Refractive Errors, Myopia, and Presbyopia
Ching-Yu Cheng, Tien Yin Wong in Ophthalmic Epidemiology, 2022
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.
Common Vitreoretinal Procedures
Pradeep Venkatesh in 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.
Medical retina
Mostafa Khalil, Omar Kouli in 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.
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
Assessment of Visual Function in Patients with Myopic Foveoschisis
Published in Current Eye Research, 2019
Qingchen Li, Hao Wang, Peng Gao
The term myopic foveoschisis (MF) indicates the splitting of retinal layers.1 MF is primarily characterized by an intraretinal cleavage that can lead to vision impairment. The condition is common, exhibiting a prevalence of approximately 9%–20% in highly myopic eyes with posterior staphyloma.2,3 With the development of optical coherence tomography (OCT), MF is gaining attention as a severe complication of pathological myopia.4 With the increasing demands for comprehensive visual information, there have been several clinical parameters developed, which help to assess visual function. In this study, we aimed to use multiple recent methods to evaluate the visual function of patients with MF and to determine potential associations between results of measurements.
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.
Related Knowledge Centers
- Cornea
- Eye
- Optic Nerve
- Uvea
- Sclera
- Anterior Segment of Eyeball
- Posterior Segment of Eyeball
- Macula
- Near-Sightedness