The Effects of 23-Gauge Pars Plana Vitrectomy on Orbital Circulation Using Doppler Ultrasonography in Diabetic Macular Edema with Epiretinal Membrane and Taut Posterior Hyaloid

PURPOSE

To evaluate using Doppler ultrasonography (DUS) how pars plana vitrectomy (PPV) affects orbital circulation in diffuse diabetic macular edema (DME) associated with either the epiretinal membrane (ERM) or taut posterior hyaloid (TPH).

METHODS

The sample included 46 eyes of 42 patients with DME associated with the ERM (n = 22, Group 1) or TPH (n = 24, Group 2). All participants received panretinal laser photocoagulation and antivascular endothelial growth factor injections preoperatively and underwent 23-gauge PPV combined with ERM or TPH removal and internal limiting membrane (ILM) peeling. Pre- and postoperative peak systolic velocity (PSV), end-diastolic velocity (EDV), and the resistivity index (RI) of the ophthalmic artery (OA), central retinal artery (CRA), posterior ciliary artery (PCA), and central retinal vein were measured with DUS.

RESULTS

Statistically significant decreases in the PSV and EDV of the OA, CRA, and PCA were detected in all groups. In Group 1, the PSV of the OA and CRA as well as the EDV and PSV of the PCA declined significantly. In Group 2, the EDV of the OA and both the PSV and EDV of the CRA and PCA decreased. Postoperatively, the CRA's PSV and EDV were lower in Group 2, while the preoperative and postoperative RI of the CRA and preoperative RI of the PCA were greater in Group 2 than in Group 1. Changes in the CRA's RI, PSV, and EDV were greater in Group 2 after surgery.

CONCLUSIONS

23-Gauge PPV combined with ERM or TPH removal and ILM peeling in DME reduces blood flow rates of both choroidal and retinal vessels. In eyes with TPH, the RIs of the CRA and PCA were significantly greater preoperatively and the changes in the CRA's RI, PSV, and EDV were greater postoperatively. The removal of the TPH may play a role in regulating blood flow.

The effects of ranibizumab injections on fluorescein angiographic findings and visual acuity recovery in age-related macular degeneration

Aim

The objective of the study reported here was to evaluate the effect of ranibizumab on retinal circulation times and vessel caliber and to analyze the correlation of these factors with visual acuity (VA) prognosis in patients with age-related macular degeneration (AMD).

Subjects and methods

This prospective cohort study included 52 eyes of 46 patients (mean age 73.5 years [standard deviation 7.7]; 28 males, 18 females). The study parameters were best-corrected visual acuity (BCVA), central macular thickness (CMT) (pre- and posttreatment: for 3 months after the last injection), retinal circulation times, diameter of retinal arteriole (DRA), and diameter of retinal vein (DRV) (pre- and posttreatment: after a loading dose of three consecutive injections of ranibizumab with a 4-week interval in the initial phase). The pretreatment, posttreatment measurements, and their differences were recorded for analyses. The injections were repeated when needed. Eyes were grouped into one of two groups according to VA recovery: Group 1, cases showing significant recovery of VA (n=21, 37%), and Group 2, cases showing preservation of VA (n=22, 42%) and deterioration of VA (n=11, 21%). Differences were compared statistically in and between groups. Logistic regression analysis was undertaken to determine the correlation of these parameters with VA recovery.

Results

There was a significant reduction in DRA (P=0.007) and CMT levels (P<0.001) in both study groups after treatment. When the two groups were compared, the differences in pretreatment values of DRA (P=0.001), DRV (P=0.017), CMT (P=0.039), and mean BCVA (P=0.00) were found to be statistically significant. Posttreatment changes in DRA (P=0.013) and mean CMT (P=0.010) were found to be factors related to VA recovery by logistic regression analysis.

Conclusion

Our findings reveal that ranibizumab treatment is associated with decrease in DRA, CMT, and significant improvement in VA recovery. Further, taking into account the cases in which VA was preserved, when needed, ranibizumab should be re-injected after the loading dose.

Scanning Electron Microscopic and Energy Dispersive Spectroscopic Findings of a Removed Iris-Claw Lens

A case of a patient whose phakic iris-claw lens fell into the anterior chamber after 15 years of implantation are reported. The surface of the lens was analyzed with scanning electron microscopy and with energy dispersive spectroscopy. Granular aggregates on the anterior surface and denser aggregates branching into wide areas on the posterior surface of the optic, irregularities on interface surfaces of the haptics due to possible manufacturing defects, and impressions due to devices used for implantation were detected, as were calcium (Ca) deposits in the aggregates. Considering the facilitated damage and atrophy of the iris by the irregularities of the interface surface of the haptics and also the dense Ca deposits on the surfaces which affect biocompatibility, it would be better to exchange the old lens, which has fallen into the anterior chamber, for a new generation one instead of reimplanting the older lens that has been in position for many years.

Endophthalmitis due to exposure of anterior chamber intraocular lens haptic tip

After bilateral implantation of an angle-supported anterior chamber intraocular lens (AC IOL) in an allergic patient, the haptic tips were exposed through the limbus in the left eye. Endophthalmitis developed in the eye and was treated by pars plana vitrectomy, IOL extraction, and intravitreal antibiotic injection. Haptic repositioning was performed in the right eye. In this report, we assess the possibility that exposure of the angle-supported AC IOL haptics caused the endophthalmitis. We hypothesized that vigorous rubbing of the eye of the atopic patient might cause limbal erosion that could lead to exposure of the angle-supported AC IOL haptic through the limbus.