Membrane removal in proliferative vitreoretinopathy
A Peyman MD Gholam, A Meffert MD Stephen, D Conway MD FACS Mandi, Chiasson Trisha in Vitreoretinal Surgical Techniques, 2019
The surgical eye must be assessed carefully and undergo a complete examination. Although the cornea does not usually present a problem, it must be sufficiently clear to permit surgery. The iris should be evaluated for rubeosis, synechiae, and pupillary dilation. Eyes with rubeosis have a poorer prognosis. Preoperative knowledge that the pupil does not dilate adequately, requiring pupil stretching or breaking of synechiae, will facilitate surgical planning. The eye should be evaluated for glaucoma and undergo gonioscopy. These eyes are more likely to develop postoperative intraocular pressure (IOP) problems, and they should be managed accordingly to minimize pressure elevation. If the eye is hypotonus, it should be examined carefully for anterior PVR and traction on the ciliary processes.
Clinical specialties
Andrew Schofield, Paul Schofield in The Complete SAQ Study Guide, 2019
Richard, a 52-year-old taxi driver, comes to see you in the eye casualty with a presenting symptom of a ‘sausage-shaped’ visual loss in his right eye. You measure the intraocular pressure to be 32 mmHg. You suspect glaucoma. What is used to measure intraocular pressure, and what is the upper limit of normal in mmHg? (2)What is gonioscopy, and why is it important in this clinical case? (2)You now suspect open-angle glaucoma.What is the most important structure to now examine, and what will you look for? (1)Name two common risk factors for open-angle glaucoma? (2)Name four medical treatments that can be used to treat this patient? (2)If his vision deteriorates, what organisation will you advise Richard to get in contact with? (1)
Glaucoma
Mary E. Shaw, Agnes Lee in Ophthalmic Nursing, 2018
Angle-closure glaucoma, which may be easily missed if it is chronic and asymptomatic, where a patient has a narrow angle, threatening angle closure but no acute episodes, the patient has a limit to the aqueous drainage so the IOP rises but the real problem is that the angle is compromised by the iris. This emphasizes the importance of performing gonioscopy on all new patients. Treatment is a peripheral iridotomy to lower the IOP without any other treatment. This is unlike the typical acute angle closure, which has a very high IOP and pain associated with it.
How to Predict Intraocular Pressure Reduction after Cataract Surgery? A Prospective Study
Published in Current Eye Research, 2019
Claudio I. Perez, Sunee Chansangpetch, Anwell Nguyen, Max Feinstein, Marta Mora, Mai Badr, Marisse Masis, Travis Porco, Shan C. Lin
Patient demographic information was obtained at the time of enrollment for each subject. The preoperative assessment included best-corrected visual acuity, IOP measurement, central corneal thickness measurement, gonioscopy, and complete slit-lamp examination including dilated fundus evaluation. All IOP measurements were performed using Goldmann applanation tonometry by the same clinician (S.C.L.) between 1 PM and 6 PM. The mean IOP measurement from two preoperative values was used in this study. If IOP measurement from the two preoperative values differed by more than 2 mmHg, a third value was obtained and the median was chosen. Gonioscopy was performed by the same glaucoma specialist (S.C.L.) using a Zeiss-style 4-mirror lens (model OPDSG, Ocular Instruments, Inc., Bellevue, WA). The angles were based on the Shaffer grading system in primary position of gaze without indentation.11 Eyes with Shaffer grade 1 or less in at least two quadrants were defined as narrow angles. After grading each quadrant, potential PAS were evaluated by performing dynamic gonioscopy in those angles which were narrow for the purpose of possible exclusion. A preoperative gonioscopy score was recorded, by summing the Shaffer gonioscopy grading in the four quadrants (range 0–16) as described previously.12
Anterior segment morphology after laser iridotomy in primary angle closure suspects
Published in Clinical and Experimental Optometry, 2018
Tarannum Mansoori, Nagalla Balakrishna
After obtaining written informed consent, all the participants underwent a comprehensive ophthalmic examination, including a medical and ocular history, uncorrected and best‐corrected visual acuity testing, refraction, slitlamp examination, intraocular pressure measurement with Goldmann applanation tonometry, gonioscopy, undilated disc evaluation and anterior segment analysis using the glaucoma analysis mode of the Scheimpflug‐Placido disc topographer system (Sirius Schwind eye‐tech‐solutions, version 2.6.3). Gonioscopy was performed with a Sussmann 4 mirror gonioscopy lens (Ocular Instruments Inc., Bellevue, Washington, USA) in a dimly illuminated room using a 1 × 1-mm slit beam, with the patient looking in the primary position of gaze and care was taken to avoid light falling on the pupil.
Controversies in Pediatric Angle Surgery and Secondary Surgical Treatment
Published in Seminars in Ophthalmology, 2023
Alexander K. Young, Deborah K. Vanderveen
Other new minimally invasive glaucoma surgery devices were designed to allow surgeons to perform nearly 360 degrees of treatment from a single incision using an ab interno approach. The OMNI Surgical System (Sight Sciences, Menlo Park, California, USA) utilizes a prolene catheter threaded through the trabecular meshwork. It can also perform viscocanalostomy, as the catheter contains a lumen that will inject viscoelastic into the canal and collector channels when retracted.16 Requirements to perform this technique are similar to traditional goniotomy, including a clear cornea to visualize the angle via gonioscopy. This approach for primary angle surgery is beginning to be described in the literature, with promising results.17 Additionally, gonioscopy-assisted transluminal trabeculotomy is another option that spares conjunctiva and performs a 360 goniotomy.18
Related Knowledge Centers
- Cornea
- Glaucoma
- Ora Serrata
- Sclera
- Ophthalmology
- Iris
- Slit Lamp
- Optometry
- Total Internal Reflection
- Aqueous Humour