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Z J Gregor

Publications and source records attributed to Z J Gregor.

At least 37 records · Page 2Linked to original sources
PubMed1999

Retained intravitreal lens fragments after phacoemulsification: a clinicopathological correlation.

AIMS: To explore the relation between clinical course and timing of vitrectomy with the nature and intensity of intraocular inflammatory response in eyes with retained intravitreal lens fragments following complicated phacoemulsification. METHODS: Prospective evaluation of 22 eyes with retained lens fragments with emphasis on corneal clarity, uveitis, intraocular pressure (IOP), timing of vitrectomy, and visual outcome. Numbers of different types of inflammatory cells in vitreous washings were counted, masked to clinical details, in three non-overlapping adjacent high power fields. Relations between clinical and pathological findings were assessed. RESULTS: The IOP was raised in 19 eyes before vitrectomy and remained high in nine postoperatively. The latter had higher median total cell count (104 cells/mm(2)) than those with normal postoperative IOP (37 cells/mm(2)) but this difference was not statistically significantly different (p=0.17). Nine of 22 eyes underwent vitrectomy within 1 week of cataract surgery. Median total cell count in these eyes was 20 cells/mm(2) compared with 140 cells/mm(2) in eyes vitrectomised later-this difference was statistically significant (p <0.001). Final visual acuity was 6/12 or better in 13 eyes, these had fewer intravitreal inflammatory cells than the remaining six with poor visual outcome and no pre-existing cause for this (three patients excluded) (p=0.02). Macrophages were the predominant inflammatory cell type. CONCLUSION: There was significantly less inflammatory cell activity in eyes which had retained lens fragments removed early (within 1 week). Later removal was associated with persistently elevated IOP and poorer visual outcome.

Follow-Up Studies↗
PubMed1998

Incidence of idiopathic full-thickness macular holes in fellow eyes. A 5-year prospective natural history study.

PURPOSE: This study aimed to determine the incidence of idiopathic full-thickness macular hole (FTMH) in normal fellow eyes and to evaluate the role of electrodiagnostic and psychophysical tests in identifying eyes at risk. PATIENTS AND METHODS: A prospective longitudinal natural history study of a cohort of patients with unilateral holes and normal, asymptomatic fellow eyes without posterior vitreous detachment was conducted. Subjects underwent baseline examination, pattern reversal electroretinography, electro-oculography (EOG), and color contrast sensitivity (CCS) testing for protan, deutan, and tritan thresholds and were recalled for clinical examination at 18 months and 5 years. RESULTS: At baseline, 114 patients were examined. Eighty were available for review at 18 months, of whom 6 had full-thickness macular holes develop in the fellow eye. At 5 years, 67 of the remaining 74 patients who had not developed holes at 18 months were re-examined and a further 5 were found to have holes develop in the fellow eye. A posterior vitreous detachment without hole formation had developed in 20 fellow eyes at 5 years. Although mean pattern reversal electroretinography and EOG responses were within normal limits in affected and fellow eyes at baseline, mean CCS protan, deutan, and tritan thresholds were elevated significantly in affected eyes at baseline (P = 0.0001). Unaffected fellow eyes showed normal mean protan and deutan thresholds, but significantly elevated mean tritan thresholds (P = 0.01) at baseline. Mean tritan CCS loss was, however, similar in fellow eyes in which holes later developed and in fellow eyes in which holes did not. CONCLUSIONS: The Kaplan-Meier estimated risk of fellow eye involvement is 15.6% (range, 8.4%-22.3%; P = 0.05) at 5 years. Although electrodiagnostic and psychophysical testing was not predictive of fellow eye involvement, tritan CCS loss at baseline, in apparently normal fellow eyes, may indicate subclinical foveal dysfunction, the nature of which is unclear.

Adult↗
PubMed1998

Systemic risk factors for idiopathic macular holes: a case-control study.

PURPOSE/BACKGROUND: The idiopathic full-thickness macular hole (IFTMH) is an important cause of poor vision in the elderly affecting predominantly women over the age of 60 years. While it is accepted that vitreoretinal traction is an important local factor in the development of IFTMH, the underlying cause is not known. The aim of this study was to identify possible systemic risk factors for the development of IFTMH. METHODS: Two hundred and thirty-seven patients with IFTMH (cases) attending the Macular Hole Clinic at Moorfields Eye Hospital were identified. These were compared with 172 patients without macular holes (controls) attending other clinics in the same hospital. Cases and controls were frequency-matched by sex. The prevalence of the following factors in both groups was ascertained by interview: ethnic origin, place of birth, housing tenure, any systemic diseases, current and lifetime consumption of medication, severe dehydrational episodes, menstrual and obstetric history, onset and severity of menopause and use of exogenous oestrogens (in women only), osteoporosis, vegetarianism, use of vitamin supplementation, and smoking and alcohol consumption. Height and weight were measured for all participants. RESULTS: Cases of IFTMH macular holes were predominantly women (67%) and aged 65 years and older (74%). We found very few systemic risk factors that were significantly associated with IFTMH. There was a higher prevalence of diabetes in controls (12% vs 5%). There was no association between the majority of indicators of oestrogen exposure in women and macular holes, but cases had a more difficult menopause as judged by the severity of hot flushes at menopause: odds ratio 2.6 (1.4-4.6). CONCLUSIONS: In common with other studies, we found only a few systemic factors associated with IFTMH. The study did confirm, however, that IFTMH is a strongly gender-related disease. There is some evidence for the role of sudden changes in hormonal balance, as seen by the increased reporting of severity of symptoms around the menopause along with (statistically non-significant) increased risks associated with hysterectomy and oophorectomy. The particular aetiological factor which puts women at increased risk of macular holes requires further studies.

Age Factors↗
PubMed1998

The use of corticosteroids for choroidal neovascularisation in young patients.

PURPOSE: To investigate the role of systemic corticosteroids in the treatment of sight-threatening choroidal neovascularisation (CNV) in patients with punctate inner choroidopathy (PIC) and multifocal inner choroiditis (MIC). METHODS: Twelve eyes of 10 patients with evidence of PIC or MIC with recent visual symptoms were identified. All eyes had CNV within the foveal avascular zone on fundus fluorescein angiography (FFA). Systemic oral prednisolone at an initial dose of 1 mg/kg (60-80 mg) was given for 3-5 days and the dose was subsequently tapered. Changes in best corrected visual acuity and leakage on FFA were recorded during follow-up. Systemic side-effects of the corticosteroids were monitored. RESULTS: In 10 of 12 eyes vision improved or stabilised. Leakage on FFA resolved in 9 eyes and was reduced in 3. Four patients required more than one course of oral corticosteroids. One patient was maintained on low-dose oral corticosteroids for recurrent CNV activity. No systemic complications from the treatment were observed. CONCLUSION: A course of oral corticosteroids in healthy young patients with subfoveal CNV in PIC or MIC may reduce subretinal vascular leakage and stabilise vision when no other proven treatment option is available.

Adult↗
PubMed1998

Fundus autofluorescence in patients with macular holes imaged with a laser scanning ophthalmoscope.

AIM: To demonstrate the usefulness of a recently developed technique of imaging fundus autofluorescence and to compare it with the results of fluorescein angiography in the diagnosis and staging of macular holes. METHODS: The intensity and distribution of fundus autofluorescence was studied in 51 patients with idiopathic macular holes and pseudoholes using a confocal laser scanning ophthalmoscope (cLSO) and the images were compared with those obtained by fundus fluorescein angiography. RESULTS: Autofluorescence imaging demonstrated bright fluorescence of macular holes with appearance similar to that obtained by fluorescein angiography. In contrast macular pseuodoholes showed no such autofluorescence. The attached operculum in stage 2 macular holes and the preretinal operculum in stage 3 macular holes showed focal decreased autofluorescence. The associated retinal elevation and the cuff of subretinal fluid were less fluorescent compared with the background autofluorescence of the normal fellow eyes. Following successful surgical treatment the autofluorescence of the macular holes was no longer visible. CONCLUSION: Autofluorescence imaging with the cLSO makes the assessment of macular holes possible with an accuracy comparable with that of fluorescein angiography. Being non-invasive and rapid, autofluorescence imaging may become a useful alternative to fluorescein angiography in the assessment and the differential diagnosis of full thickness macular holes.

Aged↗
PubMed1997

Membranectomy and autologous serum for the retreatment of full-thickness macular holes.

OBJECTIVE: To determine the efficacy of reoperation with rigorous epiretinal membrane dissection and autologous serum for full-thickness macular holes remaining open after initial surgery. METHODS: Forty-six consecutive eyes that had previously undergone unsuccessful macular hole surgery were re-treated with epiretinal membrane dissection, adjunctive autologous serum, and 16% perfluoropropane (C3F8) gas tamponade. Anatomical closure and improvement of best-corrected Snellen visual acuity were used as outcome measures, and nuclear sclerosis was graded clinically before and after reoperation. RESULTS: Epiretinal membrane was identified and dissected in 29 (63%) of the 46 eyes and anatomical closure was achieved in 37 (80%) of the 46 eyes. Of these, 23 (62%) of 37 improved by at least 2 Snellen lines, 12 (35%) of 37 by at least 3 Snellen lines, and 6 (16%) of 37 by at least 4 Snellen lines. Increase in nuclear sclerosis occurred in 30 (65%) of the 46 eyes postoperatively, leading to cataract extraction in 12 (26%) of the eyes at last follow-up (mean, 10.3 months). A longer total duration (P<.001) and a worse preoperative visual acuity (P=.001), prior to reoperation, were associated with a worse final visual acuity after surgery. CONCLUSIONS: Retreatment with rigorous membranectomy and autologous serum seems to be beneficial in most eyes in which initial macular hole surgery has failed. Although the anatomical closure rate is similar to that reported after primary surgery, final visual acuity improvement seems to be less than after successful primary closure, owing to the longer mean duration of holes in which initial surgery has failed.

Aged↗
PubMed1997

Macular hole opercula. Ultrastructural features and clinicopathological correlation.

OBJECTIVE: To investigate the ultrastructural features of idiopathic full-thickness macular hole (FTMH) opercula excised during vitrectomy and to correlate them with the outcome of surgery. METHODS: Opercula were collected from eyes undergoing vitrectomy for stage 3 FTMH using noncrushing, cupped foreign body forceps. Following immediate fixation, specimens were processed for transmission electron microscopy. The ultrastructural features were correlated with the clinical data recorded for each patient before and after surgery. RESULTS: Eighteen specimens were studied. Native vitreous collagen was identified on the surface of all 18, while fragments of internal limiting membrane were present in 11 (61%). Eleven (61%) were found to contain only glia, comprising fibrous astrocytes and Müller cells in variable proportions. The remaining 7 (39%) were found to contain, in addition to glia, neurites and synaptic complexes, of which some were typical of cone photoreceptors. The initial surgical closure rate was significantly better in eyes in which only glia were present (9/11 [82%]), compared with those with neurites (1/7 [14%]) (P = .01). Once closure had been achieved with reoperation, the median final visual acuity was 20/60 in both groups (P = .26), although the likelihood of achieving an acuity of 20/40 or better was greater in the former (50%) than the latter group (17%). CONCLUSIONS: Two distinct types of opercula occur in association with stage 3 FTMH--those containing only glia (pseudo-opercula), which are probably associated with a foveal dehiscence and little or no loss of foveal tissue, and those containing both glia and a significant number of avulsed foveal cones (true opercula), which arise from a full-thickness foveal tear. Although the loss of foveal tissue in true opercula would seem to explain the worse initial anatomical and more modest visual results in some eyes, significant visual improvement may still be achieved after successful closure. The presence of neurites in true opercula suggests that, in at least some cases, direct traction on the foveal retina leads to macular hole formation.

Aged↗
PubMed1997

Prophylactic argon laser retinopexy prior to removal of silicone oil: a pilot study.

BACKGROUND: Removal of silicone oil following successful retinal detachment surgery is usually performed in an attempt to prevent the complications of silicone oil; however, removal of the oil may result in retinal redetachment. PURPOSE: The purpose of this study was to determine whether argon laser retinopexy, 3-6 weeks prior to the removal of silicone oil, reduces the rate of retinal detachment following silicone oil removal. METHODS: A total of 31 eyes of 31 consecutive patients were followed up for a 12 month period after the removal of silicone oil. All patients had undergone retinal reattachment surgery resulting in a clinically attached retina with the absence of residual retinal traction prior to silicone oil removal. A study group of 15 of the 31 eyes received two rows of 360 degrees of peripheral argon laser retinopexy 3-6 weeks before removal of the silicone oil. The 16 eyes of the previous 16 consecutive patients, who underwent removal of silicone oil without argon laser retinopexy, were used as a control group. RESULTS: In the study group 1 of 15 eyes (6.7%) redetached following the removal of silicone oil and 4 of 16 (25%) redetached in the control group during the 12 month follow-up period from operation. CONCLUSIONS: Prophylactic argon laser retinopexy applied 3-6 weeks before the removal of silicone oil appears to reduce the retinal redetachment rate. A larger prospective randomised trial is needed to confirm these findings.

Adolescent↗
PubMed1996

Partial laser ablation of massive peripapillary subretinal neovascularization.

BACKGROUND: Although peripapillary subretinal neovascular membranes (PSRNs) are less common and often larger than neovascular complexes arising near the fovea, they may lead to severe visual loss. Very large (massive) PSRNs (MPSRNs) are 3.5 disc areas or greater in overall size, are even less common, and may contain a significant occult component, leading to slow and unpredictable growth. Such massive lesions may begin at the nasal margin of the disc and do not become symptomatic until they have extended around the disc toward the macula, threatening central vision. Although complete laser ablation has been used for symptomatic PSRNs with variable success, the optimal treatment of MPSRNs remains controversial. METHODS: The authors reviewed the clinical course of 12 eyes of seven patients with MPSRNs. Ten eyes received laser treatment, which was limited to the temporal portion of the subretinal neovascular complexes only and two received no treatment. RESULTS: Of the ten eyes receiving laser treatment, six showed stabilization of visual acuity, whereas in four the neovascular membrane progressed beneath the fovea with severe visual loss. In the two untreated eyes, the subretinal neovascular membrane progressed beneath the macula with the loss of central vision. CONCLUSIONS: In contrast to the small symptomatic PSRNs, which are usually treated by complete laser ablation, MPSRNs may stabilize with only partial laser treatment. However, both types of lesions may remain stable for long periods of time without any treatment and require treatment only if progression toward the fovea occurs.

Adult↗
PubMed1996

Recognition of vitreoschisis in proliferative diabetic retinopathy. A useful landmark in vitrectomy for diabetic traction retinal detachment.

INTRODUCTION: In the late stages of proliferative diabetic retinopathy (PDR) the vascularized posterior cortical gel (PCG) contracts leading to a partial posterior hyaloidal separation, hemorrhage, and traction retinal detachment (TRD). "Additional epiretinal membranes" have been described previously. These are thin, usually transparent epiretinal membranes which extend anteriorly from the point of attachment of the elevated posterior cortical gel to the edge of the TRD. The origin and frequency of the occurrence as well as the clinical significance of such additional epiretinal membranes are the subjects of controversy. PURPOSE: To quantitate the authors' clinical impression that additional epiretinal membranes are common in advanced PDR, to characterize them immunohistochemically, and to demonstrate the rationale for the authors' surgical approach. METHODS: Intraoperative observations for all patients undergoing diabetic vitrectomy and delamination over the last 2 years were reviewed retrospectively. The presence of additional epiretinal membrane was searched for in the initial stages of vitrectomy. When identified, their apparent continuity with the elevated portion of the PCG was confirmed. Surgical specimens were obtained from nine patients for immunohistochemical study. RESULTS: Additional epiretinal membranes were observes in 145 (81%) of 179 consecutive eyes with PDR that underwent surgery for macular TRD. Immunohistochemical staining with type II collagen antibody was positive in all specimens, suggesting that these membranes were of vitreous origin. CONCLUSIONS: It is likely that the additional epiretinal membranes represent the posterior leaf of a split PCG, the anterior leaf being the elevated portion of the PCG. The two leaves remain fused in the main, fibrovascular portion of the epiretinal membrane. These findings help explain the clinical experience that once the posterior leaf of the PCG is identified and elevated, it provides an accurate point of entry into the surgical plane facilitating delamination of the fused (vascularized) portion of the PCG from the detached retina.

Aged↗
PubMed1996

Indirect argon laser drainage of subretinal fluid.

We report on a new method of subretinal fluid drainage which uses the indirect ophthalmoscopic delivery of argon laser energy to perforate the choroid. This carries all the theoretical advantages of drainage with the endolaser probe but is simpler and less expensive. We present a prospective series of 31 patients in whom this method was applied. Satisfactory drainage was obtained in 28. There were 4 cases of limited subretinal haemorrhage attributable to the laser, and 1 case of subfoveal haemorrhage. No cases of retinal perforation or incarceration were observed.

Adult↗
PubMed1996

Surgical treatment of full-thickness macular holes using autologous serum.

BACKGROUND: Full-thickness macular holes (FTMH) are an important cause of visual loss in older patients. Recognition of tangential vitreofoveal traction as the mechanism of hole formation has led to the use of vitrectomy and gas tamponade as a treatment for macular holes. The use of growth factors as an adjunctive therapy to promote chorioretinal adhesion and hole closure has also been advocated. METHODS: Forty-four consecutive patients undergoing vitrectomy, posterior hyaloid removal, gas injection and installation of autologous serum for FTMH were studied prospectively. Patients' age, sex, duration of symptoms, best corrected pre- and post-operative Snellen visual acuities, best corrected acuity in the fellow eye, stage of macular hole, post-operative closure or persistence of the macular hole, and intra- and post-operative complications were recorded. RESULTS: Of 43 patients with adequate follow-up (minimum 6 weeks, mean 6.1 months) anatomical closure of the macular hole was achieved in 29 eyes (67%). The average visual improvement in these eyes was 2.7 lines. Twenty eyes (69%) with closed holes had visual acuity of 6/12 or better (47% of all patients undergoing surgery). Of the 14 eyes (33%) that failed, the average loss of vision was 0.4 lines and all these eyes had vision of 6/36 or worse. CONCLUSIONS: In this series, surgical treatment of FTMH with vitrectomy, gas injection and autologous serum resulted in closure of the macular hole in two-thirds of patients and restored central vision in about one-half of patients. These results compare favourably with previously reported results of macular hole surgery. The answer to the question whether the use of autologous serum leads to a higher closure rate than surgery with gas tamponade alone requires information from randomised treatment trials, one of which is currently in progress.

Adult↗
PubMed1996

Surgery for idiopathic full-thickness macular holes.

BACKGROUND: Idiopathic full-thickness macular holes (FTMH) are an important cause of loss of central vision in the elderly. Improved understanding of the natural history and pathophysiology of FTMH has led to recent advances in the surgical management of patients with this hitherto untreatable condition. METHODS: The current concepts of the natural history and surgical treatment are reviewed. Pilot studies of vitrectomy undertaken to relieve the tangential traction at the vitreomacular interface and the role of growth factors as promoters of a limited healing response are reviewed and illustrated by the results of surgical treatment of macular holes obtained by the author and others. RESULTS: Whereas early pilot studies of vitrectomy of impending (stage I) macular hole suggested beneficial results (80-95% of operated eyes did not progress to FTMH), no such benefit could be demonstrated by a subsequent randomised treatment trial. In a study of early vitrectomy and partial fluid-gas exchange hole closure was achieved in 88% of patients with stage II FTMH with visual improvement in 67%. In other studies of FTMH (stages II-IV) the addition of adjunctive substances such as growth factors, autologous serum, plasma or platelet concentrate has resulted in closure in 77-100% of cases. However, similar results have also been reported with vitrectomy and gas tamponade alone. Histologically the closure of the FTMH is associated with glial proliferation. CONCLUSION: Vitrectomy and intraocular tamponade appear to be beneficial in patients with FTMH. The role of adjunctive substances, such as growth factors and other promoters of the healing response, requires clarification by randomised treatment trials.

Blood Component Transfusion↗
PubMed1996

Giant retinal tear and retinal detachment with underlying retinitis pigmentosa and hearing loss.

Few retinal detachments have been described in patients with retinitis pigmentosa and allied retinal disorders, with only two cases (both with hearing loss) reported in association with giant retinal tears. To further characterise clinical characteristics of giant retinal tear associated with retinitis pigmentosa, we reviewed the course of four eyes of three patients. Unexpectedly, all three individuals also suffered from congenital sensorineural hearing loss. One suffered from associated myopathy. Despite aggressive surgical management, three of the four eyes became blind. The diagnosis of retinal detachment preceded the diagnosis of photoreceptor dystrophy in two of the three patients. To date, giant retinal tears occurring with underlying retinitis pigmentosa have been described in five young individuals, all of whom had associated congenital sensorineural hearing loss.

Adolescent↗
PubMed1996

Levels of vascular endothelial growth factor are elevated in the vitreous of patients with subretinal neovascularisation.

BACKGROUND: Vascular endothelial growth factor (VEGF) has been shown to play a major role in intraocular neovascularisation in ischaemic retinal diseases. Subretinal neovascularisation is an important cause of central visual loss, but little is known about the role of this growth factor in its pathogenesis. The aim of this study was to investigate the possible role of VEGF in the development of subretinal neovascularisation. METHODS: Undiluted vitreous samples were obtained from patients undergoing vitrectomy for removal of non-age-related subfoveal neovascular membranes (SFNM). For comparison vitreous from patients undergoing vitrectomy for idiopathic full thickness macular holes (FTMH) and proliferative diabetic retinopathy (PDR) was used. Indirect enzyme linked immunosorbent assay (ELISA), with an antibody directed against the conserved N-terminal region of human VEGF165, was used to determine vitreous levels of VEGF. The growth factor was also localised in the vitreous of patients with SFNM by western blot analysis. RESULTS: The mean (SE) VEGF concentration in the vitreous of patients with SFNM was 27.78 (2.22) ng/ml (n = 8), FTMH was 16.62 (0.9) ng/ml (n = 18), and PDR was 37.77 (3.28) ng/ml (n = 16). The differences between the PDR group and SFNM group versus the FTMH group were both significant (p = 0.0001 and p = 0.0015) as analysed by the Wilcoxon rank sum test). CONCLUSIONS: Vitreous levels of VEGF are significantly elevated in eyes with non-age-related subretinal neovascularisation compared with eyes with FTMH but not as elevated as in PDR. This suggests that VEGF is involved in subretinal angiogenesis.

Adult↗
PubMed1996

Visual field loss following vitrectomy for stage 2 and 3 macular holes.

AIM: To describe the phenomenon of peripheral field loss following routine pars plana vitrectomy for stage 2 and 3 full thickness macular hole and to investigate the underlying mechanism. METHODS: Five patients, who reported peripheral field defects after apparently uncomplicated vitrectomy, posterior cortical vitreous peeling, and perfluoropropane (C3F8) gas tamponade, were studied retrospectively with slit-lamp biomicroscopy, automated and kinetic perimetry, fundal fluorescein angiography, focal electroretinography (ERG), and colour contrast sensitivity (CCS) testing. RESULTS: All five patients, who were between 50 and 73 years of age, reported an inferotemporal field defect following resolution of the intraocular gas bubble. In all eyes, the scotomata encroached to within 20 degrees to 30 degrees of fixation and to within 5 degrees to 15 degrees of the blind spot. In one eye, a partial altitudinal component was evident. All scotomata subsequently remained stable and three eyes developed subtle segmental nasal disc pallor and nerve fibre loss corresponding to the field defect. CCS testing revealed absent colour contrast in the scotomatous area, in the presence of a preserved focal quadrantic flash ERG, compared with normal CCS protan thresholds and focal ERGs in unaffected quadrants, indicating preserved outer retinal function in the area of the scotoma. CONCLUSIONS: These observations support the hypothesis that field defects occur as a result of retinal nerve fibre layer damage. It is proposed, on the basis of intraoperative observations and other evidence, that the most likely site of nerve fibre damage is at the nasal portion of the optic nerve rim or peripapillary retina, probably due to traction during cortical vitreous peeling.

Aged↗