Transpupillary thermotherapy of predominantly occult choroidal neovascularization in age-related macular degeneration with 12 months follow-up

Myofibroblasts in macular fibrosis secondary to neovascular age-related macular degeneration - the potential sources and molecular cues for their recruitment and activation

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly in developed countries. Neovascular AMD (nAMD) accounts for 90% of AMD-related vision loss. Although intravitreal injection of VEGF inhibitors can improve vision in nAMD, approximately 1/3 of patients do not benefit from the therapy due to macular fibrosis. The molecular mechanism underlying the transition of the neovascular lesion to a fibrovascular phenotype remains unknown. Here we discussed the clinical features and risk factors of macular fibrosis secondary to nAMD. Myofibroblasts are key cells in fibrosis development. However, fibroblasts do not exist in the macula. Potential sources of myofibroblast precursors, the molecular cues in the macular microenvironment that recruit them and the pathways that control their differentiation and activation in macular fibrosis were also discussed. Furthermore, we highlighted the challenges in macular fibrosis research and the urgent need for better animal models for mechanistic and therapeutic studies.

Clinical observations on the use of new anti-VEGF drug, conbercept, in age-related macular degeneration therapy: a meta-analysis

PURPOSE

Conbercept is a new anti-vascular endothelial growth factor (VEGF) drug approved for the treatment of age-related macular degeneration (AMD). Although this novel drug has been widely used in clinic, unlike other anti-VEGF drugs, validation and consensus on its method of clinical application and clinical safety have not yet been achieved.

METHODS

Relevant literature was searched on PubMed, Web of Science, China National Knowledge Internet, and Wanfang Data. Stata 12.0 was used for data analysis. Random- and fixed-effect models were employed to evaluate heterogeneity. Best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were utilized to measure the improvement of AMD patients.

RESULTS

In this study, we analyzed conbercept administration and compared its application with other control clinical methods for AMD treatment. Ranibizumab, triamcinolone, and traditional transpupillary thermotherapy (TTT) were administered in the control group. No differences were found in the BCVA and CRT improvement between the groups treated with conbercept and ranibizumab. However, the conbercept group had a lower serum VEGF level. After 3 months of treatment, conbercept led to a more significant BCVA and CRT improvement than triamcinolone. A more considerable BCVA improvement was observed in the group treated with conbercept than in the group treated with TTT. Moreover, even 6 months after the treatment, the effect of conbercept on CRT improvement was still more pronounced than that of TTT.

CONCLUSION

In AMD patients, conbercept exerts considerably more positive effects on the long-term BCVA and CRT improvement than triamcinolone and TTT. The serum VEGF level in the conbercept group was lower than that in the ranibizumab group.

Transpupillary thermotherapy in chinese patients with choroidal neovascularization secondary to age-related macular degeneration: emphasis on the influence of power setting

PURPOSE

To perform a safety and efficacy study of transpupillary thermotherapy (TTT) in Chinese patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD).

METHODS

In a prospective study, patients with subfoveal or juxtafoveal CNV secondary to ARMD underwent TTT with fixed treatment and follow-up protocols. From August 2002 to December 2004, 26 patients (27 eyes) completed > or =6 months of follow-up and were included in this report.

RESULTS

Fourteen eyes (52%) had improved or stable visual acuity (loss of <3 lines) and 13 eyes (48%) had vision loss of > or =3 lines. The serial mean visual acuity initially decreased during follow-up, then stabilized by 6 months. In the subgroup of occult or minimally classic CNV (20 eyes), 13 eyes (65%) had improved or stable vision. The major complication of TTT included laser-related retinal pigment epithelium (RPE) atrophy in 10 eyes (37%). Six eyes had mild RPE atrophy, 4 eyes had severe RPE-choroid atrophy (macular burn). Analysis of possible risk factors for macular burn showed that 3 eyes had to have the power amplified due to nuclear sclerosis, and 1 pseudophakic eye had regular power.

CONCLUSIONS

TTT in Chinese ARMD patients with occult or minimally classic CNV, according to our protocol, prevented severe vision loss in the majority of patients, but power amplification due to medium lens opacity induced RPE atrophy or burn in some patients.

Perception of very small visual stimuli in the fovea: normative data for the Rarebit Foveal Test

BACKGROUND

Conventional visual tests are not sensitive enough to detect low degree neural damage, as 6/6 (1.0) visual acuity can be upheld with less than two-thirds of the normal number of optic nerve axons. The aim of the current study was to evaluate the physiologic properties of a new computerised test, the Rarebit Fovea Test (RFT), using very small stimuli, by quantifying the effect of age and binocular summation in relation to stimulus luminance.

METHODS

The RFT relies on the perception of very small (less than 0.5 minutes of arc) bright stimuli. Two different experiments were performed. 1. Thirty-five subjects (age 19 to 63 years) were tested with five different stimulus luminances, 158, 64, 53, 41 and 33 cd/m(2). 2. Nineteen subjects (age 19 to 63 years) were tested using binocular stimulation to define the binocular summation.

RESULTS

Significantly reduced median hit rates were observed at luminances of 53 cd/m(2) or below. Age and mean hit rate correlated negatively at all luminance levels below 158 cd/m(2). The mean hit rate from binocular stimulation, compared to the highest value from monocular stimulation in the same subject, was increased by a factor of 1.54 +/- 0.45 (SD). No age effect was found regarding binocular summation.

CONCLUSIONS

The results in the current study indicate that RFT can identify some of the well-known features of the visual system, that is, the effects of age and binocular summation, provided that the stimulus luminance is adequately selected.

Absorption of diode 810 nm used for transpupillary thermotherapy by blood. An in vitro study

BACKGROUND AND OBJECTIVES

To evaluate the in vitro energy attenuation by transpupillary thermotherapy (TTT) using an 810-nm diode laser after the treatment of exudative age-related macular degeneration.

STUDY DESIGN/MATERIALS AND METHODS

In this experiment, an 810-nm diode laser was coupled to a slit lamp to deliver laser energy to a laser-power sensor adjusted in the track of the laser light. The spotlight was 0.5 mm in diameter; duration of exposure, 3 seconds. Citrated Pasteur pipettes were filled with blood diluted in saline in several concentrations and placed in the path of the laser light. The absorption of the light measured by the power sensor was tested for various delivered irradiances between 50.92 and 509.29 W/cm2. The differences were analyzed statistically.

RESULTS

There were significant differences in laser blockage comparing various conditions for all power levels (P<0.05). Increasing the proportion of blood resulted in more laser blockage with all irradiances (P<0.05).

CONCLUSIONS

Blood significantly blocks the transmission of the 810-nm diode TTT laser.

Visual function following transpupillary thermotherapy with adjusted laser parameters for the treatment of exudative age-related macular degeneration: a pilot study

PURPOSE

To evaluate the efficacy of transpupillary thermotherapy (TTT) using adjusted laser parameters for the treatment of choroidal neovascularization (CNV) secondary to age-related macular degeneration.

METHODS

TTT was performed on patients with CNV using a diode laser (810 nm) for 60 s in a subthreshold manner. Power settings were varied between 460 and 1200 mW, depending on lesion size, presence of pigment epithelial detachment and the amount of fundal pigmentation and subretinal fluid. LogMAR visual acuity, contrast sensitivity (Pelli-Robson) and metamorphopsia (Amsler chart) were assessed prior to and 6 months following treatment. Subjects also self-administered the National Eye Institute 25-Item Visual Function Questionnaire.

RESULTS

Thirty occult/minimally classic and eight predominantly classic membranes were treated with TTT. At 6 months, absence or significant reduction of fluorescein leakage was observed in 20 (53%) patients. Stabilization of vision (loss of less than 15 letters) was observed in 25/30 (83%) eyes with occult/minimally classic CNV and 5/8 (63%) eyes with predominantly classic CNV. Improvement of contrast sensitivity was noted in 15 (35%) eyes, in 10 (26%) eyes it remained unchanged and in 13 (34%) eyes it deteriorated. There was no statistically significant effect of TTT on the National Eye Institute 25-Item Visual Function Questionnaire composite or subscale scores.

CONCLUSIONS

TTT using adjusted parameters depending on fundal characteristics appears to be effective in stabilizing subjective and objective visual ability in a considerable number of patients with subfoveal CNV due to age-related macular degeneration. Larger-scale studies are required to confirm the benefit of this technique as opposed to the natural history of occult CNV.

Long term results after transpupillary thermotherapy in eyes with occult choroidal neovascularisation associated with age related macular degeneration: a prospective trial

AIM

To evaluate long term results after transpupillary thermotherapy (TTT) in eyes with exudative age related macular degeneration.

METHODS

In a prospective clinical study eyes with occult or predominantly occult choroidal neovascularisation and no pretreatment were scheduled to have a TTT with a power of 630 mW. Visual acuity for far and near distances as well as contrast sensitivity were evaluated 6, 12, and 24 months postoperatively and statistically analysed.

RESULTS

47 eyes fulfilled the inclusion criteria. Overall, 70% of the patients showed an improved (14%) or had unchanged (56%) ETDRS vision after 24 months. Reading vision was stabilised (51%) or better (5%) in 56% of the eyes at this time. However, the increasing number of eyes with severe deterioration resulted in a significant decrease of both parameters over time (p = 0.0002 and p = 0.0003, respectively). Contrast sensitivity could be maintained (70%) or improved (9%) in 79%. Statistical analyses indicated a trend but no significant decrease over time (p = 0.056).

CONCLUSION

Although in the majority of patients far and near distance acuity could be stabilised on average a significant decrease over time after TTT was observed. Statistical comparison of months 12 and 24 showed no further deterioration.

Age-related macular disease: how to assess the retina using scanning laser techniques?

Age-related macular disease (AMD) is the leading cause of legal blindness among the elderly in Western nations. The magnitude of the problem will undoubtedly grow, as age is a significant risk factor and the number of people aged 65 and over is projected to increase. The most frequent cause of severe visual loss associated with AMD is irreversible degeneration of the overlying neurosensory retina, caused by the growth of choroidal neovascularization or, alternatively, the development of geographic atrophy of the retinal pigment epithelium. Today, we are able to image the human retina in vivo. Recently developed imaging techniques provide better assessment of retinal pathology than conventional ophthalmoscopy alone. This overview presents the most recent devices available for retinal imaging, which mainly exploit laser technology such as scanning laser ophthalmoscopy. Its basic principles, as well as its characteristics for imaging and functional assessment of the retina, are described. Lastly, potential benefits for clinical routine, rehabilitation strategies in AMD, and future research aspects are discussed.

Retinal function following transpupillary thermotherapy for occult choroidal neovascularization in age-related macular degeneration: a short-term study by focal electroretinography

PURPOSE

To assess short-term changes in macular function after transpupillary thermotherapy (TTT) in patients with occult subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD), using focal electroretinography (FERG).

METHODS

Twenty-five patients with occult subfoveal CNV due to AMD were treated with TTT delivered using an infrared (810 nm) diode laser (spot size 3.0 mm, laser power 400-600 mW, duration 60 seconds). All patients were clinically evaluated before, 1 and 6 weeks after treatment. Snellen visual acuity (VA) was measured at each visit. Fluorescein angiography (FA) was performed at baseline and 6 weeks after TTT. Focal ERGs were recorded in all patients immediately before and 1 week after TTT in response to an 18-degree diameter, 41 Hz flickering spot (630 nm) centred on the fovea, presented on a steady background in Maxwellian view. A subgroup of 12 patients was also re-tested by FERG at 6-weeks post-TTT.

RESULTS

No significant changes in mean FERG amplitude and phase were observed across the different recording sessions before and after TTT. One week after TTT, four patients had significant (> 2 SD from baseline variability) increases in FERG amplitude and/or phase advances, one had a decrease in amplitude and four had phase delays, compared to baseline. The remaining 15 patients had stable FERGs. Six weeks after TTT, four patients had significant increases in FERG amplitude and/or phase advances, four had decreases in amplitude and/or phase delays, and four had stable FERGs, compared to baseline. Improvement in FERG parameters after TTT was always associated with an improvement in VA and a decrease in exudation. Patients with post-TTT FERG deterioration had stable or deteriorated clinical pictures. At either 1 or 6 weeks post-TTT, the FERG amplitude increase was inversely correlated (p < 0.05) with the baseline FERG amplitude and VA.

CONCLUSIONS

Three major conclusions can be drawn: in a short-term follow-up, TTT was not found to be associated with significant changes in macular function; FERG improvement was associated with VA improvement, and the increase in FERG amplitude was greatest in patients with the worst baseline acuity.

Microdot test of foveal function. A comparison with visual acuity at high and low contrast

PURPOSE

To define normal values across age from novel computerized tests of foveal vision and to compare the findings with visual acuity (VA) at high and low contrast.

SUBJECTS AND METHODS

Sixty-one healthy volunteers, aged 22-87, with subjectively normal vision participated in the study. The right eye from each subject was tested with Snellen letter VA at high contrast, at 10% contrast using the Tri-VA test and with the Rarebit Microdot Fovea Test (RMFT), in addition to biomicroscopy and fundus examination.

RESULTS

The median letter VA was 0.77 minimum angle of resolution (MAR; range 0.63-1.54) with a significant decline in letter VA with increasing age (r = 0.7, p < 0.001). The median Tri-VA resolution threshold at 10% contrast was 1.8 MAR (range 0.9-4.1) and a significant age effect (r = 0.7) was observed, most pronounced above 65 years. The median RMFT hit rate was 100% (range 97-100) in the age group below 65 years and 87.5% (range 34-98) in subjects older than 65 years.

CONCLUSION

The study shows a decline in foveal function with age with all three methods, reflecting the loss of neural detectors with increasing age. The hit rate to microdot stimuli appears to be a sensitive measure, which can be used for fine-graded evaluation of foveal function.

Transpupillary thermotherapy for occult subfoveal choroidal neovascularization: a 1-year, prospective randomized pilot study

PURPOSE

To evaluate the 1-year effect of transpupillary thermotherapy (TTT) on occult choroidal neovascularization membranes (CNV).

METHODS

In this prospective, randomized, controlled pilot study of 28 patients with occult or minimally classic (< 10%) neovascularization membranes with a diameter less than 4500 microm, 19 patients were treated with TTT, while nine received sham treatment. Outcome measures were membrane diameter, visual acuity and reading ability.

RESULTS

The median age of patients randomized to TTT was 78 years (range 24 years); that of patients randomized to sham was 79 years (range 9 years). There was no difference regarding membrane diameter at baseline between the two groups; the median membrane diameters were 3400 microm (range 2400 microm) in the TTT group and 3200 microm (range 2300 microm) in the sham group (p = 0.639). Visual acuity (VA) was similar, with a median of 0.2 (minimum-maximum 0.08-0.5) in the TTT group and a median of 0.16 (min-max 0.10-0.32) in the sham group. A total of 21 patients were followed for 1 year, 13 in the TTT group (2.7 treatments/patient) and eight in the sham group. Membrane diameter increased in both groups, by a median of 350 microm (range 1600 microm) in the TTT group and 800 microm (range 1700 microm) in the sham group (p = 0.414), respectively, and there was a loss in VA of > or = 15 letters in 5/13 patients (38%) in the TTT group compared with 2/8 patients (25%) in the sham group (p = 0.266). Reading ability deteriorated equally over time in both groups. Seven patients were lost to follow-up due to reluctance to continue in the study (n = 4) or development of a classical component > 50% (n = 3) requiring photodynamic therapy (PDT).

CONCLUSION

The results from this randomized, prospective pilot study of TTT for occult CNV did not indicate that TTT has a beneficial effect on visual outcome 1 year after treatment compared with the visual outcome that results from the natural course of the disease. The small study size limits statistical power and results from large control studies are needed.

[Transpupillary thermotherapy for occult choroidal neovascularizations]

PURPOSE

This contribution describes the results of transpupillary thermotherapy (TTT) for age-related exudative macular degeneration (AMD) with regression.

PATIENTS AND METHODS

In exudative AMD with occult choroidal neovascularization (CNV), transpupillary thermotherapy (TTT) was performed using a diode laser (Iridex) in unselected patients. Before therapy and 1, 3, and 6 months after the initial treatment the patients were examined clinically. Additionally threshold testing in the 10 degrees field (Humphrey) and fluorescein angiographies were documented at all check-ups.

RESULTS

With respect to vision, differences in the slope of the regression lines between small, medium, and large CNV were significant (p<0.001). The slope of the regressions lines was significant except for small CNV. Regarding the 10 degrees field (Humphrey), there were no statistical differences in the slope of the regression lines (p=0.867).

CONCLUSIONS

Transpupillary thermotherapy with small CNV did not show a statistically significant decrease of VA. Thus, in clinical terms early treatment of occult CNV with TTT seems to be able to prevent a further loss of visual acuity.

Transpupillary thermotherapy for the treatment of subfoveal choroidal neovascularization associated with age-related macular degeneration

OBJECTIVE

To evaluate the efficacy of transpupillary thermotherapy (TTT) for the treatment of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).

DESIGN

Prospective, non-randomized, non-masked, case-selected series.

METHODS

All patients with subfoveal CNV due to AMD and initial visual acuity (VA) between 6/9 and 6/60 were offered the opportunity to undergo TTT. Recruited subjects were treated using a diode laser (810 nm) with a beam size of 1.2-3.0 mm and power settings of 460-1200 mW. Treatment was applied for 60 seconds in a subthreshold manner.

MAIN OUTCOME MEASURES

Differences in VA and changes in the angiographic appearance of CNV.

RESULTS

Thirty-one occult/predominantly occult and five classic/predominantly classic membranes were treated with TTT and were followed-up for a mean of 6.0 +/- 1.2 months. Following an average of 1.5 +/- 0.7 (range 1-4) laser sessions, VA remained stable ( -1 to +1 Snellen line) in 24 (66.7%) eyes, improved by > 1 line in two (5.6%) eyes and decreased significantly (> or = 2 Snellen lines) in 10 (27.8%) eyes. Angiographically confirmed closure of CNV was detected in 22 (61.1%) patients. Membranes persisted in 11 (30.6%) eyes and recurred in three (8.3%) eyes. There was no association between reduction, elimination or persistence of angiographic leakage of CNV and change in VA after treatment (p = 0.347).

CONCLUSIONS

Transpupillary thermotherapy may be effective at preserving vision and reducing CNV leakage in a number of patients with exudative AMD. Further studies are required to compare TTT with the natural course of subfoveal CNV and alternative treatment options.

Change in visual function after macular translocation with 360° retinectomy for neovascular age-related macular degeneration

OBJECTIVE

To measure the change in vision and visual outcomes at 12 months after macular translocation with 360 degrees retinectomy (MT360) and silicone oil tamponade in patients with bilateral vision loss resulting from subfoveal choroidal neovascular membranes in age-related macular degeneration (AMD).

DESIGN

A prospective, interventional, consecutive, noncomparative case series.

PARTICIPANTS

Sixty-four patients with bilateral vision loss resulting from neovascular AMD.

METHODS

Eligible patients had AMD with subfoveal choroidal neovascularization in the operative eye and a maximum of 6 months of central vision loss. Preoperative and 12-month postoperative evaluations included standardized testing of near and distance acuity and reading speed. Patients underwent MT360 with silicone oil tamponade, followed 2 months later by extraocular muscle surgery and silicone oil removal.

MAIN OUTCOME MEASURES

Change in distance acuity, near acuity, and reading speed at 12 months after MT360 compared with those values before surgery.

RESULTS

Sixty-one patients were followed up for 12 months. All eyes were translocated successfully. Median distance acuity letter score improved from 62 letters (Snellen equivalent of approximately 20/125) before surgery to 69 letters (approximately 20/80) by 12 months after surgery (P = 0.03). Median near acuity improved from 0.70 logarithm of the minimum angle of resolution (logMAR) units (approximately 20/100) before surgery to 0.44 logMAR units (approximately 20/55) at 12 months (P<0.001). Median reading speed improved from 71 words per minute (wpm) before surgery to 105 wpm at 12 months after surgery (P<0.001). At 12 months, distance acuity improved by 1 or more lines in 32 patients (52%). In patients with either preoperative distance or near acuity of 20/80 or better, 74% and 95% of patients, respectively, remained in this range of acuity. In patients with either preoperative distance or near acuity of worse than 20/80, 40% and 48% of patients, respectively, improved to 20/80 or better. Postoperative retinal detachment developed in 5 patients (8%), with the macula involved in 2 patients, and all retinas were reattached successfully.

CONCLUSIONS

Macular translocation with 360 degrees retinectomy with silicone oil tamponade is effective in significantly improving visual function in patients with neovascular AMD, as demonstrated by the improvement in distance and near acuity and reading speed at 12 months after surgery in these patients. Although this is a complex surgical intervention, patients with preoperative visual acuity of 20/80 or better at near or distance are highly likely to retain the 20/80 or better acuity at 12 months after surgery. Macular translocation with 360 degrees retinectomy is an effective treatment option for patients with vision loss in their second eye resulting from neovascular AMD.

A review of treatments for macular degeneration: a synopsis of currently approved treatments and ongoing clinical trials

PURPOSE OF REVIEW

The purpose of this report is to review recent literature and ongoing clinical trials of the treatment of neovascular age-related macular degeneration.

RECENT FINDINGS

Advances in the understanding of the pathogenesis of age-related macular degeneration and choroidal neovascularization have resulted in the emergence of pharmacotherapies targeting various aspects of angiogenesis. Preliminary results with the new agents have been encouraging. Moreover, longer follow-up and subgroup analyses of the Treatment of Age-Related Macular Degeneration with Photodynamic Therapy and Verteporfin in Photodynamic Therapy studies have suggested new potential indications for photodynamic therapy.

SUMMARY

Currently a patient with wet macular degeneration may have multiple investigational options that were unavailable several years ago. Ongoing clinical trials are aimed at determining the long-term safety and efficacy of these new pharmacologic and combination therapy modalities.

Transpupillary thermotherapy for idiopathic subfoveal choroidal neovascularization

PURPOSE

To assess the efficacy of transpupillary thermotherapy (TTT) for the management of idiopathic subfoveal choroidal neovascularization (CNV).

METHODS

This was a prospective, non-controlled, clinical case trial involving 21 eyes of 21 patients with a mean age of 36 years. All 21 eyes had idiopathic subfoveal CNV and were subjected to diode laser TTT. Laser beam size ranged from 1.2 mm to 3.0 mm and power settings ranged between 300 mW and 600 mW. The end-point was an area of no visible colour change. Pre- and post-laser evaluations of ETDRS visual acuity, contrast sensitivity, slit-lamp biomicroscopy and fluorescein angiography were carried out.

RESULTS

The nine predominantly occult and 12 predominantly classic subfoveal membranes were followed-up for a mean of 5.1 months after TTT. Overall, 17 eyes (81%) showed improvement or stabilization in ETDRS visual acuity. Contrast sensitivity improved in 17 eyes (81%). Reading speed improved in 15 eyes (71%). Retreatment was needed in three eyes (14%).

CONCLUSION

Transpupillary thermotherapy treatment is a potential strategy for treating idiopathic subfoveal CNV in both its classic and occult forms.

Current and Future Treatment Options for Nonexudative and Exudative Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the industrialised world. Although relatively simple to diagnose through direct visualisation augmented with rapid sequence fluorescein angiography, treatment has presented a far greater challenge because the true aetiology of AMD is largely unknown. Within the past decade, researchers have introduced many new, potentially promising treatment and prevention options in an attempt to minimise the damage imparted from AMD. They capitalise on many of the theoretical and known factors contributing to AMD progression. A high-dose of an orally administered combination of the antioxidants ascorbic acid (vitamin C), tocopherol (vitamin E) and beta-carotene, in addition to copper and zinc, is the only widely accepted preventive therapy. Thermal laser photocoagulation and verteporfin photodynamic therapy are the only standard treatment options available based on large scale, randomised, prospective, placebo-controlled trials; however, efficacy is limited and only a minority of patients who present with AMD are eligible for these treatments. Many other preventive and treatment options are in all phases of clinical studies and expected to change the entire approach to AMD management in the near future. For example, alternative antioxidants, drusen ablation, apheresis and HMG-CoA reductase inhibitors have shown promise in some studies by preventing or slowing the progression of certain forms of AMD. In addition, alternative photodynamic therapies, low-intensity laser, antiangiogenic medications, radiation treatment and surgery have demonstrated the ability, albeit to differing degrees, to inhibit or possibly even reverse the severe vision loss often associated with AMD characterised by choroidal neovascularisation.