ABSTRACT Background Determining the age and gender distribution of ocular disorders in Down syndrome patients aged 10 to 30 years. Methods In this study, 226 of 250 invited patients through special needs schools, the National Down Syndrome Society, and relevant nonprofit organizations were included. In Noor Eye Hospital, the patients underwent a complete eye examination by a general ophthalmologist and suspect cases were reexamined by a sub-specialist. Examinations included ocular alignment, conjunctiva, eyelid, lacrimal system, cornea, iris, and lens assessment. Results Mean age of participants was 16.05 ± 4.82 years and 53.0% were male. The most common ocular abnormalities were blepharitis (81.9%, 95% CI:78.0 to 85.3), lens opacity (37.8%, 95% CI:33.3 to 42.3), strabismus (23.4%, 95% CI:19.5 to 27.4; 21.2% esotropia, 0.9% exotropia, and 1.8% dissociated vertical deviation), floppy eyelid (19.9%, 95% CI:16.3 to 23.9), posterior embryotoxon (17.7%, 95% CI:14.2 to 21.2) and nystagmus (11.7%, 95% CI:8.9 to 15.0). Based on independent sample t test, the prevalence of nystagmus (P = .041) and congenital lens opacity (P<0.001) significantly increased with age. There was no significant inter-gender difference in the prevalence of any of the studied disorders by chi-square test. Conclusion In young patients with Down syndrome, the prevalence of ocular pathologies appears to be high and increase with aging. It can be resulted from the cumulative prevalence of undiagnosed or untreated cases. Findings of the study can be a reliable reference for health policy in terms of screening for eye disease and addressing eye care needs.

ABSTRACT Purpose: To evaluate success of nasal loop myopexy as a primary procedure in correcting the ocular deviation in primary position when combined with recession and resection procedure (R&R) in exotropia hypotropia complex in high myopia and to explore the probable cause for deviation. Case reports: We present a case series of three adult males with exotropia hypotropia complex and high myopia with large angle exotropia and hypotropia, with deflection of the courses of superior and medial recti seen intraoperatively. We performed a conventional recession and resection procedure, which was combined with a nasal loop myopexy between the superior rectus (SR) and medial rectus (MR) in the same session, under local anesthesia, to correct the deflected course of SR and MR; with the aim of correcting the deviation in primary position and improving ocular motility, mainly elevation in abduction. Results: We present a case series of three adult males with exotropia hypotropia complex, who were operated between March 2017 and October 2017. In all the three cases described above, it was noted that the preoperative exotropia and hypotropia improved following the combination of nasal loop myopexy with a conventional recession and resection procedure, as shown by improvement in ocular deviation in the primary position (measured by prism bar cover test, PBCT). First patient improved from 50 prism exotropia with 16 prism hypotropia to 5 prisms exophoria and 6 prisms hypotropia in left eye. Second patient improved from 45 prism right exotropia and 10 prism hypotropia to 10 prisms exotropia and 6 prism hypotropia. Third patient improved from 40 prism left exotropia and 20 prisms hypotropia to 10 prism esotropia and 5 prisms hypotropia. Ocular motility showed no restriction following surgery in any of the gazes. Limitation of elevation in abduction, caused due to SR deflection, improved due to repositioning of SR and MR in their anatomical positions in all the cases. In the first patient elevation in abduction improved from −4 to −1; in the second and third patients, it improved from −2 to 0. None of the three adult patients experienced any side effects following the procedure. Conclusion: The combination of recession and resection procedures with nasal loop myopexy was found to be effective in correcting the ocular deviation and limitation to elevation in abduction by correcting the deflected course of superior rectus and medial rectus to result in an effective improvement of elevation in abduction. One case had an overcorrection of exotropia. There were no other major complications.

ABSTRACT Introduction To explore the prevalence of visual impairment due to uncorrected ametropia from primary students in multi-ethnic regions of Yunnan (Southern China). Methods Primary school students of 7 ~ 12 years old from 5 multi-ethnic regions were screened. Cycloplegic refraction and subjective trial lens visual acuity were measured in all children with distance unaided visual acuity < 20/20. Gender, ages, ethnics, and regions were assessed with analysis of difference and Odds Ratio (OR) respectively, by statistics software R. Results Of all 24296 children, the incidence rate for visual impairment from ametropia was 19.18% (myopia accounted for 94.31%) for 7 ~ 12 years old in Yunnan primary schools in a multi-ethnic region. Myopia prevalence differed significantly among gender, ages, ethnics, and regions (P = .0003, P < .00001, P < .00001, P < .00001, respectively). Girls were more prone to have myopia (OR = 1.19, 95%, CI = 1.11–1.27) than boys; the risk of myopia increased with age: 9–10 years OR = 2.6 (95% CI = 2.62–3.2), 11–12 years OR = 6.6 (95% CI = 6–7.26). Three ethnic minorities surveyed were less prone to myopia than Han: Dai OR = 0.62 (95% CI = 0.47–0.8) Hani OR = 0.56 (95%CI = 0.41–0.76) Buyi OR = 0.50 (95% CI = 0.4–0.62). Conclusions Myopia, not corrected by glasses, was the most frequent cause of visual impairment in Yunnan primary schools, in a muli-ethnic region. Boys, young children and certain ethnic minorities were less prone to myopia.

ABSTRACTBackground/Aims: The Child Amblyopia Treatment Questionnaire (CAT-QoL) is a patient-reported outcome measure (PROM), designed to assess the impact of amblyopia treatment. The aim of this study was to compare the psychometric properties of two PROMs; the CAT-QoL instrument and Pediatric Quality of Life Inventory (PedsQLTM), a generic pediatric PROM. This work was part of a wider project to develop a condition-specific PROM for children with amblyopia.Methods: Three hundred and forty-two participants were recruited in a UK multi-center study. Quality of life data was collected using the CAT-QoL and the PedsQLTM instruments. The psychometric performance of the CAT-QoL and PedsQLTM were examined in terms of acceptability, reliability, and validity.Results: Both instruments demonstrated good reliability (CAT-QoL Cronbach’s α = 0.793; PedsQLTM α = 0.872). The convergent validity of the CAT-QoL and PedsQLTM instruments was tested by comparing the instruments to each other. There was a moderate correlation between the PedsQLTM and the CAT-QoL scores, and this relationship was statistically significant (rs = −0.517, p < .000). No statistical significance was found between the level of amblyopia severity and the mean PedsQLTM score (p = .420).Conclusion: It was possible to assess the impact of amblyopia treatment using the CAT-QoL and PedsQLTM instruments. The preliminary findings from this are not conclusive, and it is not possible to advocate the use of one questionnaire over another based upon psychometric performance demonstrated here. This may be due to the sample population, as there were limited numbers of participants with severe amblyopia. Both the CAT-QoL and PedsQLTM instruments were noted to have some issues with ceiling effects at an individual item level. The CAT-QoL and PedsQLTM were reliable (as determined by Cronbach’s alpha). The PedsQLTM instrument was not able to discriminate between amblyopia severity groups (discriminant validity). Further research is required to formally assess the psychometric properties of the CAT-QoL questionnaire.

ABSTRACTPurpose: Mobius sequence is a rare disorder that results from underdevelopment of the sixth and seventh cranial nerves, with subsequent facial weakness and impairment of ocular abduction. Approximately half of the affected patients have esotropia with limitation of extraocular movements. This study retrospectively reviews the long-term outcome of strabismus surgery for such patients.Methods: The long-term follow-up results in five children with Mobius sequence, who were observed after strabismus surgery for congenital esotropia, were analyzed.Results: All patients had a limitation of abduction in both eyes. Preoperative esotropia ranged from 20 to 30 prism diopters (PD) (mean 27 PD). Patient age at surgery ranged from 4.5 to 14 months. Bilateral medial rectus muscle recession was performed in all cases, ranging from 4.0 to 6.5 mm. Inferior transposition of the medial rectus muscles was performed in two patients for treatment of V-pattern, and two patients also had surgery for vertical strabismus. Follow-up ranged from 4 to 19.5 years (mean 11.7 years). The final horizontal alignment was <8 PD in all patients, and all demonstrated some binocularity.Conclusion: Bilateral medial rectus muscle recession is an effective treatment for esotropia associated with Mobius sequence, with good long-term stability.

ABSTRACTPurpose: To report the surgical outcomes of the superior oblique tuck procedure in the management of superior oblique palsies performed at a single centre over a 25-year period. Methods: A retrospective study of superior oblique tuck performed as a primary and secondary procedure by a single surgeon over a 25-year period between 1992 and 2016. We evaluated patient demographics, the angle of deviation pre- and post-surgery in prism dioptres (PD), amount of muscle tuck surgery performed (mm), complications (iatrogenic Brown’s Syndrome) and improvement of diplopia post-operatively. Results: 162 eyes from 162 patients were identified. Gender = 108 male patients (66.67%). Mean age at the time of surgery = 45.94 years; laterality = 85 left eyes (52.47%). 110 patients (67.90%) = congenital superior oblique palsy. Mean post-op follow-up time = 7.5 months. Mean pre-operative angle of deviation = 15.88 PD (range = 4–35 PD); mean post-operative angle of deviation = 5.09 PD (range = 0–20 PD; p < 0.0001). 157 patients (96.91%) displayed a reduction in angle of deviation post-operatively. Overall mean reduction in the angle of deviation = 10.79 PD (range = 0–34 PD). Mean amount of muscle tucking = 9.75 mm (range = 3–20 mm). 24 patients (14.82%) experienced post-operative iatrogenic Brown’s syndrome but only two of these required further corrective surgery. 138 patients (85.19%) experienced improvement of diplopia post-operatively. Overall, 54 patients (33.33%) required additional extraocular muscle surgery to reduce diplopia further. Conclusions: This large series of superior oblique tuck procedures performed over a 25-year period, displays excellent surgical outcomes with regards to reduction of the angle of deviation, diplopia and limited complications.

Temporary chemodenervation using botulinum toxin injection is a useful option in management of strabismus patients with good binocularity in whom the deviation is expected to naturally recover. Ease of procedure, minimal complications, and reversibility make it a promising management option.

Occasionally, strabismus not fully conforming to the earlier discussed principles is encountered and requires additional understanding to explain its mechanisms. This chapter will describe several other variants of strabismus which would interest the inquisitive mind of a postgraduate student. A general ophthalmologist should also have their basic knowledge, to identify them and suggest appropriate management.

ABSTRACTPurpose: IINS is associated with mild/moderate visual impairment, strabismus and compensatory head postures (CHP), which can negatively impact quality of life. Standard visual acuity assessments tend to underestimate the effect of IINS on visual functioning. Published evidence on the effect of INS on quality of life is slowly emerging. Our study examines visual functioning of adults with IINS using the National Eye Institute Visual Function Questionairre-25 (VFQ-25).Methods: 38 participants were recruited to participate in the study. All participants underwent detailed clinical examination, as well as appropriate investigations and were asked to complete the self administered VFQ-25.Results: 35/38 participants completed the questionnaire. The mean age of the population was 35.1 years (range 17-64). Mean overall VFQ-25 score at baseline was 65 (SD 13, range 34-91). Participants specifically demonstrated lowest scores for the impact of IINS on mental health, role limitations and dependency. 26/35 of participants were not driving, either due to sub-normal vision, lack of confidence or difficulties with contrast sensitivity.Conclusions: IINS can have a greater than expected impact on an individual’s quality of life, without necessarily causing markedly reduced visual acuity. Our study showed lowest scores in the domains of mental health and wellbeing. Patients also reported reduced visual functioning in driving, which can impact adversely on employability and independence. Visual functioning questionnaires such as the VFQ-25 may provide more functional information on the impact of nystagmus on an individual’s quality of life than objective measures such as high contrast Snellen and/or LogMAR visual acuity.

ABSTRACTPurpose: Rectus muscle resection in thyroid eye disease (TED) is generally avoided due to the risk of worsening restriction or reactivating inflammation. However, for some patients with large-angle strabismus or diplopia in primary gaze despite maximum recession surgery, rectus muscle resection may be beneficial. We report our surgical experience with rectus muscle resection in the management of vertical strabismus associated with TED.Methods: Retrospective review of eight patients with TED and vertical diplopia who underwent vertical rectus muscle resection by a single surgeon (IBM) at a tertiary referral centre in Liverpool, UK, from 2001 to 2013. The goal of surgery was elimination of diplopia in primary and reading position. Vertical deviations were measured in prism dioptres (∆) before and after surgery at one month, four months and final visit by prism alternate cover testing at ⅓ m and 6 m.Results: The mean ± standard deviation vertical deviation for near and distance reduced significantly from 14.2∆ ± 8.4∆ and 15.8∆ ± 8.8∆ pre-operatively to 5.7∆ ± 4.9∆ and 6.7∆ ± 7∆ at the four-month visit, respectively (p< 0.05). At the four-month follow-up, five (62.5%) patients achieved binocular single vision in primary and reading position with either no prisms or prisms less than 5∆. Further recession surgery, Harada-Ito procedure, or lateral rectus resection were necessary in four (50%) patients with persistent diplopia. No patient developed recurrence of inflammation or increased muscle restriction.Conclusions: Vertical rectus resection could be considered as an additional surgical strategy in the management of TED patients with vertical strabismus without adverse sequelae.