Change in retinal sensitivity due to excision of choroidal neovascularization and its influence on visual acuity outcome

Clinical utilization of microperimetry in ophthalmic surgery: A narrative review

Microperimetry is an emerging technology that provides concurrent analysis of retinal structure and function by combining retinal sensitivity and fixation analysis with fundus imaging. We summarize the substantial evidence validating the evolving role of microperimetry as an adjunctive assessment of visual function in the perioperative setting. We show that microperimetry provides useful complementary information to other established imaging and functional modalities in the perioperative setting for a wide range of vitreoretinal surgical procedures, as well as in cataract and refractive surgeries. This includes preoperative uses such as prognostication of visual and anatomical outcomes, timing of surgical intervention, and assessment of patient suitability for surgery-as well as postoperative uses including quantification of visual recovery, investigation of unexplained postoperative vision loss, and informing expected long term functional outcomes.

Choroidal neovascularization in pathological myopia

Myopic choroidal neovascularization (CNV) is one of the leading causes of visual impairment worldwide. The clinical and socioeconomic impact of myopic CNV in Asian countries is particularly significant due to rising trend in the prevalence and severity of pathological myopia. The exact pathogenesis of myopic CNV remains unclear and there is paucity of information with respect to incidence and risk factors for myopic CNV from prospective studies. Furthermore, there are no recognized measures that may prevent or delay the development of CNV in eyes with pathological myopia. Advances have been made in the diagnosis and characterization of myopic CNV over the years. Until recently, treatment modalities for myopic CNV were limited to thermal laser photocoagulation and photodynamic therapy with verteporfin, both these modalities primarily aim at prevention of further visual loss. In the last 5 years, inhibitors of vascular endothelial growth factor (VEGF) have been used successfully and may improve vision to some extent. Nevertheless, the long-term safety and efficacy of anti-VEGF agents remains unknown. Furthermore, the risk of developing chorioretinal atrophy remains the key factor in determining the final visual outcome. This review article summarizes the current literature on myopic CNV, highlighting new evolving diagnostic and treatment modalities, prognostic factors influencing visual outcome, and areas of future research.

The end of submacular surgery for age-related macular degeneration? A meta-analysis

BACKGROUND

The aim of this meta-analysis was to summarize and to discuss the results of the four main submacular surgical procedures for age-related macular degeneration (AMD) as reported in the literature through 2004 and to compare them to the Submacular Surgery Trials (SST) data.

METHODS

The existing data in the literature on submacular surgery for AMD from 1992 to 2004 were evaluated. The main outcomes were proportion of patients with two or more lines of improvement in visual acuity (VA) and proportion with two or more lines of deterioration in VA after surgery.

RESULTS

Eighty-eight studies including 1,915 cases met the inclusion criteria. Estimates for the treatment outcome within the four groups of treatment based on a logistic regression model gave comparable results for removal of choroidal neovascularization (CNV) (improvement of VA 28%, deterioration of VA 25%), macular translocation (improvement of VA 31%, deterioration of VA 27%), and for transplantation of pigment epithelium (improvement of VA 22%, deterioration of VA 21%). Estimates for removal of subretinal hemorrhage were significantly different (improvement of VA 62%, deterioration of VA 13%).

CONCLUSIONS

Selected case series showed superior results of VA compared to the SST. The question of whether this is due to selection bias that seems inevitable when dealing with medium-sized nonrandomized case series or due to better results in single centers cannot be answered. In our opinion there still seem to be indications for submacular surgery such as in patients with AMD with low preoperative VA due to large hemorrhagic or fibrotic membranes or nonresponders to photodynamic therapy (PDT).

Photodynamic therapy with verteporfin for juxtafoveal choroidal neovascularization secondary to pathologic myopia-1-year results of a prospective series

PURPOSE

To study the efficacy of photodynamic therapy (PDT) with verteporfin in the treatment of juxtafoveal choroidal neovascularization (CNV) secondary to pathologic myopia.

METHODS

Prospective, open label, two-centre, noncomparative, interventional case series. Consecutive patients with juxtafoveal CNV associated with pathologic myopia were recruited and treated with a standard regimen of PDT with verteporfin. Patients were being followed up every 3-monthly and retreatment was considered when there was evidence of angiographic leakage. Outcome measures included changes in the mean best-corrected visual acuity (BCVA) at the 1-year follow-up when compared with the baseline, the proportion of patients who had stable (within 1 line) and improved visions.

RESULTS

A total of 11 eyes from 11 patients with juxtafoveal CNV secondary to pathologic myopia were recruited and all completed the 1-year follow-up. The mean age at presentation was 44.8 years. The refractive error ranged from -6.0 to -15.0 D (+/-SD was -9.55+/-3.04 D). The logMAR BCVA improved from 0.57 to 0.39 at the 1-year follow-up (Wilcoxon signed-ranks test, P=0.027). The mean improvement was 1.8 lines. Five eyes (45.4%) had BCVA improved by >or=3 lines. None of the treated patients had visual loss of >or=1 line. The mean number of treatments over the 12-month study period was 2.3 sessions.

CONCLUSIONS

The results are encouraging, especially on considering the low retreatment rate, stable or improved BCVA in all treated eyes, and consistently good safety profile. Juxtafoveal myopic CNV may be an expanded indication for PDT with verteporfin.

Effects of verteporfin therapy on central visual field function

PURPOSE

To evaluate the effect of photodynamic therapy with verteporfin on the maintenance of central visual field function.

DESIGN

Randomized controlled clinical trial.

PARTICIPANTS

Forty-six consecutive patients with subfoveal choroidal neovascularization (CNV) caused by age-related macular degeneration including a classic component were randomly assigned. Thirty-three participants received standard verteporfin therapy, and 13 received placebo and laser treatment.

METHODS

The trial was performed as a single-center, double-masked study. Patients were examined before therapy and continuously in 3-month intervals during 2 years of follow-up. A scanning laser ophthalmoscope (SLO) was used to perform macular microperimetry. Absolute and relative scotomas were documented at each visit, and size was measured in square millimeters.

MAIN OUTCOME MEASURES

The change in size of central scotoma in the verteporfin group compared with the placebo group.

RESULTS

An absolute scotoma was seen in 88%, and a relative scotoma was seen in 100% of eyes before therapy. Absolute defects were associated with the classic CNV component localized angiographically. In the verteporfin group, the absolute scotoma grew from 2.5 mm(2) at baseline to a final size of 7.3 mm(2) at month 24. In the placebo group, the mean lesion size of the absolute scotoma enlarged from an initial size of 2.7 mm(2) to 31.5 mm(2) after 24 months. The relative scotoma increased from 7.9 mm(2) at baseline to 20.8 mm(2) at month 24 in the verteporfin group, whereas a progression from 8.5 mm(2) initially to 48.3 mm(2) at the final presentation was measured in the placebo group. Statistical analysis showed that both the mean absolute and relative scotoma sizes were significantly smaller in the verteporfin group than the placebo group for all intervals from 6 to 24 months (P<0.001).

CONCLUSIONS

Documentation of macular function with SLO perimetry demonstrated a significant benefit of verteporfin therapy for the preservation of the central visual field. Absolute and relative scotoma sizes remained smaller after therapy. This may influence reading ability and visual rehabilitation.

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.