Vitrectomy with removal of the internal limiting membrane in chronic diabetic macular oedema.

PURPOSE: To assess the effect of pars-plana vitrectomy including peeling of the internal limiting membrane (ILM) on the resolution of chronic diabetic macular oedema. METHODS: We performed a prospective evaluation of 60 eyes of 55 patients with chronic diabetic macular oedema who underwent pars-plana vitrectomy with ILM removal. All patients had a history of macular oedema of at least 6 months. In most of the eyes, grid laser photocoagulation had been performed previously. Eyes with further vitreoretinal pathologies such as vitreous haemorrhage, evident macular traction or significant loss of the foveal capillary net were excluded. Fluorescein angiography, funduscopic examination and the assessment of best-corrected visual acuity (BCVA) were performed pre- and postoperatively. The mean duration of follow-up was 3.0 months. Additionally BCVA was inquired of the referring ophthalmologists after a postoperative period of at least 9 months. RESULTS: Fluorescein angiography and clinical examination revealed a decrease of leakage within the macula or a decrease of macular thickening in 55 (93%) eyes. Mean visual acuity (LogMAR) significantly improved from 1.05 preoperatively to 0.87 postoperatively (P=0.0000034). Twenty-six eyes (43%) gained 2 or more lines of vision; four eyes (7%) lost 2 lines. Data concerning BCVA after a follow-up of at least 9 months were available in 37 patients (41 eyes) and confirmed the results 3 months postoperatively. CONCLUSION: Pars-plana vitrectomy with ILM peeling reduced macular oedema in most cases. In contrast, visual acuity improved significantly in 43% of the treated eyes only. The discrepancy between anatomical and functional results of ILM removal in chronic diabetic macular oedema is likely to be caused by structural changes of the macula due to long-standing oedema.

Impact of a modified optic design on visual function: clinical comparative study.

PURPOSE: To determine whether implantation of an intraocular lens (IOL) with a modified anterior surface designed to compensate for the positive spherical aberration of the cornea in eyes of cataract patients results in improved pseudophakic quality of vision. SETTING: Department of Ophthalmology, Bundesknappschaft's Hospital, Sulzbach, Germany. METHODS: In an intraindividual randomized study of 45 patients with bilateral cataract, an IOL with a modified anterior surface (Tecnis Z9000, Pharmacia) was compared with a biconvex lens with spherical surfaces (SI-40, Allergan). All patients had bilateral cataract surgery; in 1 eye the Z9000 IOL was implanted and in the other, the SI-40 IOL. After 1 and 3 months, the following investigations were performed: assessment of the anterior and posterior segments including IOL decentration and tilt, pupil size, high- and low-contrast visual acuities, photopic and mesopic contrast sensitivities, and wavefront aberration of the cornea and eye. RESULTS: Thirty-seven patients were examined at all follow-up visits. Although the eyes with the Z9000 IOL had significantly better best corrected visual acuity after 3 months, the improved quality of vision was more apparent when assessing low-contrast visual acuity and contrast sensitivity. Wavefront measurements revealed no significant spherical aberration in eyes with a Z9000 IOL but significantly positive spherical aberration in eyes with an SI-40 IOL. CONCLUSIONS: The clinical results confirm the theoretical preclinical calculations that the spherical aberration of the eye after cataract surgery can be eliminated by modifying the anterior surface of the IOL. The Tecnis Z9000 lens compensates for the positive spherical aberration in older eyes. This leads to a significant improvement, particularly in contrast sensitivity and mesopic visual quality.

Vitrectomy with arteriovenous decompression and internal limiting membrane dissection in branch retinal vein occlusion.

PURPOSE: The therapeutic armamentarium for functional improvement after branch retinal vein occlusion (BRVO) is limited with uncertain efficacy. Some surgeons have proposed surgical decompression of the vein at the arteriovenous (AV) crossing. METHODS: Forty-three patients with BRVO were treated in the authors' department from August 1999 to April 2001 with AV decompression. Twenty-five patients with comparable BRVO who refused this surgical intervention served as a control group. All 68 patients received an isovolemic hemodilution therapy for 10 days. The surgical procedure consisted of a standard pars plana vitrectomy and separation of the overlying artery from the vein using microscissors. In 16 cases dissection of the internal limiting membrane (ILM) in the macular area and around the AV crossing was also performed. Assessment of visual acuity, fluorescein angiography, and multifocal electroretinography were performed preoperatively and 6 weeks after surgery in seven patients. RESULTS: Surgical procedure and postoperative course were uneventful. In most of the treated eyes visual acuity improved and fluorescein angiography revealed capillary reperfusion. Functional results in patients with AV decompression were highly significantly better than in the control group. Furthermore, removal of the ILM seems to have an additional beneficial effect on the functional outcome. CONCLUSION: These results demonstrate the therapeutic effect of surgical AV decompression in BRVO. Additional removal of the ILM seems to improve the functional results. Further experience may answer some open questions.

[Comparative investigation of the etiology of visual field defects after epimacular surgery]. / Vergleichende Untersuchung zur Genese von Gesichtsfelddefekten nach epimakulärer Chirurgie.

BACKGROUND: Sectorial visual field defects after macular hole surgery were described by several authors. The intraocular gas tamponade is discussed to be a possible causative factor for this complication. PATIENTS AND METHODS: Goldmann perimetry and threshold perimetry were performed preoperatively and 6 weeks postoperatively in 48 patients who underwent epimacular surgery because of macular pucker (23 eyes) or macular holes stage II - IV (25 eyes). Laser polarimetry was performed additionally using the Nerve Fiber Analyzer. The results were compared quantitatively. In all cases an epimacular membrane was peeled off. Eyes with macular holes underwent fluid-gas exchange with SF 6 without drying up the retina completely. RESULTS: No patient showed a sectorial visual field defect. The quantitative comparison of visual field examinations did not prove a difference between both groups. CONCLUSIONS: We could not detect any impairing influence of the intraocular gas tamponade in our patients. Without complete desiccation of the vitreous cavity, visual field defects after macular hole surgery are unlikely.