Evaluation of optic nerve head vessels density changes after phacoemulsification cataract surgery using optical coherence tomography angiography.

AIM: To evaluate optic nerve head (ONH) vessel density (VD) changes after cataract surgery using optical coherence tomography angiography (OCTA). METHODS: This was a prospective observational study. Thirty-four eyes with mild/moderate cataracts were included. ONH scans were obtained before and 3mo after cataract surgery using OCTA. Radial peripapillary capillary (RPC) density, all VD, large VD and retinal nerve fiber layer thickness (RNFLT) in total disc, inside disc, and different peripapillary sectors were assessed and analyzed. Image quality score (QS), fundus photography grading and best-corrected visual acuity (BCVA) were also collected, and correlation analyses were performed between VD change and these parameters. RESULTS: Compared with baseline, both RPC and all VD increased in inside disc area 3mo postoperatively (from 47.5%±5.3% to 50.2%±3.7%, and from 57.87%±4.30% to 60.47%±3.10%, all P<0.001), but no differences were observed in peripapillary area. However, large VD increased from 5.63%±0.77% to 6.47%±0.72% in peripapillary ONH region (P<0.001). RPC decreased in inferior and superior peripapillary ONH parts (P=0.019, <0.001 respectively). There were obvious negative correlations between RPC change and large VD change in inside disc, superior-hemi, and inferior-hemi (r=-0.419, -0.370, and -0.439, P=0.017, 0.044, and 0.015, respectively). No correlations were found between VD change and other parameters including QS change, fundus photography grading, postoperative BCVA, and postoperative peripapillary RNFLT. CONCLUSION: RPC density and all VD in the inside disc ONH region increase 3mo after surgery in patients with mild to moderate cataract. No obvious VD changes are found in peripapillary area postoperatively.

Retinal vessel diameter changes induced by transient high perfusion pressure.

AIM: To investigate the effects of transient high perfusion pressure on the retinal vessel diameter and retinal ganglion cells. METHODS: The animals were divided into four groups according to different infusion pressure and infusion time (60 mm Hg-3min, 60 mm Hg-5min, 100 mm Hg-3min, 100 mm Hg-5min). Each group consisted of six rabbits. The left eye was used as the experimental eye and the right as a control. Retinal vascular diameters were evaluated before, during infusion, immediately after infusion, 5min, 10min and 30min after infusion based on the fundus photographs. Blood pressure was monitored during infusion. The eyes were removed after 24h. Damage to retinal ganglion cell (RGC) was analyzed by histology. RESULTS: Retina became whiten and papilla optic was pale during perfusion. Measurements showed significant decrease in retinal artery and vein diameter during perfusion in all of the four groups at the proximal of the edge of the optic disc. The changes were significant in the 100 mm Hg-3min group and 100 mm Hg-5min group compared with 60 mm Hg-3min group (P1=0.025, P2=0.000). The diameters in all the groups recovered completely after 30min of reperfusion. The number of RGC showed no significant changes at the IOP in 100 mm Hg with 5min compared with contralateral untreated eye (P>0.05). CONCLUSION: Transient fluctuations during infusion lead to temporal changes of retinal vessels, which could affect the retinal blood circulation. The RGCs were not affected by this transient fluctuation. Further studies are necessary to evaluate the effect of pressure during real-time phacoemusification on retinal blood circulation.

Contrast visual acuity after multifocal intraocular lens implantation: aspheric versus spherical design.

AIM: To evaluate contrast visual acuity (CVA) after implantation of an aspheric apodized diffractive intraocular lens (IOL) or a spherical apodized diffractive IOL in cataract surgery. METHOD: This prospective randomized controlled study with a 12-month follow-up compared the results of cataract surgery with implantation of an aspheric AcrySof ReSTOR SN6AD3 IOL (30 eyes) and a spherical AcrySof ReSTOR SN60D3 IOL (30 eyes). CVA with best distance correction was measured at 4 contrast levels (100%, 25%, 10% and 5%) under 3 levels of chart luminance [250, 85 and 25 candelas per square meter (cd/m(2))] using a multi-functional visual acuity tester (MFVA-100). RESULTS: At 12 months after surgery, there were no statistically significant differences in 100% CVA and 25% CVA under 250cd/m(2) (P 100%=0.875 and P 25%=0.057) and 85cd/m(2) (P 100%=0.198 and P 25%=0.193) between the aspheric group and the spherical group. However, the 10% CVA and 5% CVA were significant better in aspheric group than spherical group under 250cd/m(2) (P 10%=0.042 and P 5%=0.007) and 85cd/m(2) (P 10%=0.002 and P 5%=0.039). Under the luminance level of 25cd/m(2), no significant differences was found in the 100% CVA between the 2 group (P 100%=0.245), while aspheric group had better visual acuity in the remaining 3 contracts (P 25%=0.023, P 10%=0.026 and P 5%=0.002, respectively). CONCLUSION: [corrected] The aspheric AcrySof ReSTOR SN6AD3 IOL provided patients with better low-contrast visual acuity than the spherical AcrySof ReSTOR SN60D3 IOL.

[Comparison of visual acuity in pseudophakic eyes with multifocal intraocular lens versus fellow eyes with clear lens].

OBJECTIVE: To evaluate the visual acuity and subjective satisfaction of different aged monocular cataract patients who were implanted with ReSTOR multifocal intraocular lens (MIOL). METHODS: Prospective comparative study: the objects are 24 cases of monocular cataract patients who consecutively received phacoemulsification and implantation of ReSTOR MIOL. The patients were divided into two groups by age: the presbyopic group has 17 cases with age ≥ 45 years, the non-presbyopic group has 7 cases with ages < 45 years. Research parameters: uncorrected and corrected distance (4 m), intermediate (80 cm, 60 cm), and near visual acuity; contrast sensitivity (CS); and questionnaire survey. All data were statistically analyzed with rank sum test. RESULTS: Among presbyopia patients, the near vision of the eyes implanted with ReSTOR MIOL is better than that of the contralateral eyes with clear lens (Z = 2.864, Z = 2.911;P = 0.004), whereas the distance and intermediate vision and the CS results show no significant differences compared to that of contralateral eyes with clear lens (Z = 0.183 - 1.417, P = 0.855 - 0.156); the subjective satisfactions are 7 to 10 points with 70.6% (12/17) patients scoring higher than 9 points; and the spectacle-independent rate among presbyopia patients is 58.8% (10/17). In non-presbyopic group, the near and intermediate visions of ReSTOR MIOL implanted eyes are lower than that of the contralateral eyes with clear lens (Z = 2.197 - 2.371;P = 0.028 - 0.018); CS results of MIOL implanted eyes are also generally lower than that of the contralateral eyes, and the difference between CSs of bilateral eyes under night glare mode (3 cd/m(2)+28 Lux) with low spatial frequency (1.5 c/d) is statistically significant (Z = 1.997, P = 0.046); the subjective satisfactions are 6 to 9 points with 14.3% (1/7) patients scoring higher than 9 points; the spectacle-independent rate of both eyes is 85.7% (6/7). CONCLUSIONS: The monocular cataract patients with presbyopia are suitable for implantation of ReSTOR MIOL, because their near visual acuity of ReSTOR MIOL implanted eyes is better than that of the contralateral clear lens eyes with higher subjective satisfaction and without decrease in distance and intermediate visions and CS. For non-presbyopic young patients with monocular cataracts, the near and intermediate visions of MIOL implanted eyes are lower than that of the contralateral clear lens eyes and with lower subjective satisfaction (compared to that of presbyopic patients), though the distance visions are similar. Therefore, although ReSTOR MIOL can be implanted in non-presbyopic group, a more detailed preoperative communication with these patients is needed.