[Clinical research of the phakic foldable angle-supported intraocular lens for the correction of high myopia].

OBJECTIVE: To assess the safety, efficacy, predictability and stability of the phakic foldable angle-supported intraocular lens (IOL) (CACHET IOL, Alcon Inc., USA.) for correction of high-to-extremely high myopia in adults. METHODS: In this prospective study, 29 eyes of 15 patients were implanted with CACHET phakic angle-supported IOL and followed for 1 year postoperatively. Preoperative manifest refractive sphere was -12.08 ± 2.44 diopters (D). Visual acuity(uncorrected visual acuity, UCVA; best spectacle-corrected visual acuity, BSCVA), predictability and stability of manifest refraction spherical equivalent (MRSE), adverse events, and endothelial cell density were analyzed primarily during 1-year of follow-up. RESULTS: After 1 year of follow-up, a BSCVA of 0.6 or better was achieved by 100% of eyes; 9.7% (26/29) had a BSCVA of 1.0 or better; no eyes lost ≥ 1 line BSCVA, 62.1%(18/29) had no change in lines of BSCVA, 31.0% (9/29) gained 1 line of BSCVA, 3.4% (1/29) gained 2 line of BSCVA, and 3.4% (1/29) gained more than 2 line of BSCVA; the safety index was 1.13 (1.08/0.96); UCVA of 1.0 or better was achieved by 58.6% (17/29), 100% had an UCVA of 0.5 or better, 86.2% (25/29) of eyes achieved a UCVA of 0.8 or better, and 93.1% (27/29) of eyes achieved a UCVA of 0.6 or better; the efficacy index was 1.03(0.99/0.96). The overall mean percentage change in endothelial cell density 1 year after surgery was -0.23% ± 4.80%. Five eyes (17.2%) had increased intraocular pressure (IOP) on the day of surgery. No pupil ovalization, pupillary block, or retinal detachment events were observed. Glare (6.9%, 2/29) and halo (13.8%, 4/29) mainly appeared in the first month after surgery, and had no influence on driving in night. CONCLUSIONS: After 1 year of follow-up, the implantation of phakic foldable angle-supported IOL was proved to be safe, effective and predictable with minimal complications in patients with high myopia. Due to the limitation of visiting time, long-term of clinical investigation is necessary to verify the safety and efficacy of this IOL.

Comparative study of objective visual quality between FS-LASIK and SMART in myopia.

AIM: To compare the changes in the objective visual quality of patients with low and moderate myopia postoperatively after transepithelial photorefractive keratectomy using the smart pulse technology (SMART) and femtosecond laser in situ keratomileusis (FS-LASIK). METHODS: Corneal higher-order aberrations (HOAs), horizontal coma, vertical coma and spherical aberration were measured using Pentacam, and cutoff for modulation transfer function (MTF cutoff), objective scatter index (OSI) and Strehl ratio (SR) was measured using an optical quality analysis system (OQAS-II), before and after operation at 1, 3, and 6mo, and data were analyzed by repeated measurement two-way analysis of variance. RESULTS: The difference in uncorrected distance visual acuity between SMART and FS-LASIK was statistically significant only 1wk postoperatively. Approximately 86.36% and 80.69% of patients with spherical equivalent (SE) in ±0.50 D were observed in the SMART and FS-LASIK groups, respectively. No significant difference was observed in SE between the two groups (P=0.509). The HOAs increased postoperatively compared with those before surgery in both groups (P<0.05). No significant difference in HOA, corneal horizontal coma, spherical aberration, ΔHOA, Δhorizontal coma, and Δspherical aberration were observed between the two group (P>0.05). Corneal vertical coma and Δcorneal vertical coma in the FS-LASIK group were higher than those in the SMART group (P<0.05). The OSI of both groups at 1mo after surgery was higher than that before surgery (P<0.05). At 3 and 6mo postoperatively, the OSI in the FS-LASIK group was slightly higher than that in the SMART group (P=0.040 and 0.047, respectively). At 6mo after surgery, the MTF cutoff was statistically significant different between the two groups (P=0.026). No significant difference in SR between the FS-LASIK and SMART groups was observed at 1, 3, and 6mo postoperatively (P>0.05). CONCLUSION: The HOAs increase and visual quality is delayed in both groups postoperatively, and the long-term objective visual quality after SMART is slightly better than that after FS-LASIK.

Immunologic mechanism of fungal keratitis.

Fungal keratitis (FK) is a refractory disease that poses a serious threat to vision, with common risk factors like eye trauma, contact lens wearing, topical corticosteroids and antibiotic abuse. Nowadays, topical and systemic anti-fungal drugs and ocular surgeries are still the main therapeutic modalities. However, the pathogenesis of FK, especially the immunologic mechanism within it, has not yet been deeply clarified. A better understanding of the pathogenesis of FK is imperative for more effective therapies and prognosis. Meanwhile, the immune protection strategies are also urgently required to manage FK. This review highlights recent advances in the immunologic mechanism in the pathogenesis of FK, in hope of providing valuable reference information for more effective anti-fungal treatment.

[Performance dependence of organic light-emitting devices on the thickness of Alq3 emitting layer].

The dependence of opto-electronical characteristics in organic light-emitting devices on the thickness of Alq3 emitter layer was studied, where MoO3, NPB, and Alq3 were used as hole injector, hole transporter, and emitter/electron transporter, respectively. By increasing the thickness of Alq3 layer from 20 to 100 nm, the device current decreased gradually, and the EL spectra of devices performed a little red shift with an obvious broadening in long wavelength range but a little decrease in intensity of short wavelength range. The authors simulated the EL spectra using the photoluminescence (PL) spectra of Alq3 as Alq3 intrinsic emission, which coincided with the experimental EL spectra well. The simulated results suggested that the effect of interference takes the major role in broadening the long wavelength range of EL spectra, and the distribution of emission zone largely affects the profile of EL spectra in short wavelength range.

[Experimental study of spherical aberrations of intraocular lenses with different materials and designs].

OBJECTIVE: To study the characteristics of spherical aberrations (SA) of the traditional intraocular lenses (IOLs) produced by different materials and designs. METHODS: A special optical metrical system was established in the laboratory to measure the SA of IOLs by using the Hartmann-Shack aberrometer. Eight different types of IOLs were divided into two Groups. Group 1 consisted of 4 types of IOLs made by different materials, Group 2 consisted of 4 types of IOLs made by different designs. SA of these IOLs was measured at 3, 4, 5, 6 and 7 mm apertures separately. All data was analyzed statistically. RESULTS: With the size of aperture increased, SA in these two groups was both increased. There were positive correlations between the size of aperture and the SA (r = 0.6465, 0.7872; P < 0.01). The numbers of IOLs fitted with Rayleigh criterion at apertures of 3, 4, 5, 6, and 7 mm were 8, 5, 3, 2 and 2, respectively. In Group 1, the acrylic IOL (SA60AT) with high refractive index showed the greatest SA, and the acrylic IOL (AR40e) with low refractive index showed the smallest SA. The difference of SA between these two IOLs was statistically significant (P < 0.01). SA of the silicon IOL (SI40NB) and PMMA IOL (PC330UV) lied between these two extremities. In Group 2, the convexo-convex IOL with the posterior surface more curved than the anterior surface had the greatest SA. The convex-plano IOL had the smallest spherical aberration. The difference of SA between these two IOLs was statistically significant (P < 0.01). SA of convexo-convex IOL with the anterior surface more curved and the epuiconvex IOL was lied between these two extremities. CONCLUSIONS: IOLs made by different materials and designs under different apertures show significant difference of SA, which is useful for the improvement of optic quality of IOLs. Further studies on the exact mechanism of these differences are required.

[Application of wavefront aberration technique in the study of phakic and pseudophakic eyes].

Modern cataract surgery is routinely combined with the implantation of an intraocular lens (IOL). Although surgical technique as well as IOL materials and designs have been improved dramatically, the problems related postoperative visual acuity still occur, such as glare disability, low visual acuity at night, and so on. Wavefront aberration technique can be used to help us revealing the real reasons of such postoperative visual problems. We reviewed the relative study outcome of the application of wavefront aberration technique in phakic eyes, and summarized the current opinions on the study of pseudophakic eyes.

AcrySof phakic angle-supported intraocular lens for the correction of high to extremely high myopia: one-year follow-up results.

AIM: To assess the safety, efficacy and predictability of the AcrySof phakic angle-supported intraocular lens (IOL) (Alcon Inc., U.S.A.) for correction of high-to-extremely high myopia in adults. METHODS: In this prospective study performed in Tianjin Medical University Eye Center & College of Optometry, Tianjin, China, 25 eyes of 13 patients were implanted with AcrySof phakic angle-supported IOLs and followed for 1 year postoperatively. Preoperative manifest refractive sphere was (-12.08±2.44) diopters (D) and cylinder was (-1.35±0.62)D. Visual acuity, predictability and stability of manifest refraction spherical equivalent (MRSE), adverse events, and endothelial cell density were analyzed during 1-year of follow-up. RESULTS: After 1 year of follow-up, no eyes lost≥1 line (best spectacle-corrected visual acuity)BSCVA; an uncorrected visual acuity (UCVA) of 20/20 or better was achieved in 60% of eyes; 100% had an UCVA of 20/40 or better; a BSCVA of 20/30 or better was achieved by 100% of eyes; 84% had a BSCVA of 20/20 or better. The overall mean percentage change in endothelial cell density 1 year after surgery was (-0.27±3.60)%. Two eyes (8%) had increased intraocular pressure (IOP) on the day of surgery. No pupil ovalization, pupillary block, or retinal detachment events were observed. CONCLUSION: After 1 year of follow-up, the implantation of AcrySof phakic angle-supported IOL is proved to be safe, effective and predictable with minimal complications in patients with high-to-extremely high myopia. Due to the limitation of visiting time, long-term of clinical investigation is necessary to verify the safety and efficacy of this IOL.