Scleral Lens Applications Focused on Korean Patients with Various Corneal Disorders

Purpose@#We aimed to report on the clinical outcomes of scleral lens applications in Korean patients with various corneal disorders. @*Methods@#This retrospective review was conducted for 62 eyes of 47 patients who had been fitted with scleral lenses for various corneal disorders. The patients were referred for inadequate spectacle-corrected visual acuity and rigid gas permeable (RGP) or soft contact lens intolerance. Uncorrected visual acuity, habitually corrected visual acuity, best lens-corrected visual acuity, topographic indices, keratometry indices, and lens parameters were evaluated. @*Results@#Twenty-six eyes of 19 patients with keratoconus were enrolled. Other conditions included corneal scar (13 eyes of 12 patients), phlyctenules (three eyes), laceration (four eyes), chemical burn (one eye), keratitis (one eye), Peters’ anomaly (one eye), fibrous dysplasia (one eye), ocular graft-versus-host disease (two eyes of one patient), irregular astigmatism (18 eyes of 12 patients), and corneal transplant status (five eyes of four patients). The mean topographic values of the eyes include flat keratometric value (43.0 ± 6.1 diopters [D]), steep keratometric value (48.0 ± 7.4 D), and astigmatism (4.9 ± 3.6 D). Of the eyes fitted with scleral lenses, best lens-corrected visual acuity (0.10 ± 0.22 logarithm of the minimum angle of resolution [logMAR]) was significantly better than the habitually corrected visual acuity (0.59 ± 0.62 logMAR, p < 0.001). @*Conclusions@#Scleral contact lenses are a good alternative for patients with corneal abnormalities and those who are intolerable to RGP contact lenses, resulting in both successful visual outcomes and patient satisfaction, especially concerning keratoconus, corneal scar, and corneal transplant status.

Clinical Outcomes of Nanothin Descemet Stripping Automated Endothelial Keratoplasty in Korean Patients with Corneal Endothelial Dysfunction

Purpose@#To evaluate the clinical outcomes of nanothin Descemet stripping automated endothelial keratoplasty (DSAEK) in Korean patients with corneal endothelial dysfunction. @*Methods@#We retrospectively reviewed medical records of the patients who underwent nanothin DSAEK (graft thickness ≤50 μm) due to corneal endothelial dysfunction and followed up more than 1 year. We evaluated best-corrected visual acuity (BCVA), central corneal thickness, and corneal endothelial cell density at preoperative and 1, 3, 6, and 12 months postoperatively. @*Results@#Sixteen eyes of 16 patients with the mean follow-up period of 13.00 ± 0.96 months were included. The mean graft thickness after deswelling was 45.25 ± 4.59 µm (range, 38.0–50.0 µm). The mean logarithm of the minimum angle of resolution BCVA improved from 1.37 ± 0.53 preoperatively to 0.68 ± 0.46, 0.55 ± 0.35, 0.40 ± 0.25, and 0.39 ± 0.25 at 1, 3, 6, and 12 months postoperatively (p = 0.005, p < 0.001, p < 0.001, and p < 0.001), respectively. The mean central corneal thickness improved from 752.00 ± 129.11 to 555.75 ± 54.66 µm at 12 months postoperatively (p = 0.006). The mean graft endothelial cell density decreased from 2,859.62 ± 228.34 to 1,542.25 ± 627.34 cells/mm2 at 12 months postoperatively (p = 0.012). The postoperative complications included increased intraocular pressure (n = 3, 18.75%) and graft dislocation (n = 1, 6.25%), all of which were successfully managed by anterior chamber paracentesis or rebubbling. No other serious complications were encountered. @*Conclusions@#Nanothin DSAEK produced significant and stable visual improvements without severe postoperative complications in Korean patients with corneal endothelial dysfunction.

Patients at High Risk for Failure of Penetrating Keratoplasty

Purpose@#We report the clinical characteristics and the primary underlying diseases of patients at high risk for failure of penetrating keratoplasty (PKP) in Korea. @*Methods@#Patients at high risk of PKP failure among those who visited the ophthalmological clinics of tertiary care hospitals in Korea from April 2019 to April 2020 and who were indicated for PKP were retrospectively enrolled. We epidemiologically investigated 119 eyes of 104 patients via medical chart review. @*Results@#Herpes simplex virus (HSV) keratitis was the most common primary underlying disease (26.1%). The most common primary cause of poor bilateral visual acuity was Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) (41.7%) followed by chemical burns (19.4%). Of the 119 eyes, 40.3% had a history of previous PKP and 20.2% had undergone three or more PKP. The average number of prior PKPs was 1.02 ± 1.46. Corneal neovascularization and corneal opacity were reported in 82.4 and 92.4% of cases, respectively. As the severity of these conditions increased, the eye distributions became larger. Of all patients, 47.9 and 31.9%, respectively, received the highest corneal neovascularization and corneal opacity scores. @*Conclusions@#Our study of patients at high risk of PKP failure improves our understanding of the relevant clinical characteristics and primary underlying diseases. Such patients require careful observation and aggressive treatment. Possible alternatives to PKP should be considered if PKP consistently fails. This study will aid clinicians in deciding whether to proceed to surgery if a poor postoperative prognosis is predictable.

Analysis of Positional Relationships of Various Centers in Cataract Surgery

PURPOSE: To analyze the positional relationships of various centers in patients undergoing femtosecond laser-assisted cataract surgery (FLACS). METHODS: The locations of the pupil center (PC), limbal center (LC) and lens center were analyzed in each patient using optical coherence tomography during FLACS in 35 eyes of 35 patients. Using the preoperative corneal aberrometry device, angle kappa and the location of the visual axis (VA) were calculated. After acquiring the relative horizontal and vertical coordinates of each center, the distance and location among each center were compared. The relative location and distance of each center were statistically evaluated. RESULTS: The distance from the PC to the lens center was 0.147 ± 0.103 mm, that from the LC to the lens center was 0.205 ± 0.104 mm, and that from the VA to the lens center was 0.296 ± 0.198 mm. The distance from the PC to the VA was 0.283 ± 0.161 mm, that from the LC to the VA was 0.362 ± 0.153 mm, and that from the lens center to the VA was 0.296 ± 0.198 mm. Among the various centers, the PC was the closest to the lens center, whereas the LC and VA were the farthest. Based on the location of the lens center, the PC, LC, and VA exhibited differences in the X and Y coordinate positions (vertical p = 0.004, horizontal p < 0.001). Among them, the LC was significantly inferior and temporal compared to the PC (vertical p = 0.026, horizontal p = 0.023). Based on the location of the VA, the respective locations of the PC, LC and lens center in two dimensions did not significantly differ (vertical p = 0.310, horizontal p = 0.926). CONCLUSIONS: This study demonstrated the positional and locational relationships between the centers regarding FLACS. The locations of the PC, LC, and VA were different from the lens center with the PC being the closest. Surgeons should be aware of these positional relationships, especially in FLACS.

Reduction of Blue Light Emission in Internet-protocol Television and Its Effect on Ocular Fatigue

PURPOSE: The blue light emitted from electronic devices may be harmful to the eye. We investigated whether internet-protocol television (TV) with lowered blue light emission reduced ocular fatigue. METHODS: A total of 98 healthy subjects were recruited. They watched an animated movie (A) and an identical version except for reduced blue light (B), sequentially for 1 hour in random order. Before and after watching the movies, we measured the distance and near refraction and tear break-up time objectively. Ocular discomfort score and the earliest onset time of the ocular fatigue symptoms were also measured using our specially designed subjective ocular discomfort scale. RESULTS: The median age of the participants was 28.5 years, and there were 56 females out of 98 total participants. Both distance and near refraction were not significantly different before versus after watching the movies, nor between viewing movies A and B. However, the accommodative amplitude measured by subtracting the near refraction from the distance refraction was found to be greater after watching movie B compared with movie A in a subset of subjects with hyperopia [1.92 vs. 1.72 diopters (D) for the right eye and 2.14 vs. 1.83 D for the left eye; p = 0.04 and p < 0.01, respectively]. The ocular discomfort score was lower (15.40 vs. 12.85; p = 0.10), but not significantly, and the earliest ocular fatigue onset time was significantly delayed (23.48 vs. 34.51 minutes; p < 0.01), after watching movie B. CONCLUSIONS: Reduction of blue light emission alleviated ocular fatigue caused by TV displays. Watching TV with lower blue light may provide benefits to hyperopic individuals by reducing eye strain and improving the accommodative amplitude.

Validity of Tono-pachymetry for Measuring Corrected Intraocular Pressure in Non-surgical and Post-photorefractive Keratectomy Eyes

PURPOSE: To assess the validity of central corneal thickness (CCT) and corrected intraocular pressure (IOP) values obtained by tono-pachymetry in non-surgical and post-photorefractive keratectomy (PRK) eyes. METHODS: For the study, 108 young healthy participants and 108 patients who had PRK were enrolled. Measurements were randomly performed by tono-pachymetry, ultrasonic (US) pachymetry, and Goldmann applanation tonometry (GAT). CCT measurement by tono-pachymetry was compared to that of US pachymetry. The corrected IOP value obtained by tono-pachymetry was compared to that obtained by US pachymetry and GAT. The corrected IOP from US pachymetry and GAT was calculated using the identical compensation formula built into the tono-pachymetry. Bland-Altman plot and paired t-test were conducted to evaluate the between-method agreements. RESULTS: The mean CCT measurement using tono-pachymetry was significantly greater by 7.3 µm in non-surgical eyes (p < 0.001) and 17.8 µm in post-PRK eyes (p < 0.001) compared with US pachymetry. Differences were significant in both Bland-Altman plotand paired t-test. The mean difference of corrected IOP values obtained by tono-pachymetry and calculated from measurements by US pachymetry and GAT was 0.33 ± 0.87 mmHg in non-surgical eyes and 0.57 ± 1.08 mmHg in post-PRK eyes. The differences in the Bland-Altman plot were not significant. CONCLUSIONS: The CCT measurement determined using tono-pachymetrywas significantly thicker than that of US pachymetry. The difference in CCT was greater in post-PRK eyes than in non-surgical eyes. However, the corrected IOP value obtained by tono-pachymetry showed reasonable agreement with that calculated from US pachymetry and GAT measurements.

Clinical Outcomes of Cataract Surgery Using Nasal Clear Corneal Incision: Safety and Efficacy

PURPOSE: To compare the safety and efficacy of cataract surgery using nasal clear corneal incision (CCI) versus superior or temporal CCIs in Korean patients. METHODS: A retrospective comparative study was conducted. Patients underwent cataract surgery using CCI performed by 3 surgeons between January 2012 and December 2013.The patients were divided into the following 3 groups based on CCI direction: nasal CCIs (group I), superior CCIs (Group II), and temporal CCIs (Group III). To assess usability, surgically induced astigmatism (SIA), best-corrected visual acuity (BCVA), intraocular pressure (IOP), keratometry reading, and refractive errors at baseline and 1 month after surgery were compared. Operation times were compared between groups. To assess safety, intraoperative complications and wound stability were compared. RESULTS: A total of 1,374 eyes (Group I, 283 eyes; Group II, 587 eyes; Group III, 504 eyes) were included in the present study. The SIA was not significantly different among the 3 groups. The postoperative mean BCVA, IOP, keratometry reading and spherical equivalent as well as the mean operation times were not significantly different between the 3 groups (14.04 ± 3.79 vs. 13.80 ± 3.27 vs. 13.80 ± 3.70; p = 0.473). The rate of intraocular complications and incidence of corneal wound suture were not significantly different between the 3 groups (1.7% vs. 3.2% vs. 2.3%; p = 0.378). CONCLUSIONS: The safety and efficacy of cataract surgery using nasal CCI were not significantly different compared with the use of temporal or superior CCI. Our results showed that cataract surgery using nasal CCI can be performed safely and conveniently in Korean patients.

Lower Energy to Make a Corneal Flap with a 60 kHz Femtosecond Laser Reduces Flap Inflammation and Corneal Stromal Cell Death But Weakens Flap Adhesion

PURPOSE: To compare corneal flaps created in rabbits with a 60 kHz femtosecond (FS) laser using different levels of raster energy and to measure early inflammation, corneal stromal cell death, and late postoperative adhesion strength. METHODS: Sixty rabbits were divided into three groups of 20 each. A flap 110 micrometer thick and 9.0 mm in diameter was made in one eye of each rabbit at raster energies of 0.7 microJ, 1.1 microJ, and 2.4 microJ. Histopathological evaluation for inflammation and apoptosis using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed at 4 and 24 hours after flap creation. The adhesion strength of the flaps was measured with a tension meter at 1 and 3 months. RESULTS: Twenty four hours after flap creation, the 2.4 microJ group had more inflammatory and CD11b-positive cells than the 0.7 and 1.1 microJ groups. The number of TUNEL-positive cells increased with raster energy at 4 and 24 hours. The grams of force (gf) needed to detach the flaps at 3 months was significantly higher in 2.4 microJ group (170 gf) than in 0.7 microJ group (97.5 gf) and 1.1 microJ group (100 gf, p = 0.03). CONCLUSIONS: Using raster energy lower than 1.1 microJ to make a flap with a 60 kHz FS laser decreases inflammatory cell infiltration and corneal stromal cell death in the central cornea but may result in a weaker flap than using higher raster energy (2.4 microJ).

Lower Energy to Make a Corneal Flap with a 60 kHz Femtosecond Laser Reduces Flap Inflammation and Corneal Stromal Cell Death But Weakens Flap Adhesion

PURPOSE: To compare corneal flaps created in rabbits with a 60 kHz femtosecond (FS) laser using different levels of raster energy and to measure early inflammation, corneal stromal cell death, and late postoperative adhesion strength. METHODS: Sixty rabbits were divided into three groups of 20 each. A flap 110 micrometer thick and 9.0 mm in diameter was made in one eye of each rabbit at raster energies of 0.7 microJ, 1.1 microJ, and 2.4 microJ. Histopathological evaluation for inflammation and apoptosis using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed at 4 and 24 hours after flap creation. The adhesion strength of the flaps was measured with a tension meter at 1 and 3 months. RESULTS: Twenty four hours after flap creation, the 2.4 microJ group had more inflammatory and CD11b-positive cells than the 0.7 and 1.1 microJ groups. The number of TUNEL-positive cells increased with raster energy at 4 and 24 hours. The grams of force (gf) needed to detach the flaps at 3 months was significantly higher in 2.4 microJ group (170 gf) than in 0.7 microJ group (97.5 gf) and 1.1 microJ group (100 gf, p = 0.03). CONCLUSIONS: Using raster energy lower than 1.1 microJ to make a flap with a 60 kHz FS laser decreases inflammatory cell infiltration and corneal stromal cell death in the central cornea but may result in a weaker flap than using higher raster energy (2.4 microJ).

Visual Function and Patient Satisfaction in Pseudophakic Monovision

PURPOSE: To evaluate visual performance as well as patient satisfaction and to explore factors associated with clinical outcomes in pseudophakic monovision acquired after bilateral phacoemulsification and sequential monofocal intraocular lens (IOL) implantation. METHODS: The present retrospective study examined patients with pseudophakic monovision. Preoperative and postoperative binocular uncorrected distant visual acuity (UCDVA), uncorrected near visual acuity (UCNVA), refractive errors and postoperative near stereopsis were measured. Postoperative measurements were obtained at least 6 months after the fellow eye surgery. Patient satisfaction and independence from glasses were evaluated using a questionnaire. RESULTS: Preoperative and postoperative binocular UCDVA, UCNVA, and differences in spherical equivalent refractive error were statistically significant. Postoperative near stereopsis was 107.1 arcsec. Questionnaire responses showed that 71.4% of patients were less dependent on glasses and 85.7% were satisfied with the postoperative visual performance. Various designs of monovision, such as crossed monovision or customized minimonovision with moderate myopic defocus showed the same level of patient satisfaction. Patients who were older than 60 years or had poorer preoperative binocular UCDVA showed higher satisfaction. CONCLUSIONS: Pseudophakic monovision is an effective approach for managing loss of accommodation after cataract surgery, especially in patients older than 60 years.

Long-term Clinical Outcomes of Femtosecond LASER-Assisted Descemet's Stripping Endothelial Keratoplasty

PURPOSE: To evaluate the long-term clinical outcomes of femtosecond LASER-assisted Descemet's stripping endothelial keratoplasty (DSEK). METHODS: The clinical results of endothelial keratopathy from 11 consecutive patients who were followed up for at least 12 months after femtosecond LASER-assisted DSEK were retrospectively analyzed. The best corrected visual acuities (BCVA), manifest refractions, intraocular pressures, and perioperative complications were evaluated preoperatively and up to 24 months after the femtosecond LASER-assisted DSEK. RESULTS: The average follow-up period was 18 months. Postoperative visual acuity had significantly improved from 1.26 (logMAR) to 0.80 (logMAR) at 3 months (p < 0.05) and this change was maintained during postoperative follow-up. All eyes underwent successful transplantation and the donor discs were well-attached. The mean endothelial cell density continued to decrease during the follow-up period. The donor-recipient stromal interface was the area where varying degree of haziness and birefringent particles were found. CONCLUSIONS: The femtosecond LASER-assisted DSEK was effective in creating an endothelial donor disc which resulted in rapid visual recovery and low surgically-induced astigmatism. However, the operation caused rapid decrease in endothelial cell density which requires continuing further consideration by the physician.

Comparison of Clinical Outcomes between Different IOL Sizes after Microincisional Cataract Surgery

PURPOSE: To compare clinical outcomes between different IOL sizes after microincisional cataract surgery. METHODS: Retrospective chart review was done in 68 eyes of 68 patients who underwent phacoemulsification and implantation with two different-sized aspheric IOLs (AKREOS MI60 Bausch & Lomb, Inc., Rochester, NY). The patients were divided into 2 groups: group I consisted of 38 eyes between 15.5-22.0 diopter (D) (optic size 6.0 mm, overall size 10.7 mm), and group II consisted of 30 eyes between 22.5-30.0 D (optic size 5.6 mm, overall size 10.5 mm). The best corrected visual acuity (BCVA), refractive error, and anterior chamber depth (ACD) were measured preoperatively and postoperatively and were compared between groups. RESULTS: Postoperative 6 month BCVA was 0.08 +/- 0.10 D in group I and 0.07 +/- 0.11 D in group II. During the same period, the spherical equivalent was -0.32 +/- 0.65 D in group I and -0.16 +/- 0.59 D in group II (p > 0.05). There were no significant differences in ACD or refractive error during the postoperative period (p > 0.05). CONCLUSIONS: Comparison of postoperative visual acuity and spherical equivalent between different sizes of Akreos MI-60(TM) IOLs showed no differences.

Long-Term Quality of Life after Myopic Laser Refractive Surgery

PURPOSE: To investigate long-term satisfaction and quality of life after myopic laser refractive surgery. METHODS: This study included 231 myopic patients who underwent laser refractive surgery (LASIK, LASEK or PRK) at least five years prior, between 2002 and 2005, at 5 hospitals. Using a telephone survey, patients were asked to subjectively answer 26 questions regarding satisfaction, quality of life changes, and visual symptoms. RESULTS: The mean patient satisfaction score was 8.12 (scale of 1 to 10). Improvement in quality of life was reported by 91% of the subjects. Intention to have surgery again was reported by 87.9% of the subjects and intention to recommend refractive surgery to a friend or family was reported by 80.5% of the subjects. The most common discomfort symptoms after myopic laser refractive surgery were dry eye symptoms (57.1%), followed by night vision disturbances (54.3%). CONCLUSIONS: Long-term satisfaction and quality of life were shown to be positive in patients treated with myopic refractive surgery.

Surgical treatment for myopia

This article briefly explains surgical treatments of myopia. Laser refractive surgery using the excimer laser and/or femtosecond is the most commonly operated one. As the cornea has the greatest refractive power out of the ocular structures, the laser refractive surgery ablates the corneal stroma. Laser refractive surgeries are categorized by the surgical procedures basics: photorefractive keratectomy, laser in situ keratomilieusis (LASIK), laser epithelial keratomileusis, and Epi-LASIK. There are also some surgical treatment of myopia that does not use the laser ablation of the stroma. Intrastromal corneal ring segments implantation changes corneal shape which leads to the change of refractive power. Clear lens extraction reduces refractive power of crystalline lens by removal, and phakic intraocular lens implantation adds negative refractive power by implantation of intraocular lens. Patients are recommended to have a detailed consultation before choosing the surgical treatment based on their ocular status. There are several methods to treat myopia surgically, Laser reftractive surgery on cornea is most common method currently.

Comparison of Outcomes of Femtosecond Laser-assisted Keratoplasty and Conventional Penetrating Keratoplasty

PURPOSE: To compare the outcomes of IntraLase femtosecond laser-enabled keratoplasty (IEK) versus conventional penetrating keratoplasty (C-PKP). METHODS: This retrospective study included 18 eyes of 17 patients who underwent C-PKP and 26 eyes of 25 patients who underwent IEK. Postoperative clinical results were compared between two groups. RESULTS: The mean logMAR best spectacle-corrected visual acuity (BSCVA) was 0.70, 0.58, and 0.61 in the IEK group, and 1.06, 1.01, and 0.90 in the C-PKP group at postoperative 2, 4, and 6 months respectively. The difference between the two groups was statistically significant at 2 and 4 months postoperatively (p=0.033, 0.011). The mean refractive cylinder was 4.08 diopters (D), 4.01D, and 4.44D in the IEK group, while 5.75D, 5.75D, and 5.21D in the C-PKP group for each month, and the difference between the groups was statistically significant at 2 and 4 months postoperatively (p=0.037, 0.027). The complication rate showed no significant differences up to 6 months of follow-up between the two groups. CONCLUSIONS: The IEK showed better results in BSCVA and refractive astigmatism in the early postoperative period, in comparison with the C-PKP, and can be considered as a valuable method in penetrating keratoplasty.

Clinical Results of Wavefront-guided LASIK

PURPOSE: To investigate and compare the clinical outcomes of wavefront-guided LASIK performed by 2 different laser platforms. METHODS: A retrospective analysis of consecutive cases of eyes that underwent wavefront-guided LASIK by using the VISX S4 CustomVue system and the Zyoptix Z100 system advanced personalized mode. All procedures were performed by one surgeon. Fifty-six eyes of 36 patients were included. Of the 56 eyes, 30 eyes underwent LASIK by using the VISX S4 CustomVue system (CustomVue group), and other 26 eyes underwent LASIK by using the Zyoptix Z100 system (APT group). Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), manifest refraction, contrast sensitivity, total high order aberration (HOA), spherical aberration (SA) and Q-value were recorded preoperatively and at 1 week, 1 and 3 months postoperatively. RESULTS: There was no statistically significant difference between two groups in terms of preoperative UCVA, BCVA, manifest refraction, high order aberrations, Q-value and contrast sensitivity. Induced amount of SA was significantly lower in CustomVue group than in APT group (p = 0.02). CONCLUSIONS: Wavefront-guided LASIK performed by 2 different laser platforms caused clinically acceptable outcomes including good visual acuity and contrast sensitivity through 3 months. Furthermore, LASIK performed by VISX S4 CustomVue system caused less SA at three months after operation.

Clinical Outcomes After Microincision Cataract Surgery and In-the-bag Implantation of a New Intraocular Lens

PURPOSE: To compare visual performance after microincision cataract surgery (MICS) with the implantation of the Akreos MI-60 (MI-60) intraocular lens (IOL) through a 1.8-mm microincision with that after conventional cataract surgery with implantation of the Akreos Adapt-AO IOL (Adapt-AO). METHODS: All MICS procedures were performed by the same surgeon. The MI-60 was implanted into 25 eyes, and the Adapt-AO was place in 28 eyes. Best corrected visual acuity (BCVA), total high-order-aberration (HOA), contrast sensitivity, and surgically- induced astigmatism (SIA) were recorded one-week, one-month, and four-months postoperatively. RESULTS: There were no statistically significant differences in BCVA between eyes implanted with the MI-60 or those with the Adapt-AO (MI-60 vs. Adapt-AO, 0.09+/-0.11 at baseline (logMAR), 0.11+/-0.08 at one-week, 0.06+/-0.07, 0.06+/-0.06 at one-month, 0.05+/-0.06, 0.06+/-0.05 at four-months according to the Mann-Whitney U test, p>0.05). Refractive errors were significantly less with the Adapt-AO than with the MI-60 (MI-60 vs. Adapt-AO, -0.50+/-0.43 at baseline (diopter), -0.06+/-0.39 at one-week, -0.50+/-0.41, 0.01+/-0.57 at one-month, -0.46+/-0.36, 0.08+/-0.58 at four-months according to the Mann-Whitney U test, p<0.05). There were no statistically significant differences in total HOA or contrast sensitivity between eyes implanted with the MI-60 and those implanted with the Adapt-AO. SIAs were significantly reduced in eyes implanted with the MI-60 than in those with the Adapt-AO at one-month and four-months postoperatively (Mann-Whitney U test, p<0.05). CONCLUSIONS: Implantation with either the MI-60 or the Adapt-AO produced clinically acceptable outcomes, including good spherical aberration and contrast sensitivity. Furthermore, implantation with the MI-60 caused less SIA at one- and four-months postoperation, as compared to that with the Adapt-AO.

Early Postoperative Pain and Visual Outcomes Following Epipolis-Laser In Situ Keratomileusis and Photorefractive Keratectomy

PURPOSE: To compare early postoperative pain and visual outcomes after epipolis-laser in situ keratomileusis (epi-LASIK) and photorefractive keratectomy (PRK) in the treatment of myopia. METHODS: A retrospective chart review was designed and included 49 eyes in 30 patients who underwent epi-LASIK and 54 eyes in 29 patients who underwent PRK. During the early postoperative period (days 1 to 5), pain, uncorrected visual acuity (UCVA), and time to epithelial healing were recorded. Visual outcomes were followed for up to six months. RESULTS: Mean preoperative spherical equivalent refraction for the epi-LASIK group was -3.99+/-1.39 diopters (D) and that of the PRK group was -3.54+/-1.27 D. The pain scores on the fourth postoperative day were significantly higher in the epi-LASIK group than in the PRK group (p=0.017). Duration of pain in the epi-LASIK group was longer than in the PRK group (p=0.010). Mean healing time was significantly longer in the epi-LASIK group than in the PRK group (p<0.000). In addition, UCVA in the epi-LASIK group at postoperative days 1 and 3 were significantly lower than those in the PRK group (p=0.021 and p<0.000, respectively). Uncorrected visual acuity at one week and one month after epi-LASIK were lower than those after PRK (p=0.023 and p=0.004, respectively). CONCLUSIONS: In the epi-LASIK patients, pain relief, corneal healing, and visual recovery seemed to be slower during the early postoperative period compared to those of the PRK patients. With longer duration of follow-up, however, there were no significant differences in visual outcome between the two groups.

Late-onset Hypertrophic Corneal Scars After Laser-assisted Subepithelial Keratectomy With Mitomycin C

PURPOSE: To report late-onset hypertrophic corneal scars after laser epithelial keratomileusis (LASEK) with mitomycin C. CASE SUMMARY: Case 1. A 34-year-old man who had undergone LASEK with mitomycin C 15 months prior was referred to our clinic because of corneal opacity of his right eye. After LASEK, there have been no abnormalities in either of his eyes. However, 11 monthsafter LASEK, he experienced decreased visual acuity in his right eye. The visual acuity was 0.03 in his right eye and 1.0 in his left eye. On slit lamp examination there was a whitish, hypertrophic scarin his right cornea. The lesion was located in the corneal center and the subepithelial space. Central corneal thickness was 828 microm. Case 2. A 23-year-old woman who had undergone LASEK with mitomycin C 14 months before was referred our clinic because of corneal opacity of her left eye. After LASEK, there had been no abnormalities in either of her eyes. However, 12 months after LASEK she experienced decreased visual acuity in her left eye. The visual acuity was 1.0 in her right eye and 0.2 in her left eye. On slit lamp examination there was a whitish, hypertrophic scar in her left cornea. Central corneal thickness was 794 microm. CONCLUSIONS: Manual debridement was performed to remove the hypertrophic scar in both cases. Case 1. After manual debridement, visual acuity of the right eye improved to 0.63. Case 2. After manual debridement, best-corrected visual acuity of the left eye was 0.63.

Clinical Outcomes of LASIK Using a 213 nm Solid-State Laser System: 6-month Follow-up

PURPOSE: To present prospective clinical results of laser-assisted in situ keratomileusis (LASIK) using a solid-state laser system for the correction of mild to moderate myopia with or without astigmatism. METHODS: Thirty-eight eyes underwent LASIK using a 213 nm solid-state laser (Pulzar Z1trade mark, CustomVistrade mark, Australia). Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refractive errors, higher order aberrations (HOA) and contrast sensitivity were evaluated preoperatively and postoperatively. RESULTS: The preoperative and postoperative mean spherical and cylindrical refractive errors were -3.27+/-0.85D, +1.04+/-0.69D, -0.36+/-0.7D and +0.14+/-0.2D, respectively. UCVA over 20/25 was obtained in 27 eyes (93%). A result within 1.00D of the desired correction was achieved in 90% of the eyes. There were no decreases in BCVA within the study group. The preoperative and postoperative root-mean-square of HOA at 3 months were 0.196+/-0.092 microm and 0.326+/-0.107 microm respectively. The preoperative and postoperative contrast sensitivity values were similar. CONCLUSIONS: The clinical outcomes of LASIK using a solid-state laser system were comparable to the conventional refractive surgery in mild to moderate myopia. The 213 nm solid state laser may be an alternative option for refractive surgery.