Anatomic and functional recovery of the fovea after foveal translocation surgery without large retinotomy and simultaneous excision of a neovascular membrane

Oxidative stress and mitochondrial transfer: A new dimension towards ocular diseases

Ocular cells like, retinal pigment epithelium (RPE) is a highly specialized pigmented monolayer of post-mitotic cells, which is located in the posterior segment of the eye between neuro sensory retina and vascular choroid. It functions as a selective barrier and nourishes retinal visual cells. As a result of high-level oxygen consumption of retinal cells, RPE cells are vulnerable to chronic oxidative stress and an increased level of reactive oxygen species (ROS) generated from mitochondria. These oxidative stress and ROS generation in retinal cells lead to RPE degeneration. Various sources including mtDNA damage could be an important factor of oxidative stress in RPE. Gene therapy and mitochondrial transfer studies are emerging fields in ocular disease research. For retinal degenerative diseases stem cell-based transplantation methods are developed from basic research to preclinical and clinical trials. Translational research contributions of gene and cell therapy would be a new strategy to prevent, treat and cure various ocular diseases. This review focuses on the effect of oxidative stress in ocular cell degeneration and recent translational researches on retinal degenerative diseases to cure blindness.

TWOFOLD ILLUMINATION PHOTODYNAMIC THERAPY SCHEME FOR SUBFOVEAL CHOROIDAL NEOVASCULARIZATION IN PATHOLOGIC MYOPIA

PURPOSE

To compare the short-term efficacy and safety of standard verteporfin photodynamic therapy (PDT) to modified PDT regimen using a twofold illumination scheme for treating choroidal neovascularization in pathologic myopia.

METHODS

Randomized active-controlled clinical trial including 16 patients with subfoveal choroidal neovascularization caused by pathologic myopia and best-corrected visual acuity (BCVA) of 20/320 or better. Patients were randomly assigned (1:1) to standard PDT regimen (50 J/cm; n=8) or twofold illumination PDT scheme (50+50 J/cm; n=8). Comprehensive ophthalmic evaluation including fluorescein angiography was performed at baseline and at weeks 1, 12+/-2, and 24+/-2 following treatment. At week 12 follow-up examination, an additional treatment session with either standard or modified PDT regimens (as assigned at baseline) was applied to areas of fluorescein leakage if present. Changes in BCVA, retreatment rate, and incidence of adverse events were evaluated.

RESULTS

All patients completed the 24-week study period. Baseline median BCVA was 20/100 and 20/100 for patients assigned to standard and modified PDT regimens, respectively. At week 24, median improvement in BCVA was significantly greater in patients submitted to twofold illumination PDT scheme (P=0.005; Mann-Whitney U test). Median change from baseline in BCVA (ETDRS lines) was +1.8 (P<0.05; Wilcoxon signed-rank test), +0.4, and +0.5 lines for patients submitted to standard PDT regimen, and +1.8 (P<0.05; Wilcoxon signed-rank test), +1.9 (P<0.05; Wilcoxon signed-rank test), and +2.4 (P<0.05; Wilcoxon signed-rank test) lines for patients submitted to twofold illumination PDT scheme at week 1, 12, and 24 follow-up examinations, respectively. An additional PDT session was performed in 7/8 patients assigned to standard PDT regimen, and in 4/8 patients assigned to modified PDT (P=0.28; Fisher exact test). No PDT-related complications were observed.

CONCLUSION

Although the number of patients and length of follow-up in this study was limited, a better visual outcome and diminished retreatment rate were observed in patients assigned to twofold illumination PDT scheme in comparison to those submitted to standard PDT regimen. Larger studies with longer follow-up to look at twofold illumination PDT scheme versus standard one to confirm our preliminary results are warranted.

Retinal changes after macular translocation with 360-degree retinotomy in monkey eyes

PURPOSE

To determine the morphologic and functional changes of the fovea and retina of monkey eyes after macular translocation with 360-degree retinotomy.

DESIGN

Experimental study.

METHODS

The retinas of eight monkey eyes were surgically translocated with a 360-degree retinotomy with procedures similar to those used on human eyes. At 1, 2, and 3 months after the surgery, the six eyes that had successful surgery were studied by light and transmission electron microscopy, terminal deoxynucleotidyl transferase (TdT)-dNTP terminal nick-end labeling (TUNEL) assay, and immunohistochemistry with peanut agglutinin (PNA) lectin and glial fibrillary acidic protein (GFAP). Retinal physiology was assessed by scotopic and photopic electroretinograms (ERGs).

RESULTS

The fovea was successfully translocated approximately 30 to 40 degrees superiorly in six eyes. The translocated macula and fovea had a normal layered architecture with no TUNEL-positive cells, minimal misalignment of the outer segments, and strong immunoreactivity to GFAP. The mean amplitudes of the scotopic and photopic b-waves were significantly reduced at 1 month after the surgery, and there was only a slight recovery at 3 months. No significant changes were observed in the mean implicit times after the surgery.

CONCLUSION

These findings indicate that macular translocation surgery with 360-degree retinotomy results in minimal morphologic alterations but significant depression of electrophysiologic function.

Morphologic and angiographic assessment of the macula after macular translocation surgery with 360 degrees retinotomy

PURPOSE

To compare the optical coherence tomographic assessment of retinal thickness and the fluorescein angiographic appearance after macular translocation surgery for subfoveal choroidal neovascularization.

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Twenty-three consecutive eyes.

INTERVENTION AND TESTING

Optical coherence tomography and fluorescein angiography were performed before and 6 to 15 months (mean +/- standard error [SE], 10.4+/-0.7) after macular translocation surgery with a 360 degrees retinotomy in 23 patients, ages 48 to 79 years, with age-related macular degeneration (12 eyes), polypoidal choroidal vasculopathy (2 eyes), and high myopia (9 eyes). The diameter of the choroidal neovascularizations ranged from 0.3 to 2.6 disc diameters (mean +/- SE, 1.2+/-0.2), and the angle of rotation of the retina ranged from 11 degrees to 45 degrees (mean +/- SE, 29.1+/-2.1 degrees ).

RESULTS

The preoperative best-corrected visual acuity ranged from hand motions to 20/100, and the postoperative best-corrected visual acuity ranged from 20/667 to 20/25. Optical coherence tomography demonstrated a concave foveal configuration after surgery in all 23 eyes, with a mean foveal thickness of 150+/-11 micro m (mean +/- SE). Fluorescein angiography showed various degrees of fluorescein leakage with a pattern similar to cystoid macular edema in 16 of 23 eyes (70%).

CONCLUSIONS

The newly located macula after macular translocation surgery with a 360 degrees retinotomy had cystoid macular edema on fluorescein angiography and normal macular configuration with normal thickness in optical coherence tomography.

Review Article. New treatments in age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of legal blindness in individuals 50 years and older in the developed world. Choroidal neovascularization (CNV) in exudative AMD is responsible for the majority of severe vision loss. Until recently, laser photocoagulation was the only well-established and widely accepted treatment for CNV. However, it is beneficial only for a small subset of patients, has a high rate of CNV persistence and recurrence and results in iatrogenic, collateral damage to the overlying retina. These issues make it difficult to recommend in the case of subfoveal lesions. Consequently, numerous experimental therapeutic interventions are under investigation with the common objective of destroying the CNV but leaving the foveal neurosensory retina intact. Treatment modalities can be grouped into five major categories: photodynamic therapy; radiotherapy; transpupillary thermotherapy; anti-angiogenic and angiostatic agents; and surgical intervention. The present review aims to explain the rationale behind these new treatments, analyse the evidence for their safety and efficacy, determine their stage of development and indicate in which patients they are potentially useful.

Subretinal fibrosis after photodynamic therapy in subfoveal choroidal neovascularisation in highly myopic eyes

AIMS

To analyse the occurrence of subretinal fibrosis (SRF) after photodynamic therapy (PDT) with verteporfin in highly myopic eyes with subfoveal choroidal neovascularisation (CNV).

METHODS

PDT with verteporfin was performed on 33 eyes of 32 highly myopic patients with subfoveal CNV. Patients were followed for 14-24 months and best corrected visual acuity (BCVA) and angiographic and funduscopic findings were recorded.

RESULTS

Two patients (two eyes) were lost to follow up. SRF appeared in 14 of 31 eyes. SRF appeared more frequently in eyes with a spherical equivalent (SE) of less than -10 D, in patients of age equal to or less than 55 years, and when CNVs were larger than 1500 micro m in diameter. SRF appeared more frequently in the group of patients with worse final BCVA.

CONCLUSIONS

The appearance of SRF after treatment is correlated with size of the CNV and SE. The results of this study indicate that highly myopic eyes with CNV treated with PDT do not show a decrease in BCVA, even though they develop SRF. The appearance of SRF after PDT in highly myopic CNV does not always imply a loss of BCVA from baseline, though its presence is more frequent in eyes with lower BCVA.

Selective occlusion of subfoveal choroidal neovascularization in pathologic myopia using a new technique of ingrowth site treatment

PURPOSE

To evaluate the visual and angiographic effects as well as optical coherence tomography findings after a new technique of ingrowth site treatment of subfoveal choroidal neovascularization (CNV) secondary to pathologic myopia with the use of indocyanine green (ICG)-mediated photothrombosis.

DESIGN

Interventional, noncomparative case series.

METHOD

In the setting of a tertiary referral center, patients with pathologic myopia in whom fluorescein and conventional ICG angiography demonstrated distinct CNV vessels supplying the subfoveal neovascular complex were submitted to focal ingrowth site treatment using a new therapeutic modality termed ICG-mediated photothrombosis. Prospective evaluation including visual acuity assessment, fluorescein and ICG angiography, and optical coherence tomography (OCT) evaluation was performed at weeks 1, 12, 24, and 48 after treatment.

RESULTS

Six consecutive patients (six eyes) had treatment using a single session of ICG-mediated photothrombosis at the CNV ingrowth site. Obliteration of the entire neovascular complex was achieved immediately after treatment in all patients. At last follow-up, visual acuity improvement of 1 or more Early Treatment Diabetic Retinopathy Study lines was observed in five of six patients, and fluorescein angiography showed an absence (four eyes) or minimal leakage (two eyes) from CNV. Indocyanine green angiography demonstrated selective obliteration of the neovascular complex. Accordingly, reduction of retinal edema was observed in the OCT evaluation in all patients. There was no significant complication related to the procedure.

CONCLUSIONS

The use of lower irradiances of 810- nm continuous light application and intravenous ICG infusion for neovascular ingrowth site photothrombosis induced selective CNV hypoperfusion, as demonstrated by fluorescein and ICG angiography in patients with pathologic myopia. These findings were either consistent with the visual acuity improvement observed in five of six patients or with the partial restoration of the retinal architecture seen in OCT evaluation 12 months after treatment.

Verteporfin photodynamic therapy in highly myopic subfoveal choroidal neovascularisation

AIMS

To analyse the visual and angiographic results of photodynamic therapy (PDT) with verteporfin in highly myopic patients with subfoveal choroidal neovascularisation (CNV).

METHODS

PDT was performed on highly myopic patients with subfoveal CNV. The patient population was divided into two groups according to age at onset of CNV (group 1 aged < or = 55 and group 2 aged >55 years old). Best corrected visual acuity (BCVA) and angiographic findings were considered.

RESULTS

At the end of follow up group 2 had worse BCVA than group 1. 76% of patients in both groups showed a complete closure of CNV at the end of follow up.

CONCLUSION

Visual prognosis of myopic CNV treated by PDT is influenced by age at onset.

Retinal pigment epithelium translocation after choroidal neovascular membrane removal in age-related macular degeneration

PURPOSE

To test the feasibility of a new surgical technique and to assess visual function over the translocated retinal pigment epithelium (RPE) cells in patients operated on for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD).

DESIGN

Retrospective, noncomparative, interventional case series.

PARTICIPANTS

Nine patients with previously untreated exudative ARMD underwent surgical excision of the subfoveal CNV with RPE translocation and were observed for 12 to 32 months.

METHODS

The surgery consisted of a standard three-port pars plana vitrectomy, excision of the CNV, and RPE translocation. Pre- and postoperative ocular examination included best-corrected visual acuity measurement, fundus color stereo photography, and fundus fluorescein angiography. Optical coherence tomography and confocal laser scanning ophthalmoscopy (cLSO) were performed after surgery. A crossfixation target and a single-point flashing light were projected on different areas of the posterior pole using a cLSO. Photopic 10 to 2 perimetry, photopic fine matrix mapping, and cLSO microperimetry were also performed after surgery in six patients.

MAIN OUTCOME MEASURES

Optical coherence tomography cross-sectional scans and cLSO RPE autofluorescence were recorded to detect the presence of viable translocated RPE. Visual acuity, fixation, photopic 10 to 2 perimetry, photopic fine matrix mapping, and cLSO microperimetry were used to test central visual function.

RESULTS

Retinal pigment epithelium was translocated successfully at the time of CNV removal from the edge of the RPE defect to a subfoveal location in seven of nine patients. One patient experienced proliferative vitreoretinopathy, but significant hemorrhage was not a feature. Optical coherence tomography showed the translocated RPE as an area of increased optical reflectivity with optical shadowing external to it. Confocal laser scanning ophthalmoscopy showed autofluorescence of the translocated RPE. The crossfixation target was seen when projected on the translocated RPE. During eccentric fixation, the patients could see a flashing point-target projected on the translocated RPE. Photopic 10 to 2 perimetry, photopic fine-matrix mapping, and cLSO microperimetry showed the presence of central visual function.

CONCLUSIONS

The authors propose that translocation of RPE at the time of CNV removal, from the edge of the RPE defect to a subfoveal location, may have a role in the surgical management of ARMD.

Retinal pigment epithelium translocation and central visual function in age related macular degeneration: preliminary results

PURPOSE

To test the feasibility of a new surgical technique, and to assess visual function over the translocated retinal pigment epithelium (RPE) cells in patients operated upon for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).

MATERIALS AND METHODS

Six patients presenting previously untreated exudative AMD underwent surgical excision of the subfoveal CNV with RPE translocation and were followed from 1 to 10.5 months. The surgery consisted of a standard three port pars plana vitrectomy (TPPPV), excision of the CNV and RPE translocation. Pre and post-operative ocular examination included best-corrected visual acuity measurement, fundus color stereo photography and fundus fluorescein angiography. Optical coherence tomography (OCT) and confocal laser scanning ophthalmoscopy (cLSO) were performed post-operatively. A cross fixation target and a single-point flashing light were projected on different areas of the posterior pole using a cLSO. Photopic 10-2 perimetry, photopic fine matrix mapping, cLSO microperimetry were also performed pre and post-operatively in four patients. OCT cross-sectional scans and cLSO RPE autofluorescence were recorded to detect the presence of viable translocated RPE. Visual acuity, fixation, photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry were tested for the presence of central visual function.

RESULTS

RPE could be effectively translocated at the time of CNV removal from the edge of the RPE defect to a subfoveal location. OCT showed the translocated RPE as an area of increased optical reflectivity with optical shadowing external to it. cLSO showed autofluorescence of the translocated RPE. The cross fixation target was seen when projected on the translocated RPE. During eccentric fixation, the patients could see a flashing point-target projected on the translocated RPE. Photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry showed presence of central visual function.

CONCLUSIONS

The authors propose that translocation of RPE at the time of CNV removal, from the edge of the RPE defect to a subfoveal location, may have a role in the surgical management of AMD.

Surgical treatment of subfoveal neovascularization in myopia: macular translocation vs surgical removal

PURPOSE

To compare the visual outcome of two different surgical approaches for subfoveal neovascularization in degenerative myopia: macular translocation and surgical removal of choroidal neovascularization (CNV).

DESIGN

Interventional case series.

METHODS

Retrospectively, 32 eyes with degenerative myopia (axial length over 26 mm or refraction over -6 diopters) and subfoveal CNV of 32 consecutive patients operated on by either surgical removal of CNV or limited macular translocation were reviewed. Surgical removal of CNV was performed in 18 eyes and limited macular translocation with a twofold suture in 14 eyes. The main outcome measurements were best-corrected visual acuity (BCVA) and findings from fluorescein angiography. Postoperatively, mean +/- SD follow up was 14 +/- 15 months (range, 6-48 months) in the removal group and 11 +/- 4 months (range, 6-24 months, P =.37) in the translocation group.

RESULTS

In both groups, there was no significant difference in preoperative age, sex, refractive error, or BCVA. The average of postoperative BCVA was statistically better after macular translocation (10 ETDRS lines or 20/100) than after surgical removal (6 lines 10/125, P =.019). Visual acuity improved by 3.8 lines after macular translocation and was unchanged after surgical removal (-0.7 line, P =.011). Macular translocation was successful in shifting the CNV to an extrafoveal location in 11 out of 14 eyes. Mean foveal displacement of all 18 translocated eyes was 695 +/- 426 microm (range, 100-1520 microm). Recurrence of CNV occurred in seven eyes (39%) after surgical removal and in two eyes (14%) after translocation. Retinal detachment occurred in two eyes in each group.

CONCLUSION

In this retrospective study, eyes with degenerative myopia and subfoveal neovascularization treated with limited macular translocation had better visual acuity recovery than eyes treated with surgical removal of the choroidal neovascularization. Further studies are required to confirm these results.

Limited macular translocation with scleral retraction suture

BACKGROUND/AIMS

Macular translocation with scleral imbrication is a new technique for treating subfoveal choroidal neovascular membranes (CNV). This procedure shortens the sclera but may result in a minimal decrease in the internal circumference of the globe and limits the amount of foveal displacement. The authors propose a new scleral retraction suture aimed at decreasing the internal circumference of the globe in an effort to increase foveal displacement.

METHODS

Using a cadaver model, they compared the amount of scleral shortening using a standard scleral imbrication technique and a modified three suture scleral retraction technique. Sections of the globes were digitised and specialised software was used to estimate the amount of scleral shortening. Three patients with subfoveal choroidal neovascularisation underwent limited macular translocation using pars plana vitrectomy and macular detachment with the modified scleral suture technique. The main outcome measures were visual acuity, foveal displacement, and complications.

RESULTS

In the cadaver model, the scleral retraction suture resulted in a flatter internal scleral fold compared to the standard suture technique and created approximately 890 microm of effective scleral shortening. In the patients who underwent macular translocation and laser photocoagulation of the CNV, visual acuity improved in two patients and worsened in one patient. The range of foveal displacement was 1400-2400 microm.

CONCLUSION

The foveal displacements achieved in this limited study compared to median displacement previously published using standard suture techniques demonstrates that the scleral retraction suture technique may be a useful adjunct to limited macular translocation. The advantage of this type of suture in conjunction with translocation may depend on the effective scleral shortening offered by this retraction suture.

Macular translocation: unifying concepts, terminology, and classification

PURPOSE

To describe some unifying concepts, terminology, and classification of macular translocation so as to facilitate communication within the scientific community.

METHODS

A panel of ophthalmologists with expertise in macular translocation reviewed available data and developed some unifying concepts, terminology, and classification of macular translocation.

RESULTS

Macular translocation may be defined as any surgery that has a primary goal of relocating the central neurosensory retina or fovea intraoperatively or postoperatively specifically for the management of macular disease. It may be classified according to the size of the retinotomy and, where applicable, the technique of chorioscleral shortening used. The direction of macular translocation is denoted by the movement of the neurosensory macula relative to the underlying tissues. Effective macular translocation may be defined as successful intraoperative or postoperative relocation of the fovea overlying a subfoveal lesion to an area outside the border of the lesion. The concepts of minimum desired translocation and median postoperative foveal displacement can give some useful idea of the likelihood of effective macular translocation before surgery.

CONCLUSIONS

Use of a common standardized terminology for macular translocation will facilitate communication within the scientific community and enhance further research in this area. However, the definitions, terms, classification, and concepts concerning macular translocation are likely to continue to evolve as macular translocation undergoes further modifications and refinements.

Transpupillary thermotherapy (TTT) for the treatment of choroidal neovascularisation

AIM

To assess the effectiveness of transpupillary thermotherapy (TTT) for the treatment of classic and occult choroidal neovascularisation (CNV).

METHOD

In a retrospective, case selected, open label trial 44 eyes of 42 patients with CNV secondary to age related macular degeneration (ARMD) were studied. 44 eyes with angiographically defined CNV were treated with diode laser (810 nm) TTT. Laser beam sizes ranged between 0.8 and 3.0 mm and power settings between 250-750 mW. Treatment was given in one area for 1 minute, the end point being no visible change, or a slight greying of the retina. Outcome was assessed with Snellen visual acuity and clinical examination; in 24/44 patients angiographic follow up was available.

RESULTS

12 predominantly classic CNV and 32 predominantly occult membranes were followed up for a mean of 6.1 months (range 2-19). Mean change in vision for classic membranes was -0.75 (SD 1.75) Snellen lines and occult membranes was -0.66 Snellen lines (2.1) (p>0.05). Predominantly classic membranes were closed in 75% (95% CI: 62.5-87.5) of eyes, remained persistent in 25% (95% CI: 12.5-37.5); no recurrences occurred. Predominantly occult membranes were closed in 78% (95% CI: 70.1-85.3) of eyes, remained persistent in 12.5% (95% CI: 6.6-18.5), and were recurrent in 5.1% (95% CI: 4.2-14.3).

CONCLUSIONS

Transpupillary thermotherapy is a potential treatment for CNV. It is able to close choroidal neovascularisation while maintaining visual function in patients with classic and occult disease. Further trials of TTT are needed to compare this intervention with the natural history and other treatment modalities.

Translocation of the macula for management of subfoveal choroidal neovascularization: comparison of results in age-related macular degeneration and degenerative myopia

PURPOSE

To report the results of limited macular translocation in subfoveal choroidal neovascularization resulting from age-related macular degeneration or degenerative myopia.

METHODS

The first consecutive 32 patients (23 age-related macular degeneration eyes and nine myopic eyes) were operated on with the limited macular translocation technique described by de Juan. Before and after surgery, a complete examination included fluorescein and indocyanine-green angiographies and optical coherence tomography. Mean follow-up was 9 months in the age-related macular degeneration group (range, 6 to 14 months) and 10 months in the myopic group (range, 6 to 15 months).

RESULTS

The improvement in visual acuity was better in the myopic group than in the age-related macular degeneration group and was correlated with younger age in the myopic group (P <.05). At the end of follow-up, visual acuity improved by 2 lines or more in seven age-related macular degeneration eyes (30%), including four eyes (13%) with an improvement of 6 lines or more, and in six myopic eyes (67%), including two eyes (22%) with an improvement of 6 lines or more. Final visual acuity was unchanged in four age-related macular degeneration eyes (17%) and three myopic eyes (33%), and decreased in 12 age-related macular degeneration eyes (52%). Conversely, the mean foveal displacement was greater in age-related macular degeneration than in myopia (1,105 microm and 685 microm, respectively; P <.05). Main complications were retinal detachment (six eyes), neovascularization at the injection site (two eyes), and recurrence of neovascularization (43% of the age-related macular degeneration group and 11% of the myopic group).

CONCLUSIONS

Limited macular translocation allowed a significant improvement in visual acuity in some eyes with subfoveal neovascularization and resulted in a moderate rate of complications. Longer follow-up and additional studies are required to confirm these findings.

Complications associated with limited macular translocation

PURPOSE

To report the ocular complications associated with the limited macular translocation procedure.

METHODS

Retrospective review of 153 consecutive eyes of 151 patients that had the limited macular translocation procedure for subfoveal choroidal neovascularization between April 1996 and February 1999. The major study variables investigated included the incidence of specific ocular complications and their impact on visual acuity at 3 months after the surgery. In addition, baseline patient characteristics and operative factors were evaluated to determine whether they were significant risk factors for the development of an ocular complication. The existence of a surgical procedure learning process was investigated.

RESULTS

One hundred forty-one (92.15%) of 153 eyes achieved at least 3-month follow-up. At least one complication occurred in 53 of 153 eyes (34.6%) and in 51 of these 53 eyes (96. 22%) the complications occurred before 3 months of postoperative follow-up. The intraoperative and postoperative complications included retinal detachment (17.4%), retinal breaks (13.4%), macular holes (7.8%), macular fold (4.6%), and intraocular hemorrhage (vitreous, subretinal, or choroidal; 9.2%). Eyes that developed retinal detachment, subretinal hemorrhage, and macular fold had significantly more loss of visual acuity than eyes without each of these complications (P =.0001, P =.038, and P =.027, respectively). The presence of predominantly classic choroidal neovascularization, the occurrence of an intraoperative retinal break, any intraocular hemorrhage, or macular fold formation were significantly associated with retinal detachment (P =.021, P =.025, P =.013, and P =.014, respectively). The incidence of any complication, retinal detachment, and hemorrhage significantly decreased during the study period, suggesting a learning process (P =.03, P =.006, P =.027, respectively).

CONCLUSIONS

A variety of ocular complications can occur during or after limited macular translocation, and some are associated with reduced postoperative visual acuity. Improved surgical techniques and experience may significantly reduce the incidence of these complications.

Inhibition of experimental choroidal neovascularization by overexpression of tissue inhibitor of metalloproteinases-3 in retinal pigment epithelium cells

PURPOSE

To evaluate the feasibility of introducing exogenous tissue inhibitor of metalloproteinases-3 gene into the rat retinal pigment epithelium using hemagglutinating virus of Japan liposomes and to assess the effect of tissue inhibitor of metalloproteinases-3 overexpression in retinal pigment epithelium cells on the formation of experimental choroidal neovascularization.

METHODS

Hemagglutinating virus of Japan liposomes containing hemagglutin epitope-tagged tissue inhibitor of metalloproteinases-3 gene were injected into the subretinal space in rat eyes. Localization of oligonucleotides was evaluated by fluorescence microscopy. Exogenous tissue inhibitor of metalloproteinases-3 mRNA expression was assessed by reverse transcribed polymerase chain reaction. Exogenous tissue inhibitor of metalloproteinases-3 protein expression was visualized by immunostaining with monoclonal antibody 12CA5 against the hemagglutin epitope. Three days after transfection of tissue inhibitor of metalloproteinases-3 gene into retinal pigment epithelium cells, intense laser photocoagulation was performed and the incidence of choroidal neovascularization was assessed by fluorescein fundus angiography.

RESULTS

Exogenous tissue inhibitor of metalloproteinases-3 mRNA expression in the choroid and retina was detected on day 3. The efficiency of tissue inhibitor of metalloproteinases-3 gene transfection into retinal pigment epithelium cells was greatest on day 7 and decreased gradually thereafter. The incidence of choroidal neovascularization in tissue inhibitor of metalloproteinases-3 gene-transfected eyes was markedly decreased compared with controls.

CONCLUSIONS

This study shows that tissue inhibitor of metalloproteinases-3 gene can be transferred into rat retinal pigment epithelium using the hemagglutinating virus of Japan-liposome method and that tissue inhibitor of metalloproteinases-3 gene overexpression can inhibit development of experimental choroidal neovascularization. This method may represent a future treatment modality for human macular degeneration associated with choroidal neovascularization.

Macular translocation: histopathologic findings in swine eyes

PURPOSE

Macular translocation has been proposed as an alternative technique in the treatment of some cases of choroidal neovascularization. The purpose of the paper is to report the histopathologic findings in the retina of swine eyes undergone macular translocation.

METHODS

Ten eyes of ten Yucatan pigs underwent posterior pars plana vitrectomy and scleral imbrication to achieve macular translocation. Mattress sutures were preplaced at the equator of the eyes. After a pars plana vitrectomy, balanced saline solution was injected under the temporal retina to produce a retinal detachment. Scleral imbrication was achieved by tightening the mattress sutures. An air-fluid exchange was performed and the eye was filled with sulfur hexafluoride 18%. The eyes were enucleated 2, 4, 8 and 12 weeks after surgery and analyzed under light and electron microscopy.

RESULTS

Macular translocation was achieved in all cases. The major findings consist of a minimal decrease in the number of photoreceptors outer segments; also a change in the morphology was noted. This included some degree of loss of vertical alignment and an increase in the interphotoreceptor space. There was a recovery in the morphology of the photoreceptors over time.

CONCLUSIONS

Minimal changes in the photoreceptors and retinal pigment epithelium are observed when macular translocation is performed with recovery of these changes over time. Scleral imbrication is an effective technique to achieve translocation of the fovea.

Optical coherence tomography: an introduction to the technique and its use

This report describes the new optical imaging technique of optical coherence tomography (OCT). OCT is capable of high-resolution, micrometer-scale, cross-sectional imaging of biological tissue. The OCT for ophthalmic application uses 843-nm, near-infrared light, which produces a longitudinal resolution of 10 to 20 microm and a penetration depth of a few millimeters. The scans are displayed in a false color representation scale on which warm colors represent areas of high optical reflectivity and cool colors represent areas of minimal or no reflectivity. A cross-sectional view similar to a histology section is obtained. The cornea, iris, and lens may be visualized as well as the retina and optic nerve. OCT has been used to investigate several ocular diseases. These include macular disease, genetic retinal disease, retinal detachment and retinoschisis, choroidal tumors, optic nerve disorders, and glaucoma.

Macular translocation

Macular translocation is a term used to describe any surgical procedure that involves the deliberate detachment of the retina with subsequent repositioning of the macula to a new location relative to the underlying retinal pigment epithelium. By moving the fovea away from abnormal pigment epithelium and/or choroid and repositioning it over more normal tissue, macular function can be stabilized or improved. Various techniques have been developed to accomplish this movement. Although this approach holds great promise for selected conditions (in particular, subfoveal choroidal neovascularization), the optimal technique to be used and the long-term prognosis are uncertain.

The management of subfoveal choroidal neovascular membranes and hemorrhage

At the beginning of the past decade (1990), the Macular Photocoagulation Studies (MPS) were underway evaluating the efficacy of the treatment of subfoveal choroidal neovascularization (CNV) with conventional lasers. When this proved to limit the loss of vision and give little chance for improving vision, vitreoretinal surgeons turned to surgical approaches to treating these lesions. The surgical excision of subfoveal CNV has been under study for the remainder of the decade with the recent addition of macular/retinal translocation to attempt vision improvement for these patients. Other modalities including interferon therapy and external beam irradiation have proven ineffective, but new laser studies may offer promise with photosensitizing chemicals. Despite much study a single therapy that can reliably return sight to the majority of patients has not been developed. This article reviews the various therapies of the 1990s and renders some thoughts for the future.

Foveal relocation by redistribution of the neurosensory retina

AIM

To describe a new surgical technique for foveal relocation, and to report the outcome in nine patients treated with this procedure.

METHODS

Nine consecutive patients with subfoveal choroidal neovascular membranes (CNVMs) secondary to age related macular degeneration underwent foveal relocation surgery by redistribution of the neurosensory retina (RNR). The technique involved induction of a retinal detachment via a single retinotomy, relocation of the fovea by "sweeping" the retinal tissue with a retinal brush, and stabilisation of the retina in its new location using perfluorocarbon liquid peroperatively and silicone oil postoperatively.

RESULTS

In eight of nine eyes successful relocation of the fovea was achieved; in one eye the CNVM remained in a subfoveal location postoperatively. Visual acuity improved in two eyes, remained unchanged in three, and decreased in four eyes after a median follow up of 4 months (range 2.5-6 months). Complications included rupture of a foveal cyst with the development of a macular hole in one eye and epimacular membrane formation in another eye. In two eyes, macular retinal vessel closure occurred at the time of laser photocoagulation; one of these eyes later developed cystoid macular oedema and the other an epiretinal membrane. Recurrence of the CNVM was observed in one eye, but was controlled with further laser treatment.

CONCLUSIONS

Foveal relocation by RNR appears to be feasible, obviating the need for extensive retinotomies or scleral shortening.