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Refractive Errors, Myopia, and Presbyopia
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Ka Wai Kam, Chi Pui Pang, Jason C. S. Yam
The definition of pathologic myopia has not been standardized for early studies. In 2015, the META-analysis for Pathologic Myopia (META-PM) study group proposed a classification.60 Pathologic myopia was defined as myopic chorioretinal atrophy – either equal to or more serious than diffuse atrophy – and/or the presence of posterior staphylomas.61 In China, the Beijing Eye Study showed a prevalence of pathologic myopia of 3.1% among 4,319 Chinese subjects over 40 years.62 The Handan Eye Study showed a much lower rate of 0.9% among 6,603 Chinese subjects over 30 years.30 Beijing is an urbanized city and Handan is more rural. Notably, both studies defined pathological myopia as myopic chorioretinal atrophy, staphyloma, lacquer cracks, or Fuchs spot. In Taiwan, the Shihpai Eye Study reported a prevalence of myopic maculopathy with posterior staphyloma at 3% among 1,058 adults over 65 years.63 In Japan, the Hisayama study reported a prevalence of pathological myopia at 1.7% among 1,892 adults aged 40 years and older.64 The Central India Eye and Medical Study reported a prevalence of 0.2% among 4,561 adults aged 30 years and older.65 For Australian whites, the BMES reported a prevalence of 1.2% among 3,583 adults aged 49 years and older.66 There is no obvious regional or ethnic discrimination in the occurrence of pathologic myopia.
Medical retina
Published in Mostafa Khalil, Omar Kouli, The Duke Elder Exam of Ophthalmology, 2019
Posterior staphyloma An outpouching of the posterior wall of the eye that has a different radius of curvature than the rest of the eye.One of the hallmarks of pathological myopia, associated with poor prognosis.
Common Vitreoretinal Procedures
Published in Pradeep Venkatesh, Handbook of Vitreoretinal Surgery, 2023
Challenges during vitreoretinal surgery are similar to those encountered during surgery for retinal detachment in patients with high myopia: poor contrast owing to thinned retina and atrophic choriocapillaris, vitreoschisis, difficult access owing to increased axial length, and risk of suboptimal retinopexy. Careful study of preoperative OCT may help in planning and implementing surgical dissection meticulously. Taking appropriate measures to improve visualization of the vitreous (triamcinolone suspension) and membranous structures such as EMM and ILM (dyes such as indocyanine green or brilliant blue) add to the safety of the surgery. ILM peeling, even in the absence of macular hole, is considered important to the success of surgery. Use of a flat contact lens provides the best resolution, so one must resist dissection of membranes at the macula using a wide-field lens. Instruments (forceps and cannula) with longer shafts, when available, must be requisitioned from the inventory or surgical store prior to surgery. Surgery assisted by intraoperative OCT, 3D viewing, and digital filters may be helpful. Long-term tamponade is probably not indicated if there was no pre-existing macular hole and if the surgery was uneventful. Controversy on choice of tamponade and duration of prone positioning persists owing to conflicting reports on the rapidity of MTM resolution, incidence of post-surgery macular hole, and final visual recovery. Fovea-sparing ILM peeling is considered to be a safer approach in these patients owing to the high risk of deroofing a thinned-out, central foveal schitic cavity. Despite ILM peeling, tractional forces on the fovea may not be completely eliminated in patients with macular hole and posterior pole detachment. This has been linked to straightened and stretched retinal vessels running from the optic disc to the temporal retina and to scleral vector forces from the posterior staphyloma. Non-compliant Bruch’s membrane could also be a contributive factor.
Fentanyl as an adjuvant to the local anesthetic in the peribulbar block for vitrectomy operations
Published in Egyptian Journal of Anaesthesia, 2023
Abeer A Hassanin, Hossam Elden M Moharam, Shimaa H Hassan, Sahar A Hashish
A thorough medical background.Heart rate, arterial blood pressure, and breathing rate for a general checkup.Physical examination of the abdomen, heart, chest, and other systems.Regular diagnostic procedures include a full blood count, a liver and renal function test, a blood sugar test, and a chest x-ray.Detecting staphyloma, the axial length of the eye, hemorrhage, and retinal detachment using ophthalmic ultrasonography and biometry.
Ultra-Widefield Imaging for Evaluation of the Myopic Eye
Published in Seminars in Ophthalmology, 2021
Cassie A. Ludwig, Jade Moon, Itika Garg, John B. Miller
UWF OCT provides a clinically practical alternative to characterize the staphylomatous shape of high myopes. Recent prototypes of UWF OCT using multiple scan lines generate maps that allow for the 3D reconstruction of posterior staphylomas.36,37 Currently, this is limited to a region of interest of 23 mm × 20 mm and a depth of 5 mm. In a study by Shinohara et al., all staphylomas detected by 3D-MRI were visualized in their entirety on UWF OCT in 100 eyes of 57 patients with a mean axial length of 30.0 ± 2.3 mm (range 25.1–36.5 mm), with the exception of two very large staphylomas.38 The same group reported a prevalence of posterior staphyloma in 482 of 729 eyes (66.1%) with a mean axial length of 30.2 ± 2.1 mm. With the aid of UWF OCT, they detected a spatial association between myopic retinoschisis and staphylomas, with potential implications for causality (see Figure 2). Using UWF OCT in highly myopic children less than 20 years of age, another group found that changes in the choroidal thickness adjacent to the edge of staphylomas with posterior displacement of the sclera were an early predictor of future protrusion of the staphyloma.39
Prevalence and Associations of Posterior Segment Manifestations in a Cohort of Egyptian Patients with Pathological Myopia
Published in Current Eye Research, 2019
Ayman G. Elnahry, Mohamed M. Khafagy, Soheir M. Esmat, Hassan A. Mortada
In a Japanese study, 65.8% had posterior staphyloma compared with 33.1% in our study, although the mean age and axial length were very similar to our study.15 In another study from Japan, the prevalence of posterior staphyloma among high myopes was 90%, the mean age, however was higher than our study.26 In a study of high myopes from Mexico, posterior staphyloma was present in 35.3% of eyes.27 This suggests a possible difference in the prevalence of staphyloma across different populations which may have important implications since posterior staphyloma is known to be associated with an increased risk of various macular complications as shown in the study from Mexico which showed that the prevalence of macular anatomical changes rose from 22.4% to 53.7% in patients with staphyloma, and in our study which showed a significant association between posterior staphyloma and several retinal pathologies. A limitation of our study with regards to posterior staphyloma assessment is that we did not grade posterior staphylomas according to their severity, as done by Steidl and Pruett and Hsiang et al., who graded posterior staphylomas according to their severity into 4 grades using indirect ophthalmoscopy and B-scan ultrasonography, respectively.23, 26 This can be useful in associating retinal pathologies with the grade of staphyloma.