Purpose: To assess long-term clinical results following bilateral Tecnis Symfony ZXR00 intraocular lens implantation with mini-monovision. Methods: The medical records of cataract patients who underwent bilateral implantation of ZXR00 with intended mini-monovision (target refraction of –0.3 diopters [D] in dominant eye and –0.6 D in nondominant eye) between April 2019 and March 2021 were assessed. Postoperative uncorrected distance visual acuity (UDVA), corrected distance VA (CDVA), uncorrected intermediate VA (UIVA), uncorrected near VA (UNVA), and rate of spectacle dependence for near distance were investigated at 3 months and 2 years after surgery. Results: This study included 61 patients (122 eyes) with average age of 61.8 ± 7.7 years. At 2 years postoperatively, binocular logarithm of the minimum angle of resolution UDVA, UIVA, UNVA, and CDVA were 0.086 ± 0.094, 0.056 ± 0.041, 0.140 ± 0.045, and 0.012 ± 0.024, respectively. The monocular manifest refraction spherical equivalent was –0.31 ± 0.38 in the dominant eye and –0.53 ± 0.47 in the nondominant eye at 3 months postoperatively, and –0.38 ± 0.43 in the dominant eye and –0.61 ± 0.54 in the nondominant eye at 2 years postoperatively. Eight out of 61 patients (13.1%) needed glasses 3 months after surgery, and nine out of 61 patients (14.8%) needed glasses 2 years after surgery. Conclusions The bilateral implantation of ZXR00s with mini-monovision allows for a good VA at wide range of distance from far to near, thereby resulting in high rate of spectacle independence. These results have held up well even after 2 years after surgery.

Purpose: We aimed to compare the accuracy of the intraocular lens (IOL) calculation formula using the standard keratometry (K) and total K (TK) during the femtosecond laser-assisted cataract surgery (FLACS) with a monofocal IOL with enhanced intermediate function using currently used formulas. Methods: A retrospective review of 125 eyes from 125 patients who had undergone FLACS with implantation of monofocal IOL with enhanced intermediate function was conducted. The predicted refractive power was calculated using an optical biometer (IOLmaster 700) according to the K and TK in the Barrett Universal II, SRK/T, Haigis, and Holladay 2 formulas. Absolute prediction error (APE) obtained from the actual postoperative refractive outcomes and the refractive error predicted in each formula was compared one month after surgery. Results: Mean APE ranged between 0.29 and 0.39 diopters (D) regardless of the calculation formula and the method of measuring corneal curvature. Significant differences were observed in the APE from the four formulas and the two keratometric measurements (p = 0.014). In a total of 125 eyes from 125 patients, the mean APE was lowest with the Barrett Universal II formula. Across all formulas, both the mean APE and the median APE tended to be lower for K than for TK, although there was no significant difference. Approximately 70% to 80% of the patients were included within 0.5 D of the refractive error across all formulas. The percentage of eyes within 0.5 D of APE outcomes was not statistically different between the K and TK data when using each formula. Conclusions Keratometric measurements considering the poster corneal curvature did not show any additional advantages when implanting the monofocal IOL with enhanced intermediate function during the FLACS.

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.

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.

Purpose: To examine the efficacy and biocompatibility of a new artificial cornea using a rabbit model. Methods: Artificial cornea were transplanted into 20 New Zealand white rabbits. The disc-shaped artificial cornea is of diameter 8.0 mm (the core, clear optical zone diameter is 5.0 mm and that of the peripheral skirt 1.5 mm); of thickness 0.5 mm; and is fabricated from PHEMA, PMMA, and PETTA. Transplantation proceeded in two stages; all rabbits were then observed weekly to 12 weeks. Anterior segment photographs were taken, and anterior segment optical coherence tomography and histological analysis performed, to confirm the biocompatibility of the skirt and the extents of cell proliferation in surrounding tissues. Results: Two rabbits were sacrificed for histological examination in weeks 4 and 8 (one each). Four eyes failed because of surgical errors (artificial corneal decentration or excessively thin flaps). Of the 12 eyes for which surgery was technically successful, six (50.0%) maintained the optical zone structure and transparency to 12 weeks. Histology revealed that cells proliferated in the skirt and bound to surrounding tissues. Six eyes (50.0%) evidenced protrusions of the artificial cornea. Conclusions Transplantation of a new artificial cornea into rabbits met with some success (as confirmed anatomically and optically). However, corneal improvement and new surgical techniques are required to increase the success rate. Also, long-term follow-up is needed.

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.

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.
Aberrometry ; Cataract ; Humans ; Pupil ; Surgeons ; Tomography, Optical Coherence

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.
Fatigue ; Female ; Healthy Volunteers ; Humans ; Hyperopia ; Motion Pictures as Topic ; Tears ; Television

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.
Astigmatism ; Cataract* ; Humans ; Incidence ; Intraocular Pressure ; Intraoperative Complications ; Refractive Errors ; Retrospective Studies ; Surgeons ; Sutures ; Visual Acuity ; Wounds and Injuries

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.
Compensation and Redress ; Corneal Pachymetry ; Healthy Volunteers ; Humans ; Intraocular Pressure* ; Manometry ; Photorefractive Keratectomy ; Ultrasonics