L.V. Del Priore

Vitrectomy with silicone oil infusion in severe diabetic retinopathy

Aims: To determine the results of pars plana vitrectomy (PPV) and silicone oil infusion (SOI) in severe proliferative diabetic retinopathy (PDR). Methods: The records of 23 eyes (21 patients: 12 males, nine females) with PDR who had undergone PPV and SOI were reviewed retrospectively. Results: Average follow up was 5.4 months (range 1–25). Surgical indications were tractional retinal detachment (TRD) (17.4%), traction-rhegmatogenous retinal detachment (TRRD) (8.7%), TRD with vitreous haemorrhage (VH) (48%), TRD with neovascular glaucoma (NVG) (8.6%), TRD with fibrinoid syndrome (FS) (17.3%). With one operation, the retinal reattachment rate was 17/23 (74%). Among these 23 eyes, 11 (48%) had previously failed vitrectomy, and the retina was attached in 8/11 (73%) with a single procedure. With additional surgery employing PPV and SOI, the final reattachment rate was 20/23 (87%). The only cases with intraocular pressure <5 mm Hg had retinal detachment. Postoperative visual acuity (VA) improved in 10 eyes (44%), was unchanged in three (12%), and decreased in 10 eyes (44%). Conclusion: SO tamponade is useful in severely diseased eyes with PDR, even in the presence of rubeosis iridis (RI) and NVG, FS, or in cases with previously failed vitrectomy, especially in the presence of RI.

Postoperative abnormalities of the choriocapillaris in exudative age-related macular degeneration.

AIMS: To study the incidence and possible cause of abnormalities of the subfoveal choriocapillaris after surgical excision of subfoveal choroidal neovascularisation in age-related macular degeneration (ARMD). METHODS: The postoperative fluorescein angiograms and colour photographs of 29 eyes of 29 patients were reviewed after surgical excision of subfoveal choroidal neovascularisation in exudative ARMD. Preoperative and postoperative fluorescein angiograms were examined for perfusion of the subfoveal choriocapillaris. The excised subfoveal choroidal neovascular membranes from eight eyes that demonstrated postoperative abnormalities of the choriocapillaris were embedded in paraffin, serially sectioned and examined for the presence of the choriocapillaris. RESULTS: Postoperative fluorescein angiograms revealed abnormal perfusion of the subfoveal choriocapillaris in 26 of the 29 eyes (90%) and in all eight eyes that had histopathological examination of the surgical specimens. Examination of serial sections demonstrated that none of the excised neovascular membranes contained choriocapillaris. CONCLUSIONS: Abnormal perfusion of the subfoveal choriocapillaris was frequently present following removal of the subfoveal neovascular membrane in ARMD. The histopathological study demonstrated that abnormalities of the choriocapillaris were not due to removal of the choriocapillaris at the time of surgery.

Age-related accumulation of 3-nitrotyrosine and nitro-A2E in human Bruch's membrane

Age-related macular degeneration (AMD) is a disease leading to severe visual loss and legal blindness in the elderly population. The pathophysiology of AMD is complex and may include genetic predispositions, accumulation of lipofuscin and drusen, local inflammation and neovascularization. Recently four independent research groups have identified a commonly inherited variant (Y402H) of the complement factor H gene in the genome from different groups of AMD patients. The Y402H variant of CFH significantly increases the risk of AMD and links the genetics of the disease with inflammation. During inflammation there is activation of inducible nitric oxide synthase and release of nitric oxide, which in principal could lead to non-enzymatic nitration within extracellular deposits and/or intrinsic extracellular matrix protein components of human Bruchs membrane. We have identified two biomarkers for non-enzymatic nitration in aged human Bruchs membrane, indicative of inflammation, that include 3-nitrotyrosine identified in Bruchs membrane preparations and nitrated A2E from the lipid soluble extract of the Bruchs membrane preparation. Approximately 30-40 times more A2E is observed in samples of the organic soluble extract of lipofuscin compared to the extract of Bruchs membrane. It is of interest to note that although A2E is a major constituent of RPE lipofuscin, nitrated A2E could not be detected in RPE extracts. We show here that nitro-A2E is a specific biomarker of nitrosative stress in Bruchs membrane and its concentration correlates directly with tissue age.

Duration of action of intravitreal ranibizumab and bevacizumab in exudative AMD eyes based on macular volume measurements

Background/aims: Sequential macular volume and central foveal point thickness (CFPT) measurements on optical coherence tomography (OCT) were used to determine the efficacy and duration of action of ranibizumab versus bevacizumab in wet age-related macular degeneration (AMD). Methods: Retrospective chart review of patients who received their first treatment of intravitreal ranibizumab or bevacizumab for exudative AMD. 316 patients (202 ranibizumab;114 bevacizumab) who received 823 injections (313 ranibizumab;510 bevacizumab) were identified. 74 patients had pre- and post-treatment OCTs performed to determine CFPT and macular volume changes. Results: Ranibizumab caused a significant reduction in CFPT (278 (SD 84) before treatment vs 227 (80) µm after treatment; p = 0.001) and macular volume (7.22 (0.96) vs 6.69 (0.74) mm3; p = 0.002). Intravitreal bevacizumab caused a similar reduction in CFPT (288 (94) vs 220 (55) µm; p = 0.008) and macular volume (7.36 (1.08) vs 6.50 (0.42) mm3; p<0.001). The mean duration of action was 74.0 (19.1) days for ranibizumab compared with 101.8 (16.6) days for bevacizumab (p = 0.036; t test). The ratio of the relative duration of action of bevacizumab versus ranibizumab was 1.40 (0.19). Conclusions: Both drugs are equally effective at reducing CFPT or macular volume. Bevacizumab appears to take longer to achieve the minimum macular volume, and its effects take longer to wear off, suggesting it can be given less often.

Epiretinal membrane removal in diabetic eyes: comparison of viscodissection with conventional methods of membrane peeling

Aims: To compare conventional methods of epiretinal membrane peeling with viscodissection. Methods: 154 eyes with proliferative diabetic retinopathy (PDR) that underwent pars plana vitrectomy with membrane dissection (89 traditional, 65 viscodissection) were studied retrospectively. Incidence of retinal breaks (RBs), length of time under anaesthesia, postoperative intraocular pressure, retinal reattachment rate, and final visual acuity (VA) were measured. Results: To compare cases of similar complexity, a “complexity score” was defined. The average complexity score for cases done with and without viscodissection was 4.7 and 3.2, respectively. The mean frequency of RBs in eyes undergoing viscodissection was 0.43 (SD 0.5) v 0.14 (0.35) RBs/eye without viscodissection. In complex cases, the frequency of posterior/peripheral RBs was 0.31 (0.47)/0.13 (0.34) RBs/eye, respectively, with viscodissection v 0.12 (0.33)/0.23 (0.43) RBs/eye without viscodissection. None of these differences were statistically significant. The average preoperative/postoperative VA (logMAR) in the viscodissection cohort was 1.7/1.3 (range 0.3 to >1.9/0.1 to >1.9) v 1.4/1 (range 0.48 to >1.9/0.1 to >1.9) in the non-viscodissection cohort, among eyes with 6 months of follow up. Anaesthesia duration was significantly shorter for cases done without viscodissection (p=0.03), but cases done with viscodissection were significantly more complex than cases done without viscodissection (p<0.0001). Conclusion: Viscodissection appears to be a safe and effective alternative technique in eyes with PDR. Owing to the retrospective nature of the study, additional studies are warranted.

Linezolid induced toxic optic neuropathy

Linezolid is a new oxazolidinone antibiotic with activity against many important pathogens including methicillin resistant S taphylococcus and penicillin resistant Streptococcus .1 We report a case of toxic optic neuropathy from chronic treatment with linezolid. Correct diagnosis and discontinuation of the drug resulted in significant recovery of vision. A 56 year old man presented with bilateral, progressive decline in visual acuity for 6–8 months. Medical history included chronic diabetes mellitus, below the knee amputation of the right leg, hypertension, sinusitis with nasal allergies, and asthma. Several years earlier he had fractured his left ankle and developed osteomyelitis from methicillin resistant Staphylococcus . He had received linezolid 600 mg by mouth twice a day for 12 months, then once daily for 44 months. Other medications included rosiglitazone, metoprolol, rifampin, furosemide, lisinopril, amlodipine, insulin, and vitamin B complex/folic acid for assistance with wound healing. He was a non-smoker and consumed less than one unit of alcohol per week. Best corrected visual acuities were 20/400 in both eyes with eccentric fixation. Ishihara colour plates were 1/8 …

Use of viscodissection and silicone oil in vitrectomy for severe diabetic retinopathy

Improvement in surgical techniques has led to improved anatomic and functional success rates following surgery for severe complications of proliferative diabetic retinopathy (PDR). We compared the anatomic and functional outcomes of surgery in a non-randomized, consecutive case series of patients with severe PDR. We found that viscodissection using Healon® provides outcomes comparable to conventional pick and scissors dissection. We also found that adjunctive use of silicone oil can salvage selected cases with particularly severe manifestations of PDR (e.g., the fibrinoid syndrome). With proper selection of patients and techniques, the anatomic success rate can exceed 80% even in the most severe cases. The goal of this paper is to show the applicability of using viscodissection and silicone oil infusion during vitrectomy in eyes with severe PDR.

Isolated foveolar detachment in Irvine‐Gass syndrome

Irvine-Gass syndrome, which describes visual loss after cataract surgery as a result of cystoid macular oedema (CMO), typically produces petalloid leakage around the fovea on fluorescein angiography (FA) often associated with late hyperfluorescence of the optic disc.1 Recently, optical coherence tomography (OCT) has confirmed the presence of perifoveal cystic spaces in vivo, consistent with histological specimens with CMO. OCT is increasingly used as a first test, before FA, for diagnosing unexplained visual loss after cataract surgery. Here we report a case of Irvine-Gass syndrome that demonstrated perifoveal leakage and late optic disc staining on FA, whose predominant OCT finding was a localised foveolar detachment. Isolated foveal detachment has been described in diabetic …