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J B Jonas

Publications and source records attributed to J B Jonas.

At least 91 records · Page 5Linked to original sources
PubMed2000

Optic disk and retinal nerve fiber layer damage after transient central retinal artery occlusion: an experimental study in rhesus monkeys.

PURPOSE: To evaluate the retinal tolerance time to acute ischemic insult in middle-aged or elderly rhesus monkeys with pre-existing atherosclerosis and arterial hypertension. METHODS: In 39 eyes of 39 middle-aged and elderly rhesus monkeys with a mean age of 19.5 +/- 2. 8 years, occlusion of the central retinal artery was produced by temporary clamping of the central retinal artery at its site of entry into the dural sheath of the optic nerve for 97 to 300 minutes. Stereoscopic color fundus photography and fluorescein fundus angiography were performed before central retinal artery occlusion and serially thereafter. Retinal nerve fiber layer damage and optic disk changes were assessed by comparing morphometric evaluation of the color fundus photographs taken before central retinal artery occlusion and color fundus photographs taken at the end of the study. RESULTS: There was a significant correlation between duration of central retinal artery occlusion and decreased visibility of retinal nerve fiber layer (P =.018) and increasing optic disk pallor (P =. 014), and a trend between residual retinal circulation and decreased visibility of retinal nerve fiber layer (P =.085) and optic disk pallor (P =.162). However, there was a marked interindividual variation between the length of central retinal artery occlusion and degree of increased optic disk pallor and decreased visibility of the retinal nerve fiber layer, even among eyes with similar duration of central retinal artery occlusion. Complete or almost total optic nerve atrophy and nerve fiber damage were present in all eyes in which the duration of central retinal artery occlusion was 240 minutes or more. CONCLUSIONS: The findings of this study, compared with our previous study in young healthy rhesus monkeys, indicate that in middle-aged or elderly atherosclerotic and arterial hypertensive rhesus monkeys, central retinal artery occlusion for less than 100 minutes produced no apparent morphometric evidence of optic nerve damage; however, central retinal artery occlusion of 105 minutes but less than 240 minutes produced a variable degree of damage; central retinal artery occlusion for 240 minutes or more produced total or almost total optic nerve atrophy and nerve fiber damage.

Animals↗
PubMed2000

Appearance of the optic disk and retinal nerve fiber layer in atherosclerosis and arterial hypertension: an experimental study in rhesus monkeys.

PURPOSE: To evaluate changes in the appearance of the optic nerve head and retinal nerve fiber layer of rhesus monkeys with chronic arterial hypertension and atherosclerosis. METHODS: Color stereoscopic fundus photographs of 25 eyes of 25 rhesus monkeys (mean age +/- SD of 20.4 +/- 1.87 years) with chronic experimental systemic arterial hypertension and atherosclerosis (for a mean duration of 89.1 +/- 39.1 months and 104.6 +/- 62.2 months, respectively) were morphometrically evaluated. They were compared with color stereoscopic fundus photographs of 17 eyes of 17 normal monkeys (mean age +/- SD of 19.76 +/- 2.19 years) without any detectable systemic or ocular disease. There was no significant difference in age between the two study groups (P =.22). RESULTS: In the atherosclerotic-arterial hypertensive group, visibility of the retinal nerve fiber layer was significantly (35.691 +/- 5.95 units vs 28.72 +/- 9.18 units, P =.009) less and frequency of localized retinal nerve fiber layer defects was significantly (six of 25 or 24% vs zero of 17 or 0%, P =.01) more than in the normal control group. The two groups did not differ significantly in size of the neuroretinal rim (P =.66), shape of the neuroretinal rim (P >.15), size of alpha (P >.44) and beta (P >.65) zones of parapapillary chorioretinal atrophy, or regional distribution of alpha and beta zones (P >.40). CONCLUSIONS: Chronic experimental arterial hypertension and atherosclerosis do not markedly change the size and shape of the neuroretinal rim or parapapillary atrophy; however, they do lead to reduced visibility of the retinal nerve fiber layer, with localized retinal nerve fiber layer defects indicating optic nerve damage. Thus, unlike glaucomatous optic neuropathy, experimental arterial hypertension and atherosclerosis are not associated with a significant change in the parapapillary atrophy or the neuroretinal rim of the optic disk despite the loss of nerve fibers.

Animals↗
PubMed2000

Postoperative analgesia by reinjections of local anesthetic through an indwelling retrobulbar catheter.

PURPOSE: To evaluate an indwelling retrobulbar catheter for repeatable postoperative retrobulbar injections of local anesthetics for titratable analgesia after intraocular surgery. METHODS: The prospective study included all 124 patients (124 eyes) who consecutively underwent retinal or cyclocryocoagulation (n = 22), pars plana vitrectomy, or retinal detachment surgery (n = 102), and who were operated on by the same surgeon with local anesthesia within a period of 12 months. Using commercially available retrobulbar needles with a diameter of 0.60 mm or 0.80 mm and a length of 38 mm, 5 ml of mepivacaine 2% with hyaluronidase were injected. Through the same needle, a 28-gauge commercially available flexible catheter was introduced into the retrobulbar space, the needle was withdrawn, and the catheter was fixed in place. When the patients started to feel pain after surgery, 2 ml of mepivacaine 2% or 2 ml of bupivacaine 0.75% were reinjected through the catheter. The catheter was removed 24 to 72 hours after surgery. RESULTS: Because of increasing pain in the postoperative period, 93 patients (93 of 124, or 75%) received a reinjection 4.2+/-2.0 hours after the preoperative injection. Seventy patients received a second reinjection after an additional 2.7+/-1.9 hours, and 42 patients received a third reinjection 3.1+/-2.0 hours later. After each reinjection, the patients became pain free. Removal of the catheter after surgery was unremarkable. CONCLUSIONS: An indwelling retrobulbar catheter for repeatable postoperative injection of short-acting local anesthetics is useful and effective for titratable postoperative analgesia after intraocular surgery, and it allows patients to avoid the side effects of systemic analgesics and sedatives.

Adult↗
PubMed2000

Ophthalmoscopic detectability of the parafoveal annular reflex in the evaluation of the optic nerve: an experimental study in rhesus monkeys.

OBJECTIVE: To evaluate whether assessment of the ophthalmoscopic visibility of the parafoveal annular reflex is helpful in the detection of optic nerve fiber and optic nerve damage. DESIGN: Experimental animal study. ANIMALS: The study was performed in rhesus monkeys, divided into four study groups, with no significant difference in ages of the animals in the various groups. Three of these groups had (1) experimental chronic high-pressure glaucoma (n = 37 monkeys), (2) experimental temporary occlusion of the central retinal artery (n = 19 monkeys), and (3) systemic atherosclerosis and arterial hypertension (n = 13 monkeys). The fourth group was the normal control group (n = 10 monkeys). METHODS: In 60-degree color fundus photographs, taken at baseline and at the end of the study, the ophthalmoscopic detectability of the parafoveal annular reflex was graded, the visibility of the retinal nerve fiber layer was assessed, and neuroretinal rim and parapapillary atrophy were measured. MAIN OUTCOME MEASURES: Ophthalmoscopic detectability of the parafoveal annular reflex; visibility of the retinal nerve fiber layer; neuroretinal rim area; size of parapapillary atrophy. RESULTS: The parafoveal annular reflex was significantly (P < 0.0001) better detectable at baseline of the study than at the end of the study. In all study groups, detectability of the parafoveal annular reflex decreased significantly (P < 0.0001) with decreasing visibility of the retinal nerve fiber layer. In the glaucoma group, parafoveal annular reflex detectability additionally decreased significantly (P < 0.001) with increasing area of beta zone of parapapillary atrophy and with decreasing neuroretinal rim area. In the normal group, the parafoveal annular reflex detectability decreased with increasing age, parallel to a loss in the visibility of the retinal nerve fiber layer. In 23 of 25 (92%) eyes with a complete loss of the visibility of the retinal nerve fiber layer at the end of the study, the parafoveal annular reflex was no longer detectable. CONCLUSIONS: The findings suggest that evaluation of the detectability of the parafoveal annular reflex in routine ophthalmoscopy is a useful additional tool in the qualitative assessment of the retinal nerve fiber layer and optic nerve.

Animals↗
PubMed2000

Prognostic factors in ocular injuries caused by intraocular or retrobulbar foreign bodies.

OBJECTIVE: To evaluate prognostic factors associated with final visual outcome, development of posttraumatic infectious endophthalmitis, and occurrence of proliferative vitreoretinopathy in patients with penetrating ocular injuries caused by intraocular or retrobulbar foreign bodies (FBs). DESIGN: Clinic-based cross-sectional study. PARTICIPANTS: One hundred thirty patients presenting with penetrating ocular injuries caused by lacerations from FBs were operated on by one of two surgeons between 1989 and 1997. Follow-up time was an average of 20.84 +/- 20.76 months (median: 17.0 months). All FBs were located posterior to the lens. INTERVENTIONS: Pars plana vitrectomy; foreign body removal; additional surgical procedures according to the clinical situation. MAIN OUTCOME MEASURES: Postoperative visual acuity; posttraumatic infectious endophthalmitis; proliferative vitreoretinopathy. RESULTS: Occurrence of posttraumatic infectious endophthalmitis developing in seven patients (7/130 = 5.4%) was significantly (P = 0.026) associated with removal of the FB later than 24 hours after the accident and with the type of the FB (P < 0.01). Size (P = 0.37) of the FB, preoperative visual acuity (P = 0.62), presence of traumatic cataract (P = 0.75) or a retinal lesion by the FB (P = 0.16), age (P = 0.39), and gender (P = 0.46) did not show a statistically significant influence on the occurrence of endophthalmitis. Statistically significant risk factors for the development of proliferative vitreoretinopathy occurring in 27 patients (27 of 99 [27.6%] patients with a minimal follow-up of 3 months) were size of the FB (P < 0.001), preoperative visual acuity (P = 0.02), presence of a retinal lesion (P = 0.002), and traumatic cataract (P = 0.03). The time between FB removal and the accident was statistically marginally associated with the development of proliferative vitreoretinopathy (P = 0.07). Postoperative visual acuity depended significantly on size of the FB (P = 0.002), preoperative visual acuity (P < 0.001), presence of a retinal lesion (P = 0.049), and location of the retinal lesion (P < 0.001). Three eyes had to be enucleated because of endophthalmitis or phthisis bulbi. CONCLUSIONS: Prognosis in open-globe injuries with intraocular or retrobulbar foreign bodies depends on the size and type of the foreign body, presence and location of retinal lacerations, additional involvement of other intraocular structures, preoperative visual acuity, and timing of surgery. These factors may be important in preoperative counseling of the patient and for planning surgery.

Adolescent↗
PubMed2000

Optic nerve head appearance in juvenile-onset chronic high-pressure glaucoma and normal-pressure glaucoma.

OBJECTIVE: To evaluate the appearance of the optic nerve head in chronic high-pressure glaucoma and normal-pressure glaucoma. DESIGN: Clinic-based cross-sectional study. PARTICIPANTS: The study included 52 eyes with normal-pressure glaucoma and 28 eyes with juvenile-onset primary open-angle glaucoma that served as models for chronic high-pressure glaucoma. METHODS: Color stereo optic disc photographs and wide-angle retinal nerve fiber layer photographs were morphometrically examined. MAIN OUTCOME MEASURES: Localized retinal nerve fiber layer defects; parapapillary chorioretinal atrophy; disc hemorrhages; optic cup shape; retinal arteriole narrowing. RESULTS: Both study groups did not vary significantly in count of localized retinal nerve fiber layer defects, size of parapapillary atrophy, optic cup depth, steepness of disc cupping, rim/disc area ratio, diameter of retinal arterioles, and frequency and degree of focal retinal arteriole narrowing. In normal-pressure glaucoma versus juvenile open-angle glaucoma, localized retinal nerve fiber layer defects were significantly broader, disc hemorrhages were found significantly more often and were larger, and neuroretinal rim notches were present more frequently and were deeper. CONCLUSIONS: Chronic high-pressure glaucoma and normal-pressure glaucoma show morphologic similarities in the appearance of the optic nerve head. The lower frequencies of detected disc hemorrhages and rim notches in high-pressure glaucoma may be due to a smaller size of hemorrhages and localized retinal nerve fiber layer defects in high-pressure glaucoma. Both glaucoma types have morphologic features in common, suggesting that they may possibly belong to a spectrum of the same pathologic process.

Adolescent↗
PubMed2000

Diagnosis and pathogenesis of glaucomatous optic neuropathy: morphological aspects.

Glaucomatous optic neuropathy is classified by morphologic changes in the intrapapillary and parapapillary region of the optic nerve head and the retinal nerve fibre layer. These changes can be evaluated using descriptive optic nerve head variables which are the size and shape of the optic disc; size, shape and pallor of the neuroretinal rim; size of the optic cup in relation to the area of the disc; configuration and depth of the optic cup; cup-to-disc diameter ratio and cup-to-disc area ratio; position of the exit of the central retinal vessel trunk on the lamina cribrosa surface; presence and location of splinter-shaped haemorrhages; occurrence, size, configuration and location of parapapillary chorioretinal atrophy; diffuse and/or focal decrease of the diameter of the retinal arterioles; and visibility of the retinal nerve fibre layer. Assessment of these variables is useful for the early detection of glaucomatous optic nerve damage, to follow-up patients with glaucoma, to differentiate various types of the chronic open-angle glaucomas, and to get hints for the pathogenesis of glaucomatous optic nerve fibre loss.

Diagnosis, Differential↗
PubMed2000

[Monitoring of morphometric changes of optic discs with morphologic progression of glaucomatous optic atrophy by means of laser scanner tomography].

AIM: Aim of this study was to measure morphometric changes in optic discs with laser-scanning tomography (HRT, Heidelberg-Retina-Tomograph, Heidelberg) in eyes with early glaucomatous morphologic progression. PATIENTS AND METHODS: 61 eyes of 36 patients with marked neuroretinal rim loss or its early morphologic signs (1. optic disc hemorrhages, 2. reduced visibility of the retinal nerve fiber layer (RNF), 3. appearance of narrowing of retinal vessels, 4. enlargement of the choroidal, parapapillary atrophy) were compared to 74 normal eyes of 39 probands. 15 degrees stereographs of the optic discs were evaluated for morphologic changes. The morphometric variables of the neuroretinal rim and excavation measured by the HRT were examined in the course of the disease. RESULTS: In the group of normals no significant changes of the neuroretinal rim in the course of 2.0 +/- 1.2 years were found. In the group of glaucomatous eyes (3.0 +/- 1.5 years follow-up) 34 eyes showed marked neuroretinal rim loss, 17 disc hemorrhages, 4 vessel narrowing, 3 an increased chorioidal atrophy, 3 a decreased visibility of the retinal nerve fiber layer. In these eyes a significant loss of rim area (p = 0.01) and an increase of excavation area (p = 0.0001) and volume (p = 0.003) was measured by the HRT. Only three eyes showed a perimetric loss of sensitivity (0.8-3.4 db) in Octopus static perimetry. CONCLUSIONS: Laser-scanning tomography of the optic disc seems to be able to measure morphometric changes in eyes with morphologic progression of glaucomatous optic atrophy, even before perimetric changes occur.

Adult↗
PubMed2000

Influence of optic disc size on neuroretinal rim shape in healthy eyes.

PURPOSE: To evaluate the influence of optic disc size on segmental neuroretinal rim area in healthy eyes. PATIENTS AND METHODS: The study included 193 eyes of 193 healthy patients with physiologic disc cupping. On 15 degrees color stereophotographic optic disc diapositives, optic disc area and neuroretinal rim area were morphometrically determined in 36 radial optic disc segments each measuring 10 degrees. RESULTS: The correlations of segmental rim area to disc area were significantly strongest (P < 0.01) and the regression lines were steepest in the inferior disc region, and the values were lowest in the temporal disc region. Complementary to the rim data, the correlations of segmental cup area to disc area were significantly strongest (P < 0.01) and the regression lines were steepest in the temporal disc region, and the values were lowest in the inferior disc region. In comparison with neuroretinal rim area, cup area was significantly (P < 0.01) more strongly correlated with disc area and the regression line was steeper in the whole optic disc and in each disc segment. The regional distribution of the widest rim part and smallest rim part was independent of disc size. CONCLUSIONS: The increase of rim area and cup area with increasing disc size differs between various disc regions. Because cup area increases more than rim area with increasing disc size, correction for disc size may be more important for segmental cup area than for segmental rim area. The rim shape with respect to the location of the smallest or broadest rim part is independent of disc size.

Adolescent↗
PubMed2000

Discriminant analysis models for early detection of glaucomatous optic disc changes.

AIM: To evaluate and compare four different mathematical formulas for the early detection of morphometric optic nerve head changes in chronic open angle glaucoma. METHODS: The optic nerve heads of 161 patients with perimetrically defined glaucomatous optic nerve damage and of 194 normal subjects were examined by confocal laser scanning tomography. Using four formulas of linear discriminant analysis and the optic cup shape measure as the single optic disc variable, the predictive power of each of these methods was examined to differentiate between the normal eyes and the glaucoma eyes. RESULTS: The highest predictive power had an optic disc sector based formula, in particular in eyes with medium and large optic discs. This optic disc sector based formula was the one with the best agreement with the other formulas examined. It achieved a better predictability than any single optic disc variable evaluated. CONCLUSIONS: Combining quantitative optic disc variables by discriminant analysis functions, the predictive power of semiautomatic quantitative optic nerve head evaluation can be improved by providing the ophthalmologist with a diagnostic score for the detection of glaucomatous optic nerve damage. Because of the pattern of glaucomatous neuroretinal rim loss, an optic disc sector based discriminant formula may have a higher diagnostic precision than other formulas in detecting early glaucomatous damage.

Adult↗
PubMed2000

Intravitreal injection of crystalline cortisone as adjunctive treatment of proliferative vitreoretinopathy.

AIM: To report on clinical outcome and complications of intravitreal injection of crystalline cortisone in patients undergoing pars plana vitrectomy for treatment of proliferative vitreoretinopathy. METHODS: The study included all 16 patients who underwent pars plana vitrectomy for treatment of proliferative vitreoretinopathy, who received an intravitreal injection of 10-20 mg crystalline triamcinolone acetonide at the end of surgery, and who were operated on by the same surgeon. Most of the vehicle of the solution containing the cortisone crystals was removed before performing the injection. Mean follow up time was 1.64 (SD 2.15) months (median 1. 23 months; range 0.20-9.20 months). The study group was compared with a control group which consisted of 144 patients undergoing pars plana vitrectomy for proliferative vitreoretinopathy performed by the same surgeon. RESULTS: In the study group compared with the control group, intraocular inflammation, as estimated clinically by slit lamp biomicroscopy, was lower, appearance of the fundus upon ophthalmoscopy in the first postoperative week was clearer, and postoperative pain in the first two postoperative days was reduced. Intraocular pressure measured at the end of the first postoperative week did not vary significantly between the groups. A pseudohypopyon consisting of cortisone crystals in the inferior anterior chamber angle was detected in one patient. Postoperative infectious endophthalmitis was not encountered. CONCLUSIONS: This pilot study suggests that intravitreal injection of crystalline cortisone with most of the vehicle removed is not toxic to intraocular structures, reduces postoperative intraocular inflammation, and may be a potentially useful additional tool in the treatment of proliferative vitreoretinopathy.

Anti-Inflammatory Agents↗
PubMed2000

Multivariate approach for quantification of morphologic and functional damage in glaucoma.

PURPOSE: To determine the usefulness of confirmatory factor analysis in examination of morphometric, electrophysiological, and psychophysical quantitative methods that measure the extent of global glaucomatous damage without referring to a preselected gold standard. METHODS: In a cross-sectional clinical study, 406 eyes of 203 glaucoma patients and 200 eyes of 100 normal control subjects 18 to 70 years old underwent optic disc morphometry, automated perimetry, measurement of temporal contrast sensitivity by a full-field flicker test, blue-on-yellow visually evoked potential (VEP), and black-and-white pattern-reversal electroretinogram (ERG). Diagnosis of glaucoma was based on a qualitative classification of the optic nerve head and retinal nerve fiber layer independent of intraocular pressure and visual field. Confirmatory factor analysis was performed in the patient group as a whole and in a subgroup showing moderate to advanced glaucomatous optic nerve head damage. RESULTS: The confirmatory factor analysis models explained the data satisfactorily (P > 0.18, all patients; P > 0.34, subgroup). Global glaucomatous damage was quantified best by the mean defect of automated perimetry (r = 0.81; r = 0.87), followed by the area of the neuroretinal rim (r = 0.64; r = 0.73), the full-field flicker test (r = 0.59; r = 0.65), the pattern-reversal ERG amplitude (r = 0.54; r = 0.55), and the VEP peak time (r = 0.55; r = 0.54). CONCLUSIONS: Confirmatory factor analysis allows quantification of the validity of established and new procedures that measure global glaucomatous damage using cross-sectional data. The results are not dependent on the preselection of a specific gold standard. Psychophysical testing and morphometry quantified glaucomatous damage best, compared with electrophysiological procedures.

Adolescent↗
PubMed2000

Ranking of optic disc variables for detection of glaucomatous optic nerve damage.

PURPOSE: To describe optic disc variables assessed by evaluation of clinical optic disc photographs and to compare sensitivity and specificity of these optic disc parameters in identifying patients with ocular hypertension who have nerve fiber layer defects and normal visual fields and patients with visual field defects. METHODS: The study included 500 normal subjects, 132 patients with ocular hypertension with retinal nerve fiber layer defects and normal visual fields (preperimetric glaucoma), and 840 patients with glaucomatous visual field defects. Color stereo optic disc photographs were morphometrically evaluated. RESULTS: Highest diagnostic power for the separation between the normal group and the preperimetric glaucoma group had the vertical cup-to-disc diameter ratio corrected for its dependence on the optic disc size, total neuroretinal rim area, rim-to-disc area ratio corrected for disc size, and cup-to-disc area ratio corrected for disc size. Diagnostic power was lower for rim area in the temporal inferior and temporal superior disc sector, cup area corrected for disc size, and horizontal cup-to-disc diameter ratio corrected for disc size. Less useful for the differentiation between the normal subjects and the preperimetric glaucoma group were size of zones alpha and beta of parapapillary chorioretinal atrophy, and ratios of neuroretinal rim width and rim area comparing various optic disc sectors with each other. CONCLUSIONS: In subjects with ocular hypertension with retinal nerve fiber layer defects and normal conventional achromatic visual fields, the vertical cup-to-disc diameter ratio corrected for optic disc size, total neuroretinal rim area, rim-to-disc area ratio, and cup-to-disc area ratio corrected for disc size are the most valuable optic disc variables for early detection of glaucomatous optic nerve damage. Correction for optic disc size is necessary for optic disc variables directly or indirectly derived from the optic cup. Parapapillary atrophy is less important in the early detection of glaucoma.

Adolescent↗
PubMed2000

Indwelling temporary retrobulbar catheter for long-lasting titratable local anesthesia.

OBJECTIVE: To evaluate an indwelling temporary retrobulbar catheter for repeatable injections of local anesthetics for long-lasting and titratable retrobulbar anesthesia in intraocular surgery. PARTICIPANTS: The prospective clinic-based study included 153 patients who underwent vitreoretinal surgery (n=111) or buckling procedures with cryocoagulation (n=34). The mean duration of surgery was 84.7 +/- 49.5 minutes (range, 25-310 minutes). Using commercially available retrobulbar needles with a diameter of 0.60 or 0.80 mm and a length of 38 mm, 5 mL of 2% mepivacaine hydrochloride was injected. Through the same needle, a 28-gauge commercially available flexible catheter was introduced into the retrobulbar space. The needle was withdrawn and the catheter was fixed. When the patients started to feel pain during surgery, 2 mL of mepivacaine hydrochloride was reinjected through the catheter. RESULTS: Ten to 240 minutes after the start of the operation, 96 patients needed an intraoperative reinjection of mepivacaine after which they felt comfortable again. Forty-two patients needed a second reinjection of mepivacaine 30 to 270 minutes after the start of the operation, and 13 patients needed a third reinjection 45 to 145 minutes after the start of surgery. Removal of the catheter after surgery was unremarkable. No infections were observed. Microbiologic examination results of the catheter tip were negative for organisms. Diplopia or other motility problems were not detected. Introduction and fixation of the catheter took less than 5 minutes in all patients. CONCLUSIONS: An indwelling temporary retrobulbar catheter for repeatable intraoperative injections of local anesthetics is simple, effective, and useful, and in comparison with general anesthesia, it is a time-saver for long-lasting and titratable local anesthesia in intraocular surgery. Arch Ophthalmol. 2000;118:996-1000

Aged↗