Acute onset comitant esotropia (AOCE) is a rare ophthalmic complication associated with opiate withdrawal. As the prevalence of opioid use disorder remains high, it is critical for clinicians to recognize this condition as a differential diagnosis for acute diplopia in adults, especially after ruling out emergent neurological pathologies. This case report details the clinical presentation, diagnostic workup, and management of AOCE secondary to acute heroin withdrawal in a 34-year-old male. The patient reported the sudden onset of constant, horizontal diplopia three days after stopping heroin use. An initial outside consultation three weeks after onset measured a 25 prism diopter (PD) esotropia. Upon presentation to our clinic, his deviation had reduced, and a comprehensive workup, including magnetic resonance imaging (MRI) and angiography (MRA), was performed to rule out intracranial pathology. All were found to be unremarkable. The patient’s symptoms were managed with a temporary 12 PD base-out Fresnel prism, and his esotropia and diplopia spontaneously and completely resolved over the following three weeks. Opiate withdrawal-induced AOCE is theorized to result from a reversible disuse atrophy of the motor fusion system. Chronic opiate-induced miosis decreases accommodative demand; acute withdrawal causes a relative parasympatholytic state (mydriasis), increasing accommodative demand that the atrophied motor fusion system cannot meet with appropriate divergence, resulting in esotropia. This patient’s history of uncorrected hyperopia and convergence excess likely predisposed him to this condition. This case highlights that acute esotropia following opiate withdrawal is a transient condition where a thorough history is paramount, allowing for conservative management and avoiding unnecessary procedures.

PurposeTo evaluate the clinical outcomes and safety of the Nishida muscle transposition procedure performed without tenotomy or muscle splitting in patients with severe paralytic horizontal or vertical strabismus.MethodsThis retrospective case series included 16 patients with complete paralytic strabismus who underwent Nishida transposition between January 2020 and September 2021. Eleven patients had abducens nerve palsy and five had vertical paralytic strabismus (elevation or infraduction deficiency). The procedure involved scleral fixation of adjacent rectus muscles closer to the paralyzed muscle without tendon disinsertion, preserving anterior ciliary circulation and allowing simultaneous antagonist recession when indicated. Outcomes included ocular alignment in primary position, ocular motility, binocular single vision, and postoperative complications over a follow-up period of 5-15 months.ResultsIn abducens nerve palsy, combined transposition with medial rectus recession-performed using a standardized protocol based on preoperative deviation (6 mm for ≥80 prism diopters [PD] and 5 mm for <80 PD)-achieved a mean correction of 69.2 ± 12.8 PD, whereas isolated transposition resulted in a correction of 29 PD. In vertical paralytic strabismus, the mean correction was 38 ± 19.8 PD. All patients demonstrated improved duction beyond the midline postoperatively. Eight patients achieved binocular single vision in primary position and four with compensatory head posture. No anterior segment ischemia, induced secondary deviations, or other major complications were observed.ConclusionsThe Nishida procedure provides effective and safe correction of severe paralytic strabismus while preserving muscle insertions and anterior ciliary circulation. Its compatibility with simultaneous antagonist recession makes it a valuable single-stage approach for large-angle paralytic deviations.

To propose which tests may be used for diagnosing convergence excess. A prospective study of a consecutive clinical sample was performed. Patients (18–35 years) attending optometric care underwent subjective refraction, cover test, and Symptom Questionnaire for Visual Dysfunctions (SQVD). Based on cover test and SQVD scores, two groups were recruited: 64 symptomatic subjects with near esophoria and 64 asymptomatic with normal binocular vision. Accommodative and binocular tests were assessed, identifying those with significant statistical differences between groups. Diagnostic validity was analysed using ROC curves, sensitivity, specificity, and likelihood ratios. A serial testing strategy combining tests was also evaluated. ROC analysis showed best diagnostic accuracy for binocular accommodative facility (BAF) failing with −2.00 D (area under the curve, AUC = 0.865) and vergence facility (VF) failing with base-in prisms (AUC = 0.864). Using cutoffs from ROC analysis (BAF: ≤8.25 cpm and VF ≤ 12.75 cpm), their combination showed best validity (S = 0.625, Sp = 0.938, LR+ = 10, LR− = 0.4). The combined AUC was 0.932. The proposal for diagnosing convergence excess is to use, in addition to near esophoria with normal distance heterophoria, the combination of failing BAF with negative lenses and failing vergence facility with base-in prisms.

Comparison of the Nishida method and double-under muscle transposition in paralytic strabismus.

ABSTRACT To evaluate dynamic intraocular microvascular changes in vascular paralytic strabismus using optical coherence tomography angiography (OCTA) and choroidal vascularity index (CVI), and to assess their reversibility after clinical recovery. In this prospective study, 31 patients with acute-onset vascular paralytic strabismus involving the third, fourth, or sixth cranial nerve were enrolled. OCTA and enhanced depth imaging (EDI)-OCT were performed during the paralytic phase and after full recovery. Parameters included vessel density (VD) in the superficial (SCP) and deep capillary plexuses (DCP), foveal avascular zone (FAZ), choriocapillaris flow, CVI and peripapillary vessel density (ppVD). Inter-eye and inter-phase differences were analysed. Statistical analysis was performed using generalised estimating equations (GEE) to account for within-subject correlations between eyes. During the paralysis phase, the affected eyes showed significantly reduced VD in the SCP across all macular regions, while changes in the DCP were limited to the fovea (p < .001). The FAZ area was larger (p = .012), and CVI was lower (p < .001) in the affected eye. After clinical recovery, SCP VD, choriocapillaris flow, and CVI in the previously affected eyes increased significantly, while FAZ and non-flow area decreased (p < .001 for both). Intradisc ppVD also improved (p = .048). Retinal and choroidal thickness remained stable. Vascular paralytic strabismus causes reversible ischaemic alterations, primarily in the macular SCP and choroid. These findings support a functional vascular disturbance rather than structural damage. This is the first study to evaluate the CVI in this condition, highlighting the utility of OCTA and EDI-OCT as noninvasive tools for monitoring dynamic ocular perfusion alterations.

ABSTRACT Purpose To evaluate the effect of unilateral medial rectus (MR) recession for the correction of 20 to 30 ∆ of esotropia. Methods Pediatric patients with esotropia (ET) with a surgical target of 20 to 30 prism diopters (∆) were included in a prospective study to determine the effect of unilateral MR recession. The surgical target angle was calculated as the average of the distant angle with glasses and near without glasses, or the average of distant and near angles without glasses (if non-significant refractive error), or the average of near angles with and without glasses (if ET was measured using the modified Krimsky test). The study endpoint was the last follow-up visit, conducted at least 3 months postoperatively. A successful motor outcome was defined as orthotropia or a horizontal tropia of 10∆ or less at distance and near. Results The study included 21 patients, 1 to 12 years of age. Patients were followed up for 3 to 43 (mean+/-SD 12.5+/-10.6) months. A successful outcome was achieved in 85.7%, with no correlation to the surgical target angle or the amount of recession (p > .05). The 14.3% failure rate was attributed to undercorrections. Persistent lateral incomitance was observed in 10.5% of cases and was not correlated with the surgical target angle or the amount of recession (p > .05). Persistent limited ductions were mild (−1). Conclusions This prospective study of pediatric patients showed that unilateral MR recession is a reasonable surgical approach for treating esotropia of 20–30 ∆, with small rates of undercorrection and duction limitation, and no overcorrection.

PurposeTo compare the effectiveness of two distinct surgical methods for treating near-distance disparity (NDD) esotropia: fenestration and combined resection-recession of medial rectus (MR) muscle.MethodsThis retrospective study involved 44 patients with convergence excess esotropia who had been using their full cycloplegic refraction and/or bifocal glasses for at least 6 months and still had NDD esotropia. We compared results of two surgical techniques: Group I underwent fenestration of both medial recti muscles, which involved excising a central rectangle from the muscle insertion to a point 5–8 mm back, depending on the angle of the esotropia, while preserving the superior and inferior longitudinal muscle sleeves. Group II received a combined resection of both medial recti, 2.5 mm from the insertion, then recession based on near-angle esotropia, adding 1 mm of recession for each muscle. Satisfactory outcome was defined as deviation of ≤ 8 prism diopters within orthophoria and a reduction of NND to ≤ 8 prism diopters at 6-month follow-up.ResultsThere was statistically significant difference between both groups at 6-month follow-up. In Group I, 71.4% of patients achieved a NDD of ≤ 8 prism diopters, with 6 cases showed undercorrection. In Group II, 96% of cases achieved satisfactory results, with no undercorrection; one case had overcorrection resulting in consecutive exotropia.ConclusionFenestration technique showed inferior results to combined resection–recession. However, it offers good alternative to combined resection-recession as it is simple, suture-less and quick operation. Though, surgical doses may need to be revised in future studies.

The congenital dysferlinopathy phenotype is the rarest and earliest manifestation variant, described in two closely related Spanish and Turkish families, with a homozygous pathogenic frameshift variant in exon 26 of the DYSF gene.This article presents a 1.6-year-old patient from a consanguineous Uzbek family with a clinical diagnosis of congenital dysferlinopathy phenotype and Marinesco–Sjögren syndrome with transient postnatal hypotonia, motor development delay, muscle weakness in the flexors of the neck and proximal limbs, convergent strabismus, cerebellar truncal ataxia, minimal intention tremor of the upper limbs, a slight increase in the levels of creatinine phosphokinase (CK) to 353 U/L (2.4×N) and that of myoglobin to 40µg/mL (2×N).Magnetic resonance imaging (MRI) revealed pronounced edematous changes in the gastrocnemius muscle on short tau inversion recovery (STIR). MRI signs of minimal fat replacement and hypotrophy were noted in the medial and posterior thigh and gastrocnemius muscles. MRI of the head revealed hypoplasia of the vermis and cerebellar hemispheres. Whole-exome sequencing revealed compound heterozygous DYSF variants: NM_001130987.2:c.1000C > T (p.(Arg334Trp)) and NM_001130987.2:c.518C > T (p.(Thr173Met)), and a previously described homozygous SIL1 variant NM_022464.5:c.178G > T (p.(Glu60Ter)). Histopathological examination revealed minimal signs of myopathy and dysferlin in only 1% of the muscle fibers. At the ultrastructural level, signs of dysferlinopathy and Marinesco–Sjögren syndrome were detected.This clinical case is an example of the cosegregation of two diseases that mutually potentiate damage to skeletal muscles.

Strabismus Increases Glaucoma Risk in California Medicare Beneficiaries.

Sagging eye syndrome (SES) is an acquired strabismus characterized by distance esotropia (ET) and cyclo-vertical deviation, affecting older people. This study identified demographic, systemic, and ocular factors associated with SES and compared them to other forms of ET in older adults. Retrospective cohort study. Demographic data, systemic comorbidities, ocular history, and strabismus were reviewed in esotropic patients at least 55 years old diagnosed with SES between 2013 and 2024 at a single institution, and compared with age-matched controls diagnosed with other forms of ET. A total of 383 patients were studied, of whom 67 had SES, and 316 had ET without SES ET. Male SES patients were significantly older at 81.5 ± 10 years (standard deviation) than esotropic males without SES at 76 ± 10 years (P = .04), and symptom onset was significantly older for SES in both genders (male: 72 ± 10 years vs 68 ± 11 years, P = .02; female: 75 ± 9 years vs 69 ± 9 years, P = .04). Women with SES had significantly lower mean body mass index (BMI) at 23 ± 4 than esotropic women without SES at 25 ± 5 (P = .02). Logistic regression demonstrated that lower BMI was associated with higher odds of SES in women, with the odds of SES increasing by approximately 9.4% for each 1-unit decrease in BMI (odds ratios = 0.91, 95% confidence intervals [CI]: 0.84-0.99). Osteopenia was more prevalent at 77% among esotropic women with SES than women without osteopenia at 51% (P = .003), and remained an independent risk factor for SES after adjusting for age (odds ratios = 1.81, 95% CI: 1.02-3.23, P = .04) and BMI (95% CI, 1.14-6.18; P = .02). There were no significant differential associations with SES for gender, smoking, alcohol use, hypertension, hyperlipidemia, type 2 diabetes, cataract surgery, glaucoma, or use of progressive addition spectacles. SES is associated with advanced age at symptom onset in both genders and with lower BMI and osteopenia in women.

To evaluate the surgical outcomes of a combined modified Nishida's procedure with medial rectus (MR) recession augmented with lateral rectus (LR) plication in patients with long-standing complete sixth nerve palsy presenting with large-angle esotropia (ET). This retrospective interventional case series included three patients with chronic traumatic complete sixth nerve palsy and large-angle ET (70 to 75 prism diopters [PD]). Postoperatively, two patients achieved orthophoria at distance and near and one patient had a small residual ET of 5 PD at 6 months. The combination of modified Nishida's procedure with MR recession and LR plication appears to be an effective single-stage surgical approach for large-angle esotropia (approximately 70 PD) associated with complete sixth nerve palsy. The technique provides substantial alignment correction, improved abduction, resolution of diplopia, and a reduced risk of anterior segment ischemia compared to full-tendon vertical rectus transposition.

Acute acquired comitant esotropia (AACE) once considered rare, is now becoming more prevalent. Surgery in these cases can get delayed when the strabismus angle varies or if the patient is unwilling. In such cases optical management and vision therapy can be considered. We present the outcomes of such management for AACE. This retrospective study included a cohort of patients diagnosed with non-accommodative or non-neurological AACE, managed in our institute between January to October, 2023. Prisms were prescribed to patients experiencing constant double vision. All patients were given vision therapy exercises. Eso deviation and divergence range were measured pre and post therapy. Fourteen patients were included. Of these, 5 patients (with eso deviation ≤20PD) were relieved with vision therapy exercises alone. For the remaining 9 patients, prisms were prescribed along with vision therapy. Post-vision therapy, 2 patients could achieve binocular single vision without prisms, and in 4 patients the prism power was reduced. In the remaining 3, full prism correction was warranted, one of them opted for surgery. The median reduction in eso deviation by 6.5PD (range:2-25PD) and increase in divergence by 7PD (range:0-17PD) after vision therapy was significant (p < 0.03). Non-surgical intervention reduced the eso deviation in 79% (11/14) of patients. Certain types of AACE seem to be amenable to vision therapy and/or optical management. Temporary Fresnel prisms can be considered in majority of these patients and tapered away later, if their divergence range can be improved with vision therapy.

Purpose: We compared the surgical outcomes of medial rectus recession (MR Rc) and lateral rectus resection (LR Rs) in patients with divergence insufficiency esotropia, characterized by greater esotropia (ET) at distance than at near.Methods: This retrospective comparative study included 22 patients who underwent either MR Rc or LR Rs for divergence insufficiency esotropia, defined as comitant ET with &gt;8 prism diopters (PD) difference between distance and near, with persistent diplopia at distance. Surgical success was defined as final deviation &lt;8 PD with diplopia-free status at distance and near at 12 months postoperatively. The mean dose-response ratio (PD/mm) of each surgical technique was analyzed.Results: Of the 22 patients, 13 underwent MR Rc and 9 underwent LR Rs. The surgical success rate was higher in the LR Rs group than in the MR Rc group; however, the difference was not statistically significant (69% vs. 100%, &lt;i&gt;p&lt;/i&gt; = 0.11). In the MR Rc group, three patients had under-correction and one had over-correction. The mean dose-response ratio for distance was 2.43 ± 0.51 PD/mm at 1 week and 2.15 ± 0.93 PD/mm at 12 months, whereas for near it was 1.89 ± 0.83 and 1.69 ± 1.06 PD/mm, respectively. In the LR Rs group, all patients achieved surgical success. The mean dose-response ratio for distance was 1.96 ± 0.46 and 1.91 ± 0.51 PD/mm at 1 week and 12 months, whereas for near it was 1.23 ± 0.42 and 1.13 ± 0.52 PD/mm, respectively.Conclusions: Both surgical techniques demonstrated favorable outcomes for divergence insufficiency esotropia. However, the dose-response ratio was more predictable in LR Rs surgery. For MR Rc, augmented surgical approaches may be considered to improve predictability and success rates.

Strabismus and Strabismus Surgery Reoperation Rates at 1, 3, and 5 Years: Analyses from the IRIS® Registry (Intelligent Research in Sight).

The mitochondrial tRNALeu (MT-TL1) m.3243A > G mutation is one of the most frequent pathogenic variants in mtDNA which is associated with various clinical syndromes including Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes (MELAS). The onset of symptoms associated with the MT-TL1 mutation typically occurs in adolescence or early adulthood. Due to the diversity of its clinical presentation, there is a need to report all cases that do not fully meet the criteria of well-established clinical syndromes. This paper reports a case of a 3-year-old male patient with a complex perinatal history, whose symptoms emerged at 6months of age and included epileptic seizures, developmental delay, bilateral convergent strabismus, hypertonia, hyperreflexia, and radiological brain abnormalities. The family history is positive for epilepsy and hearing impairment in females on the maternal side. Genetic testing revealed a pathological variant in the MT-TL1 gene m.3243A > G with a high heteroplasmy level of 76.5% in the blood sample. The case presents an atypical manifestation of the m.3243A > G mutation, highlighting the importance of genetic screening for mitochondrial disorders in patients with a maternal family history.

To investigate the long-term surgical outcomes of augmented bilateral lateral rectus recession (BLRrec) for intermittent exotropia (XT). Patients treated with BLRrec for basic-type XT were divided into two groups. In the standard surgery group, the standard formula for BLRrec was used, whereas in the augmented surgery group, 1.0–1.5 mm was added bilaterally to the standard formula for BLRrec. Patients were followed up for 3 years. In total, 119 patients were enrolled, including 56 in the standard surgery group and 63 in the augmented surgery group. The success rate in the augmented surgery group was 44.4% at 3 years, which was higher than that in the standard surgery group (25.0%; P = .011). The incidence of consecutive esotropia (ET) was significantly higher in the augmented surgery group 1 year after surgery; however, the significance disappeared after 2 years. Immediate postoperative overcorrection in the standard surgery and augmented surgery groups was 14.8 prism dioptre (PD) ET and 21.0 PD (P < .001), respectively; moreover, the total exotropic drift at 3 years was 25.6 PD and 27.9 PD (P = .602), respectively. Augmented BLRrec showed better long-term surgical outcomes than standard BLRrec because of the larger immediate postoperative overcorrection. Although consecutive ET was more frequent in the augmented surgery group in the first year after surgery, it gradually resolved with conservative management.

Comitant exotropia in adults poses distinct surgical challenges and has been less extensively studied compared with paediatric cases. Evaluating surgical outcomes in this population can inform treatment approaches and help establish realistic expectations for patients and clinicians. Retrospective chart review of adults 18-60 years old who underwent surgery for comitant exotropia between 2014 and 2024 at a single institution. Patients were classified as intermittent (X(T)) or constant exotropia (XT) and divided into three groups: basic exotropia (BXT), divergence excess (DEXT) and convergence insufficiency (CIXT). Surgical motor success was defined as a postoperative deviation≤10 prism dioptres (PDs) and sensory success as resolution of diplopia. 165 patients (mean age 38.2±12.1 years, 50.3% male) were included. The mean preoperative deviation was 44.8±17.5 PD at distance and 48.3±20.1 PD at near. After initial surgery, the overall motor success was 62.4%, highest in BXT (69.4%), followed by CIXT (52.8%) and DEXT (50%) (p=0.08). Motor success was significantly higher in X(T) than XT (69.2% vs 52.2%, p=0.026), and in cases with adjustable sutures rather than non-adjustable (p=0.033), however, similar in unilateral recess-resect and bilateral lateral rectus recessions (62.7% vs 59.1%, p=0.81). Preoperative diplopia was present in 28.5% (47/165) and resolved in 89.4% (42/47). The final motor success was 66.7% after a second surgery in nine patients. The motor outcomes in adults are comparable to those reported in children. Higher motor success is found in X(T) and with the use of adjustable sutures. Surgical intervention provides relief of diplopia and meaningful gains in stereopsis.

Prism adaptation test (PAT) was shown to be an effective assessment for esotropia (ET) surgeries. However, the effectiveness of long-term PAT for ET remains uncertain. This study aimed to evaluate the effectiveness of the long-term PAT for patients with ET by comparing the preoperative deviations before PAT (simple PACT), after short-time PAT (15–30 min/set), and after long-term PAT (1–6 months). This prospective, longitudinal study enrolled 24 consecutive patients who underwent strabismus surgery for ET after long-term PAT. Ocular deviation was measured by prism and alternate cover test (PACT) at pre-PAT, post-short‑time PAT, and post-long‑term PAT. We analyzed the correlation between the effect of long-term PAT and preoperative parameters. The pre-PAT, post-short-time-PAT, and post-long-term-PAT deviations were 13.0 ± 5.2° (23.0 ± 9.0 Δ), 14.4 ± 5.9° (25.7 ± 10.4 Δ), and 15.8 ± 6.3° (28.2 ± 11.0 Δ), respectively. The post-long-term-PAT deviation was larger than that at pre-PAT (p = 0.001). Multivariable analysis revealed that the long-term PAT effect was correlated with PAT duration and short-time PAT effect. Our findings suggest that long-term PAT reveals latent deviation and is associated with surgical success in patients with ET. Future comparative studies with control groups are needed to validate these findings.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-34637-5.

Dear Editor, Strabismus, a prevalent ocular motility disorder, affects approximately 2%–4% of the global population and is characterized by misalignment of the visual axes due to neuromuscular imbalance or cranial nerve dysfunction. It can lead to diplopia, amblyopia, and impaired depth perception, particularly in pediatric patients, if not diagnosed early.[1] Traditional diagnostic methods, such as the Hirschberg test, cover–uncover test, and prism alternate cover test, require trained personnel and clinical infrastructure, limiting access in underserved or remote settings.[1] These limitations have prompted the development of automated, accessible tools to improve early detection and monitoring of strabismus. A recent innovation, a smartphone-based digital ruler (DRS), offers automated measurement of ocular deviation using deep learning and three-dimensional (3D) reconstruction algorithms. This tool analyzes short video recordings of cover tests to quantify horizontal and vertical strabismus angles with ophthalmologist-level accuracy, eliminating the need for manual prism bars. Beyond strabismus, this technology holds diagnostic potential for conditions such as thyroid eye disease, cranial nerve palsies, convergence insufficiency, and myasthenia gravis, where precise ocular alignment assessment is essential for clinical decision-making.[2,3] Recent multicenter validation studies have demonstrated strong translational promise. Wang et al. reported in NEJM AI that the DRS achieved 95% agreement with manual prism testing across pediatric and adult cohorts, including esotropia, exotropia, and paralytic strabismus.[4] Complementing this, Kurdthongmee et al. validated artificial intelligence (AI)-based strabismus detection in monocular eye images for telemedicine applications, confirming feasibility in resource-limited MDPI. Together, these findings illustrate complementary strengths: smartphone-based tools can reduce interobserver variability in clinics while enabling scalable screening in teleophthalmology programs.[5] Validated in a 2025 multicenter study (NEJM AI), the DRS achieved 95% concordance with prism alternate cover testing across pediatric and adult cohorts, including esotropia, exotropia, and paralytic strabismus.[4] Beyond strabismus, similar AI-based ocular alignment tools have shown promise in: Thyroid eye disease: Automated detection of ocular misalignment and activity scoring Cranial nerve palsies: Quantifying deviation angles for diagnosis and monitoring Convergence insufficiency and myasthenia gravis: Tracking subtle motility changes critical for treatment decisions. Yarkheir et al. demonstrated that deep learning analysis of facial images could classify strabismus with high accuracy, supporting telemedicine applications.[2] Shin et al. validated AIbased assessment of thyroid eye disease using facial images, reinforcing the broader applicability of ocular alignment algorithms.[3] Together, these studies highlight that smartphonebased tools can extend beyond strabismus, offering scalable diagnostics for multiple ocular motility disorders. The ubiquity of smartphones makes the DRS particularly feasible in low-resource settings. Unlike prism bars or synoptophores, which require specialized equipment and trained ophthalmologists, the DRS can be deployed by community health workers or school screening programs. Offline inference allows use in areas with limited internet connectivity, while teleophthalmology platforms enable remote specialist review. Despite its promise, limitations remain: accuracy may be affected by poor lighting, unstable fixation, or low-resolution video capture, and performance in complex strabismus patterns such as dissociated vertical deviation is still under investigation.[4] Nevertheless, feasibility in developing countries is strengthened by portability, cost-effectiveness, and integration with telemedicine platforms.[5] The smartphone-based digital ruler represents a significant advancement in accessible, AI-assisted strabismus diagnostics. Future directions should include algorithm refinement for complex motility patterns, integration with electronic health records, and deployment in school screening and primary care settings. Cost-effective implementation and clinician training will be essential for widespread adoption. Accurate strabismus diagnosis is well established as critical for preventing amblyopia and visual dysfunction.[1] What is new here is the introduction of a smartphone-based digital ruler that utilizes AI and 3D reconstruction to provide automated, ophthalmologist-level measurements of deviation. Recent validation shows high concordance with prism testing and reduced variability, supporting its role as a scalable, noninvasive tool to enhance early detection, teleophthalmology, and equitable access to care.[2–5] Author contribution statement E.H: Conceptualization, Methodology, Software, Data curation, Writing Original draft preparation, Reviewing and Editing; S.N.U.S: Writing Original draft preparation, Reviewing and Editing. Competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Use of generative AI and AI-assisted technologies No AI or AI-assisted technologies were used in the preparation of this manuscript. Consent for publication Consent for publication is not applicable as this study involves publicly available data. Provenance and peer review Not commissioned, externally peer-reviewed. Data availability statement The data are available for access. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Purpose: To describe the diagnostic workflow and clinical outcomes of a mixed reality (MR)-assisted endoscopic dacryocystorhinostomy (EnDCR) using the Magic Leap 2 (ML2) headset, performed for a patient with secondary acquired nasolacrimal duct obstruction resulting from extremely distorted post-traumatic maxillofacial anatomy. Case Presentation: A 40-year-old male with a history of massive maxillofacial trauma 10 years earlier presented to the Department of Ophthalmology of Jozef Strus City Hospital with recurrent dacryocystitis and a dacryocele. Physical examination showed a marked post-traumatic groove over the left orbit, inferior dislocation of the left globe, paralytic strabismus, ptosis, and a large left dacryocele. Nasal endoscopy demonstrated severe bilateral septal deformities obscuring visual access to the nasal cavity. Endoscopic septoplasty was done to obtain surgical access, followed by EnDCR assisted with MR. Preoperative planning included patient-specific 3D prints reconstructed from CT (OsiriX MD TM ), refined (MeshLab TM , Blender TM ), exported as GLB files, and visualized on ML2; an ML Spectator mobile phone app documented the procedure. MR was used preoperatively and intraoperatively as a non-dynamic 3D image reference tool (no instrument tracking) to enable the surgeon to maintain a consistent spatial orientation for the lacrimal sac fossa and adjacent bones during septoplasty and EnDCR. Over 9 months post-operation, the patient reported no symptoms (Munk score: 0), lacrimal irrigation confirmed a widely patent ostium, and no further dacryocystitis occurred. Conclusions: This case supports the use of MR in preoperative and intraoperative planning in extremely complex anatomical distortions.