Femtosecond laser-assisted posterior capsulotomy for the treatment of capsular block syndrome.

We present a novel use of femtosecond laser to treat capsular block syndrome (CBS) in a patient with dense opaque capsular block, who presented 16 years postcataract surgery. The extensive posterior capsular distension and densely opaque, milky fluid trapped behind the intraocular lens (IOL) prevented the use of neodymium-doped yttrium aluminum garnet (Nd: YAG) laser posterior capsulotomy as primary treatment. Intra-operative optical coherence tomography enabled visualization of the posterior capsule and iris hooks were used to increase the pupillary diameter to enable femtosecond laser-assisted posterior capsulotomy to be performed in a minimally invasive technique. CBS was relieved successfully and Nd: YAG laser performed subsequently to remove residual posterior capsule opacification safely and with good visual outcomes. This method avoids risks associated with posterior vitrectomies and compromised IOL stability from inadvertent capsular bag damage, and adds to the expanding uses of femtosecond laser technology.

Steady-State Pattern Electroretinography in Eyes with Glaucoma and High Myopia.

PURPOSE: To investigate features of the steady-state pattern electroretinogram (ssPERG) in subjects with glaucoma (G), high myopia (HM; spherical equivalent ≤-6D) and glaucoma with high myopia (GHM). PATIENTS AND METHODS: Our study included 48 participants divided into 3 groups (G, HM, and GHM) who each underwent monocular ssPERG testing with Diopsys NOVA PERG protocols. The ConStim protocol detects distinct topographic patterns of dysfunction 16° and 24° around the central macula. MagD is the amplitude of the average signal and MagD/Mag ratio indicates the consistency of the response. ssPERG indices were compared between groups and correlated with functional (ie, visual field mean deviation (VFMD)) and structural (ie, average retinal nerve fibre layer (RNFL) thickness; Cirrus optical coherence tomography) features. RESULTS: Participants had an average age of 59.4±7.6 years. Mean Humphrey VFMD was -14.22 ± 2.88dB, -2.62 ± 1.18dB and -12.80 ± 2.60dB for G, HM and GHM groups, respectively. Mean RNFL thickness was 63.0 ± 8.20µm, 69.5 ± 15.7µm and 60.6 ± 5.0µm for G, HM and GHM groups, respectively. For the 24° setting, no significant differences were noted for any of the parameters. For the 16° setting, MagD was lower in the GHM group compared to the HM group (0.29µV vs 0.52µV; p = 0.02). Significant differences were noted for the MagD/Mag ratio between HM and G groups (0.58 vs 0.40; p = 0.02) and between HM and GHM groups (0.58 vs 0.35; p = 0.002). There were positive correlations between both MagD 16° and MagD/Mag ratio 16° with VFMD (correlation coefficient [r]=0.37, p = 0.009; and r = 0.44, p = 0.002, respectively) and RNFL (r = 0.43, p = 0.002; and r = 0.48, p = 0.001, respectively). CONCLUSION: MagD/Mag ratio at 16° was significantly lower in glaucomatous eyes (with or without high myopia) compared to those with high myopia without glaucoma, suggesting that glaucoma has a distinct impact on MagD/Mag ratio at 16° irrespective of the presence of myopia.

Retinal Vascular Oxygen Saturation and Its Variation With Refractive Error and Axial Length.

PURPOSE: To evaluate the relationships between refractive error, axial length (AL), and retinal vascular oxygen saturation in an adult population. METHODS: This was a hospital-based, prospective observational study. The left eyes of phakic adult subjects without media opacity were analyzed. Subjective undilated manifest refraction was performed, and refractive errors were defined as myopia (spherical equivalent [SE], <-1 D), emmetropia (SE between -1 D and +1 D) and hyperopia (SE >+1 D). Retinal oximetry was performed using the Oxymap system (Oxymap Inc., Reykjavik, Iceland). Multivariate linear regression models were constructed to assess the relationship between retinal vascular oxygen saturation, SE, and AL obtained with optical biometry, with adjustments for age, sex, race, blood pressure, hyperlipidemia, and diabetes mellitus. RESULTS: There were 85 subjects, with mean age of 66.1 ± 11.3 years. The majority were female (60%) and Chinese (84%). A total of 60% were myopic, 28% emmetropic, and 12% hyperopic. Mean SE was -5.29 ± 6.51 D and mean AL was 25.30 ± 2.99 mm. In multivariate analyses, more myopic SE and longer AL were associated with lower retinal arteriolar oxygen saturation (regression coefficient B = 0.61 [95% confidence interval, 0.28, 0.95], P = 0.001; and B = -1.13 [95% confidence interval, -1.71, -0.56], P < 0.001, respectively). Subjects with myopic SE and AL also had lower retinal arteriolar oxygen saturation than emmetropes and hyperopes (P = 0.03 and P = 0.02, respectively). CONCLUSIONS: Eyes with more myopic SE and longer AL have lower retinal arteriolar oxygen saturation. TRANSLATIONAL RELEVANCE: This study provides direct evidence of a link between retinal oxygenation and hypoxia and myopia by using a novel device that quantifies retinal vascular oxygenation in vivo.