Changes in higher-order aberrations after iris-fixated phakic intraocular lens implantation.

PURPOSE: To evaluate surgically induced changes in corneal, internal, and ocular higher-order aberrations (HOAs) after phakic intraocular lens (PIOL) implantation and compare them between two PIOLs with different pupillary diameters. METHODS: Twenty-three eyes with an Artisan PIOL (Ophtec BV, Groningen, The Netherlands) (Artisan group) and 30 eyes with an Artiflex PIOL (Ophtec BV) (Artiflex group) were retrospectively evaluated. The corneal, internal, and ocular HOAs and refractive data were recorded preoperatively and 6 months postoperatively. The root mean squares (RMSs) of the total HOAs from the third- to sixth-order Zernike coefficients were calculated. The RMSs of the third- and fourth-order coefficients represented coma-like aberrations (S3) and spherical-like aberrations (S4), respectively. The main outcome measures were the differences in the parameters among the groups with different pupillary diameters. RESULTS: The mean postoperative spherical equivalents decreased from -11.84 ± 4.90 to -0.16 ± 0.40 diopters and -9.78 ± 3.20 to -0.09 ± 0.26 diopters in the Artisan and Artiflex groups, respectively. With the 4- and 5-mm pupillary diameters, the postoperative internal and ocular spherical aberrations (Z4(0)) were significantly lower in the Artiflex group than in the Artisan group (4 mm, P = .002, .024; 5 mm, P = .004, .022, respectively). With the 6-mm pupillary diameter, there were no significant postoperative differences in any parameter measured between groups; both groups had positive spherical aberration values. CONCLUSIONS: The postoperative ocular spherical aberrations were positive after Artisan and Artiflex implantation. The postoperative ocular spherical aberration was greater in the Artisan group, possibly due to differences in the SAs of both PIOLs.

Improvement of functional visual acuity after cataract surgery in patients with good pre- and postoperative spectacle-corrected visual acuity.

PURPOSE: To report the changes in functional visual acuity in cataract surgery patients with good pre- and postoperative visual acuity. METHODS: Functional visual acuity was evaluated in 13 eyes of 10 patients before and 1 month after phacoemulsification with implantation of acrylic intraocular lenses. Pre- and postoperative best spectacle-corrected visual acuities (BSCVA) were better than 20/25 in all patients. Low contrast visual acuity and Schirmer tests were also performed before and after surgery. RESULTS: Mean pre- and postoperative logMAR BSCVA were -0.02 +/- 0.06 and -0.05 +/- 0.04, respectively (P > .05). Mean preoperative logMAR functional visual acuity improved from 0.29 +/- 0.17 to 0.092 +/- 0.13 postoperatively (P < .05). The visual maintenance ratio in functional visual acuity and low contrast visual acuity also improved significantly after cataract surgery (P < .05). CONCLUSIONS: Measurement of functional visual acuity seems to be useful in the evaluation of timing of surgery, visual quality, and changes in kinetic vision after phacoemulsification surgery.

Effect of spherical aberration on visual function under photopic and mesopic conditions after cataract surgery.

PURPOSE: To evaluate the effect of spherical aberration on visual function under natural pupil conditions after cataract surgery. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: This study comprised cataract patients who had cataract extraction with implantation of an acrylic intraocular lens. Preoperative and postoperative visual acuity, higher-order aberration in the whole eye, contrast sensitivity function, and pupil diameter under photopic and mesopic conditions 1 month after surgery were measured. The area under log contrast sensitivity function (AULCSF) and spherical aberration corresponding to the individual pupil diameter under photopic and mesopic conditions were evaluated. RESULTS: One hundred seven eyes of 79 patients (30 men, 49 women; mean age 68.0 years +/- 9.6 [SD]) were evaluated. The mean pupil diameter was 2.9 +/- 0.50 mm under photopic conditions and 3.6 +/- 0.57 mm under mesopic conditions. The mean spherical aberration was 0.03 +/- 0.04 mum (range -0.12 to 0.34 mum) under photopic conditions and 0.05 +/- 0.10 mum (range -0.14 to 0.55 mum) under mesopic conditions. The postoperative AULCSF without glare under photopic conditions was significantly negatively correlated with spherical aberration (P = .014). The postoperative AULCSF with and without glare under mesopic conditions was significantly negatively correlated with spherical aberration (P<.001 and P = .01, respectively). CONCLUSIONS: Postoperative spherical aberration had a significant effect on visual function under photopic and mesopic conditions. This result indicates that reduced postoperative spherical aberration improves postoperative visual function under photopic and mesopic conditions.

The evaluation of the treatment response in obstructive meibomian gland disease by in vivo laser confocal microscopy.

PURPOSE: To evaluate the status of periglandular inflammation, ocular surface and tear function alterations in patients with obstructive meibomian gland disease (OMGD) by in vivo confocal microscopy before and after anti-inflammatory treatment, and to compare the results with patients receiving only topical non-preserved artificial tears and sodium hyaluronate eye drops without anti-inflammatory agents. METHODS: Thirty-two eyes of 16 OMGD patients receiving anti-inflammatory treatment (treatment group) and 22 eyes of 11 OMGD patients receiving only topical non-preserved artificial tears and sodium hyaluronate eye drops (control group) were recruited in this prospective study. All subjects underwent slit-lamp examinations, tear film break-up time (BUT) measurements, fluorescein and Rose-Bengal stainings, Schirmer test capital I, Ukrainian without anesthesia, transillumination of the lids (meibography), and in vivo laser confocal microscopy of the lids (HRTII-RCM). RESULTS: The mean BUT, fluorescein staining scores, and inflammatory cell densities observed by in vivo confocal microscopy improved significantly in the group receiving anti-inflammatory treatment (p < 0.05), whereas no significant alterations of these parameters were observed in the group not receiving anti-inflammatory agents (p > 0.05). CONCLUSIONS: In vivo confocal microscopy was able to effectively demonstrate the treatment responses in patients with OMGD. Inflammatory cell density calculation seems to be a promising new parameter of in vivo confocal microscopy in the evaluation of treatment responses.

Comparison of the Accuracy of Newer Intraocular Lens Power Calculation Methods in Eyes That Underwent Previous Phototherapeutic Keratectomy.

PURPOSE: To evaluate the accuracy of intraocular lens (IOL) power calculations using ray tracing software in patients who had undergone phototherapeutic keratectomy (PTK). METHODS: In this retrospective case series, 37 eyes of 22 patients (mean age: 69.4 years; range: 56 to 85 years) who underwent cataract surgery after PTK were reviewed. The prediction error, defined as the difference between the estimated postoperative spherical equivalent and the postoperative manifest refraction at the spectacle plane, was calculated using the following formulas: OKULIX (Tedics, Dortmund, Germany), PhacoOptics (IOL Innovations ApS, Aarhus, Denmark), Barrett True K No History (NH), and Camellin-Calossi. The PhacoOptics formula was used in three different ways: historical method (H), no history method (NH), and C-constant method (C). The median values of the arithmetic and absolute prediction errors among these six IOL calculation methods were compared. RESULTS: The median arithmetic errors (in diopters [D]) and percentages of eyes within ±0.50 D of the absolute errors were as follows: OKULIX (0.33, range: -2.20 to 2.50, 30.6%), PhacoOptics (H) (-0.12, range: -3.28 to 4.85, 22.2%), PhacoOptics (NH) (-0.25, range: -2.08 to 1.70, 48.4%), PhacoOptics (C) (0.04, range: -1.40 to 2.18, 48.5%), Barrett True K (NH) (-0.35, range: -1.90 to 1.89, 48.6%), and Camellin-Calossi (-0.19, range: -1.78 to 1.47, 59.5%). CONCLUSIONS: The PhacoOptics, especially the C-constant method (C), and Camellin-Calossi formulas were good options for calculating IOL powers in eyes that underwent PTK. [J Refract Surg. 2019;35(5):310-316.].

Alterations in the anterior chamber angle after implantation of iris-fixated phakic intraocular lenses.

PURPOSE: To evaluate anterior chamber angle alterations after phakic intraocular lens (pIOL) implantation using the Pentacam rotating Scheimpflug camera (Oculus) and the effect on intraocular pressure (IOP) and anterior chamber inflammation. SETTING: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. METHODS: Twenty eyes of 11 patients with high myopia who had implantation of pIOLs (Artisan/Verisyse, model 204, Ophtec BV) were included. All pIOLs were fixated on the iris near the 3 o'clock and 9 o'clock positions. Angles at the 2, 3, 4, 8, 9, and 10 o'clock positions, IOP, and postoperative flare were evaluated retrospectively. RESULTS: The mean angle degree at 2, 3, 4, 8, 9, and 10 o'clock was 40.3 degrees +/- 3.3 (SD) preoperatively and 36.5 +/- 5.8 degrees postoperatively; the postoperative angles were significantly narrower than the preoperative angles (P<.001). The mean angles at 3 o'clock and 9 o'clock were 39.8 +/- 3.7 degrees and 40.6 +/- 3.5 degrees, respectively, preoperatively and 32.7 +/- 6.0 degrees and 31.3 +/- 5.4 degrees, respectively, postoperatively. The postoperative angles at 3 o'clock and 9 o'clock were narrower than the preoperative angles (P<.001). There was no significant difference between preoperative IOP and postoperative IOP (P = .22). The flare at 1 month (r = 0.573, P = .0071) and 1 year (r = 0.700, P = .004) was significantly correlated with the angle change. CONCLUSION: Partial localized narrowing of anterior chamber angles that occurred after pIOL implantation induced acute and chronic anterior chamber inflammation in patients with large angle alterations.

No forward shifting of posterior corneal surface in eyes undergoing LASIK.

PURPOSE: To evaluate structural changes in the cornea and anterior chamber (AC) after LASIK for myopia. DESIGN: Retrospective nonrandomized study. PARTICIPANTS: One hundred sixty-one eyes of 83 patients (mean age, 34.5+/-8.3 years) who underwent uneventful LASIK for myopia and myopic astigmatism. The preoperative refractive error (spherical equivalent) and corneal thickness were -6.02+/-2.10 diopters (D) and 549.9+/-29.3 mum, respectively. METHODS: The AC volume (ACV), AC depth (ACD), corneal thickness, central corneal true net power, and posterior corneal tangential curvature were measured using a rotating Scheimpflug camera before and 1 week and 1 month after surgery. In 84 eyes of 42 cases, anterior and posterior corneal elevations and corneal thicknesses also were measured by scanning-slit topography before and 1 month after surgery. MAIN OUTCOME MEASURES: Time course of the ACV, ACD (central, midperiphery, periphery), corneal thickness, central corneal true net power, posterior corneal tangential curvature using the Scheimpflug camera, and amount of forward shifting of the posterior corneal surface at the center of the difference map using scanning-slit topography. RESULTS: Preoperative and 1-month postoperative mean ACVs were 198.1 mm3 and 196.4 mm3, respectively, and preoperative and postoperative mean ACDs (center, midperiphery, periphery) were 3.24, 2.65, and 1.89 mm, and 3.21, 2.63, and 1.87 mm, respectively. The corneal thickness within the optical zone, subjective refraction, and central corneal true net power significantly changed by tissue subtraction after LASIK (P<0.0001). There were no significant differences in the ACV, ACDs (center, midperiphery, periphery), peripheral corneal thickness, and posterior corneal tangential curvature from preoperatively to 1 month after LASIK. However, using scanning-slit topography, the posterior corneal surface displayed a mean forward shift of 29.0+/-19.0 microm 1 month after surgery. CONCLUSION: The posterior corneal curvature, peripheral corneal thickness, ACDs, and ACV were consistent. These observations indicated that neither forward shifting of the central posterior corneal surface (bulging) nor backward shifting of the peripheral posterior corneal surface due to corneal swelling after ablation occurred after LASIK.

Roles of NF-kappaB and MAPK signaling pathways in morphological and cytoskeletal responses of microglia to double-stranded RNA.

Following virus infection of the central nervous system, microglia become activated and undergo morphological as well as functional transformations, thereby initiating effective antiviral actions. Herein, we have examined the contribution of nuclear factor kappaB (NF-kappaB) and mitogen-activated protein kinase (MAPK) signaling pathways to cell shape determination and cytoskeletal organization in microglia upon stimulation with double-stranded RNA (dsRNA), a conserved molecular pattern of virus infection. Under non-proliferative condition, microglial MG6-1 cells displayed a distinctive morphology with spinescent processes and small somata. Following dsRNA stimulation, the process-bearing microglial cells exhibited swift and drastic changes in cell morphology, filamentous actin (F-actin) structure, and intracellular signaling. In the dsRNA-stimulated microglial cells, the activation of c-Jun N-terminal kinase (JNK) pathway was involved in morphological alteration into an ameboid state. We also found that p38 signaling pathway negatively regulates the formation of cytoplasmic vacuoles in microglial cells. Furthermore, the dsRNA-induced accumulation of F-actin was partly mediated by NF-kappaB, JNK, and p38 pathways. These results indicate that NF-kappaB and MAPK signaling pathways mediate morphological and cytoskeletal changes during dsRNA-induced microglial activation.

Suppressive effect of simvastatin on interferon-beta-induced expression of CC chemokine ligand 5 in microglia.

Despite the pivotal role of microglia in immune system of the brain, a growing body of evidence suggests that the excessive microglial activation provokes neuronal and glial damages, leading to neurodegenerative and neuroinflammatory disorders. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, or statins, have recently received much attention for their suppressive effects on inflammation in the central nervous system. In the current study, we have examined the statin-mediated inhibition of microglial function, especially that of chemokine production. Stimulation of microglial cells with interferon-beta (IFN-beta) resulted in the expression of CC chemokine ligand 5 (CCL5), a major chemoattractant of inflammatory cells. Microglial CCL5 response was synergistically potentiated by costimulation with IFN-beta and tumor necrosis factor-alpha (TNF-alpha). The simvastatin treatment significantly diminished the microglial CCL5 expression induced by IFN-beta alone or by IFN-beta/TNF-alpha combination. In the presence of simvastatin, the IFN-beta-induced activation of Janus kinase (Jak)-signal transducer and activator of transcription (STAT) pathway was attenuated, although this compound had little or no effect on the TNF-alpha-evoked activation of nuclear factor kappaB and c-Jun N-terminal kinase pathways. In addition, chemical inhibitor of Jak-STAT signaling significantly diminished the IFN-beta-induced expression of CCL5 in microglia. Taken together, these results suggest that simvastatin suppresses the IFN-beta-induced expression of CCL5 via down-regulation of Jak-STAT signaling pathway.

Successful tear lipid layer treatment for refractory dry eye in office workers by low-dose lipid application on the full-length eyelid margin.

PURPOSE: To test tear lipid layer treatment by low-dose lipid application on the full-length eyelid margin for the treatment of office workers with dry eyes refractory to conventional treatments. DESIGN: Prospective interventional case series. METHODS: Thirty eyes of 30 office workers with dry eyes with dark tear interference images, which did not respond to conventional treatments, were included. To supply lipid using a commercially available nonpreserved topical medication having both polar and nonpolar lipid base, ofloxacin eye ointment (Santen Pharmaceutical, Osaka, Japan) was selected. Low-dose ofloxacin ointment application on the full-length eyelid margin was carried out three times a day for two weeks. The symptom of ocular dryness using a visual analog scale, tear interferometry to assess lipid layer thickness (LLT), corneal fluorescein staining, tear-film breakup time (BUT), and meibum expressibility gradings were compared. RESULTS: After the treatment, the symptom score of ocular dryness decreased from 91.4 +/- 11.9 to 33.6 +/- 21.0 (P < .0001), LLT increased from 39 +/- 4 nm to 161 +/- 91 nm (P < .0001), BUT was prolonged from 2.6 +/- 1.6 seconds to 4.8 +/- 2.1 seconds (P = .01), and meibum expressibility gradings decreased from 2.8 +/- 1.3 to 1.6 +/- 1.3 (P = .0005). CONCLUSION: For office workers with refractory dry eyes, tear lipid layer treatment by low-dose ointment applied on the full-length eyelid margin was shown to be an effective approach. The applied lipid formed a uniform lipid layer, which contributed to tear stability, leading to the improvement of the symptom.

Effect of neodymium:YAG laser capsulotomy on visual function in patients with posterior capsule opacification and good visual acuity.

PURPOSE: To evaluate the effect of neodymium:YAG (Nd:YAG) laser capsulotomy on the visual function in patients with posterior capsule opacification (PCO) and good visual acuity. SETTING: Keio University Hospital, Tokyo, Japan. DESIGN: Observational case series. METHODS: Eyes were evaluated that had previous cataract surgery with a clinical diagnosis of PCO requiring Nd:YAG laser capsulotomy regardless of a good corrected distance visual acuity (CDVA) (at least 20/20). The CDVA, 10% low contrast visual acuity (LCVA), wavefront aberrations from the 3rd to 6th order, and retinal straylight were measured before and after Nd:YAG laser capsulotomy. RESULTS: The study included 16 eyes of 16 patients (10 men, 6 women; mean age 69.5 years ± 9.3 [SD]). The mean CDVA, LCVA, and straylight after Nd:YAG laser capsulotomy improved significantly (P < .05). The root mean square (RMS) of the 3rd Zernike coefficients (S3) and the RMS of the total higher-order aberrations (HOAs) from the 3rd to 6th order decreased significantly after capsulotomy (P < .05). The straylight correlated significantly with the total HOAs (r = 0.727, P = .002) and S3 (r = 0.748, P = .001) before capsulotomy. Subjective symptoms resolved after capsulotomy in all cases. CONCLUSIONS: Neodymium:YAG laser capsulotomy enabled a significant improvement in visual function even in patients with PCO with good visual acuity. Straylight measurements might be useful to determine the indications for Nd:YAG laser capsulotomy when patients report visual disturbances without decreased visual acuity.

Changes in corneal aberrations after cataract surgery.

PURPOSE: To study the changes in corneal aberrations after cataract surgery. METHODS: This study comprised 36 eyes of 36 patients (mean age, 67.3 years) who underwent cataract surgery through a 2.2-mm superior sclerocorneal incision. The anterior, posterior, and total corneal wavefront aberrations for the 6.0-mm pupillary diameter were measured preoperatively and 1 month postoperatively. The postoperative changes in corneal aberrations were evaluated for individual Zernike terms (Z 2 (-2) , Z 2 (0) , Z 2 (2) , Z 3 (-1) , Z 3 (1) , and Z 4 (0) ) and the root mean squares of the third, fourth, and total higher-order aberrations (S3, S4, and THOA). RESULTS: No significant postoperative changes were observed in S3 and S4 of the total and anterior cornea, although significant changes were observed in S4 and THOA of the posterior cornea. Regarding the preoperative and postoperative Zernike terms of the total cornea, the oblique astigmatism (Z 2 (-2) ) changed significantly (P = 0.02). Significant positive correlations were observed in the Z 2 (-2) , Z 2 (0) , Z 2 (2) Z 3 (-1) , Z 3 (1) and Z 4 (0) between the changes in the total and the anterior cornea (P < 0.001 for all comparisons). However, no correlations were observed in the changes in the Zernike terms between the total and the posterior cornea, except for the Z 2 (0) . CONCLUSIONS: The oblique astigmatism (Z 2 (-2) ) of the total cornea significantly changed after 2.2-mm-incision cataract surgery. The changes in the lower- and higher-order aberrations of the anterior cornea mainly contributed to the changes in the total cornea.

Comparison of the accuracy of intraocular lens power calculations for cataract surgery in eyes after phototherapeutic keratectomy.

PURPOSE: To compare the accuracy of several methods of intraocular lens (IOL) power calculations used for cataract surgery in eyes treated with phototherapeutic keratectomy (PTK) that results in changes in the anterior corneal surface and axial length; these results make power calculations less predictable. METHODS: We evaluated the medical records of 23 eyes of 13 patients (mean age, 68.8 years; range 62-80 years) who underwent cataract surgery after PTK at Keio University Hospital, Tokyo, Japan. The prediction error, defined as the difference between the estimated postoperative spherical equivalent and the postoperative manifest refraction at the spectacle plane, was calculated using five formulas: SRK/T, Haigis-L, Shammas-PL, Camellin-Calossi, and OKULIX ray tracing software. We compared the median values of the arithmetic and absolute prediction errors among the five formulas. RESULTS: The median arithmetic errors after cataract surgery for the five formulas were 0.70 D (diopter) (range -0.41 to 2.78), -0.96 D (range -2.14 to 0.81), -0.81 D (range -1.89 to 1.15), -0.04 D (range -1.35 to 1.47), and 0.68 D (range -0.61 to 2.50), respectively. CONCLUSION: The Camellin-Calossi formula is a good option for calculating IOL powers in eyes that underwent PTK.

Functional Visual Acuity of Early Presbyopia.

PURPOSE: To evaluate visual function in patients with early presbyopia using the functional visual acuity (FVA) test. METHODS: This study included 27 eyes of 27 healthy older volunteers (mean age, 44.1 ± 2.6 years) and 14 eyes of 14 healthy young volunteers (mean age, 28.4±4.8 years). The distance-corrected visual acuity (DCVA), distance-corrected near VA (DCNVA), subjective amplitude of accommodation (AA), and distance and near pupillary diameters were measured. The distance FVA and distance-corrected near FVA (DCNFVA) were measured using the FVA Measurement System. The standard Schirmer test and standard tear break-up time measurement also were performed. RESULTS: The logarithm of the minimum angle of resolution (logMAR) DCVA was better than 0 in all subjects. The percentages of subjects with logMAR DCNVA below 0 was significantly lower in the presbyopia group than in the young group. The DCNFVA in the presbyopia group was significantly (P < 0.001) poorer than the DCNVA in that group. Significant linear negative correlations were seen between the DCNVA and AA (r = -0.507, P < 0.001) and the DCNFVA and AA (r = -0.681, P < 0.001) in the older subjects. Stepwise regression analysis showed that only the AA was a significant factor predictive of the DCNFVA in the presbyopia group. Tear function parameters were not adopted in the regression model. CONCLUSIONS: Measurement of the DCNFVA can detect decreased AA in early presbyopia better than measurement of the conventional near VA. The DCNFVA is a good index for early presbyopia.

Apparent progression of presbyopia after laser in situ keratomileusis in patients with early presbyopia.

PURPOSE: To assess the effect of laser in situ keratomileusis (LASIK) on near visual function in presbyopic patients. DESIGN: Retrospective cohort study. METHODS: Fifty-three eyes of 40 patients 45 years of age and older who had undergone LASIK for high myopia (-6 diopters [D] and over) were included. The minimal add powers for obtaining the best-corrected near visual acuity (add powers) were measured preoperatively and 3 months postoperatively, and the correlations with the powers corrected by LASIK, corneal higher-order aberrations (HOAs), ocular HOAs, and patient ages were evaluated using univariate analysis. Factors correlated with the changes in add powers were evaluated further by multivariate analysis. RESULTS: The mean ± standard deviation patient age was 50.0 ± 4.1 years; the power corrected by LASIK was -7.56 ± 1.06 D. The mean add power was 1.80 ± 0.60 D preoperatively, which increased significantly (P < .001) to 2.18 ± 0.69 D postoperatively. Significant correlations with the increased add powers were detected with age (P = .01) and the power corrected by LASIK (P = .04) but not with corneal and ocular HOAs (P > .05). Multivariate analysis showed that only age was correlated significantly (P = .01). The percentage of eyes with increased add powers of 0.5 D or more was 60.4%, which was significantly (P = .02) higher in younger patients. CONCLUSIONS: This study verified the apparent progression of presbyopia after LASIK and the importance of obtaining informed consent from patients, especially those with early presbyopia.

Ray tracing software for intraocular lens power calculation after corneal excimer laser surgery.

PURPOSE: To evaluate the accuracy of intraocular lens (IOL) power calculations using ray tracing software in eyes after myopic laser in situ keratomileusis (LASIK). METHODS: Twenty-four eyes of 17 cataract patients who underwent phacoemulsification and IOL implantation after myopic LASIK were analyzed retrospectively. The IOL power calculation was performed using OKULIX ray tracing software. The axial length was measured using the IOLMaster and keratometry data using TMS2N. The accuracy of the IOL power calculation using OKULIX was compared with those using the Camellin-Calossi, Shammas-PL, Haigis-L formulas and the double-K SRK/T formula using 43.5 diopters (D) for the Kpre. RESULTS: The mean values of the arithmetic and absolute prediction errors were 0.63 ± 0.85 and 0.80 ± 0.68 D, respectively. The arithmetic prediction error by OKULIX was a significant hyperopic shift of the distribution of the postoperative refractive errors compared to the Camellin-Calossi, Shammas-PL and Haigis-L formulas (P < 0.05), and the absolute prediction error showed no significant difference with other formulas. The prediction errors using OKULIX were within ± 0.5 D in 10 eyes (41.7 %) and within ± 1.0 D in 18 eyes (75.0 %). The percentages of eyes within ± 1.0 D using OKULIX were comparable to those obtained using the Camellin-Calossi, the Shammas-PL formulas and the double-K SRK/T formula using 43.5 D for the Kpre, and significantly (P < 0.05) higher than that obtained using the Haigis-L formula. CONCLUSIONS: IOL power calculations using OKULIX provided predictable outcomes in eyes that had undergone a previous myopic LASIK.

Deep stromal opacity after corneal cross-linking.

PURPOSE: To describe 3 cases with deep corneal stromal opacity that occurred several months after corneal cross-linking. METHODS: A 36-year-old man, a 19-year-old man, and a 14-year-old girl underwent corneal cross-linking for their progressive keratoconus. Corneal cross-linking was performed according to the Dresden protocol. The corneal epithelium was ablated using an excimer laser in 2 cases and manually in 1 case. After 30 minutes of riboflavin presoaking, hypotonic riboflavin solution was applied until the corneal stroma swelled, after which the eyes were exposed to ultraviolet irradiation. Slit-lamp microscopy findings, uncorrected visual acuity, best-corrected visual acuity, manifest refraction, intraocular pressure, and corneal endothelial cell counts were evaluated, and corneal topography with Scheimpflug imaging was performed. RESULTS: In all cases, the epithelium healed without delay. All eyes showed mild stromal infiltration a few days after the procedure; however, the inflammation was resolved within 1 week. The corneal stroma revealed no opacity up to 1 month after the procedure. A deep stromal opacity that extended to the inferior paracentral area developed after a few months and remained for 6 months to 1 year. Because the opacity was not on the visual axis, the visual acuity was not involved. CONCLUSIONS: Deep stromal opacity developed several months after uneventful corneal cross-linking. Postoperative inflammation may play a crucial role in its pathogenesis.

Modified double-K method for intraocular lens power calculation after excimer laser corneal refractive surgery.

PURPOSE: To propose the new anterior-posterior method (A-P method) that does not require historical data to calculate intraocular lens (IOL) power after laser in situ keratomileusis (LASIK) and to compare the accuracy of the method with other IOL formulas after LASIK. SETTING: Keio University Hospital, Tokyo, Japan. DESIGN: Case series. METHODS: Eyes having phacoemulsification and IOL implantation after myopic LASIK were analyzed retrospectively. The A-P method is a modification of the double-K method using the SRK/T formula in which the estimated pre-LASIK keratometry (K) power calculated from the post-LASIK posterior sagittal power in the 6.0 mm zone is used for the preoperative K value in the double-K method and the post-LASIK anterior sagittal power is used for the postoperative K value. The accuracy of the A-P method was compared with that of other formulas that do not require preoperative data and with formulas that require preoperative data. RESULTS: The median values of the arithmetic and absolute prediction errors using the A-P method were 0.16 diopter (D) and 0.54 D, respectively. The prediction errors using the A-P method were within ± 0.50 D in 46.4% of eyes and within ± 1.00 D in 75.0%. The percentage of eyes within ± 1.00 D of the prediction errors with the A-P method was highest with the no-history methods. CONCLUSION: The A-P method may be a good option for calculating IOL power in eyes having cataract surgery after LASIK when preoperative LASIK data are unavailable.

A new central-peripheral corneal curvature method for intraocular lens power calculation after excimer laser refractive surgery.

PURPOSE: To propose the central-peripheral (C-P) method, which requires no data history to calculate intraocular lens (IOL) powers for eyes that underwent laser in situ keratomileusis (LASIK), and compare the accuracy of the C-P method with other IOL formulas for eyes after LASIK. METHODS: Sixteen patients with cataract (25 eyes) who underwent myopic LASIK were analysed retrospectively. The C-P method is a modified double-K method using the SRK/T formula, in which the estimated pre-LASIK keratometric power calculated from the post-LASIK peripheral anterior sagittal power (also called the axial power) is used for the Kpre in the double-K method using the SRK/T formula, and the post-LASIK anterior sagittal power is used for the Kpost. We compared the accuracy of the C-P method with other popular IOL calculation formulas for use in eyes after LASIK. RESULTS: The median values of the arithmetic and absolute prediction errors with the C-P method were 0.11 diopter (D) (range, -1.67 to 1.97 D) and 0.55 D (range, 0.02-1.97 D), respectively. The prediction error using the C-P method was within ±0.5 D in 48% of eyes, within -1.0 to +0.5 D in 60% of eyes, and within ±1.0 D in 68% of eyes. The C-P method resulted in a significantly higher percentage of eyes within ±0.5 D than the BESSt formula, Shammas-PL formula, true net power method, double-K method using 43.5 D for Kpre, and Feiz-Mannis method. CONCLUSION: The C-P method may be a good option for calculating IOL powers in eyes undergoing cataract surgery after LASIK when the preoperative LASIK data are unavailable.