Prospective three-dimensional analysis of structure and function in vitreomacular adhesion cured by pharmacologic vitreolysis

Clinical Update on Metamorphopsia: Epidemiology, Diagnosis and Imaging

Purpose: To discuss the pathophysiology of metamorphopsia, its characterisation using retinal imaging and methods of assessment of patient symptoms and visual function.Methods: A literature search of electronic databases was performedResults: Metamorphopsia has commonly been associated with vitreomacular interface disorders (such as epiretinal membrane) and has also regularly been noted in diseases of the retina and choroid, particularly age-related macular degeneration and central serous chorioretinopathy. Developments in optical coherence tomography retinal imaging have enabled improved imaging of the foveal microstructure and have led to the localisation of the pathophysiology of metamorphopsia within the retinal layers of the macula. Alteration of alignment of inner and outer retinal layers at various retinal loci has been identified using multimodal imaging in patients with metamorphopsia in a range of conditions. Although the Amsler Grid assessment of metamorphopsia is a useful clinical indicator, new emerging methods of metamorphopsia assessment with psychophysical tests such as M-CHARTS and preferential hyperacuity perimetry, have been developed.Conclusions: It appears that there is a complex relationship between visual acuity and metamorphopsia symptoms that vary between retinal conditions. Although metamorphopsia has traditionally been challenging to measure in the clinic, advances in technology promise more robust, easy-to-use tests. It is possible that home assessment of metamorphopsia, particularly in conditions such as age-related macular degeneration, may help to guide the need for further clinic evaluation and consideration of treatment.

STRUCTURAL AND FUNCTIONAL CHARACTERISTICS OF LAMELLAR MACULAR HOLES

PURPOSE

Lamellar macular holes (LMHs) can been subdivided into tractional and degenerative subtypes. This cross-sectional cohort study compared structural and functional characteristics in these subtypes hypothesizing that tractional LMH has a higher prevalence of vitreopapillary adhesion and tangential traction (macular pucker), whereas degenerative LMH has more ellipsoid zone disruption and worse vision, measured three different ways.

METHODS

Tractional LMH (n = 22) and degenerative LMH (n = 15) were distinguished by optical coherence tomography criteria. Separate spectral domain optical coherence tomography scanning of the macula and optic disk was performed. Visual acuity, contrast sensitivity function (Weber Index, %W), and the degree of visual distortions (3-dimensional threshold Amsler grid; % volume lost [%VL]) were quantified.

RESULTS

Vitreopapillary adhesion was present in 14/22 (64%) tractional, but in only 3/15 (20%) degenerative LMH (P = 0.006). Macular pucker was present in 19/22 (86%) tractional, but in only 8/15 (53%) degenerative LMH (P = 0.011). Ellipsoid zone disruption was present in 13/15 (87%) degenerative, but in only 2/22 (9%) tractional LMH (P = 0.0001). Visual acuity was better in tractional than degenerative LMH (P = 0.006), as was contrast sensitivity function (tractional = 3.44 ± 1.07 %W, degenerative = 4.66 ± 1.73 %W; P = 0.015). Visual distortions were less in tractional (0.33 ± 0.61 %VL) than in degenerative (0.85 ± 0.68 %VL) LMH (P = 0.014).

CONCLUSION

Structure and visual function differ significantly in subtypes of LMH. Tractional LMH has 3-fold higher prevalence of vitreopapillary adhesion and 2-fold higher prevalence of macular pucker. Degenerative LMH has 9-fold more ellipsoid zone disruption, worse visual acuity and contrast sensitivity function, and 3-fold more distortions. Thus, outer retinal integrity seems more closely correlated with vision than anterior structural abnormalities in LMH.

Quantifying Visual Dysfunction and the Response to Surgery in Macular Pucker

PURPOSE

To measure the effects of macular pucker (MP) on macular structure and quantify function by measuring visual acuity (VA), contrast sensitivity (CS), and distortions. The effects of surgery were quantitatively evaluated using these measures.

DESIGN

Prospective, comparative case series.

PARTICIPANTS

Fifty-three patients with unilateral MP and normal fellow eyes: 24 operated MP subjects, 17 unoperated controls, and 12 reproducibility subjects.

METHODS

Posterior vitreous detachment was diagnosed by ultrasound and ellipsoid zone disruption (EZD) was determined by OCT, which also measured macular thickness and volume. Vision was assessed, by measuring VA (logMAR) and CS (Freiburg acuity contrast testing: Weber index, %W). A visual distortions index (%DI) was calculated using 3-dimensional threshold Amsler grid testing. Comparisons to controls were performed before surgery and at 1, 3, 6, and 12 months after vitrectomy/membrane peel without chromodissection.

MAIN OUTCOME MEASURES

Posterior vitreous detachment (ultrasound), EZD (OCT), macular thickness and volume (OCT), VA (logMAR), CS (%W), distortions (%DI).

RESULTS

Posterior vitreous detachment was present in 90% of MP eyes, but only 50% of fellow eyes (P < 0.001). All structural and functional indices were worse (28% to 5-fold) in the 24 operated MP eyes than the 17 unoperated MP eyes (P < 0.001). Before surgery, EZD was present in 33% of operated MP eyes but none of the unoperated MP eyes (P < 0.02). The macula was thicker (514±85 μm vs. 257±59 μm; P < 0.001) with greater volume (3.22±0.56 μl vs. 2.14±0.22 μl; P < 0.001) in operated MP eyes than normal fellow eyes. Before surgery, MP eyes had VA = 0.53 logMAR (Snellen equivalent, 20/67) vs. controls = 0.21 (20/32); P < 0.001; CS was 8.61±5.36 %W vs. controls = 3.71±1.47 %W (P < 0.001); and distortions were 7.61±12.6 %DI vs. controls = 0.13±0.61 %DI (P < 0.001). EZD was associated with worse VA (P < 0.01) and CS (P < 0.03) before and after surgery. Each outcome measure improved progressively at 1, 3, 6, and 12 months after surgery, but only %DI and macular volume normalized.

CONCLUSIONS

These quantitative measures characterize the impact of MP on macular structure and function. All indices improved after surgery, but only distortions and macular volume normalized. Contrast sensitivity measurements and quantification of distortions can objectively assess visual dysfunction in MP and may be useful outcome measures of therapy.