Surgical options and clinical outcomes for high myopia.

PURPOSE OF REVIEW: Higher degrees of myopia are currently being treated with refractive surgery. However, there is limited characterization and outcomes data for this cohort. This article aims to review the literature on highly myopic patients who had refractive surgery and present a retrospective analysis of 149 patients (270 eyes) with high to extreme myopia (≤-5.0D SE) who underwent refractive surgery [laser-assisted subepithelial keratomileusis (LASIK), photorefractive keratectomy (PRK), or implantable collamer lense (ICL)] at a single practice. RECENT FINDINGS: There is substantial literature on the efficacy of LASIK, PRK, and phakic intraocular lenses for refractive error correction, but a dearth of studies on patients with high to extreme myopia undergoing different types of refractive surgery. Our study reveals that this cohort of patients has excellent outcomes with minimal complications. SUMMARY: Our study reveals that the average preoperative myopia was highest in ICL patients (-10.03D), followed by PRK (-7.21D), and LASIK (-7.04D) patients. Not surprisingly, eyes with high myopia and thin corneas were offered and elected ICLs for their procedure. Highly myopic patients achieved outcomes consistent with data reported in the literature- average postoperative uncorrected visual acuity was 20/20 for LASIK and ICL eyes and 20/25 for PRK eyes.

Refractive lens exchange - who is getting it, what are they getting, how are they doing?

PURPOSE OF REVIEW: The purpose of this article is to provide a review of the literature on refractive lens exchange and present a retrospective analysis of 55 patients who underwent refractive lens exchange at a single practice. RECENT FINDINGS: Our study substantiates refractive lens exchange as an important option for presbyopic patients, hyperopic patients or patients with extremely high refractive error who desire spectacle independence. SUMMARY: Our study reveals that the refractive lens exchange population is younger than the average cataract population and their primary motivations are to resolve hyperopic or myopic refractive errors, gain spectacle independence, and address near vision loss. A variety of presbyopia-addressing intraocular lens options are available and we present our experience with multifocal, extended depth-of-focus, light-adjustable, and monofocal lenses.

Pilocarpine 1.25% and the changing landscape of presbyopia treatment.

PURPOSE OF REVIEW: Despite affecting approximately 1.8 billion individuals worldwide, until recently, a pharmacologic treatment for presbyopia was not available. This special commentary reviews the treatment of presbyopia with a focus on the recently approved medication Vuity (pilocarpine 1.25%, Allergan, an AbbVie Company). RECENT FINDINGS: Vuity is a re-engineered formulation of pilocarpine 1.25% specifically designed for the treatment of presbyopia. Recently published results from the GEMINI 1 Phase 3 clinical trial reported improvement in distance corrected near vision without significant compromise in distance vision. No unexpected safety findings were reported with mild headache being the most common adverse event. Notably, there were no reported cases of retinal detachment or angle closure during the 30-day phase 3 clinical trials. SUMMARY: Vuity is the first treatment designed and FDA approved to treat the growing presbyopia market. Phase 3 clinical trials demonstrated its ability to improve near vision without significant compromise in distance vision. We recognize this paradigm shift in the treatment of presbyopia and anxiously await additional treatment options for this ubiquitous condition.

Artificial intelligence in cornea, refractive, and cataract surgery.

PURPOSE OF REVIEW: The subject of artificial intelligence has recently been responsible for the advancement of many industries including aspects of medicine and many of its subspecialties. Within ophthalmology, artificial intelligence technology has found ways of improving the diagnostic and therapeutic processes in cornea, glaucoma, retina, and cataract surgery. As demands on the modern ophthalmologist grow, artificial intelligence can be utilized to help address increased demands of modern medicine and ophthalmology by adding to the physician's clinical and surgical acumen. The purpose of this review is to highlight the integration of artificial intelligence into ophthalmology in recent years in the areas of cornea, refractive, and cataract surgery. RECENT FINDINGS: Within the realms of cornea, refractive, and cataract surgery, artificial intelligence has played a major role in identifying ways of improving diagnostic detection. In keratoconus, artificial intelligence algorithms may help with the early detection of keratoconus and other ectatic disorders. In cataract surgery, artificial intelligence may help improve the performance of intraocular lens (IOL) calculation formulas. Further, with its potential integration into automated refraction devices, artificial intelligence can help provide an improved framework for IOL formula optimization that is more accurate and customized to a specific cataract surgeon. SUMMARY: The future of artificial intelligence in ophthalmology is a promising prospect. With continued advancement of mathematical and computational algorithms, corneal disease processes can be diagnosed sooner and IOL calculations can be made more accurate.

The 3-year outcomes of corneal tattooing for severely disfigured corneas.

BACKGROUND: To evaluate the efficacy of corneal tattooing for various clinical applications. METHODS: The medical charts of 62 eyes of 62 patients who underwent corneal tattooing between March 2016 and August 2017 were retrospectively reviewed. The causes of opacity and various methods of corneal tattooing were analyzed. RESULTS: Among our 62 patients, 38 were males and 24 were females. Average age was 48.47 ± 15.30 (range, 12-74) years old. The mean follow-up period was 40.19 ± 2.34 (range, 36-43) months. The most common causes of corneal opacity were ocular trauma (33 eyes, 53.2%), prior retinal surgery (9 eyes, 14.5%), congenital etiologies (8 eyes, 12.9%) and measles (5 eyes, 8.0%). The most common associated ocular findings were strabismus (23 eyes, 37.0%), phthisis bulbi (17 eyes, 27.4%) and band keratopathy (13 eyes, 20.9%). Cosmetic outcomes improved without serious complications in all cases. CONCLUSIONS: Corneal tattooing is a viable option with an expanding set of indications, such as discolored previous corneal tattoos, white pupil due to inoperable cataract with clear cornea and dense corneal opacities in blind eyes. Elective corneal tattooing seems to be a viable and convenient method to improve cosmesis with minimal complications and high patient satisfaction.

Descemet membrane endothelial keratoplasty for endothelial decompensation after previous radial keratotomy.

PURPOSE: To report Descemet membrane endothelial keratoplasty (DMEK) for endothelial decompensation in an eye with previous radial keratotomy. OBSERVATIONS: A history of radial keratotomy may hasten endothelial dysfunction. Previously reported surgical treatments include penetrating kerotoplasty and Descemet stripping automated endothelial keratoplasty. CONCLUSIONS AND IMPORTANCE: DMEK may be successfully used in post-RK eyes with good recovery of visual acuity and patient satisfaction.

Effectiveness of intracorneal ring segments for keratoconus.

PURPOSE OF REVIEW: To review the efficacy of intrastromal corneal ring segments (ICRS) for keratoconus and with other interventions such as contacts lens, keratoplasty, and corneal collagen cross-linking. RECENT FINDINGS: Changes in ICRS thickness and size, combination of procedures, and the adaptation of a more sophisticated classification system have broadened our application of ICRS. Recent studies have shown the long-term efficacy of ICRS in visual acuity, keratometry, and astigmatism. SUMMARY: Studies have demonstrated the short-term and long-term efficacy of ICRS implantation in patients with keratoconus.

Toxic anterior segment syndrome-an updated review.

BACKGROUND: Toxic anterior segment syndrome (TASS) can be a rare complication of anterior segment surgery. Here we reviewed the most recent advances in the understanding of TASS. METHODS: English articles related to TASS were retrieved from "PubMed" using the following keywords; "toxic anterior segment syndrome" or "TASS". The authors of this paper reviewed all the retrieved literature and critical findings were summarized. RESULTS: The onset of TASS can vary from hours to months. The clinical manifestations are also variable. The causes of TASS are broad and continue to expand and could not be elucidated in over half of the reported cases. Prompt and thorough investigation to explore the causes of TASS is critical. Surgeons should be fully aware and updated regarding possible etiologies and make ceaseless efforts to prevent TASS. This effort begins with establishing TASS prevention protocols and regularly training surgical staff. Proper cleaning of surgical instruments is critical and should follow the guidelines set by The American Society of Cataract and Refractive Surgery TASS Task Force. When TASS occurs, sharing information with other ophthalmologists and reporting new causes is crucial for the prevention of outbreaks. CONCLUSIONS: Anterior segment surgeons should be reminded that TASS is mostly preventable by the establishment of TASS prevention protocols, regular surgical staff training and thorough adherence to recommendations for cleaning and sterilizing intraocular surgical instruments.

Effect of Diabetes Mellitus and Metformin on Central Corneal Endothelial Cell Density in Eye Bank Eyes.

PURPOSE: To determine whether metformin use and diabetes mellitus (DM) affect central corneal endothelial cell density (ECD) by examining an eye bank corneal donor database. METHODS: The Lions Eye Institute corneal donor database, which consists of 38,318 corneal samples, was examined. Associations of ECD with metformin use and DM were tested by mixed effects linear models that account for correlations of outcomes between eyes within subjects adjusting for age, intraocular lens status, and glaucoma. Subjects (N = 17,056) with observed ECD counts for both eyes are included for analysis. RESULTS: Average donor age was 56.3 (SD = 15.0). ECD was not associated with metformin use (mean ± SE = 2592 ± 11.9 (N = 1014) versus nonuse [2592 ± 3.0 (N = 16,042), P = 0.302]; further analysis showed that ECD was not significantly associated with metformin use in patients with diabetes. However, metformin use was significantly associated with lower ECD among patients with glaucoma: [2658 ± 50.7 (N = 27) for use versus 2789 ± 19.0 (N = 164) for nonuse, P = 0.018]. The presence of DM was significantly associated with lower ECD 2581 ± 5.6 (N = 4766) for DM versus 2595 ± 3.4 (N = 12,290) for non-DM, P = 0.031). CONCLUSIONS: Lower ECD was associated with DM. Lower ECD was not associated with metformin use except in a subgroup of patients with glaucoma, in which subgroup analysis showed lower ECD. The differences in ECD observed were small and unlikely to affect the suitability for transplantation of donor corneas.

Low recurrence rate of anchored conjunctival rotation flap technique in pterygium surgery.

BACKGROUND: To report the recurrence rate for an anchored conjunctival rotation flap technique in primary pterygium surgery. METHODS: Primary pterygium surgeries performed using anchored conjunctival rotation flap techniques (110 eyes in 110 patients) with a minimum follow-up of 12 months were reviewed. In this technique, a conjunctival flap is rotated to cover the bare sclera and suture-fixated with either 8-0 polyglactin (41 eyes) or 10-0 nylon (69 eyes). The recurrence rate was determined, and the two suture materials utilized were compared. RESULTS: The recurrence rate was 2.71% (3 cases in 110 eyes) when an anchored conjunctival rotation flap technique was used and patients were monitored for 26.40 ± 17.09 months. Interestingly, the recurrences were only observed in polyglactin-sutured eyes. No recurrence was detected in nylon-sutured eyes. No other complications were observed in either group. CONCLUSIONS: The anchored conjunctival rotation flap technique for pterygium surgery has a relatively low recurrence rate. Nylon suture-fixation of the flap was found to be superior to polyglactin suture-fixation in preventing recurrence.

Reversible opacification of hydrophobic acrylic intraocular lens- two cases report.

BACKGROUND: The opacification of the intraocular lens (IOL) can cause significant visual deterioration. It is known that opacity of hydrophobic acrylic IOLs is rare. We report 2 cases of reversible optic opacification of hydrophobic acrylic intraocular lenses (Tecnis ZCB00, Abbott), observed within 2 months after uneventful cataract surgery. CASE PRESENTATION: Case 1: Uneventful cataract surgery was performed on the left eye of an 86-year-old diabetic man with chronic open-angle glaucoma. A hydrophobic acrylic intraocular lens (IOL; Tecnis ZCB00, Abbott, Lake Bluff, IL) was implanted in the bag. Eye drops containing 0.5% levofloxacin and 1.0% prednisolone were used after surgery along with topical anti-glaucoma medications. At 7 weeks postoperative, cloudy, concentric IOL opacification developed, accompanied by decreased visual acuity and increased intraocular pressure. However, the opacification completely disappeared after 9 weeks. Case 2: Uneventful cataract surgery was performed on the left eye of a 72-year-old woman. A hydrophobic acrylic IOL (Tecnis ZCB00) was implanted in the bag. At 2 weeks postoperative, cloudy, concentric IOL opacification developed, accompanied by ocular discomfort. After 4 weeks, opacification and discomfort completely disappeared. CONCLUSIONS: We observed two cases of completely reversible opacification of hydrophobic acrylic IOLs. The exact nature of the transient opacity remains unclear, but an inflammatory origin cannot be completely ruled out.

The effect of ocular biometric factors on the accuracy of various IOL power calculation formulas.

BACKGROUND: To evaluate how differences in ocular biometry affects the Hoffer Q, Holladay 1, SRK/T, and Haigis intraocular lens power calculation formulae predictions. METHODS: This study was performed on 91 eyes of 91 patients who underwent uneventful cataract surgery. Ocular biometry values were measured using the IOL Master 500, and intraocular lens (IOL) power was calculated using the Haigis, Hoffer Q, Holladay 1, and SRK/T formulas. We calculated the expected difference (ED) of each 3rd generation formula from the Haigis formula by subtracting the predicted refraction of the Haigis formula from the predicted refraction of each 3rd generation formula. Post-operative anterior chamber depth (ACD) was measured at 1 month after surgery using the IOL master. We calculated errors of each formula by subtracting predicted from manifest refraction at post-operative 1 month. Correlation analysis was performed between ocular biometry values, formula expectation values, formula errors and absolute formula errors. RESULTS: Multiple regression analysis revealed that preoperative ACD was the only significant factor for ED prediction in all of the 3rd generation formulas. For mean errors, axial length and post-operative 1-month change of ACD (delta ACD) correlated significantly with the errors in all 3rd generation formulas, but not with errors of the Haigis formula. Median absolute error (MedAE) of the formulas were 0.40 D for the Hoffer Q formula, 0.37 D for the Holladay formula, 0.34 D for the SRK/T formula, and 0.41 D for the Haigis formula. The MAE of the formulas were 0.50 ± 0.47 D for the Hoffer Q formula, 0.50 ± 0.50 D for the Holladay formula, 0.47 ± 0.51 D for the SRK/T formula, and 0.50 ± 0.47 D for the Haigis formula. CONCLUSION: Regarding ED between the third generation and Haigis formulas, preoperative ACD demonstrated the greatest influence. Calculating mean absolute errors of the formulas, all IOL formulas showed excellent and comparable accuracy. Post-operative change (delta) of ACD correlated significantly with errors of third generation formulas according to simulated ACD.

Revisiting the Cornea and Trabecular Meshwork Junction With 2-Photon Excitation Fluorescence Microscopy.

PURPOSE: To investigate the collagen and elastin architecture at the junction of the human cornea and trabecular meshwork (TM). METHODS: The cornea, TM, and ciliary body (CB) tendons of unfixed human corneal buttons were imaged with an inverted 2-photon excited fluorescence microscope (FluoView FV-1000; Olympus, Central Valley, PA). The laser (Ti:sapphire) was tuned to 850 nm for 2-photon excitation. Backscatter signals of second harmonic generation and autofluorescence were collected through a 425/30-nm emission filter and a 525/45-nm emission filter, respectively. The second harmonic generation signal corresponds to collagen fibers, and the autofluorescence signal corresponds to elastin-containing tissue. Tissue structure representations were obtained through software-generated reconstructions of consecutive and overlapping (z-stack) images through a relevant sample depth. RESULTS: Collagen-rich CB tendons insert into the cornea between Descemet membrane (DM) and posterior stroma along with elastin fibers originating from the TM. The CB tendons directly abut DM, and their insertion narrows as they course centrally in the cornea, giving a wedge appearance to these parallel collagen fibers. Approximately 260 µm centrally from the edge of DM, the CB tendons fan out and merge with pre-DM collagen. As the CB tendons enter the cornea, they form a dense collagenous comb-like structure orthogonal to the edge of DM and supported by a delicate elastin network of interwoven fibers originating from the TM. CONCLUSIONS: Two-photon excited fluorescence microscopy has improved our understanding of the peripheral corneal architecture. CB tendon insertions in this region may contribute to the radial tears encountered when preparing DM endothelial keratoplasty grafts.