Peripapillary Tissue Research Articles

Deformation of the Rodent Optic Nerve Head and Peripapillary Structures during Acute Intraocular Pressure Elevation

PURPOSE. To evaluate the effect of acutely elevated intraocular pressure (IOP) on retinal thickness and optic nerve head (ONH) structure in the rat eye by spectral domain-optical coherence tomography (SD-OCT). METHODS. Fourteen adult male Brown-Norway rats were studied under anesthesia (ketamine/xylazine/acepromazine, 55:5:1 mg/kg intramuscularly). Both eyes were imaged by SD-OCT on two baseline occasions several weeks before and again 2 and 4 weeks after the acute IOP imaging session. During the acute IOP session, SD-OCT imaging was performed 10 minutes after IOP was manometrically set at 15 mm Hg and then at 10, 30, and 60 minutes after IOP had been elevated to 50 mm Hg (n = 8) and again 10 and 30 minutes after IOP had been lowered back to 15 mm Hg (recovery). In two additional groups, IOP elevation was set to 70 mm Hg (n = 4) or 40 mm Hg (n = 2). Acute IOP results are reported for a pattern of 49 horizontal B-scans spanning a 20° square and follow-up results for peripapillary circular B-scans. Retinal and retinal nerve fiber layer (RNFL) thicknesses were measured with custom software by manual image segmentation. Friedman and Dunn's tests were used to assess acute and longer-term effects of acute IOP elevation. RESULTS. Acute IOP elevation to 50 mm Hg caused rapid (within seconds) deformation of the ONH and peripapillary structures, including posterior displacement of the ONH surface and outward bowing of peripapillary tissue; retinal thickness decreased progressively from 10 to 30 to 60 minutes by 16%, 18%, and 20% within the area of Bruch's membrane opening (BMO; P < 0.0001) by 8%, 9%, and 11% within the central 10° (excluding the BMO; P < 0.0001) but only by 1%, 2%, and 2.4% beyond the central 10° (P < 0.0001). Recovery was progressive and nearly complete by 30 minutes. Acute IOP elevation to 40 and 70 mm Hg produced similar structural changes, but 70 mm Hg also interfered with retinal blood flow. There were no changes in peripapillary retinal or RNFL thickness (P = 0.08 and P = 0.16, respectively) measured 2 and 4 weeks after acute elevation to 50 mm Hg. CONCLUSIONS. Acute IOP elevation in the rodent eye causes rapid, reversible posterior deformation of the ONH and thinning of the peripapillary retina, with only minimal retinal thinning beyond 5° of the ONH. No permanent changes in peripapillary retinal or RNFL thickness (for up to 1 month of follow-up) were caused by 60 minutes of IOP elevation to 50 mm Hg.

Peculiar arcuate scotoma in pathologic myopia—optical coherence tomography to detect peripapillary neural tissue loss over the disc crescent

Optical coherence tomography (OCT) was used to detect peripapillary neural tissue loss (PPNTL) over the disc crescent in pathologic myopia. The retinal neural tissue loss located inside the disc crescent in pathologic myopia is a newly recognized fundus lesion. Review of ten eyes of ten patients with peripapillary yellowish-white retinal lesions who underwent OCT for evaluation of the nature of PPNTL in pathologic myopia. OCT, fluorescein angiography, automated visual fields, axial length measurement with ultrasound A scan, and ultrasound B scan were performed. Ten eyes of ten patients were identified during a 14-year period to have findings characteristic of PPNTL. The mean age of the patients was 46 years. They were followed up for an average of 9 years. The mean spherical equivalent correction was -10.50 diopters (D) (range -6.0--16.0 D). The mean axial length was 28.6 mm (range 26.30-31.50 mm). In each case, OCT showed a complete retinal discontinuity in the PPNTL lesion. Automated visual field examination showed corresponding arcuate scotoma. During the follow-up period, the inner retina layer of the retinal defect margin was elevated by posterior hyaloid and partial retinal detachment developed in one eye. PPNTL in pathologic myopia is a relatively asymptomatic, yellowish-white peripapillary retinal discontinuity. Recognition of this lesion is important because the visual field defect may mimic glaucomatous changes owing to the loss of nerve fiber layer. Progressive partial retinal detachment may ensue as one of the complications of the peripapillary lesion.

Treatment of Central Retinal Vein Occlusion by Vitrectomy with Lysis of Vitreopapillary and Epipapillary Adhesions, Subretinal Peripapillary Tissue Plasminogen Activator Injection, and Photocoagulation.

Abstract PURPOSE: To report a case of subretinal peripapillary tissue plasminogen activator (tPA) injection with vitreopapillary and epipapillary membrane dissection and peripheral photocoagulation in the treatment of central retinal vein occlusion. DESIGN: Interventional case report. METHODS: A 79-year-old woman with a history of branch vein occlusion in the left eye presented with visual loss in the right eye for 4 months secondary to unresolved central retinal vein occlusion. She underwent vitrectomy, right eye, with lysis of vitreopapillary and epipapillary adhesions and hyaloid separation, subretinal peripapillary tissue tPA injection, peripheral photocoagulation, and air-fluid exchange. RESULTS: Postoperatively, funduscopic and fluorescein angiographic features of venous obstruction improved rapidly, with prompt reduction in intraretinal hemorrhages and disk and macular edema. The patient reported subjective improvement of vision in her right eye, although measured improvement was modest, from finger counting to 20/400. CONCLUSION: Subretinal administration of tPA, lysis of adhesions, and endophotocoagulation may be of value in resolving the obstructive component of selected cases of chronic central retinal vein occlusion associated with vitreopapillary and epipapillary traction.

Treatment of central retinal vein occlusion by vitrectomy with lysis of vitreopapillary and epipapillary adhesions, subretinal peripapillary tissue plasminogen activator injection, and photocoagulation

PURPOSE: To report a case of subretinal peripapillary tissue plasminogen activator (tPA) injection with vitreopapillary and epipapillary membrane dissection and peripheral photocoagulation in the treatment of central retinal vein occlusion. DESIGN: Interventional case report. METHODS: A 79-year-old woman with a history of branch vein occlusion in the left eye presented with visual loss in the right eye for 4 months secondary to unresolved central retinal vein occlusion. She underwent vitrectomy, right eye, with lysis of vitreopapillary and epipapillary adhesions and hyaloid separation, subretinal peripapillary tissue tPA injection, peripheral photocoagulation, and air-fluid exchange. RESULTS: Postoperatively, funduscopic and fluorescein angiographic features of venous obstruction improved rapidly, with prompt reduction in intraretinal hemorrhages and disk and macular edema. The patient reported subjective improvement of vision in her right eye, although measured improvement was modest, from finger counting to 20/400. CONCLUSION: Subretinal administration of tPA, lysis of adhesions, and endophotocoagulation may be of value in resolving the obstructive component of selected cases of chronic central retinal vein occlusion associated with vitreopapillary and epipapillary traction.

Heidelberg retinal flowmetry: factors affecting blood flow measurement

AIMSTo evaluate factors affecting Heidelberg retinal flowmeter (HRF) measurements of retinal and optic nerve head blood flow in human subjects.METHODSThe angle of incidence between laser beam and fundus, and camera...

Intraductal ultrasound (IDUS) in preoperative staging of tumors of the papilla of Vater

An adenoma-carcinoma-sequenee also applies to adenomas of the papilla of Vater. ERCP alone does not provide any information on infiltrative growth. Endoscopic ultrasound (EUS) is usually limited in detection of processes smaller than 10 nun. High-frequency ultrasonic probes adjusted to the dimension of the pancreatic and biliary tract can, if applied during ERCP, visualize the peripapillary tissue at highest resolution. As diagnostic imaging influences the choice of therapeutical procedures we studied the diagnostic impact of miniprobe sonography in polypoid proce~es of the papilla of Vater.

Clinical Histologic Correlation of Human Peripapillary Anatomy

The various types of peripapillary crescents which are observed clinically are generally interpreted to represent misalignments of the edges of the neural retina, retinal pigment epithelium (RIPE), choroid, and sclera at the disc margin. In order to test the validity of conventional assumptions about the anatomic basis for each type of crescent, the authors compared histologic sections to previously obtained clinical photographs and fluorescein angiograms of 21 eyes enucleated for choroidal melanomas. The authors' results define several configurations of peripapillary tissue, but also show that there can be more than one anatomic basis for some appearances. A scleral lip, which consists of an anterior extension of sclera to separate the choroid from the optic nerve head, is nearly always present, and ophthalmoscopically appears as a white rim that marks the disc margin and accumulates fluorescein after the vascular transit in an angiogram. A chorioscleral crescent occurs when the RPE is retracted from the disc margin, most prominent when associated with a tilted exit canal for the axon bundles through the sclera. In such a crescent, the choroid may be thinned or absent next to the disc, exposing to view some of the underlying sclera. Malposition of the embryonic fold occurs when the boundary between the neural retina and the RIPE does not coincide with the embryologically formed fold in the neuroectoderm that occurs at the disc. When this occurs, there is either a double layer RIPE (forming a very dark pigment crescent) or a double layer of incompletely formed neural retina adjacent to the disc. Irregular pigmentation occurs when the RPE adjacent to the disc lacks pigment or is hyperpigmented, mimicking misalignment of the layers when viewed by ophthalmoscopy.