patient history, ocular motility, fundus torsion, Lancaster red-green plots, and radiographic findings were analyzed. For patients who had surgery, intraoperative findings also were considered.

RESULTS

A total of 28 patients with inferior rectus muscle underaction were identified. Of these, 13 (46%) presented with inferior rectus muscle underaction after orbital trauma; 25 (89%) showed no increase in hypertropia >4(Δ) on head tilt to either side. Fundus intorsion was present in all patients. Of 15 patients evaluated by Lancaster red-green testing, 12 (80%) showed subjective intorsion. Twenty patients underwent orbital imaging via computed tomography or magnetic resonance imaging, and the results in 8 (40%) revealed obvious changes in the inferior rectus muscle. Nineteen patients underwent surgery; intraoperatively, the muscle appeared grossly normal in 8 patients (42%) and showed posterior muscle slippage in 4 (26%). Less common findings included stretched scar formation, flap tear, missing tissue, extensive muscle adhesions, or inability to identify the muscle.

CONCLUSIONS

Clinical findings in patients with inferior rectus muscle underaction are not sufficiently different to identify the cause, and orbital imaging identified a specific abnormality in only 40% of cases.

Changes in binocular function in anisometropic nonstrabismic children with optical correction and occlusion therapy

PURPOSE

To identify factors that influence binocular function in anisometropic, nonstrabismic children before and after optical correction and amblyopia therapy.

METHODS

This was a prospective observational study of consecutive patients with nonstrabismic anisometropia. Visual acuity and responses to the 4(Δ) base-out prism test, the Worth 4-dot test, and the TNO test were recorded after spectacle correction and every 3 months for 1 year. Factors affecting visual acuity and binocular function were analyzed using univariate and multiple stepwise regression analysis.

RESULTS

A total of 118 subjects were enrolled. At the end of the first year, the mean improvement in visual acuity was 2.6 ± 2.3 lines. The percentage of patients showing a positive response to the 4(Δ) base-out prism test increased from 47% to 79%; fusion in the Worth 4-dot test, from 37% to 66%; and measurable stereopsis on TNO testing, from 59% to 80%. Better initial visual acuity and better final visual acuity were associated with better binocular function. Interocular refractive error difference was a predictor of poor binocular function in multiple regression analysis if the difference in spherical error exceeded 4 D. Patients with amblyopia showed significantly worse binocular function compared to those with no amblyopia.

CONCLUSIONS

Binocular function of anisometropic children can be improved with refractive correction and amblyopia therapy.

Evaluation of intralesional propranolol for periocular capillary hemangioma

BACKGROUND

The purpose of this study was to evaluate the use of intralesional propranolol injection in the management of periocular capillary hemangioma.

METHODS

A prospective study was performed in 22 consecutive patients with periocular hemangioma. Twelve patients underwent intralesional propranolol injection and ten patients underwent intralesional triamcinolone injection. The size of the lesion was measured serially every week during the first month, every 2 weeks for the second month, and then monthly for another 2 months. The refractive error and degree of ptosis if present were measured before injection and at the end of the study.

RESULTS

There was reduction in the size of hemangioma, astigmatic error, and degree of ptosis in both groups. The difference in outcome between both groups was not statistically significant. Rebound growth occurred in 25% of the propranolol group and 30% of the steroid group but responded to reinjection. No adverse effects were reported during or after intralesional propranolol injection.

CONCLUSION

Intralesional propranolol injection is an alternative and effective method for treatment of infantile periocular hemangioma.

Adjustable suture strabismus surgery in infants and children

PURPOSE

To evaluate the success rate of adjustable suture techniques in horizontal eye muscle surgery in children aged 10 years and younger.

METHODS

A retrospective review of children who had horizontal eye muscle surgery at or before the age of 10 years. Patients were divided into 1 of 2 groups according to whether a nonadjustable or an adjustable technique was used. The preoperative measurements, type of strabismus, and postoperative results were analyzed.

RESULTS

A total of 98 cases in the nonadjustable group and 298 cases in the adjustable group were identified. Early success rate, defined as alignment within 8(Delta) of straight at the end of 3 months, was notably greater in the adjustable group (79%) than in the nonadjustable group (64.5%). The difference was statistically significant (p < 0.01). In the adjustable group, adjustment was performed in 64% of the cases, either because of an undercorrection or overcorrection. The adjustment procedure was performed under topical proparacaine in 20% of cases and under intravenous propofol in 80%. No complications were reported during the adjustment procedure.

CONCLUSIONS

The use of adjustable sutures can provide an improved success rate over nonadjustable sutures in eye muscle surgery in children aged 10 years or younger.

Bilateral inferior oblique myectomy for asymmetric primary inferior oblique overaction

PURPOSE

To evaluate the effects of bilateral symmetric inferior oblique myectomy on the symmetry of versions of patients with bilateral asymmetric primary inferior oblique overaction.

METHODS

A prospective interventional study was performed on 32 consecutive patients with bilateral asymmetric inferior oblique overaction. All patients were treated with bilateral symmetric inferior oblique myectomy. The versions, degree of inferior oblique overaction, and degree of fundus torsion were analyzed in all patients before and after surgery. Patients were included in the study only if they achieved a minimum follow-up of 6 months.

RESULTS

There was marked improvement in the degree of the inferior oblique overaction in all patients. Eighty-one percent of the patients had no residual inferior oblique overaction on either side by the end of the 6-month follow-up period. None of the patients developed clinically significant inferior oblique underaction. Consequently, there was marked improvement in the comitance of the versions. None of the patients developed significant A or V pattern after surgery.

CONCLUSIONS

In the presence of asymmetric inferior oblique overaction, bilateral symmetric inferior oblique myectomy may have a "symmetrizing" effect on the inferior oblique overaction and greatly improve the comitance of the versions.

The retinal ciliopathies

While the functions of many of the proteins located in or associated with the photoreceptor cilia are poorly understood, disruption of the function of these proteins may result in a wide variety of phenotypes ranging from isolated retinal degeneration to more pleiotropic phenotypes. Systemic findings include neurosensory hearing loss, developmental delay, situs-inversus, infertility, disorders of limb and digit development, obesity, kidney disease, liver disease, and respiratory disease. The concept of "retinal ciliopathies" brings to attention the importance of further molecular analysis of this organelle as well as provides a potential common target for therapies for these disorders. The retinal ciliopathies include retinitis pigmentosa, macular degeneration, cone-dystrophy, cone-rod dystrophy, Leber congenital amaurosis, as well as retinal degenerations associated with Usher syndrome, primary ciliary dyskinesia, Senior-Loken syndrome, Joubert syndrome, Bardet-Biedl syndrome, Laurence-Moon syndrome, McKusick-Kaufman syndrome, and Biemond syndrome. Mutations for these disorders have been found in retinitis pigmentosa-1 (RP1), retinitis pigmentosa GTPase regulator (RPGR), retinitis pigmentosa GTPase regulator interacting protein (RPGR-IP), as well as the Usher, Bardet-Biedl, and nephronophthisis genes. Other systemic disorders associated with retinal degenerations that may also involve ciliary abnormalities include: Alstrom, Edwards-Sethi, Ellis-van Creveld, Jeune, Meckel-Gruber, Orofaciodigital Type 9, and Gurrieri syndromes. Understanding these conditions as ciliopathies may help the ophthalmologist to recognize associations between seemingly unrelated diseases and have a high degree of suspicion that a systemic finding may be present.

"Inverted Brown pattern": a tight inferior oblique muscle masquerading as a superior oblique muscle underaction--clinical characteristics and surgical management

PURPOSE

To characterize, and evaluate the surgical management of, patients with unilateral deficiency of depression in adduction, suggesting superior oblique muscle underaction, without significant ipsilateral inferior oblique muscle overaction.

METHODS

Such patients were identified who also had received either ipsilateral inferior oblique (IO) muscle weakening or contralateral inferior rectus muscle recession. Their histories, motility patterns, intraoperative findings, types of strabismus surgery, and postoperative results were analyzed.

RESULTS

Twelve patients were identified with unilateral deficiency of depression in adduction, with no or minimal ipsilateral IO muscle overaction. Three of these patients (25%) had previously had surgery for Brown syndrome. Four (33%) had prior orbital floor trauma. On exaggerated forced duction testing recorded for nine patients, a tight IO muscle was recorded in 78%, with no laxity of the superior oblique tendon. Four patients (33%) underwent contralateral inferior rectus muscle recession, but in all four the deficiency of depression in adduction recurred. The other eight (67%) had an IO muscle weakening procedure and achieved overall improvement of ocular alignment. Nine subsequent patients with a similar pattern of misalignment were each managed with an IO weakening procedure, with good results.

CONCLUSIONS

This motility pattern, which we are calling an "inverted Brown pattern," is caused by a tight or inelastic IO muscle. In such cases, IO muscle weakening yields better results than contralateral inferior rectus muscle recession, even though there is no significant IO muscle overaction preoperatively.