Mean logMAR Uncorrected Visual Acuity Research Articles

Relationship of Density, Depth, and Surface Irregularity of Superficial Corneal Opacification with Visual Acuity

Purpose To explore the relationship between the density, depth, and surface irregularity of superficial corneal opacities and vision. Methods This prospective imaging study included 19 patients with unilateral superficial corneal opacification due to scarring post-microbial keratitis. Each eye underwent an assessment of uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contact lens corrected visual acuity (CLCVA), and Scheimpflug and anterior segment optical tomography imaging. Regression analysis was performed to detect the association between density, depth of scarring, and the surface irregularity in terms of higher order aberrations (HOA), and keratometry and UCVA, CLCVA, and the difference between BSCVA and CLCVA. Results The mean logMAR UCVA, BSCVA, and CLCVA were 0.76, 0.35, and 0.28, respectively. The corneal scars had a mean thickness of 158.7 ± 61 µ and density of 65.73 ± 24.46 GSU. Bivariate analysis model for UCVA showed an association with Z4 2 secondary astigmatism (p = 0.02), Z4 4 quadrafoil (p = 0.01), combined coma Z3 ± 1(p = 0.03), and combined HOA Z3–Z6 (p = 0.045), out of which Z4 4 Quadrafoil (p = 0.04) was most significant with multivariate analysis. Bivariate analysis for BCVA-CLVA showed association with Z3 1 coma horizontal (p = 0.04), Z3 3 oblique trefoil (p = 0.02), Z4 0 primary spherical aberration (p = 0.008), and Z5 − 5 (p = 0.007), out of which Z3 1 horizontal coma (p = 0.04) and Z4 0 spherical aberration (p = 0.009) were significant on multivariate analysis. Change in densitometry, corneal thickness, epithelial:stromal reflectivity ratio, scar depth, and keratometry did not show any significant association with UCVA, BSCVA-CLCVA, or CLCVA. Conclusion In superficial corneal stromal scarring, deranged surface irregularity parameters like higher-order aberrations affect the final visual acuity more than the depth or density of the opacity.

Efficacy and safety of accelerated corneal collagen cross-linking in patients with keratoconus

AIM: To study the efficacy and safety of accelerated collagen cross-linking in keratoconus. METHODS: Medical records of keratoconic corneas underwent accelerated collagen cross-linking at King Chulalongkorn Memorial Hospital, Thailand between April 2015 and August 2018 were reviewed. Preoperative and postoperative data at 1y of visual acuity, auto-refraction, corneal topography, higher-order aberrations (HOA), topometric indices and corneal densitometry were evaluated. Age of 24-30 (mean age 23.43±7.26)y, maximum keratometric value (Kmax) of 55 D, and baseline best corrected visual acuity (BCVA) of 20/40 (or 0.3 in LogMAR unit) were used as cut-off values to highlight the cross-linking effects. The effect of age, preoperative Kmax and BCVA were analyzed. The association between the change of corneal densitometry and other factors including preoperative Kmax, Kmean, manifest refraction spherical equivalent (MRSE), visual acuity, thinnest pachymetry, the change in Kmax, and the change of those parameters were also analyzed. P<0.05 was considered statistically significant. RESULTS: One hundred and fifty-five patients (185 eyes) were included. Male to female ratio was 3:31. According to Amsler-Krumeich classification, stage 1 and 2 were dominant (37.84% and 35.14% respectively). At 1y, mean LogMAR uncorrected visual acuity (UCVA) improved by 0.1 (P<0.05). The number of eyes of which postoperative BCVA improved more than 0.2 LogMAR was higher in the worse baseline BCVA group (preoperative BCVA ≥0.3) compared to the better baseline BCVA group (preoperative BCVA <0.3) (78.26% vs 21.74%, P<0.05). Mean Kmax decreased from baseline by 2.36 diopters (D) (P<0.05). Seventy-three percent of the eyes of which Kmax reduced more than 2.0 D had preoperative Kmax ≥55 D. Q-value showed less prolate by 0.06 (P<0.05). Corneal HOA at 6 mm from corneal apex decreased by 0.40 (P<0.05). Corneal densitometry at 0-6 mm zone increased at 1mo and persisted 1y postoperatively (P<0.05). The relationship of the increase in densitometric value and the decrease of thinnest pachymetry at 1y were in linear fashion. Index of surface variance, index of vertical asymmetry, keratoconus index, index of height decentration decreased at 1y (P<0.05). Success rate at 1y was 90.24%. Postoperative corneal haze was found 11.35%, 30.27%, 15.67%, 10.27% and 2.16% at 1wk, 1, 3, 6mo and 1y respectively. No eyes developed corneal edema. There was one case of sterile keratitis. CONCLUSION: Accelerated collagen cross-linking in keratoconus was effective to flatten, reshape the cornea, improved visual acuity, HOA and topometric indices. Great Kmax reduction was found in advanced keratoconus. The magnitude of Kmax reduction is also greatest among previous reports.

Long-term changes in visual outcomes and ocular morphometrics after myopic and toric phakic intraocular lens implantation: Five- and 10-year results

To evaluate the long-term refractive and visual, anterior chamber depth, and axial length (AL) changes and complications after rigid iris-fixated phakic intraocular lens (pIOL) implantation to treat myopia or astigmatism. University Eye Clinic Maastricht, Maastricht UMC+, the Netherlands. Prospective case series. The study evaluated patients who had implantation of an Artisan myopic or toric iris-fixated pIOL as of January 1998. Changes were measured annually and reported after 1, 5, and 10years postoperatively. The study comprised 460 eyes (250 patients; mean age 41.1years±10.7 [SD]). Over 10years, the mean myopization was -0.79 diopters (D) (P<.001), with 52% of eyes within ±1.0 D of target. The mean increase in the logarithm of the minimum angle of resolution (logMAR) corrected distance visual acuity (CDVA) over 10years was 0.05 (P<.001); 95% of eyes had a CDVA of 20/40or more and 7% lost 2 or more lines of CDVA. The mean logMAR uncorrected visual acuity (UDVA) increased by 0.14 over 10years (P<.001); 96% had a UDVA 20/40 or better. The AL increased by 1.14mm over 10years (P=.009). Ten percent of pIOLs were explanted because of cataract formation after amean of 97.9±34.9months. A higher preoperative age (hazardratio [HR], 1.08; P<.001) and longer AL (HR, 1.34; P<.001) were risk factors for shorter survival because of cataract formation. Ten years after rigid iris-fixated pIOL implantation, the CDVA and UDVA decreased significantly as a result of significant myopization caused by an increased AL unrelated to the pIOL.

Bimanual irrigation-aspiration for ectopia lentis and use of a small incision for 4-point scleral-sutured foldable intraocular lens and anterior vitrectomy in patients with Marfan syndrome.

Purpose:This study evaluated bimanual intracapsular irrigation-aspiration for ectopia lentis with use of a small incision for 4-point scleral fixation of a foldable posterior-chamber intraocular lens (IOL) and anterior vitrectomy in patients with Marfan syndrome.Methods:We performed a retrospective study of 18 eyes from 10 patients with Marfan syndrome who underwent surgical intervention for ectopia lentis at our clinic between July 2012 and September 2018. In this study, intraoperative and postoperative complications, uncorrected visual acuity, best-corrected visual acuity, spherical equivalent, intraocular pressure, and endothelial cell density were evaluated.Results:No intraoperative complications were reported. In all cases, early postoperative evaluation revealed a clear cornea, round pupil, and well-centered IOL. Mean logMAR uncorrected visual acuity improved from 1.09 preoperatively to 0.56 postoperatively (P < 0.05). Mean logMAR best-corrected visual acuity improved from 0.45 preoperatively to 0.17 postoperatively (P < 0.05). Aside from transient ocular hypertension, no postoperative complications were reported.Conclusion:The combined surgical technique presented above yields excellent visual outcomes with an extremely low incidence of complications. This approach is simple, safe, and effective in the treatment of ectopia lentis in patients with Marfan syndrome.

Corneal tomography and biomechanics in primary pterygium.

To study the Scheimpflug's imaging and corneal biomechanics in primary pterygium. A prospective observational study of 55 patients with unilateral primary nasal pterygium was done. The normal fellow eyes of patients with pterygium were taken as controls. Clinical parameters noted included visual acuity, values of corneal curvature by doing Scheimpflug imaging, wavefront aberrations in terms of higher and lower-order aberrations and corneal hysteresis (CH) as well as corneal resistance factor (CRF) values by using ocular response analyzer. Of the total 55 patients, mean age was 43.0+11.4years (range: 20-72years). Mean LogMar uncorrected visual acuity in pterygium eyes and control eyes was 0.21+0.20 and 0.12+0.15, respectively (p=0.016). On Scheimpflug imaging the mean anterior corneal curvature values (Ka1/Ka2 D) were 41.09+3.38/44.33+2.29 in pterygium eyes, 43.13+1.79/43.98+2.17 in control eyes (p<0.0005) and mean posterior corneal curvature (Kp1/Kp2 D) values were 6.14+0.39/6.53+0.43 in pterygium eyes and 6.13+0.28/6.46+0.47 in control eyes (p>0.05). Analysis of corneal aberrations showed significantly higher corneal wavefront aberrations in pterygium eyes. Highest correlation of corneal astigmatism was noted with corneal area encroached by pterygium (ρ=0.540 for LOA and 0.553 for HOA) and distance from pupillary center (ρ=0.531 for LOA and 0.564 for HOA). Corneal biomechanical parameters including CH and CRF were found to be lower in the pterygium eyes, though not statistically significant (p value 0.60 and 0.59, respectively). Pterygium leads to deterioration of visual performance not only by causing refractive and topographic changes but also by causing a significant increase in corneal wavefront aberrations.

Short-term result of collagen crosslinking in pellucid marginal degeneration.

Background:To evaluate effectiveness of collagen crosslinking in pellucid marginal degeneration patients.Materials and Methods:Twenty-one eyes of 15 patients treated by collagen crosslinking were enrolled in our non-controlled clinical trial study. After evaluation of patients about inclusion and exclusion criteria, preoperative examination was done and then patients underwent CXL procedure and seen 6 months after surgery for postoperative examinations.Results:Mean preoperative LogMar uncorrected visual acuity (UCVA) was 0.63 (SE = 0.08), and mean preoperative LogMar BCVA was 0.26 (SE = 0.04). At 6 months postoperative, mean LogMar UCVA was 0.59 (SE = 0.06) and mean LogMar BCVA was 0.19 (SE = 0.02). The non-parametric test (Wilcoxon) showed reduction of LogMar BCVA was significant (P value = 0.02), but reduction of LogMar UCVA was not significant (P value = 0.5). Mean preoperative K1 was 42.23 ± 2.85 and mean postoperative K1 significantly decreased to 41.68 ± 2.44 (P value = 0.008). Also, mean preoperative K2 was 48.39 ± 2.37 and mean postoperative K2 significantly reduced to 47.64 ± 2.16 (P value = 0.002).Conclusion:Most remarkable findings of our study were improvement of visual acuity and reduction K1 and K2 parameters. Stability of other values and absence of detectable change after study period implies halting of the progression of the disease. We suggest CXL can be useful for management of PMD, but we need more studies with larger sample size and longer follow up.

Clinical Performance of Toris K Contact Lens in Patients with Moderate to Advanced Keratoconus: A Real Life Retrospective Analysis.

Objectives. To evaluate the visual performance of Toris K soft contact lenses in patients with moderate-to-advanced keratoconus and also to compare the results according to cone types, cone location, and severity of keratoconus. Materials and Methods. Sixty eyes of 40 participants were included in this retrospective study. Uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BCVA), best-contact lens corrected visual acuity (BCLCVA), and comfort rating via visual analogue scales (VAS) were measured. Results. The mean age was 27.3 ± 8.6 years (range: 18 to 54). The mean logMAR UCVA, BCVA, and BCLCVA were 0.85 ± 0.38 (range: 0.30–1.30), 0.47 ± 0.27 (range: 0.10–1.30), and 0.16 ± 0.20 (range: 0–1.00). There were significant increases in visual acuities with contact lenses (p < .05). BCLCVA was significantly better in oval type than globus type (p = .022). UCVA and BCLCVA were significantly better in moderate keratoconus group (p = .015, p = .018). The mean line gain in Snellen was 3.6 ± 1.8 lines (range: 0–7 lines). The mean line gain was higher in central cone group than paracentral cone group and oval group than globus group (p = .014, p = .045). The mean VAS score was 8.14 ± 1.88 (range: 6–10). Conclusions. Toris K can improve visual acuity of patients with keratoconus. Toris K is successful even in the moderate and advanced form of the disease.

Results and safety profile of trainee cataract surgeons in a community setting in East Africa

Purpose:To evaluate the results and safety profile of assistant medical officer ophthalmologists (AMO-O) performing cataract surgery in the last stage of their surgical training, before their appointment to local communities.Methods:We retrospectively analyzed the records of patients who underwent cataract surgery by AMO-Os at Dar es Salaam, Comprehensive Community Based Rehabilitation for Tanzania Disability Hospital between September 2008 and June 2011. Surgical options were either extracapsular cataract extraction (ECCE) or manual small incision cataract surgery (MSICS), both with polymethylmethacrylate intraocular lens implantation.Results:Four hundred and fourteen patients were included in the study. Two hundred and twenty-five (54%) underwent ECCE and 189 had MSICS. Mean logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA) improved from 2.4 ± 0.6 preoperatively to 1.3 ± 0.8 1 week postoperatively (t-test, P < 0.001) and to 1.1 ± 0.7 3 months postoperatively (t-test, P < 0.001). Mean logMAR best-corrected visual acuity (BCVA) was 0.7 ± 0.5 1 week postoperatively and 0.6 ± 0.5 3 months postoperatively. There was no significant difference in mean logMAR UCVA (P = 0.7) and BCVA (P = 0.7) postoperatively between ECCE and MSICS. 89.5% achieved BCVA better than 6/60 and 57.3% better than 6/18 with a follow-up of 3 months. Posterior capsule rupture and/or vitreous loss occurred in 34/414 patients (8.2%) and was more frequent (P = 0.047) in patients undergoing ECCE (10.2%) compared with MSICS (5.3%).Conclusion:AMO-O cataract surgeons at the end of their training offer significant improvement in the visual acuity of their patients. Continuous monitoring of outcomes will guide further improvements in surgical skills and minimize complications.

A control-matched comparison of flap off and flap on laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia and myopic astigmatism

PurposeTo compare the visual and refractive outcomes of flap off and flap on, Laser Assisted Subepithelial Keratectomy (LASEK) for low to moderate myopia. MethodsA prospective non-randomized control-matched study was conducted in which 53 patients underwent LASEK for the treatment of low to moderate myopia and myopic astigmatism. Right eye of each patient had the flap removed (flap off) while in the left eye the flap was recapped (flap on). Equal number (N=53) of flap on was matched with flap off having preoperative manifest refraction spherical equivalent within ±0.75Diopters (D). Primary outcome variables included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA) and manifest refraction. ResultsPreoperatively, the mean spherical equivalent (SE) was −3.59±1.46D for flap off and −3.67±1.51D for flap on (p=0.779). The mean preoperative sphere was −3.32±1.58D for flap off group and −3.36±1.61D for flap on group (p=0.338) whereas, the mean preoperative cylinder was −0.55±0.70D and −0.63±0.68D for flap removal and flap preservation groups respectively (p=0.576). Postoperatively, the mean LogMAR UCVA was −0.035±0.079 for flap off and −0.043±0.085 for flap on. The percentages of eyes that had UCVA of 20/40 or better were 98.1% for flap off group and 100% for flap on group (p=0.317). Mean postoperative SE was 0.00±0.19D for flap off group and −0.03±0.43D for flap on group. In flap removal group, 100% eyes were within ±0.50D of the intended correction while in flap preservation group, 92.5% and 100% eyes were within ±0.50D and ±1.00D of the intended correction, respectively. Mean postoperative LogMAR BSCVA was −0.013±0.044 for flap removal group and −0.016±0.049 for flap preservation group (p=0.727). ConclusionsThe differences in the visual and refractive results between flap preservation and flap removal groups were not clinically significant. Both procedures seemed safe and effective for the treatment of myopia and myopic astigmatism.

Hyperopic corneal refractive surgery in patients with accommodative esotropia and amblyopia

To explore whether hyperopic excimer corneal refractive surgery can affect ocular alignment and stereopsis in patients with both accommodative esotropia and amblyopia. In this prospective study, 26 eyes of 13 patients with accommodative esotropia and amblyopia underwent bilateral hyperopic corneal refractive surgery: 9 patients underwent laser in situ keratomileusis (LASIK); 4, laser epithelial keratomileusis (LASEK). The main ocular examinations included pre- and postoperative best-corrected and uncorrected visual acuity, refractive error, ocular alignment, and stereopsis. Preoperative cycloplegic refraction in the right eyes was +5.64 ± 2.09 D; in the left eyes, +5.91 ± 1.97 D. After surgery, refraction in the right eyes was +1.13 ± 1.21 D; in the left eyes, +1.44 ±1.53 D. The mean logMAR uncorrected visual acuity was 0.46 ± 0.30 before surgery and 0.32 ± 0.25 after surgery (t = 5.72, P = 0.001). The mean pre- and postoperative best-corrected visual acuity were 0.31 ± 0.28 and 0.29 ± 0.25, respectively; there was no significant difference between the two groups (t = 1.23, P = 0.22). The average uncorrected esotropia was 37.92(Δ) ± 9.12(Δ) before surgery and 2.76(Δ) ± 2.80(Δ) after (P<0.001). Using a synoptophore, 2 patients (15.3%) had preoperative stereopsis and 11 patients (84.6%) had postoperative stereopsis. No patients experienced lower stereopsis postoperatively. In this cohort, hyperopic corneal refractive surgery can improve the alignment, uncorrected visual acuity, and stereopsis in patients with accommodative esotropia and amblyopia.

Comparison of contrast sensitivity and visual acuity between deep anterior lamellar keratoplasty and penetrating keratoplasty in patients with keratoconus.

To evaluate postoperative visual acuity and contrast sensitivity results following deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus (KC). All the patients' records with KC who had PK or DALK surgery between May 2010 and May 2011 were retrospectively reviewed. Sixty patients who underwent successful corneal transplantation for KC: 30 eyes underwent DALK and 30 eyes underwent PK were included in this study. Preoperative and postoperative mean logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA), logMAR best spectacle-corrected visual acuity (BSCVA) and intraocular pressure (IOP) were evaluated. Contrast sensitivity tests (CS) were done preoperative and 2 months after all sutures had removed. All surgeries were performed under regional anesthesia (retrobulbar anesthesia) by 1 surgeon (B.K.) who was experienced in penetrating and lamellar keratoplasty techniques. The mean age of the DALK group was 29.67±4.95 (range 18-40) years and the PK group was 28.7±3.53 (range 18-39) years. Preoperatively there was no significant difference in the logMAR UCVA, logMAR BSCVA and IOP between the DALK (1.281±0.56; 0.97±0.85; 12.07±2.12mmHg) and PK (1.34±0.21; 0.98±0.21; 13±2.12mmHg) groups. One-year after surgery there was no significant difference in the mean logMAR UCVA and IOP between the DALK (0.46±0.37; 11.73±2.1mmHg) and PK (0.38±0.21; 12±2.12mmHg) groups. The mean contrast sensitivity was evaluated by CC-100 Topcon LCD at 1.5, 2.52, 4.23, 7.10 and 11.91 cycles per degree (cs/deg) spatial frequencies before and 2 months after the all sutures had removed. All patients with keratoconus in both DALK and PK groups performed good visual function postoperatively. The mean contrast sensitivity increased considerably at all spatial frequencies compared with preoperative levels in the DALK and PK groups.The mean post-operative evaluation of contrast sensitivity measurements was not significantly different between the two groups.

Comparison of outcomes of conventional WaveLight&amp;reg; Allegretto Wave&amp;reg; and Technolas&amp;reg; excimer lasers in myopic laser in situ keratomileusis

ObjectiveTo compare the results of laser in situ keratomileusis for myopia using WaveLight® Allegretto Wave® Eye-Q® and Technolas® 217z excimer lasers.MethodA retrospective, comparative case series of 442 eyes matched for age and myopia: half each were treated with Allegretto’s wavefront-optimized algorithm and Technolas PlanoScan. Outcome measures were postoperative mean logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA), manifest refraction spherical equivalent (MRSE), cylinder, safety and efficacy indices, refractive predictability, and optical zone size selection. Refractive predictability of a subgroup treated for −2.50 to −4.0 diopter (D) was analyzed separately.ResultsAt mean follow-up of 80.5 days, mean logMAR UCVA, mean MRSE and mean postoperative cylinder were 0.02 ± 0.07 (range −0.12 to 0.30), 0.27 ± 0.36 D (range −1.25 to 1.50 D) and −0.33 ± 0.30 D (range 0.00 to −1.50 D) for Allegretto versus 0.02 ± 0.08 (range −0.12 to 0.40), 0.095 ± 0.47 D (range −1.25 to 1.13 D) and −0.44 ± 0.5 2 D (range 0.00 to −2.25 D) for Technolas (P = 0.98, 0.80 and 0.006). Mean safety and efficacy indices were 1.05 ± 0.13 (0.75–1.33) and 0.97 ± 0.13 (0.50–1.33) for Allegretto and 1.07 ± 0.14 (0.75–1.49) and 0.97 ± 0.17 (0.40–1.49) for Technolas (P = 0.23 and 0.69). Proportions of eyes achieving postoperative MRSE within ±1.0 D, ±0.5 D, and ±0.25 D were 98.2%, 91.9% and 75.6% for Allegretto and 99.1%, 97.8% and 72.4% for Technolas (P = 0.68, 0.20 and 0.51). Mean optical zone size selected was 6.48 ± 0.10 mm (range 6.0–6.5 mm) for Allegretto and 6.38 ± 0.19 mm (range 5.6–6.6 mm) for Technolas (P < 0.001). Of the subgroup with treatment between −2.5 and −4.0 D, 86.8% and 58.5% of eyes treated with Allegretto achieved postoperative MRSE within ±0.50 D and ±0.25 D versus 70.4% and 44.4% for Technolas (P = 0.006 and 0.057).ConclusionNo differences were seen in postoperative mean logMAR UCVA, MRSE, safety and efficacy indices between the two lasers. Allegretto produced less residual astigmatism, possibly improved refractive predictability, and required smaller optical zone selection.

Efficacy, predictability, and safety of laser-assisted subepithelial keratectomy for the treatment of myopia and myopic astigmatism

Purpose:The purpose was to report the refractive and visual outcomes of laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia.Materials and Methods:A retrospective, noncomparative consecutive case series of 173 of 91 patients who had undergone LASEK is presented. Primary outcome variables included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, epithelialization time, pain, haze, and complications.Results:Preoperatively, the mean spherical equivalent (SE) was –3.71 ± 1.63 D (range, –0.875 D to 8.25 D), and the mean LogMAR BSCVA was –0.0374 ± 0.0767 D (range, –0.47 D to 0.00 D). On the final visit, the mean SE was –0.05 ± 0.335 D (range, –1.63 D to 1.00 D), the mean LogMAR UCVA was 0.04674 ± 0.0771 D (range, –0.3010 D to 0.1249 D) and the mean LogMAR BSCVA was –0.0164 ± 0.0497 (range –0.3010 to 0.124). All eyes achieved vision of 20/40 or better, and 83.2% of the eyes achieved a vision of 20/25 or better. One 64 (94.94%) and all the eyes were within ± 0.50 D and ± 1.00 D of the attempted correction respectively. Complete epithelialization occurred in 4.70 ± 2.09 days (range, 2-10 days). At the final visit, 79.7% of eyes had a clear cornea. Grade 1 haze developed in 17.34% of the eyes, grade 2 haze developed in 2.89% of eyes developed; no eyes developed grade 3 or 4 haze.Conclusions:LASEK is a safe, effective, and predictable method for the treatment of myopia and myopic astigmatism.

Artisan iris-claw lenses for the correction of aphakia in children following lensectomy for ectopia lentis

PurposeTo describe the results of Artisan iris-claw lens implants in children with aphakia following lensectomy for ectopia lentis.MethodWe measured visual acuity, refractive error and endothelial cell counts and recorded complications...

Correcting post‐keratoplasty anisometropia with the implantable collamer phakic intraocular lens

We evaluate the Visian Implantable Collamer Lens (Staar, Monrovia, CA, USA) phakic intraocular lens for treating post-keratoplasty anisometropia. Case series of three eyes (2 phakic and 1 pseudophakic). The mean age was 47.3 years (range 30-73 years), with a minimum of 3-month follow up. The mean preoperative spherical equivalent was -8.75 ± 5.17 D (-4.00 to -14.25 D) improving to -0.29 ± 1.21 D postoperatively (range 0.75 to -1.625 D). Mean logMAR uncorrected visual acuity improved from 1.66 ± 0.60 (6/240) preoperatively to 0.41 ± 0.52 (6/15(2) ). Mean logMAR best spectacle-corrected visual acuity improved from 0.32 ± 0.15 (6/12) preoperatively to 0.10 ± 0.11 (6/7.5). Anisometropia improved from a difference of 6.37 ± 2.59 D preoperatively to 2.09 ± 1.37 D postoperatively, and there were no complications. Our technique for this clinical indication shows that the Visian Implantable Collamer Lens is a safe and effective alternative for treating post-keratoplasty anisometropia.

Epithelial Removal and Phototherapeutic Keratectomy for Residual Refractive Error Following LASIK in Eyes With Corneal Epithelial Basement Membrane Degeneration

To retrospectively evaluate the efficacy of epithelial removal followed by phototherapeutic keratectomy (PTK) for reducing residual refractive error in eyes with corneal epithelial basement membrane degeneration after LASIK. Eight eyes of four patients with residual refractive error and signs of epithelial basement membrane degeneration after LASIK were followed until their refractive error stabilized. Epithelium was debrided and PTK performed. Refractive error and visual acuity outcomes were analyzed. In the six eyes that underwent LASIK for myopic astigmatism, mean spherical equivalent refraction after LASIK was -1.75 +/- 0.62 diopters (D) and mean astigmatism was +0.75 +/- 0.59 D. After PTK, mean spherical equivalent refraction was -0.33 +/- 0.35 D and mean astigmatism was +0.50 +/- 0.27 D. Mean logMAR uncorrected visual acuity (UCVA) improved from 0.39 +/- 0.31 before PTK to 0.03 +/- 0.05 after PTK. Mean Snellen UCVA improved from 20/50 before PTK to 20/20 after PTK. In two eyes that underwent LASIK for hyperopic astigmatism, mean spherical equivalent refraction after LASIK was +4.38 +/- 0.35 D and mean astigmatism was +3.25 D. After PTK, mean spherical equivalent refraction decreased to +1.56 +/- 0.44 D and mean astigmatism decreased to +2.13 +/- 0.53 D. Mean logMAR UCVA improved from 0.24 to 0.14. Mean Snellen UCVA improved from 20/35 to 20/27. In eyes with epithelial basement membrane degeneration and refractive error after LASIK, epithelial removal followed by PTK may reduce refractive error, both myopic and hyperopic, bringing it close to emmetropia and avoiding the need for traditional stromal enhancement.

One-Year Clinical Results after Epi-LASIK for Myopia

To evaluate the clinical results of epi-LASIK for the treatment of low to moderate myopia and myopic astigmatism. Retrospective, noncomparative, interventional case series. Two hundred thirty-four eyes of 138 patients underwent epi-LASIK for the correction of low to moderate myopia. Mean preoperative spherical equivalent ranged from -1.0 to -7.25 diopters (D) (-3.74+/-1.46, mean+/-standard deviation [SD]) and baseline logarithm of the minimum angle of resolution (logMAR) best spectacle-corrected visual acuity (BSCVA) from 0.10 to -0.18 (mean+/-SD, 0.00+/-0.06). All enrolled eyes underwent epi-LASIK using the Centurion SES epikeratome (Norwood Abbey EyeCare, Victoria, Australia) and the Allegretto (Wavelight Laser Technologie AG, Erlangen, Germany) laser platform. The enrolled patients were followed up daily until the epithelial healing was complete as well as at the 1-, 3-, 6-, and 12-month postoperative intervals. The main parameters assessed were subjective evaluation of postoperative pain, uncorrected visual acuity (UCVA) and BSCVA, manifest refraction, haze grade, and contrast sensitivity of the operated eyes. The mean epithelial healing time was 4.70+/-0.87 days (range, 3-7 days), with mean logMAR UCVA on the day of reepithelization of 0.26+/-0.14 (range, 0.7-0.0). One year after the treatment, the spherical equivalent of the treated eyes (n = 222) ranged from -1.25 to +0.625 D (mean+/-SD, -0.18+/-0.6 D), with 80.33% of the eyes within 0.5 D (96.72% within 1 D) of the attempted correction. At the same interval, 86% of the eyes had clear corneas and 14% clinically insignificant (trace) haze, whereas 60% of the eyes had a line gain of 1 or more lines of BSCVA. Mean logMAR contrast sensitivity of the treated eyes at 4 different spatial frequencies was improved or remained unchanged throughout the follow-up period. One-year visual and refractive results after epi-LASIK suggest that it is a safe and efficient method for the correction of low to moderate myopia and myopic astigmatism.

Epi-LASIK: Preliminary clinical results of an alternative surface ablation procedure

To evaluate the clinical results of epi-LASIK, a new surface ablation surgical technique for the treatment of low myopia. Vardinoyannion Eye Institute of Crete, University of Crete, Greece. Forty-four eyes of 31 patients had epi-LASIK for the correction of low myopia. Mean preoperative spherical equivalent was 3.71 diopters (D) +/- 1.2 (SD) (range -1.75 to -7.00 D) and the mean baseline logMAR best spectacle-corrected visual acuity was -0.01 +/- 0.06 (range 0.10 to -0.10). All the epithelial separations were performed with the Centurion epikeratome (CIBA Surgical). The enrolled patients were followed daily until the epithelial healing was complete as well as at 1- and 3-month intervals. On the operative day, patients filled out a questionnaire grading visual performance and pain score of treated eyes every 2 hours for a total of 5 records. The mean epithelial healing time was 4.86 +/- 0.56 days (range 3 to 5 days). The mean logMAR uncorrected visual acuity on the day of reepithelization was 0.19 +/- 0.09 (range 0.40 to 0.10). At 1 month, the mean was spherical equivalent of the treated eyes (N=44), -0.3 +/- 0.6 D (range -1.0 to 0.87 D), and at 3 months it was (N=37), -0.10 +/- 0.4 D (range -0.75 to 0.75 D); 97% of eyes had clear corneas or trace haze 3 months after treatment. Preliminary clinical results suggest that epi-LASIK is a safe and efficient method for the correction of low myopia. Further studies will establish this method as an alternative surface ablation procedure.

Higher-order aberrations of lenticular opacities

Purpose: To measure and quantify higher-order aberrations induced by different types of lenticular opacities. Setting: Department of Ophthalmology, University of Auckland, and Department of Ophthalmology, Auckland Public Hospital, Auckland, New Zealand. Methods: Patients with lenticular opacities were recruited from outpatient clinics of a major tertiary referral center for ophthalmology. Patients were included if they had clinically evident, mild to moderate lenticular opacity with no coexisting ocular pathology. Patients were examined using standard preoperative techniques with additional assessment by wavefront aberrometry (Zywave®, Bausch & Lomb) and Scheimpflug photography (EAS-1000, Nidek). For comparison, 20 eyes of 10 subjects with no lenticular opacity (control group) were recruited and assessed in an identical manner. Results: Thirty persons were recruited and 40 eyes assessed, 20 with lenticular opacities. Ten eyes had predominantly cortical opacification, and 10 had mainly nuclear opacification. In eyes with predominantly cortical opacification, the mean logMAR uncorrected visual acuity (UCVA) was 0.5 ± 0.2 (SD) (6/18 Snellen equivalent) and the mean logMAR best spectacle-corrected visual acuity (BSCVA), 0.2 ± 0.2 (6/9). Analysis of aberrometry data for a 6.0 mm pupil in this group revealed an increase in coma of cosine phase (Z 3 1 , P = .06) and tetrafoil of cosine phase (Z 4 4 , P = .07) compared to eyes in the control group. Eyes with predominantly nuclear opacification had a mean logMAR UCVA of 0.7 ± 0.2 (6/30) and a logMAR BSCVA of 0.4 ± 0.2 (6/15). Aberrometry data for this cohort for a 6.0 mm pupil showed a statistically greater amount of spherical aberration (Z 4 0, P = .001) and tetrafoil of cosine phase (Z 4 4 , P = .005; Z 4 –4, P = .004). Conclusions: This pilot study suggests that different types of early lenticular opacities induce different wavefront aberration profiles. Predominantly cortical opacification produced an increase in coma and nuclear opacification induced an increase in spherical aberration compared to eyes without opacities. Both types of lenticular opacities also induced a higher amount of tetrafoil. This could explain the significant visual symptoms in patients with early cataract and relatively good high-contrast Snellen acuity.