New components of 'basal laminar deposits' in age-related macular degeneration.

Two new components of basal laminar deposit (BlamD) occurring in samples of submacular neovascular membranes surgically removed from patients with a wet (exudative) form of age-related macular degeneration are described. They are: (1) minute ribbon-like structures which occur singly and/or in a bunch and extend from the inner surface of the BlamD layer into the extracellular matrix (ECM) beneath the retinal pigment epithelium (RPE). The ribbons are composed of polarized molecules, aggregating in parallel, aligned transversally in register, morphologically similar to isolated collagen molecules of the short-chain type. Deeper in the BlamD but always close to its inner surface, aspects suggesting a transition between ribbons and (2) long-spacing collagen (LSC)-like aggregates characterized by periods bordered by a single dense band were observed. This band could arise from the globular domains of the polarized monomers, which assemble in parallel and display all their terminal extensions at the same end of each period resulting in the single dense band. The presence of ribbons and of LSC-like aggregates in the BlamD layer and the concomitant choroidal neovascularization (CNV) suggest that the events might be correlated. The newly formed vessels crossing Bruch's membrane and invading the BlamD layer could induce physicochemical changes in the ECM of the RPE, providing the required environmental conditions for the polymerization of collagen molecules into aggregates with the LSC-like pattern. With the deposition of new components, the thickness of BlamD increases and further impairs the supply of nutrients and oxygen, thus sustaining CNV.

Macular hole surgery with air tamponade and optical coherence tomography-based duration of face-down positioning.

PURPOSE: To evaluate the closure rate after macular hole surgery with air tamponade and face-down positioning whose duration is based on postoperative optical coherence tomography (OCT). METHODS: In a prospective study, data were gathered on 33 eyes of 33 consecutive patients undergoing macular hole surgery. Postoperatively, OCT images were obtained in a face-down position to minimize the interfering reflections created by the air bubble. The face-down positioning was ended as soon the OCT revealed closure of the hole. RESULTS: Opacity of the media in 8/33 eyes 24 hours postoperatively precluded OCT. In 18/33 eyes (54.5%), the hole was closed on OCT 24 hours postoperatively and in 25/33 (75.7%), 48 hours postoperatively. In 4/33 eyes (12.1%), the hole was judged to be open on OCT 24 hours postoperatively. Despite continued face-down positioning, the hole had closed on the third day postoperatively in only one of these four eyes. In two of the remaining three eyes, the macular hole could be closed by a second surgery which was performed 5 to 6 days after the first vitrectomy. Using OCT monitoring, more than half (54%) of our patients could quit the face-down position after 24 hours, 21% after 48 hours, and 24% after 3 days. CONCLUSION: Vitrectomy and air tamponade combined with 1- to 3-day face-down positioning produced an excellent rate of macular hole closure. Already on the first and second day postoperatively OCT on patients in a prone position enabled the monitoring of the progress of the macular hole closure through the air bubble. This method allows effective adjustment of the duration of face-down positioning based on OCT findings.

Macular translocation in a patient with adult-onset foveomacular vitelliform dystrophy with light- and electron-microscopic observations on the surgically removed subfoveal tissue.

PURPOSE: To correlate the functional results of macular translocation (MT) in a patient suffering from an adult-onset foveomacular vitelliform dystrophy (AFVD) with the microscopic findings of the surgically removed subfoveal retinal pigment epithelium (RPE). METHODS: A 78-year-old woman with AFVD underwent MT with 360 degrees retinotomy 3-4 months after loss of reading ability. Most of the vitelliform material was lost during surgery; the subfoveal tissue was excised, fixed in aldehydes, postfixed in reduced OsO4 and embedded in epoxy resin. Semithin sections were stained with toluidine blue for light microscopy (LM) and thin sections with uranyl acetate and lead citrate for transmission electron microscopy (TEM). RESULTS: Postoperatively, the patient developed a retinal detachment complicated by proliferative vitreoretinopathy (PVR) requiring two additional vitreoretinal procedures before finally the silicone oil could be removed. Twenty-two months after MT the distance visual acuity was unchanged at 0.2; the near visual acuity had improved from less than 0.1 before MT to 0.4. The retina was completely attached. LM and TEM revealed serious alterations indicative of a breakdown of the outer layer of the retina. CONCLUSION: Through the present single case it is not possible to determine whether MT could be a therapeutic approach in patients with AFVD. The most important cause for the limited postoperative visual improvement seems to be a primary injury of the foveal function due to the AFVD. This is supported by the extensive subfoveal degeneration and necrosis affecting not only the RPE cells but also their basement membrane and the interposed basal laminar deposits.