Clock Hours Research Articles

Surgical Approach in Intraocular Tumors

Surgery in intraocular tumors is done for excision/biopsy and the management of complications secondary to the treatment of these tumors. Excision/biopsy of intraocular tumors can be done via fine-needle aspiration biopsy (FNAB), transretinal biopsy (TRB), partial lamellar sclerouvectomy (PLSU), and endoresection. FNAB, TRB, and PLSU can be used in tumors that cannot be diagnosed by clinical examination and other ancillary testing methods. PLSU is employed in tumors involving the iridociliary region and choroid anterior to the equator. Excisional PLSU is performed for iridociliary and ciliary body tumors with less than 3 clock hours of iris and ciliary body involvement and choroidal tumors with a base diameter less than 15 mm. However, for biopsy, PLSU can be employed with any size tumor. Endoresection is a procedure whereby the intraocular tumor is excised using vitrectomy techniques. The rationale for performing endoresection is based on the fact that irradiated uveal melanomas may cause complications such as exudation, neovascular glaucoma, and intraocular pigment and tumor dissemination (toxic tumor syndrome), and removing the dead tumor tissue may contribute to better visual outcome. Endoresection is recommended 1-2 weeks after external radiotherapy. Pars plana vitrectomy is also used in the management of complications including vitreous hemorrhage, retinal detachment, and epiretinal membrane that can occur after treatment of posterior segment tumors using radiotherapy and transpupillary thermotherapy. It is important to make sure the intraocular tumor has been eradicated before embarking on such treatment.

Effect of discretisation on extreme rainfall analysis: A study of Jaipur city in India

A location-based evaluation of the effect of discretisation on extreme rainfall estimates has been reported in the present study using the hourly rainfall records. This analysis aims to develop a correction model to find rainfall correction factor (RCF) for the metro city, Jaipur in the state of Rajasthan, India. Further, the study addressed the effect of clock hour correction factor (CHCF) on extreme rainfall recorded in the discrete-time interval and compared with the corresponding value suggested by IS 5542-2003. The CHCF was computed using annual maxima series (AMS), and peak-over-threshold (POT) approaches in deriving the rainfall values. The hourly rainfall measurement used to evaluate the differences in extremes evaluated using sliding window (SW) aggregation and fixed window (FW) observation for 24-hour maximum rainfall depth. The extreme value analysis was performed, and the model was checked for its reliability. The peak rainfall depth-duration-frequency curve was plotted for observed 24-hr and 1-hr duration peak rainfall depth. The 1-hour duration peak rainfall was computed for 25-, 50- and 100-year return period using the conversion factor given in Flood estimation report (sub-zone 1b) and compared with the present study results. The peak rainfall for the different return periods for 1-hour and 24-hour duration was worked out which will be useful to the design engineer as per the recent guidelines of the Central Public Health and Environmental Engineering Organization (CPHEEO, 2019).

Outcomes of combined single-use dual blade goniotomy and cataract surgery

PurposeSingle-use dual blade goniotomy (SBG) is a novel ab interno procedure that removes three to five clock hours of trabecular meshwork (TM). We analysed the reduction of intraocular pressure (IOP) and topical glaucoma medication (Meds) in eyes following combined cataract surgery and SBG (Cat-SBG).MethodsIOP and Meds were evaluated retrospectively in 55 eyes of 38 patients. 44 eyes had high tension glaucoma (HTG) and eleven eyes had normal tension glaucoma (NTG). Complete success (no Meds) and qualified success (with Meds) for IOP levels ≤ 21, ≤ 18 , ≤ 16 mmHg or ≥ 20% IOP reduction at the two- and six-month follow-up were evaluated.ResultsIOP and Meds were significantly reduced from before to two months after Cat-SBG in HTG- and NTG-patients (HTG: IOP 19.4 ± 3.3 to 15.1 ± 3.3 mmHg; p < 0.001; Meds 2.1 ± 1.3 to 0.8 ± 1.3; p < 0.001; NTG: IOP 14.0 ± 2.3 to 11.5 ± 2.3 mmHg; p = 0.004; Meds 1.6 ± 0.7 to 0.3 ± 0.7; p < 0.001). IOP and Meds did not change significantly from two to six months after Cat-SBG.In HTG, complete and qualified success rates were 43% (19/44) and 93% (41/44) for IOP ≤ 18 mmHg, 36% (16/44) and 64% (28/44) for IOP ≤ 16 mmHg and 30% (13/44) and 43% (19/44) for ≥ 20% IOP reduction six months after surgery. In NTG, complete and qualified success was 81% (9/11) and 100% (11/11) for IOP ≤ 18 and ≤ 16 mmHg, and 27% (3/11) for IOP reduction ≥ 20%.IOP and Meds reduction were comparable between HTG and NTG eyes.Only minor postoperative complications occurred.ConclusionCat-SBG is an efficient method to significantly lower IOP in patients with HTG and NTG.

Ocular rigidity and neuroretinal damage in patients with vasospasticity: a pilot study

ObjectifIl existe des données selon lesquelles la dérégulation du débit sanguin oculaire chez des sujets qui présentent un trouble vasospastique découlerait de stimuli biomécaniques, d'où une sensibilité de la tête du nerf optique en présence de glaucome. Nous nous penchons ici sur le rôle du trouble vasospastique dans l'association entre la rigidité oculaire et les lésions neurorétiniennes, en posant comme hypothèse qu'il existe une corrélation entre une faible rigidité oculaire et l'apparition de lésions glaucomateuses plus importantes chez les patients qui présentent un trouble vasospastique. NatureÉtude transversale. ParticipantsPatients qui présentent un glaucome à angle ouvert (GAO), dont le disque optique a une allure suspecte ou qui n'ont pas de glaucome. MéthodesLa rigidité oculaire a été mesurée au moyen d'une méthode non invasive mise au point et validée par notre équipe. On a eu recours à la tomographie par cohérence optique en domaine spectral pour mesurer l’épaisseur des couches de fibres nerveuses rétiniennes (RNFL, pour retinal nerve fiber layer) et du complexe des cellules ganglionnaires. Le trouble vasospastique a été évalué grâce à un questionnaire standardisé créé à partir de questionnaires validés et adapté aux besoins de notre étude. L'athérosclérose a été évaluée d'après le score de maladie cardiovasculaire de Broadway et Drance (1998). On a recherché des corrélations entre la rigidité oculaire et les paramètres structuraux chez des patients présentant un trouble vasospastique de même que chez des patients présentant une athérosclérose. RésultatsSur les 118 patients – qui avaient un GAO (n = 67), dont le disque optique avait une allure suspecte (n = 26) ou qui ne présentaient pas de glaucome (n = 25) – recrutés de manière consécutive, 10 ont reçu un diagnostic de trouble vasospastique, et 37, d'athérosclérose. Dans le groupe trouble vasospastique, il a été possible d’établir des corrélations significatives entre la rigidité oculaire et le complexe des cellules ganglionnaires le plus mince (rs = 0,681; p = 0,030), l’épaisseur moyenne des RNFL (rs = 0,745; p = 0,013) et l’épaisseur des RNFL dans le quadrant temporal (rs = 0,772; p = 0,009), ce qui dénote un dommage accru à mesure que diminue la rigidité oculaire. Les tendances se sont maintenues, même après avoir réalisé une correction de tests multiples. Cependant, seule la huitième heure de l'horloge des RNFL correspondant au quadrant temporal inférieur de la région péripapillaire demeurait significativement corrélée avec la rigidité oculaire dans le groupe trouble vasospastique (p = 0,015). En revanche, aucune corrélation n'a pu être mise au jour dans le groupe athérosclérose (p > 0,05). ConclusionsLes résultats de la présente étude pilote révèlent une tendance selon laquelle les patients qui présentent un trouble vasospastique et dont la rigidité oculaire est moindre sont sujets à plus de lésions des structures neuronales. Il est donc possible que la rigidité oculaire joue un plus grand rôle dans le glaucome chez les patients qui présentent un trouble vasospastique que chez les patients qui présentent une athérosclérose. Si ces résultats jettent une lumière intéressante sur la physiopathologie du GAO, d'autres études devront étayer nos observations.

Genetic and phenotypic variation and consistency in cow preference and circadian use of robotic milking units

Many dairy herds use automatic milking stations (AMS), with cows in large herds often having access to 2 or more AMS, and must choose between them when they go for milking. Individual cows acquire routines of either consistently using a specific milking box or consistently using any available milking box. Here, we hypothesized that the degree of use of the same milking box was an expression of preference, and quantified it as preference consistency score (PCS). The PCS was calculated as a ratio between the excess frequencies of the first choice over the base frequency of "not first choice" over 15-d segments of lactation. This ratio was 0 if all choices were taken equally, and became 1.0 if only the first choice was taken in all events. We investigated the consistency of milking box preference in 2 cohorts (one Holstein and one Jersey) across 6 commercial dairy herds in Denmark (n = 4,665 cows total). In addition to PCS, we recorded and analyzed associated milking and behavior traits, including a time profile index showing use of specific clock hours when cows were milked (Time_profile, based on excess use of specific clock hours), milking frequency, time spent in the milking box, and milk yield. Records from each milking event were condensed into 15-d segments based on days in milk. The data were analyzed using a linear mixed model, with random genetic and individual cow effects, to estimate heritability (h2), repeatability (t), and individual level correlations (ri) between traits. The average PCS was 0.43 and 0.41 in Holstein and Jersey, respectively, showing that cows developed routines for consistently using the same milking box; however, some cows had lower preference (i.e., greater flexibility in use). The Time_profile indicated that some cows were milked in a few hour-bins, whereas others were more flexible. The PCS and Time_profile traits had low heritability (h2, PCS/Time_profile = 0.07 ± 0.02/0.11 ± 0.02 Holstein, 0.13 ± 0.03/0.04 ± 0.02 Jersey) and moderate repeatability (t, PCS/Time_profile = 0.47/0.40 Holstein, 0.50/0.42 Jersey). The 2 traits were weakly correlated with each other (ri = 0.18 and 0.17), and were weakly correlated with milk yield (ri range: 0.0 to -0.10). However, the time profile was strongly correlated with milking frequency (ri range: -0.81 to -0.73), and was moderately correlated with daily box time (ri range: -0.43 to -0.35). In general, Holstein and Jersey parameter estimates were of similar size, and thus in good agreement. Overall, individual cows covered a broad spectrum of preference consistency, both regarding the use of specific milking boxes and time profiles, with these 2 traits representing different aspects or dimensions of milking behavior. The findings that some cows have strong preferences for specific AMS may be most useful in herd management and farm design. The weak correlation to milk yield indicated that yield minimally affected these 2 milking associated behavior traits. In conclusion, although the traits were repeatable, heritability was low; thus, genetic selection for milk yield might minimally affect these 2 traits.

Iris melanocytic tumours in New Zealand/Aotearoa: presentation, management and outcome in a high UV exposure environment

Background/ObjectivesIris melanoma, a rare intraocular malignancy, represents the smallest subgroup of uveal melanoma. This first, comprehensive study of iris melanocytic lesions in the high ultraviolet environment in New Zealand/ Aotearoa (NZ) examines diagnosis, management and outcomes.Subjects/MethodsRetrospective study of iris melanocytic tumours referred to tertiary referral centres in Auckland, NZ, over 20 years (1999-2018). Data analysed include demographics, tumour characteristics, histology, genetic analyses, treatment modalities, recurrence, metastasis, 5-year and overall survival.ResultsCohort (N = 51) was predominantly NZ European (98.0%) with no indigenous Māori, or Pasifika. Median age at presentation was 58 years. Tumours involved a median of two clock hours of iris. The posterior tumour margin extended to the anterior chamber angle in 22 patients (45.8%). Management included initial observation 54.9%, iridectomy/excision biopsy 29.4%, irido-cyclectomy 7.8%, plaque radiotherapy 7.8%, proton beam radiotherapy 7.8%, and ultimately enucleation 17.6%. Histology was performed in 19 cases (37%) with 16 confirmed melanomas (84%). Mean follow-up 4.2 years with median visual acuity of 6/7.5 two years post intervention. Melanoma-related metastasis and mortality occurred in two cases with five-year melanoma-related mortality of 2.0%.ConclusionIn a climate with high ultraviolet exposure iris melanocytic tumours occurred almost exclusively in NZ Europeans, however, the majority of cases were category T1, possibly reflecting early diagnosis in the NZ health system. Nonetheless, >50% underwent surgery or radiotherapy, often utilising more than one modality. A high index of suspicion and early referral of iris melanocytic lesions should be considered in regions with high UV exposure.

Clinical and ultrasound biomicroscopic (UBM) correlation in eyes with closed globe injury

To correlate UBM and clinical findings in patients with closed globe injury. Prospective observational study of 75 patients, ≥ 12 years of age presenting to ophthalmic outpatient department within one week of sustaining closed globe injury. Patients with seriously ill polytrauma and open globe injuries were excluded from the study. Comprehensive ophthalmic examination including Visual acuity assessment, slit lamp examination, fundus examination and IOP measurement. Gonioscopy and UBM examination was done in all patients on presentation except for patients with hyphema (UBM and gonioscopy done at 4 weeks to prevent rebleed).Mean age of the patients was 31.4 ±8 years, most common external findings included lid ecchymosis (47%), subconjunctival hemorrhage (93%). The common anterior segment finding included traumatic iritis (87%), traumatic hyphema (61%) and traumatic cataract in 27% of patients. Clinical evidence of zonular dialysis was seen in 13% of patients. UBM was able to detect zonular defects in 62% patients (P=0.008). Most of the patients (57%) had zonular dialysis less than 3 clock hours on UBM examination. UBM confirmed the presence of other clinical findings like iridodialysis, cyclodialysis. UBM is a safe and effective adjunctive tool for clinical assessment and management of ocular trauma. It can diagnose subtle zonular dialysis and other anterior segment changes following blunt trauma. UBM should be an integral part of ophthalmic examination especially in patients requiring surgical intervention after closed globe injury.

Risk Factors for Retinal Detachment in Acute Retinal Necrosis

Retinal detachment (RD) is associated with poor visual outcomes in patients with acute retinal necrosis (ARN). This research was undertaken to assess the risk factors for RD in ARN. Retrospective cohort study. Patients diagnosed with ARN at a tertiary referral center from 2010 to2020. A chart review was performed for all clinical and surgical encounters. Univariate and multivariate logistic analyses of demographic and clinical variables associated with RD were performed. Survival analyses with Kaplan-Meier estimates were performed to compare the time to RD in herpes simplex virus (HSV)- and varicella zoster virus (VZV)-associated ARN. Demographic information, clinical information (including visual acuity [VA]), intraocular pressure (IOP), intraocular inflammation level, the extent of retinitis, incidence and timing of retinal detachment, date of diagnosis, and treatments performed (including intravitreal injections of antiviral medications). Fifty-four eyes of 47 patients who were diagnosed with ARN were included, with equal proportions of eyes (n= 27; 50%) with VZV-ARN and HSV-ARN. Patients with VZV-ARN were, on average, older, more likely to be men, and more likely to be immunosuppressed compared with patients with HSV-ARN. The clinical characteristics, including the initial VA, initial IOP, anterior segment inflammation, clock hours, and posterior extent of retinitis, were similar between eyes with VZV- and HSV-ARN. In the univariate analysis of clinical and demographic variables associated with the development of RD, initial VA (P= 0.0083) and greater clock hours of retinitis (P= 0.009) were significantly associated with RD. These 2 variables remained significant in the multivariate logistic regression; worse VA at presentation had an odds ratio of 2.34 (95% confidence interval [CI], 1.01-5.44; P= 0.042), and greater clock hours of retinitis had an odds ratio of 1.23 (95% CI, 1.02-1.47; P= 0.025). A Kaplan-Meier survival analysis demonstrated no statistical difference in RD-free survival between HSV- and VZV-ARN. Patients with VZV-ARN were more likely to be older, male, and immunosuppressed compared with those with HSV-ARN, although no clear difference was observed in RD by viral etiology. Poor initial VA and clock hours of retinitis were significantly associated with RD development and may be relevant for patient counseling and prognosis.

The evaluation of the efficacy of adalimumab in refractory non-infectious uveitis with ultra-widefield fundus fluorescein angiography.

To investigate the efficacy of adalimumab in the cases with refractory non-infectious uveitis and evaluate retinal vascular leakage changes on ultra-widefield fundus fluorescein angiography. Twenty-three patients with refractory uveitis were included in study. Forty-four eyes of 23 patients with non-infectious uveitiswere evaluated. Clinically active inflammation was present in 19 eyes (43.18%), while 25 (56.8%) were inactive. The mean drug burden was a 9.91 ± 3.78 (5-21) in baseline, 7.3 ± 4.25 at third and 8.0 ± 4.71 at sixth month (p = 0.022). The mean choroidal thickness was 256.65 ± 43.63μm in baseline, 240.49 ± 36.73μm at third and 224.81 ± 34.91μm at sixth month (p ≤ 0.05). In terms of leakage extend, leakage was initially present in a mean of 2.95 ± 4.55 clock hours, 2.41 ± 3.91 at third and 1.76 ± 3.44 at sixth month (p < 0.001). Adalimumab was found to be effective in establishing inflammation control by reducing drug burden, controlling retinal vascular leakage and choroidal inflammation in refractory uveitis.

Results of pars plana vitrectomy with inferior retinotomy in inferior rhegmatogenous retinal detachments with inferior retinal breaks and proliferative vitreoretinopathy grades B or C

AbstractPurposeTo report the surgical outcomes of pars plana vitrectomy (PPV) with inferior retinotomy without the need for scleral buckling in primary inferior rhegmatogenous retinal detachment (RRD) with inferior retinal breaks and Proliferative vitreoretinopathy (PVR) grades B or C.MethodsRetrospective, consecutive series, single‐center study of patients that underwent PPV with inferior retinotomy for primary inferior RRD with inferior retinal breaks (4:00 to 8:00 clock hours) and PVR grades B or C. Data were obtained from patients’ medical records from October 2014 to November 2020. The primary outcomes of the study were retinal reattachment and visual acuity improvement. Data collected before and after surgery was compared between groups using chi‐square analysis and paired samples t‐test. The resulting p‐values significance level was set at p = 0.05.ResultsThirty‐two patients (32 eyes) met the inclusion criteria. PVR in stage B was present in 19 patients and stage C in 13 patients. Macula‐off RRD was diagnosed in 25 patients while the other 7 patients had RRD with the macula attached. Regarding primary outcomes, 31 out of 32 (97%) patients achieved retinal reattachment with no differences between PVR groups (p = 0.406). The best‐corrected visual acuity (BCVA) improved significantly in eyes with macula‐off RRD at presentation (p &lt; 0.001). Although macula‐attached RRD eyes had higher final BCVA, its improvement was not statistically significant (p = 0.370). Besides one retinal redetachment, no other significant complications were reported after surgery.ConclusionsInferior retinal breaks are associated with surgical failure following PPV for inferior RRD repair, especially if advanced PVR is present. Our results suggest that, in these less common and more challenging cases, PPV with an inferior retinotomy is associated with very favorable anatomic and visual outcomes.

Clinical Experience in Patients with Ocular Burns Treated with Boston Type I Keratoprosthesis Implantation with or Without Prophylactic Ahmed Glaucoma Valve Implantation.

IntroductionTo compare outcomes in eyes with ocular burns following Boston Type I keratoprosthesis (KPro) implantation with and without prophylactic pars plana tube surgery.MethodsA retrospective review of patients with ocular burns who underwent KPro surgery at Zhongshan Ophthalmic Center was performed. Twenty-six eyes of 26 patients without a preoperative diagnosis of glaucoma before KPro surgery met the inclusion criteria. Preoperative glaucoma was defined as a history of a durable elevated intraocular pressure (IOP) ≥ 25 mmHg at different time points, which resulted in the introduction of anti-glaucoma medication or surgical intervention. Sixteen eyes underwent KPro alone (Group 1), and 10 eyes received KPro with prophylactic pars plana tube surgery (Group 2).ResultsGroup 1 and Group 2 were similar in the proportions of the ocular burn type and preoperative clock hours of peripheral anterior synechiae by ultrasound biomicroscopy (1.88 ± 1.63 vs. 2.30 ± 1.83; P = 0.54). Before KPro surgery, 62.5% of eyes in Group 1 and 50.0% of eyes in Group 2 had intraocular surgeries (P = 0.53). The follow-up time was 18 months. At the final follow-up time, the two groups had similar visual acuity (1.34 ± 0.87 logMAR, 1.03 ± 0.71 logMAR; P = 0.35) and eyes with a C/D ratio ≥ 0.8 (7/16, 2/10; P = 0.21), but more eyes in Group 1 developed glaucoma de novo than eyes in Group 2 (62.5%, 20%; P = 0.04) and had undergone secondary glaucoma surgery after KPro implantation (7/16 vs. 0/10; P = 0.02).ConclusionIn eyes injured with ocular burns, KPro implantation with prophylactic pars plana tube surgery may be a feasible option to rehabilitate visual acuity and decrease the incidence of glaucoma de novo.

An Analysis of the Progression of Conjunctivalisation after Transplantation of Cultivated Corneal Epithelium.

Purpose To analyse the recurrence of superficial neovascularisation after previous corneal surface reconstruction with cultivated corneal epithelial cells. Materials and Methods Forty-eight eyes underwent autologous transplantation of cultivated corneal epithelium to treat partial or total limbal stem cell deficiency caused by chemical or thermal injury. The carrier for the epithelial sheets was a denuded amniotic membrane. Follow-up was conducted for up to 120 months. Recurrent revascularisation (measured in terms of clock hours affected) was evaluated with slit-lamp examination and the support of confocal microscopy. Results During the long-term observation, only 7 eyes had stable epithelia with no neovascularisation from the conjunctiva. Nineteen eyes developed pathologic vessels in 1 quadrant, with additional 4 eyes developing them in 2 quadrants. Twelve patients developed subtotal or total conjunctivalisation of the corneal surface. They were referred for second cultivated epithelium transplantation (3 patients), allogenic keratolimbal transplantation (7 patients), or keratoprosthesis (2 patients). Six patients withdrew consent. The use of confocal scans of up to 100 µm in resolution enabled the detection of pathologic microvasculature originating from the conjunctiva and the exclusion of stromal vascular ingrowth. Conclusions Local ingrowth of the conjunctiva is a common complication after the transplantation of cultivated epithelial cells. Severe and progressive vascularisation inevitably leads to graft failure. However, if local ingrowth stops before reaching the central cornea, the treatment even with this complication can be considered a success.

Surgical Management of Unilateral Partial Limbal Stem Cell Deficiency: Conjunctival Autografts versus Simple Limbal Epithelial Transplantation.

PurposeTo evaluate the clinical outcomes of conjunctival autograft (CAG) versus simple limbal epithelial transplant (SLET) for management of unilateral partial limbal stem cell deficiency (LSCD).MethodsThis retrospective, comparative, interventional case series evaluated 30 eyes of 30 patients with unilateral partial LSCD. After corneal pannus dissection, 17 patients underwent CAG where graft was harvested from the ipsilateral or contralateral eye, while 13 patients underwent SLET where limbal biopsy was harvested from the contralateral eye. The primary outcome measure was anatomical success in the form of restoration of a completely epithelised, stable, and avascular corneal surface at last follow-up.ResultsBoth groups were comparable in terms of age at time of surgery, preoperative best-corrected visual acuity, median duration since injury, number of clock hours of limbus involved, and number of previous surgeries performed. The most common etiology for LSCD was chemical burns in both groups. The median duration of post-operative follow-up was 5.6 months [interquartile range [(IQR): 3.6–15.1] in the CAG group versus 6.2 months (IQR: 4.5–12.2) in the SLET group (p=0.75)]. The anatomical success rates were 86.5 ± 8.9% in the CAG group and 28.3 ± 13.7% in the SLET group at final follow-up visit (p = 0.025). Most failures in both groups occurred within the first 8 months after surgery.ConclusionFor eyes with unilateral partial LSCD secondary to chemical burns, CAG is a safe and effective method for restoring the corneal epithelium. Limbal transplantation may not be necessary for the treatment of partial LSCD.

Association of peripheral anterior synechia, intraocular pressure, and glaucomatous optic neuropathy in primary angle-closure diseases.

To investigate the association of peripheral anterior synechiae (PAS) with intraocular pressure (IOP) and glaucomatous optic neuropathy (GON) in primary angle closure (PAC) and primary angle-closure glaucoma (PACG). Totally 355 eyes (238 PAC and 117 PACG) of 181 patients were included in this retrospective analysis of baseline data from a randomized clinical trial. All patients had undergone a comprehensive ophthalmic examination. The extent of PAS in clock hours as determined on gonioscopy was documented. The independent effect of the extent of PAS on IOP and the prevalence of GON were determined using multivariable generalized estimating equation (GEE) models. The frequency of GON increased with the extent of PAS and a higher IOP. PAS were more extensive (8 vs 1 clock hour, P<0.001) and IOP higher (28.01 vs 18.00 mm Hg, P<0.001) in PACG compared to PAC. The prevalence of GON among the PAS quartiles were 10.2% (PAS<0.5 clock hours), 16.9% (PAS≥0.5 and PAS<3 clock hours), 29.6% (PAS≥3 and PAS<7 clock hours), and 74.4% (PAS≥7 clock hours), respectively. After adjusting for IOP, age, gender, spherical equivalent, average Shaffer score and number of medications, the odds ratio (OR) for GON was 4.4 (95%CI: 1.5-13.0; P=0.007) with PAS≥3 clock hours and 13.8 (95%CI: 4.3-43.6; P<0.001) with PAS≥7 clock hours as compared to eyes with PAS<0.5 clock hours. The frequency of GON increased linearly with the extent of PAS. Extent of PAS was also associated with higher IOP. Eyes with both PAS≥6 clock hours and IOP≥21 mm Hg had the highest risk of GON compared to eyes with both PAS<6 clock hours and IOP<21 mm Hg (OR=18.0, 95%CI: 7.5-43.4; P<0.001). The extent of PAS in PAC and PACG is an important predictor of higher IOP and is linearly associated with GON independent of IOP, suggesting other factors related to PAS formation may be involved in the development of GON in PACG.

Mini-conjunctival autograft combined with deep anterior lamellar keratoplasty for chronic sequelae of severe unilateral chemical burn: A case report.

Introduction and importanceThis case describes a novel technique combining a mini-conjunctival limbal autograft (CLAU) with a deep anterior lamellar keratoplasty (DALK) in a case of chemical injury sequelae.Case presentationA 19-year-old female presented with total limbal stem cell deficiency (LSCD) and a vascularized corneal scar in the visual axis of the left eye, 4 years following a chemical injury. In order to treat the LSCD and simultaneously visually rehabilitate the patient, a mini-CLAU with DALK was carried out. Two separate one clock-hour CLAUs were harvested from the right eye and secured in the left. The graft was clear in the initial postoperative period and maintained its clarity over 15 months of follow period with a visual acuity of 20/30 with scleral contact lenses. The mini-CLAUs sustained a stable and well epithelialized corneal surface during the same period.Clinical discussionThe use of the mini-CLAUs instead of the traditional CLAU circumvents the complication of an iatrogenic LSCD in the donor eye as the size of the donor grafts is smaller (1–2 clock hours versus 6–8 clock hours). Despite the smaller size, these grafts are efficacious in maintaining a well epithelialized corneal surface even in cases of total LSCD. The autologous nature of the graft defers the need for immunosuppression and its peripheral location facilitates ease of the surgical technique when combined with a keratoplasty.ConclusionThis novel single-staged procedure is an effective technique to reestablish a stable ocular surface and to visually rehabilitate cases of chronic chemical injury with good long-term outcomes.

Pneumatic retinopexy: an update

Pneumatic retinopexy (PR) is a minimally invasive, non-incisional procedure for repairing uncomplicated rhegmatogenous retinal detachment. It consists of an intravitreal gas injection followed by the maintenance of a postoperative head position and the use of laser or cryopexy to seal the retinal breaks. It was initially indicated for a single or a group of retinal breaks no larger than 1 clock hour involving the superior 8 clock hours in phakic eyes with no proliferative vitreoretinopathy. We aim to perform a narrative review on pneumatic retinopexy since the last major review of 2008, based on a Medline search up to June 20 2021 using multiple search words including pneumatic retinopexy, pneumoretinopexy, retinal detachment, and pars plana vitrectomy. Indications for PR have been expanded and include pseudophakic eyes, eyes with mild PVR, and even breaks in the inferior fundus. Depending on the case selection, PR has a single-operation success rate ranging from 45 to 80%. Despite the lower single operation success rate, the functional outcomes of those eyes repaired successfully by primary PR exceed those of scleral buckling (SB) and pars plana vitrectomy (PPV). Best corrected visual acuity, metamorphopsia scores, mental health scores, and vision-related functioning scores were all better in PR-treated eyes compared to PPV-treated eyes. PR should be strongly considered for eligible patients with a primary uncomplicated rhegmatogenous retinal detachments.

PERIPAPILLARY RETINAL NERVE FIBER LAYER THICKNESS IN MYOPIA USING OPTICAL COHERENCE TOMOGRAPHY

This is a observational cross sectional study conducted in tertiary care hospital in the department of ophthalmology to evaluate the effect of myopia on peripapillary retinal nerve fiber layer thickness in various quadrants and clock hour positions using optical coherence tomography ,with a sample size of 100 myopic eyes.Out of 100, 30 were males and there is significant decrease in peripapillary retinal nerve fibre layer thickness in high myopics when compared to low and moderate myopics and also decrease retinal fibre layer thickness in all quadrants except temporal quadrant.

PREOPERATIVE GAS FOR PARS PLANA VITRECTOMY: A SURGICAL TECHNIQUE FOR REPAIR OF RHEGMATOGENOUS RETINAL DETACHMENTS WITH MULTIPLE, LARGE, OR INFERIOR BREAKS.

To describe the role of preoperative gas for pars plana vitrectomy (PGP) as an adjunct to surgical repair of rhegmatogenous retinal detachment (RRD). This is a retrospective consecutive case series of all rhegmatogenous retinal detachments with multiple breaks in more than one quadrant, large breaks extending greater than one clock hour, and/or inferior breaks requiring PPV, who received intravitreal injection of sulfur hexafluoride (SF 6 ) or perfluoropropane (C 3 F 8 ) 1-2 weeks before PPV between 2016 and 2020 at a tertiary care center. A total of 109 eyes underwent the PGP technique, 73% of which had macular involvement. The rhegmatogenous retinal detachments on average involved 5.5 (SD 2.1) clock hours with inferior retinal breaks in 51%. Based on clinical examination, subretinal fluid was noted to be dissipated in parts of the detached retina before PPV in 57% of cases. The use of perfluorocarbon heavy liquid or posterior drainage retinotomy was required in 16% of cases. A 95% primary anatomical success rate was achieved over the median 177 (interquartile range 105-526) follow-up days. A final visual acuity of 20/50 or better was achieved in 65%. PGP as an adjunct to PPV may facilitate ease of surgery, as well as anatomical and functional success for rhegmatogenous retinal detachments with multiple, large, and/or inferior breaks.

Young pupils’ articulations of time spent in school in the wake of a policy reform

Advancing the ‘temporal turn’ in the sociology of education, this article explores how a strong national discourse on the length of the school day influences pupils’ articulations of their temporal experiences. The discourse of ‘the long school day’ emerged as part of a fierce debate on the implications of a Danish school reform passed in 2014. We use a discourse-analytical framework to examine focus group data from pupils aged 8–12 to show how the discursive context of the reform influences the pupils’ articulations of their temporal experiences. The pupils’ reproduction of the adult discourse of ‘the long school day’ conceals a diversity in temporal experiences and reduces them to being a concern about the number of clock hours spent in school. To understand the broader impact of pupils’ temporal experiences of their school day, we need to rethink the linearity between clock hours and articulations of time.

Ultrasound Biomicroscopy for Zonular Evaluation in Eyes with Ocular Trauma.

PurposeTo evaluate the role of ultrasound biomicroscopy (UBM) in detecting zonular abnormalities in eyes with ocular trauma.Patients and MethodsProspective study of 143 eyes of 143 patients with ocular trauma and having opaque media was evaluated using a UBM. The presence or absence of zonular damage (zonular tears and/or zonular stretching) was examined and the clock-hour involvement was noted.ResultsOne-hundred and one eyes had blunt trauma (70.63%; group 1), while 42 eyes had penetrating trauma (29.37%; group 2) The mean age of the patient population was 48.01±17.93 years with a male:female ratio of 2.11:1. Group 1 had significantly greater visual acuity than group 2 (p = 0.03). Zonular damage was present in 79 (55.2%) eyes, including zonular tears (48 eyes; 33.6%) and zonular stretching (31 eyes; 21.7%). Zonular damage was seen significantly more in eyes with blunt trauma (64.28%) as compared to penetrating trauma (25.74%) (p = 0.015). On quantitative analysis, zonular damage between 3 and 6 clock hours was most frequent, both in eyes having zonular tears (70.83%) and zonular stretching (96.77%). Additionally, 3–6 clock hours of zonular stretching was seen significantly more in blunt trauma as compared to penetrating trauma (p = 0.015).ConclusionUBM is an effective imaging modality to diagnose zonular abnormalities in patients with ocular trauma having opaque media. The ability to detect the presence of zonular weakness and their quantification by performing a UBM is critical to formulate the optimal surgical approach and avoid any untoward surgical complications.