Tzyy-Chang Ho

Foveola nonpeeling technique in internal limiting membrane peeling of myopic foveoschisis surgery.

Foveola Nonpeeling Technique in Internal Limiting Membrane Peeling of Myopic Foveoschisis Surgery Myopic foveoschisis is a unique complication of posterior staphyloma in highly myopic eyes. The formation of macular hole and posterior retinal detachment are well-known consequences of this unstable condition. Early stages of such degenerative changes can only be detected using the high-resolution imaging technique optical coherence tomography (OCT). Tangential traction is believed to be one of the main causes of the disease, along with anteroposterior traction. The significant role of vitreous and internal limiting membrane (ILM) traction is confirmed by the good results obtained by vitrectomy with gas tamponade and facedown positioning. However, postoperative development of full-thickness macular hole in some of the cases required surgery, jeopardizing the central fovea tissue, which existed preoperatively. The present report describes an ILM peeling technique that leaves the epifoveolar tissue in situ and thus prevents the development of macular hole.

Photodynamic Therapy With or Without Intravitreal Bevacizumab for Polypoidal Choroidal Vasculopathy: Two Years of Follow-Up

PURPOSE To compare the long-term results of the efficacy of photodynamic therapy (PDT) with or without intravitreal bevacizumab (IVB) injections for polypoidal choroidal vasculopathy. DESIGN Retrospective, comparative, interventional case series. METHODS We included 69 eyes of 69 patients with macula-involved polypoidal choroidal vasculopathy. All patients were followed up for more than 2 years. We compared the treatment outcomes between groups and investigated the factors influencing visual improvement at 24 months of follow-up. RESULTS Thirty-six patients received PDT combined with IVB and 33 patients received PDT monotherapy. At 3 months, the mean logarithm of minimal angle of resolution (logMAR) best-corrected visual acuity (BCVA) improved from 0.73 to 0.53 in the combined therapy group (P < .001) and from 0.79 to 0.72 in the PDT monotherapy group (P = .02), with a significant difference in treatment efficacy between the 2 groups (P < .001). However, the improvements in BCVA were not statistically significant after 21 months in the combined therapy group and 15 months in the monotherapy group. The difference in treatment efficacy between the 2 groups was not significant after 6 months. Initial BCVA (P = .005), lesion size (P = .011), patient age (P = .018), and location of polyps (P = .006) significantly predicted the final visual outcome rather than treatment modality (P = .243). CONCLUSIONS PDT combined with IVB for symptomatic PCV was temporarily superior to PDT monotherapy, and the treatment efficacy decreased with time. Initial BCVA, lesion size, and location were more significant than treatment modality as the factors influencing final visual improvement.

Peripapillary intrachoroidal cavitation in high myopia: reappraisal

PurposeTo evaluate optical coherence tomography (OCT) and clinical findings of a peripapillary lesion in high myopia recently named peripapillary detachment in pathologic myopia (PDPM) or intrachoroidal cavitation.MethodsObservational case report by chart review, analysis of colour fundus photography, fluorescein angiography, and OCT in 16 eyes of 12 patients with myopic degeneration and the presence of a slightly elevated, patchy peripapillary, yellow-orange lesion on the fundus.ResultsPatients were mean age 53.1±10.7 years, with a spherical-equivalent refractive error of −10.99±3.33 D and mean axial length of 27.34±1.44 mm. The mean best-corrected visual acuity was log MAR 0.3±0.2 (between 20/100 and 20/20). Six eyes also showed myopic maculopathy. In 13 eyes, OCT showed an intrachoroidal hyporeflective space located below the normal plane of the retinal pigment epithelium. Six of these 13 eyes were found to have apparent communication between the intrachoroidal cavity and the vitreous space at the junction of the lesion and the myopic conus. In three eyes, OCT revealed intrachoroidal splitting. The fluorescein angiogram showed early hypofluorescence, without pooling or staining in late phase.ConclusionsThe yellow–orange elevated patchy lesions adjacent to the peripapillary conus in high myopic eyes may represent either intrachoroidal cavitation or choroidal schisis, which may be different stages of one disease spectrum. Vitreous fluid may be the source of the disruption of choroid and fluid accumulation.

Characteristics of primary rhegmatogenous retinal detachment in Taiwan

PurposeTo investigate the epidemiological characteristics and related risk factors for primary rhegmatogenous retinal detachment (RRD) in Taiwan.MethodsThe case–control study was based on retrospective chart review of hospital patients treated for primary RRD from 1995 to 2001, inclusively. The preoperative fundus findings and refractive status were collected for each patient. Controls were selected from a nationwide survey of visual impairment in the adult population during the same period. Risk factors for RRD were analysed by logistic regression. A total of 1032 RRD cases and 3537 controls were enrolled for the study.ResultsA pronounced bipeak pattern was evident in the age distribution for primary RRD in the third and sixth decades of life. Atrophic hole with lattice degeneration was preferential to younger (20–30 years) and highly myopic individuals (−7.4±5 D), whereas the flap tear tended to occur in middle-aged individuals (50–60 years) and those with moderate myopia (−4.1±5 D). The odds ratio for primary RRD with myopia, male gender, and older age (>40 years) were 1.33/D, 2.15, and 1.69, respectively.ConclusionsMyopia is an important RRD risk factor for young Taiwanese. The increasing prevalence of myopia has predisposed the young population to RRD.

Ciliary detachment after pars plana vitrectomy: an ultrasound biomicroscopic study.

Purpose To determine the incidence, duration, risk factors, and clinical outcomes for ciliary detachment after pars plana vitrectomy (PPV). Methods A total of 109 eyes of 103 patients who underwent PPV for various disease entities were included. Ultrasound biomicroscopy was applied to determine the tomographic features of the ciliary body before and 1, 3, and 7 days after the surgery. All eyes were then examined once weekly for 2 months. Demographic, preoperative, intraoperative, and postoperative parameters were evaluated to assess their predictive value in the formation of postvitrectomy ciliary detachment. Results Ciliary detachment was observed in 46 eyes (42%) after surgery and persisted for less than 3 weeks in 40 of 46 eyes. It most frequently occurred in eyes of patients with proliferative diabetic retinopathy (PDR) (64%) or retinal vascular obstructive diseases (RVO) (47%). Extensive retinal photocoagulation and retinal cryopexy positively predisposed to its formation whereas fluid–gas exchange had a protective effect. No clinical complications were observed in eyes with postoperative ciliary detachment. Conclusion Ciliary detachment occurred frequently after PPV. A diagnosis of PDR or RVO and surgical procedures with extensive retinal photocoagulation and retinal cryopexy may have a higher incidence of its occurrence.

Visual Outcome in Primary Macula-Off Rhegmatogenous Retinal Detachment Treated With Scleral Buckling

BACKGROUND AND PURPOSE To evaluate the visual outcome of primary macula-off rhegmatogenous retinal detachment after successful scleral buckling. METHODS A retrospective, non-controlled case series study was conducted in 93 patients (93 eyes) who underwent primary successful scleral buckling procedure for retinal detachment. Factors including duration of macular detachment, patient age, preoperative best-corrected visual acuity (VA), surgical management of subretinal fluid, and refractive error were analyzed statistically to determine their association with final visual outcome. RESULTS Postoperative VA of 20/50 or better was found in 53.6% of eyes with duration of macular detachment within 7 days, and 29.7% of eyes with macular detachment for more than 7 days (Fishers exact test, p = 0.019). VA better than 20/50 was found in 61% of eyes with preoperative VA better than 20/400 and in 33.9% with preoperative VA worse than 20/400 (Fishers exact test, p = 0.008). Patients aged 30 years or less achieved better mean postoperative VA than those aged 31 to 50 and those aged 50 years and older (ANOVA, p = 0.003). Patients with low-grade myopia (< -6D) regained significantly better mean postoperative VA as compared with high myopia (> -6D) and emmetropic eyes (0 to +3D) (ANOVA, p < 0.001). Subretinal fluid drainage procedure did not affect postoperative visual result. Multivariate logistic regression analysis revealed that the duration of macular detachment was the only variable affecting the visual result. CONCLUSION Scleral buckle surgery performed within the first week, preoperative vision more than 20/400, age younger than 30 years old, and low-grade myopia were associated with significantly better visual recovery from macular-off rhegmatogenous retinal detachment.

Anatomical and functional outcome of surgery of primary rhegmatogenous retinal detachment in high myopic eyes.

Purpose To analyse the anatomical and functional outcome of surgery for primary rhegmatogenous retinal detachment (RRD) in highly myopic eyes.Methods We retrospectively reviewed the medical records of 111 high myopic patients (111 eyes) with primary RRD treated by scleral buckling or pars plana vitrectomy in a tertiary referral university hospital. The postoperative retinal status and best-corrected visual acuity were recorded. Risk factors including age, refractive error, duration of retinal detachment, preoperative visual acuity, extent of detachment, and intraoperative and postoperative complications were evaluated. Multiple logistic regression analysis was used to determine the independent correlation of each variable on anatomical and functional outcome.Results Primary surgery resulting in retinal reattachment was achieved in 96 (86.5%) eyes with more than 6 months follow-up (range, 6–60 months). Sixty-eight (61.3%) eyes had postoperative corrected visual acuity 20/50 or more. Postoperative complications in high myopic eyes were variable, and the most common was cataract progression (19.8%). Upon multiple logistic regression analysis, young patients had significantly better anatomical outcome, although the variables including less refraction error, better preoperative visual acuity, scleral buckling procedure, and less surgical intervention showed better functional outcome in our series.Conclusions The anatomical outcome of surgery for primary RRD in highly myopic eyes was favourable, and young patients tended to have a higher success rate. Functional outcome was significantly correlated with refractive error, preoperative visual acuity, surgical procedure, and number of vitreoretinal surgery.

The development and evolution of full thickness macular hole in highly myopic eyes

PurposeTo evaluate the morphological changes before and after the formation of a full-thickness macular hole (MH) in highly myopic eyes.Patients and methodsRetrospective observational case series. From 2006 to 2013, clinical records of patients with MH and high myopia who had optical coherence tomography (OCT) before the development of MH were reviewed. All patients had been followed for more than 1 year since MH formation to observe the morphological changes.ResultsTwenty-six eyes of 24 patients were enrolled. The initial OCT images could be classified into four types: (1) normal foveal depression with abnormal vitreo-retinal relationship (eight cases), (2) macular schisis without detachment (six cases), (3) macular schisis with concomitant/subsequent detachment (nine cases), and (4) macular atrophy with underlying/adjacent scar (three cases). After MH formation, one case in type 1 and one case in type 4 group developed retinal detachment (RD). In type 2 group, four cases developed RD at the same time of MH formation. The preexisting detachment in type 3 group extended in eight cases and improved in one case. Among all the cases, 14 eyes received vitrectomy and 7 eyes received gas injection. MH sealed in nine eyes after vitrectomy and four eyes by gas injection.ConclusionThe study revealed four pathways of MH formation in highly myopic eyes. MH from macular schisis tended to be associated with detachment. However, the evolution and the results of surgical intervention were not always predictable.

Experimental myopia in chickens induced by corneal astigmatism

Abstract Astigmatism has been suggested to be an important factor in the production and/or progression of myopia. Chickens have been used as a myopic animal model for several years. In the present investigation our aim was to evaluate the importance of surgically induced corneal astigmatism by peripheral corneal incision with compression suture in one eye, the right, of 3‐day‐old chicks. Vertical incision (2 mm) with compression suture (nylon 9‐0, one stitch) induces against‐the‐rule astigmatism, horizontal incision with compression induces with‐the‐rule astigmatism. Four groups were studied 1) with one vertical cut, 2) one horizontal cut, 3) two vertical cuts, 4) two horizontal cuts. The eyes were measured by caliper after 8 weeks. Eye enlargements were induced in all groups, however, less by one cut (astigmatism around 5 diopters) than by two cuts (astigmatism 10 diopters, or more). In the latter groups the pattern of equatorial eye enlargement dependend on the axis of the induced astigmatism, the greater elongation being associated with the strongest refracting corneal meridian. All considered, the results suggest that significant corneal astigmatism could be another factor in the production of myopia, possibly acting by way of optical degradation of retinal image quality.

Blood-aqueous Barrier Function in a Patient with Choroideremia

The purpose was to determine whether there was a breakdown of the blood-aqueous barrier in a patient with choroideremia. A 27-year-old man with typical choroideremia underwent standardized ophthalmo-logical evaluation, including quantitative measurement of aqueous flare intensity, by a laser flare-cell meter. The results showed areas of atrophy of the choriocapillaries and retinal pigment epithelium in the mid-periphery and posterior pole, although not in the macula. Fluorescein angiography showed areas of loss of the choriocapillaries and retinal pigment epithelium. The fovea was spared with a surrounding zone of hy-perfluorescence. Electroretinography showed a subnormal photopic amplitude and extinguished scotopic response. Electrooculography revealed that the light peak/dark trough ratio was reduced. Goldmann perimetry showed constricted peripheral fields. Laser photometry showed an increase in the aqueous flare intensity in both eyes, as compared with normal subjects. We conclude that the function of the blood-aqueous barrier might be affected in patients with choroideremia.