A rare presentation of esotropia in high myopia in a young adult: a case report.

Esotropia in myopia is an uncommon occurrence. Most common cause of esotropia in high myopic elderly is Heavy Eye Syndrome. An uncommon cause in young adults is Acute Acquired Comitant Esotropia often associated with excessive indulgence in near work. A 21 year old male patient presented with diplopia for one year, more for distance than near and spent more than 8-10 hours for near tasks. Unaided visual acuity in BE was 2/60 and was 6/9 in RE and 6/6 in LE with correction. Prism base cover test revealed 25 BO PD for distance and 20 BO PD for near. Diplopia was seen in all position of gaze. Right Eye Lateral rectus resection 8 mm was done and HPE report revealed features of Lateral rectus Muscle atrophy. It is important to understand the pathogenesis of this entity and consider other possible causes of esotropia in myopia. Key words: Myopia, Esotropia, Comitant, Diplopia.

Femtosecond Laser-Assisted Small Incision Sutureless Intrastromal Lamellar Keratoplasty (SILK) for Corneal Transplantation in Keratoconus.

PURPOSE: To describe a femtosecond laser-assisted small incision sutureless intrastromal lamellar keratoplasty in an eye with severe keratoconus and report on the outcome with a 1-year follow-up. METHODS: A 20-year-old man with a history of keratoconus presented for evaluation at the Tilganga Institute of Ophthalmology, Kathmandu, Nepal. The patient had previously undergone a deep anterior lamellar keratoplasty in the left eye. Examination of the right eye revealed an uncorrected distance visual acuity (UDVA) of counting fingers with a manifest refraction of -5.00 -3.50 × 170, giving a corrected distance visual acuity (CDVA) of 20/80. Thinnest pachymetry was 425 µm and progression of both anterior and posterior corneal elevation tomography and maximum keratometry was noted compared to examination 2 years prior. The VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) was used to prepare the donor and recipient cornea. The donor graft was inserted into the recipient through the 3-mm small incision. No sutures were applied. RESULTS: At 2 weeks postoperatively, UDVA was 20/50 with a manifest refraction of -1.00 -5.00 × 145 (20/32). One year postoperatively, UDVA was 20/80 with a manifest refraction of -2.50 -3.50 × 125 (20/40-2), with the maximum keratometry decreasing from 64.08 to 56.74 diopters. CONCLUSIONS: This femtosecond laser-assisted sutureless intrastromal corneal transplantation technique may provide an option to improve the quality of vision for some patients with keratoconus, affording a simpler postoperative follow-up course compared to traditional anterior lamellar or full-thickness corneal transplantation. [J Refract Surg. 2019;35(10):663-671.].

Small Incision Lenticule Extraction (SMILE) for Hyperopia: 12-Month Refractive and Visual Outcomes.

PURPOSE: To evaluate visual and refractive outcomes of small incision lenticule extraction (SMILE) for hyperopia. METHODS: This was a prospective study of vertex-centered hyperopic SMILE using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D). Lenticule parameters were 6.3- to 6.7-mm diameter, 2-mm transition zone, 30-µm minimum thickness, and 120-µm cap thickness. A standard outcomes and stability analysis was performed for the 12-month data, including contrast sensitivity using the Functional Vision Analyzer. RESULTS: For the 93 eyes treated, last follow-up was 12 months for 72 eyes (77%) and 3 months for 11 eyes (12%), with 10 eyes (11%) lost to follow-up. Attempted spherical equivalent refraction (SEQ) was +5.61 ± 1.21 D (range: +1.00 to +6.90 D) and cylinder was -1.01 ± 0.64 D (range: 0.00 to -3.50 D). For eyes targeted for emmetropia (n = 37), uncorrected distance visual acuity was 20/40 or better in 95% of eyes. SEQ relative to target was -0.17 ± 0.85 D (range: -2.20 to +3.00 D) at 3 months and -0.19 ± 0.90 D (range: -2.07 to +3.50 D) at 12 months with 53% within ±0.50 D. For 70 eyes with data at 3 and 12 months, the mean change in SEQ was -0.06 ± 0.53 D (range: -2.00 to +1.75 D) and the mean change in keratometry was -0.22 ± 0.48 D (range: -1.00 to +1.00 D). There was one line loss of corrected distance visual acuity (CDVA) in 16% of eyes and no loss of two or more lines. There was no clinically significant change in contrast sensitivity. CONCLUSIONS: Refractive and visual outcomes 12 months after SMILE for hyperopia were promising, given the high degree of hyperopia corrected and relatively reduced CDVA in this population. There was good refractive and topographic stability between 3 and 12 months. [J Refract Surg. 2019;35(7):442-450.].

Small Incision Lenticule Extraction for Hyperopia: 3-Month Refractive and Visual Outcomes.

PURPOSE: To evaluate visual and refractive outcomes of small incision lenticule extraction (SMILE) for hyperopia. METHODS: This prospective study of vertex-centered hyperopic SMILE used the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and corrected distance visual acuity (CDVA) of 20/40 or better. Lenticule parameters were 6.3- to 6.7-mm diameter, 2-mm transition zone, 30-µm minimum thickness, and 120-µm cap thickness. Standard outcomes analysis was performed for the 3-month data, including contrast sensitivity using the Functional Vision Analyzer. RESULTS: For 93 eyes treated, 3-month data were available for 82 (88%). Attempted spherical equivalent refraction was +5.62 ± 1.20 D (range: +1.00 to +6.90 D) and cylinder was -0.91 ± 0.68 D (range: 0.00 to -3.50 D). For eyes targeted for emmetropia (n = 36), uncorrected distance visual acuity was 20/40 or better in 89%. Spherical equivalent refraction relative to target was -0.17 ± 0.85 D (range: -2.20 to +3.00 D), with 59% within ±0.50 D and 76% within ±1.00 D. There was one line loss of CDVA in 17% of eyes, and one eye lost three lines (1.2%) but recovered to one line lost at 9 months. There was no clinically significant change in contrast sensitivity. CONCLUSIONS: Refractive and visual outcomes 3 months after SMILE for hyperopia were promising, given the high degree of hyperopia corrected and relatively reduced CDVA in this population. Undercorrection of more than 1.00 D in 5 eyes might be partly explained by latent hyperopia in these young patients. [J Refract Surg. 2019;35(1):24-30.].

Role of laser refractive surgery in cross-subsidization of nonprofit humanitarian eyecare and the burden of uncorrected refractive error in Nepal: Pilot project.

PURPOSE: To establish a refractive surgery unit at Tilganga Institute of Ophthalmology through support from international donations and provide knowledge transfer for doctors and management to make the unit self-sustaining, nonprofit laser refractive surgery, and financial support for other eyecare projects at Tilganga. SETTING: Tilganga Institute of Ophthalmology, Kathmandu, Nepal. DESIGN: Retrospective study. METHODS: A foundation was created to establish a refractive surgery unit using a cost-recovery model; that is, patients are charged according to their financial status to cover running costs, patients without funds to pay for surgery, and other eyecare projects for the underprivileged population of Kathmandu, Nepal. Donations were obtained to fund refurbishment within Tilganga Hospital and purchase equipment and technology. A Nepalese surgeon was selected from Tilganga and completed an 8-month fellowship and proctorship of the first series of surgeries. The refractive surgery unit was opened in January 2012, and the cost-recovery model was evaluated up to December 2016. RESULTS: During the period evaluated, 74.8% of patients were treated at full cost, 17.2% at subsidized cost, and 8.6% free of charge. The refractive surgery unit generated a profit representing 28% of the running cost in this period, which was used to reduce the deficit of the main hospital. Surgical outcomes achieved were comparable to those reported by groups in the developed world. CONCLUSION: A self-sustaining nonprofit laser refractive surgery clinic, operating with high quality, was successfully implemented supported by international donations for initial setup costs and a cost-recovery model thereafter.

Small Incision Lenticule Extraction (SMILE) for Hyperopia: Optical Zone Diameter and Spherical Aberration Induction.

PURPOSE: To evaluate optical zone diameter efficacy and spherical aberration change in hyperopic small incision lenticule extraction (SMILE). METHODS: Prospective study of 60 consecutive hyperopic SMILE procedures using the VisuMax femtosecond laser (Carl Zeiss Meditec, Jena, Germany) and matched LASIK procedures with the VisuMax and MEL 80 excimer (Carl Zeiss Meditec) lasers. Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D). For SMILE, the transition zone was 2 mm and the mean optical programmed zone was 6.37 mm (range: 6.3 to 6.7 mm). Two LASIK control groups (6.5- and 7-mm optical zone) matched for spherical equivalent treated were generated. Both tangential and axial curvature difference maps were generated for each eye at 3 months. A fixed grid and set of concentric circles were superimposed on the difference map to measure the achieved optical zone diameter. RESULTS: Mean attempted spherical equivalent refraction was +5.58 ± 0.95 D (range: +3.20 to +6.50 D) in the SMILE group. By tangential mapping, SMILE programmed at a mean optical zone of 6.37 mm achieved a diameter of 5.03 ± 0.30 mm, similar to 7-mm LASIK (4.96 ± 0.25 mm, P = 0.33) but larger than 6.5-mm LASIK (4.53 ± 0.25 mm, P < .001). By axial mapping, the achieved optical zone diameter was 6.75 ± 0.31 mm for 6.37-mm SMILE, larger than for both 6.5-mm (6.61 ± 0.21 mm) and 7-mm (6.92 ± 0.14 mm) LASIK (P < .01). Spherical aberration changed on average by -0.45 ± 0.22 µm for 6.37-mm SMILE, similar to 7-mm LASIK (-0.50 ± 0.21 µm, P = .29) and less than for 6.5-mm LASIK (-0.69 ± 0.22 µm, P < .001). CONCLUSIONS: The mean achieved optical zone diameter of hyperopic SMILE was found to be larger than the mean achieved optical zone diameter of hyperopic LASIK. Consequently, spherical aberration induction was similar for 6.37-mm SMILE and 7-mm LASIK. [J Refract Surg. 2017;33(6):370-376.].

Small Incision Lenticule Extraction (SMILE) for Hyperopia: Optical Zone Centration.

PURPOSE: To evaluate optical zone centration of hyperopic small incision lenticule extraction (SMILE). METHODS: This prospective study of 60 consecutive hyperopic SMILE procedures used the VisuMax femtosecond laser and matched LASIK procedures with the VisuMax and MEL 80 excimer lasers (Carl Zeiss Meditec AG, Jena, Germany). Inclusion criteria were maximum attempted hyperopic meridian of between +1.00 and +7.00 diopters (D) and astigmatism up to 6.00 D. For SMILE, the optical zone was between 6.3 and 6.7 mm, with a 2-mm transition zone. Two LASIK control groups (6.5- and 7-mm optical zone) were generated matched for spherical equivalent treated. In SMILE, the corneal vertex of the coaxially fixating eye was aligned with the vertex of the curved contact glass. In LASIK, the treatment was centered on the coaxially sighted corneal light reflex (first Purkinje image) with the contralateral eye (Seiler method). A tangential (instantaneous) curvature preoperative to 3 months postoperative difference map was generated for each eye. A fixed grid and set of concentric circles were superimposed on the difference map to measure the offset between the optical zone center and corneal vertex (0,0), and vector analysis was used for comparative analysis. RESULTS: Mean attempted spherical equivalent was +5.61 ± 0.96 D (range: +3.20 to +6.50 D) and mean cylinder was -0.96 ± 0.62 D (range: 0.00 to -2.75 D) in the SMILE group. Mean age was 29 ± 7 years (range: 19 to 52 years) in the SMILE group. Mean centration offset was 0.23 ± 0.15 mm (range: 0 to 0.61 mm) for the SMILE group, 0.33 ± 0.14 mm (range: 0.14 to 0.85 mm) for the 6.5-mm LASIK group, and 0.31 ± 0.19 mm (range: 0.05 to 0.85 mm) for the 7-mm LASIK group. The mean centration offset for SMILE was less than that of both LASIK groups (P < .05). CONCLUSIONS: Optical zone centration of hyperopic SMILE was found to be similar to eye-tracker-centered hyperopic LASIK with the MEL 80 laser. [J Refract Surg. 2017;33(3):150-156.].

Quality control outcomes analysis of small-incision lenticule extraction for myopia by a novice surgeon at the first refractive surgery unit in Nepal during the first 2 years of operation.

PURPOSE: To evaluate the outcomes of small-incision lenticule extraction for myopia using the Visumax femtosecond laser at the first refractive surgery unit in Nepal during the first 30 months of operation. SETTING: Tilganga Institute of Ophthalmology, Kathmandu, Nepal. DESIGN: Retrospective noncomparative case series. METHODS: Consecutive myopic small-incision lenticule extraction procedures by a fellowship-trained surgeon were evaluated. Inclusion criteria were a preoperative spherical equivalent (SE) refraction up to -10.00 diopters (D) and corrected distance visual acuity (CDVA) of 20/20 or better. Outcomes analysis using the Standard Graphs for Reporting Refractive Surgery was performed over a 3-month follow-up. RESULTS: Three-month data were available for 1396 eyes. The mean attempted SE was -5.78 D ± 1.81 (SD) (range -0.96 to -10.00 D) and the mean cylinder, 0.79 ± 0.69 D (range 0.00 to 5.25 D). Postoperatively, the mean SE relative to target was -0.28 ± 0.29 D (range -1.31 to +1.50 D) and was within ± 0.50 D in 80% of eyes and ± 1.00 D in 99% of eyes. The uncorrected distance visual acuity was 20/20 or better in 95% of eyes and 20/25 or better in 99% of eyes. One line of CDVA was lost in 2% of eyes; no eye lost 2 or more lines. There was a small improvement in contrast sensitivity (P < .01). CONCLUSIONS: The outcomes of myopic small-incision lenticule extraction up to -10.00 D performed at the first refractive surgery unit in Nepal by a fellowship-trained surgeon with no corneal refractive surgery experience were as safe and effective as outcomes in previous studies. FINANCIAL DISCLOSURE: Dr. Reinstein is a consultant to Carl Zeiss Meditec AG and has a proprietary interest in the Artemis technology (Arcscan, Inc.) through patents administered by the Center for Technology Licensing at Cornell University, Ithaca, New York, USA. Drs. Pradhan and Carp have travel expenses to conferences paid by Carl Zeiss Meditec AG. No other author has a financial or proprietary interest in any material or method mentioned.

Biomechanical Modeling of Femtosecond Laser Keyhole endokeratophakia Surgery.

PURPOSE: To apply a finite element model to endokeratophakia and evaluate anterior and posterior corneal surface changes. METHODS: Spatial elevation data (Pentacam HR; Oculus, Wetzlar, Germany) were obtained for the front and back corneal surfaces of an eye prior to undergoing an endokeratophakia procedure. These were used to warp a spherical template finite element model of the cornea to create a patient-specific finite element mesh and the initial stress distribution was computed with an iterative approach. The finite element model (Optimeyes; Integrated Scientific Services, Biel, Switzerland) included non-linear elastic characteristics of the stroma. The endokeratophakia procedure was recreated in the model: a donor lenticule (-10.50 diopters [D], 5.75-mm zone, 127-µm thick) was inserted into a lamellar pocket (180-µm deep, 6.25-mm diameter) and two 2-mm small incisions were made at 150° and 330°. Anterior and posterior surfaces, computed by the finite element model, were compared to clinical data to assess accuracy and reliability of finite element modeling. RESULTS: The postoperative axial curvature produced by the model closely resembled the patient data; average curvature was 48.01 D clinically and 48.23 D in the simulation, and corneal astigmatism was 3.01 D clinically and 2.88 D in the simulation. The posterior best-fit sphere elevation map also matched the patient data, replicating inward bulging of the posterior surface by approximately 40 µm. Stress distribution modeling predicted a stress increase by 159.94% ± 73% in the cap and a stress decrease by 32.41% ± 21% in the stromal bed. CONCLUSIONS: Finite element modeling of the cornea reproduced the clinically observed anterior and posterior corneal surface changes following an endokeratophakia procedure. This case sets the stage for further study to refine and yield predictive finite element modeling for the evaluation of corneal refractive surgical procedures.

Femtosecond laser-assisted keyhole endokeratophakia: correction of hyperopia by implantation of an allogeneic lenticule obtained by SMILE from a myopic donor.

PURPOSE: To describe endokeratophakia in which a small incision lenticule extraction (SMILE) lenticule from a myopic patient is implanted into a recipient eye through a small incision to correct hyperopia. METHODS: A 23-year-old aphakic woman presented following cataract surgery to remove a childhood congenital cataract with hyperopia of +12.00 -1.50 × 155, corrected distance visual acuity of counting fingers, and exotropia. A SMILE procedure using the VisuMax femto-second laser (Carl Zeiss Meditec, Jena, Germany) was performed on a donor patient with high myopia and the extracted lenticule was stored (power -10.50 diopter sphere, optical zone 5.75 mm, central lenticule thickness 127 µm). In the recipient eye, a pocket lamellar incision was created using the VisuMax SMILE software. The upper interface was separated and the donor lenticule was inserted through the small incision. RESULTS: One year postoperatively, retinoscopy refraction was +7.50 -3.00 × 150, a spherical equivalent refraction reduction of 5.25 diopters. Mean keratometric power increased by 2.91 diopters. The posterior surface elevation changed significantly with a central bulge into the anterior chamber. Central corneal thickness by Pentacam (Oculus Optikgeräte, Wetzlar, Germany) increased by 121 µm. Central lenticule thickness was 130 µm and central epithelial thickness was 43 µm measured by RTVue OCT (Optovue Inc., Fremont, CA). The cornea remained clear over the 1-year postoperative period. CONCLUSIONS: Endokeratophakia appears to be a viable procedure for correcting hyperopia on the cornea by implantation of an extracted myopic SMILE lenticule from a donor patient. However, posterior surface changes and epithelial remodeling resulted in only 50% of the intended correction. No adverse side effects were observed following implantation of donor tissue for 1 year.