Femtosecond laser assisted cataract surgery (FLACS) offers a level of precision, accuracy and customization that is not possible with manual phacoemulsification (MP). With the increase of patient expectations and premium intraocular lens utilization in the era of refractive cataract surgery, predictability and accuracy has become of utmost importance. FLACS has four main functions: creation of a consistently sized round capsulotomy, treatment of keratometric astigmatism with arcuate incisions, construction of clear corneal incisions, and fragmentation and/or softening of the lens. However, FLACS may have limitations due to suction loss, incomplete capsulotomy or poor pupillary dilation. Patient selection and surgeon experience is critical. This review article will focus on the various platforms available for FLACS, the steps in cataract surgery it can perform, and overall advantages and limitations of the technology.
PURPOSE: To evaluate the defocus curves of 4 presbyopia-correcting intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Goethe University, Frankfurt, Germany. DESIGN: Prospective case series. METHODS: Patients included in the study had bilateral surgery with implantation of diffractive panfocal, diffractive trifocal, segmental refractive (SegRef), or extended-depth-of-focus (EDOF) presbyopia-correcting IOLs. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities, uncorrected intermediate and near visual acuities, distance-corrected intermediate (DCIVA) and near (DCNVA) visual acuities, defocus curve, and spectacle independence were measured. RESULTS: The UDVA and CDVA were not significantly different between groups (P > .05); however, the EDOF group had worse near CDVA (P < .001). The trifocal and EDOF groups showed better DCIVA than the panfocal and SegRef group at 80 cm (P < .001); the EDOF and panfocal groups had comparable DCIVA at 60 cm (P > .05). Defocus curves showed no significant between-group differences from 4 m to 2 m (P > .05). The EDOF group had better visual acuity from 1 m to 67 cm than the trifocal and SegRef groups and better visual acuity than the panfocal group at 1 m (P > .05). Compared with the other IOLs, the panfocal IOL yielded significantly better visual acuity at 50 cm (P < .001) and the EDOF IOL worse visual acuity at 40 cm (P < .01). There was a significant difference in spectacle independence between the panfocal group and EDOF group (P < .05) but no difference between the other groups. CONCLUSIONS: The 4 IOLs provided equally good CDVA. The EDOF IOL yielded slightly better DCIVA but worse DCNVA than the other IOLs. Only the panfocal IOL gave better DCIVA at 50 cm.
PURPOSE: To compare agreement of anterior segment parameter measurements using an intraoperative optical coherence tomography (iOCT) of a femtosecond laser (LenSx) during interface docking to the eye to preoperative Scheimpflug-tomography (Pentacam AXL) and swept-source optical coherence tomography (IOL Master 700). SETTING: Department of Ophthalmology, Goethe University, Frankfurt, Germany. DESIGN: Retrospective study. METHODS: Ninty-five eyes of 66 patients who had planned OCT-guided femtosecond laser-assisted lens surgery were included. Anterior segment measurements were performed in mydriasis prior to surgery using Scheimpflug-tomography and swept-source optical coherence tomography. After surgery iOCT images were analysed using a modification of the FIJI image processing program. Outcome measures included external anterior chamber depth (ACD), central corneal thickness (CCT) and central lens thickness (LT). RESULTS: The ACD measured with the iOCT was -0.011±0.126mm smaller (p=0.389) than with theswept-source OCT and -0.059±0.185mm than with the Scheimpflug-tomography (p=0.003). The swept-source OCT measures a -0.047±0.146mm smaller ACD than the Scheimpflug-tomography (p=0.002). The measurements of CCT using the iOCT and the Scheimpflug-tomography (-0.705±20.837μm, p=0.742) and the LT measurements of swept-source OCT and iOCT (-0.050±0.089mm, p<0.001) show no clinically relevant difference. Just the ACD between the iOCT and the Scheimpflug-tomography shows a clinically relevant difference. CONCLUSION: The comparison of the anterior segment parameters of intraoperative optical coherence tomography with swept-source optical coherence tomography showed no clinically relevant differences regarding the ACD and the lens thickness. However, Scheimpflug-tomography versus intraoperative optical coherence tomography measures a small clinically relevant difference for ACD.
OBJECTIVES: To evaluate the impact of a comprehensive cataract surgery curriculum on the incidence of intraoperative complications. DESIGN: We retrospectively compared the total number of cataract surgeries that the residents performed in all of the teaching sites, and the incidences of intraoperative complications (anterior capsule tear, posterior capsule rent, vitreous loss, anterior vitrectomy, zonular dialysis, iris trauma, hemorrhage, dropped lens fragment, corneal wound burn, incorrect intraocular lens) for the surgeries performed at Massachusetts Eye & Ear by residents in the pre-intervention group (residents graduating in 2004 and 2005), before the implementation of a surgical curriculum, and the residents in the post-intervention group (residents graduating in 2014 and 2015). SETTING: Ophthalmology residency program at a major academic institution. PARTICIPANTS: Residents graduating in 2004, 2005, 2014, and 2015. RESULTS: We reviewed 4373 charts. 2086 of those surgeries were performed at Massachusetts Eye & Ear. The incidence of posterior capsule rent/vitreous loss/anterior vitrectomy was lower in the post-intervention group (1.4% versus 7.7%, p < 0.0001). Other complications were also lower in the post-intervention group. CONCLUSIONS: Implementation of a comprehensive cataract surgery curriculum focusing on pre-operative, intra-operative and post-operative interventions, with an emphasis on patient outcomes resulted in a decrease in the rate of intraoperative complications.
PURPOSE: To ascertain the incidence of unexpected management changes at the postoperative week 1 visit in asymptomatic patients who have had an uncomplicated cataract surgery and a routine postoperative day 1 examination. DESIGN: Retrospective observational study. METHODS: A retrospective chart review was conducted of all cases of cataract extraction by phacoemulsification with intraocular lens insertion performed by the Comprehensive Ophthalmology Service at Massachusetts Eye and Ear between January 1, 2014 and December 31, 2014. The preoperative consultation, operative report, and postoperative day 1 and week 1 (postoperative days 5-14) visits were reviewed. Cases with intraoperative complications, as well as clinical findings at postoperative day 1 requiring close follow-up, were excluded. The main outcome measure was incidence of unexpected management changes at the postoperative week 1 visit after cataract surgery, defined as an unanticipated change in postoperative drops, additional procedures, or urgent referral to a specialty service. RESULTS: Overall, 1938 surgical cases of 1471 patients were reviewed, and 1510 cases (77.9%) underwent uncomplicated phacoemulsification with intraocular lens implantation with a routine postoperative day 1 examination. Of these 1510 cases, 238 (15.8%) reported symptoms at the postoperative week 1 visit, including flashes, floaters, redness, pain, or decreased vision, which warranted an examination. In total, 1272 cases were asymptomatic, and only 11 of these cases (0.9%) had an unexpected management change at postoperative week 1. Eight of 11 patients were asymptomatic steroid responders requiring alteration of their postoperative drops. Two of these patients had an intraocular pressure >30 mm Hg. CONCLUSIONS: Unexpected management changes at the postoperative week 1 timepoint after cataract surgery are rare in asymptomatic patients who have had uncomplicated cataract surgery and a routine postoperative day 1 examination. Limited data are available to outline an optimal postoperative regimen after cataract surgery. The results of this study suggest that postoperative week 1 examinations could potentially be performed on an as-needed basis in the appropriate subgroup of patients after cataract surgery.
PURPOSE: To characterize long-term strabismus outcomes in children in the Infant Aphakia Treatment Study (IATS). METHODS: This study was a secondary data analysis of long-term ocular alignment characteristics of children aged 10.5 years who had previously been enrolled in a randomized clinical trial evaluating aphakic management after unilateral cataract surgery between 1 and 6 months of age. RESULTS: In the IATS study, 96 of 109 children (88%) developed strabismus through age 10.5 years. Half of the 20 children who were orthophoric at distance through age 5 years maintained orthophoria at distance fixation at 10.5 years. Esotropia was the most common type of strabismus prior to age 5 years (56/109 [51%]), whereas exotropia (49/109 [45%]) was the most common type of strabismus at 10.5 years (esotropia, 21%; isolated hypertropia, 17%). Strabismus surgery had been performed on 52 children (48%), with 18 of these (35%) achieving microtropia <10Δ. Strabismus was equally prevalent in children randomized to contact lens care compared with those randomized to primary intraocular lens implantation (45/54 [83%] vs 45/55 [82%]; P = 0.8). Median visual acuity in the study eye was 0.56 logMAR (20/72) for children with orthotropia or microtropia <10Δ versus 1.30 logMAR (20/400) for strabismus ≥10Δ (P = 0.0003). CONCLUSIONS: Strabismus-in particular, exotropia-is common irrespective of aphakia management 10 years following infant monocular cataract surgery. The delayed emergence of exotropia with longer follow-up indicates a need for caution in managing early esotropia in these children. Children with better visual acuity at 10 years of age are more likely to have better ocular alignment.
PURPOSE: To evaluate outcomes of unilateral cataract surgery in children 7 to 24 months of age. DESIGN: Retrospective case series at 10 Infant Aphakia Treatment Study (IATS) sites. PARTICIPANTS: The Toddler Aphakia and Pseudophakia Study is a registry of children treated by surgeons who participated in the IATS. METHODS: Children underwent unilateral cataract surgery with or without intraocular lens (IOL) placement during the IATS enrollment years of 2004 and 2010. MAIN OUTCOME MEASURES: Intraoperative complications, adverse events (AEs), visual acuity, and strabismus. RESULTS: Fifty-six children were included with a mean postoperative follow-up of 47.6 months. Median age at cataract surgery was 13.9 months (range, 7.2-22.9). Ninety-two percent received a primary IOL. Intraoperative complications occurred in 4 patients (7%). At 5 years of age, visual acuity of treated eyes was very good (≥20/40) in 11% and poor (≤20/200) in 44%. Adverse events were identified in 24%, with a 4% incidence of glaucoma suspect. An additional unplanned intraocular surgery occurred in 14% of children. Neither AEs nor intraocular reoperations were more common for children with surgery at 7 to 12 months of age than for those who underwent surgery at 13 to 24 months of age (AE rate, 21% vs. 25% [P = 0.60]; reoperation rate, 13% vs. 16% [P = 1.00]). CONCLUSIONS: Although most children underwent IOL implantation concurrent with unilateral cataract removal, the incidence of complications, reoperations, and glaucoma was low when surgery was performed between 7 and 24 months of age and compared favorably with same-site IATS data for infants undergoing surgery before 7 months of age. Our study showed that IOL implantation is relatively safe in children older than 6 months and younger than 2 years.
Diplopia after cataract extraction is an unexpected outcome for the patient and often a source of confusion for the physician, owing to its relative infrequency. This article reviews the pertinent literature on the subject. Mechanisms include anesthetic myotoxicity, surgical trauma, optical aberrations, cortical disorders in patients with congenital strabismus, and the unmasking of previously unnoticed ocular misalignment. As the population continues to age and cataract extraction is performed in increasing volume, familiarity with this uncommon but important outcome may help to clarify and effectively treat post-cataract-extraction diplopia.
BACKGROUND/AIMS: Prophylactic laser peripheral iridotomy (LPI) is performed in primary angle-closure suspect (PACS) eyes to prevent acute angle-closure attacks. However, accelerated cataractogenesis is a potential risk of the procedure that may result in decreased visual acuity. We aimed to assess the long-term impact of LPI on cataract formation in Chinese PACS. METHODS: In the Zhongshan Angle Closure Prevention Trial, eligible bilateral PACS participants received LPI in one randomly selected eye, while the fellow eye remained untreated. Cataract was graded using the Lens Opacity Classification System III, and progression was defined as an increase in grade by at least two units in any category or cataract surgery. RESULTS: In total, 889 participants were randomly assigned to LPI in one eye only (mean age 59±5 years, 83% female). At 72 months, treated eyes had slightly higher average nuclear grades (p<0.001). However, there were no differences between eyes for predefined cataract progression (cumulative probability at 72 months: 21.2% in LPI vs 19.4% in control, p=0.401) or cataract surgery (1% for both). While LPI-treated eyes had a 10% higher risk of progression over 6 years (HR=1.10 (95% CI 0.88 to 1.36)), this was not statistically significant. Visual acuity at 72 months was similar in treated and untreated eyes (p=0.43). CONCLUSION: Although lenses were graded on average as slightly more opaque in laser-treated eyes, prophylactic neodymium:yttrium-aluminum-garnet LPI did not cause significant cataract progression. Our results suggest that LPI treatment of asymptomatic narrow angles does not increase the risk of developing clinically meaningful cataract worsening over time. TRIAL REGISTRATION NUMBER: ISRCTN45213099.
Importance: Routine preoperative medical testing is not recommended for patients undergoing low-risk surgery, but testing is common before surgery. A 30-day preoperative testing window is conventionally used for study purposes; however, the extent of routine testing that occurs prior to that point is unknown.
Objective: To improve on existing cost estimates by identifying all routine preoperative testing that takes place after the decision is made to perform cataract surgery.
Design, Setting, and Participants: This cross-sectional study assessed preoperative care in a 50% sample of Medicare beneficiaries older than 66 years who underwent ambulatory cataract surgery in 2011. Data analysis was completed from March 2016 to October 2017.
Main Outcomes and Measures: Using ocular biometry as a procedure-specific indicator to mark the start of the routine preoperative testing window, we measured testing rates in the interval between ocular biometry and cataract surgery and compared this with testing rates in the 6 months preceding biometry. We estimated the total cost of testing that occurred between biometry and cataract surgery.
Results: A total of 440 857 patients underwent cataract surgery. A total of 423 710 (96.1%) had an ocular biometry claim before index surgery, of whom 264 514 (60.0%) were female; the mean (SD) age of the cohort was 76.1 (6.2) years. A total of 111 998 (25.4%) underwent surgery more than 30 days after biometry. Among patients with a biometry claim, the mean number of tests/patient/month increased from 1.1 in the baseline period to 1.7 in the interval between biometry and cataract surgery. Although preoperative testing peaked in all patients in the 30 days preceding surgery (1.8 tests/patient/month), the subset of patients with no overlap between postbiometry and presurgery periods experienced increased testing rates to 1.8 tests per patient per month in the 30 days after biometry, regardless of the elapsed time between biometry and surgery. The total estimated cost of routine preoperative testing in the full cohort was $22.7 million; we estimate that routine preoperative testing costs Medicare up to $45.4 million annually.
Conclusions and Relevance: In this study of Medicare beneficiaries, routine preoperative medical testing occurs more often and is costlier than has been reported previously. Extra costs are attributable to testing that occurs prior to the 30-day window preceding surgery. As a cost-cutting measure, routine preoperative medical testing should be avoided in patients with cataracts throughout the interval between ocular biometry and cataract surgery.
PURPOSE: Delaying cataract surgery is associated with an increased risk of falls, but whether routine preoperative testing delays cataract surgery long enough to cause clinical harm is unknown. We sought to determine whether the use of routine preoperative testing leads to harm in the form of delayed surgery and falls in Medicare beneficiaries awaiting cataract surgery. DESIGN: Retrospective, observational cohort study using 2006-2014 Medicare claims. PARTICIPANTS: Medicare beneficiaries 66+ years of age with a Current Procedural Terminology claim for ocular biometry. METHODS: We measured the mean and median number of days between biometry and cataract surgery, calculated the proportion of patients waiting ≥ 30 days or ≥ 90 days for surgery, and determined the odds of sustaining a fall within 90 days of biometry among patients of high-testing physicians (testing performed in ≥ 75% of their patients) compared with patients of low-testing physicians. We also estimated the number of days of delay attributable to high-testing physicians. MAIN OUTCOME MEASURES: Incidence of falls occurring between biometry and surgery, odds of falling within 90 days of biometry, and estimated delay associated with physician testing behavior. RESULTS: Of 248 345 beneficiaries, 16.4% were patients of high-testing physicians. More patients of high-testing physicians waited ≥ 30 days and ≥ 90 days to undergo surgery (31.4% and 8.2% vs. 25.0% and 5.5%, respectively; P < 0.0001 for both). Falls before surgery in patients of high-testing physicians increased by 43% within the 90 days after ocular biometry (1.0% vs. 0.7%; P < 0.0001). The adjusted odds ratio of falling within 90 days of biometry in patients of high-testing physicians versus low-testing physicians was 1.10 (95% confidence interval [CI], 1.03-1.19; P = 0.008). After adjusting for surgical wait time, the odds ratio decreased to 1.07 (95% CI, 1.00-1.15; P = 0.06). The delay associated with having a high-testing physician was approximately 8 days (estimate, 7.97 days; 95% CI, 6.40-9.55 days; P < 0.0001). Other factors associated with delayed surgery included patient race (non-White), Northeast region, ophthalmologist ≤ 40 years of age, and low surgical volume. CONCLUSIONS: Overuse of routine preoperative medical testing by high-testing physicians is associated with delayed surgery and increased falls in cataract patients awaiting surgery.
PURPOSE: To compare the operating room performance of ophthalmology residents trained by traditional wet-lab versus surgical simulation on the continuous curvilinear capsulorhexis (CCC) portion of cataract surgery. SETTING: Academic tertiary referral center. DESIGN: Prospective randomized study. METHODS: Residents who chose to participate and provided informed consent were randomized to preoperative CCC training in the wet lab or on a simulator. Residents completed pre-practice demographic questionnaires including habits of daily living. After completion of their preoperative training (wet lab versus simulator), residents performed their first CCC of the clinical rotation under the direct supervision of an attending physician as part of their standard training at the facility. Residents then completed satisfaction questionnaires regarding their preoperative training. Two attending surgeons reviewed and graded each video of operating room performance. The mean score between the 2 attending physicians was used as the individual performance score for each of the 12 performance criteria. The overall score was calculated as the sum of these 12 individual performance scores (standardized). RESULTS: Ten residents trained in the wet lab and 11 on the simulator. There was no significant difference in overall score between the 2 groups (P=.608). There was no significant difference in any individual score except time (wet-lab group faster than simulator group) (P=.038). CONCLUSIONS: Preoperative simulator training prepared residents for the operating room as effectively as the wet lab. The time to pass the simulator curriculum was predictive of the time and overall performance in the operating room. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
PURPOSE: To determine incidence, risk factors for, and outcomes of dropped nucleus (DN) during cataract surgery. METHODS: This is a matched case-control study at the Aravind Eye Hospital in Madurai, India. Out of 184 consecutive DN cases, 171 were included. The case immediately preceding the DN case by the same surgeon served as matched concurrent control. The proportion of cataract surgeries with DN was calculated with a 95% confidence interval (CI). Conditional logistic regression was used to generate odds ratios for potential risk factors. RESULTS: Among 415,487 consecutive cataract surgeries, incidence risk of DN was 0.044% [95% CI 0.038%, 0.051%], or 0.44 per 1,000 surgeries in 52 months. Significant preoperative risk factors were posterior polar cataract (adjusted odds ratio [aOR] 21.73, p = .003); suspected loose zonules (aOR 8.85, p < .001); older age (aOR 1.57, p = .001); and presence of diabetes mellitus (aOR 1.79, p = .03). Associated intraoperative complications included zonular dialysis (OR 34.49, p < .001), vitreous disturbance (OR 193.36, p < .001), and posterior capsule rent (OR 384.39, p < .001). Phacoemulsification and manual small incision cataract surgery did not significantly differ in DN incidence. DN most commonly occurred during nucleus removal (35.1%) or during/immediately following hydrodissection (24.0%). Visual outcomes of DN were worse than controls on average, but 51.9% achieved visual acuity 20/40 or better at 1 month. CONCLUSIONS: DN occurred rarely, with low absolute risk even when a strong risk factor was present. Nearly all cases followed posterior capsular rent or zonular dialysis, usually with observed vitreous loss. In spite of increased risk of postoperative complications in the DN group, the majority achieved favorable results.
OBJECTIVES: To assess resident cataract surgery outcomes at an academic teaching institution using 2 Physician Quality Reporting System (PQRS) cataract measures, which are intended to serve as a proxy for quality of surgical care. DESIGN: A retrospective review comparing cataract surgery outcomes of resident and attending surgeries using 2 PQRS measures: (1) 20/40 or better best-corrected visual acuity following cataract surgery and (2) complications within 30 days following cataract surgery requiring additional surgical procedures. SETTING: An academic ophthalmology center. PARTICIPANTS: A total of 2487 surgeries performed at the Massachusetts Eye and Ear Infirmary from January 1, 2011 to December 31, 2012 were included in this study. RESULTS: Of all 2487 cataract surgeries, 98.95% achieved a vision of at least 20/40 at or before 90 days, and only 0.64% required a return to the operating room for postoperative complications. Of resident surgeries, 98.9% (1370 of 1385) achieved 20/40 vision at or before 90 days follow-up. Of attending surgeries, 99.0% (1091 of 1102) achieved 20/40 vision at or before 90 days (p = 1.00). There were no statistically significant differences between resident and attending cases regarding postoperative complications needing a return to the operating room (i.e., 0.65%, or 9 of 1385 resident cases vs 0.64%, or 7 of 1102 attending cases; p = 1.00). CONCLUSIONS: Using PQRS Medicare cataract surgery criteria, this study establishes new benchmarks for cataract surgery outcomes at a teaching institution and supplemental measure for assessing resident surgical performance. Excellent cataract outcomes were achieved at an academic teaching institution, with results exceeding Medicare thresholds of 50%. There appears to be no significant difference in supervised trainee and attending cataract surgeon outcomes using 2 PQRS measures currently used by Medicare to determine physician reimbursement and quality of care.
BACKGROUND: Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder characterized by benign hamartomas occurring in multiple organ systems including the brain, kidneys, heart, lungs, liver, skin, and the eyes. Typical retinal findings associated with TSC include astrocytic hamartoma and achromic patch. While rare cases of cataract occurring in the setting of TSC have been reported, this is the first analysis of a large series of individuals with TSC that aims to quantify the frequency of this finding and to describe its clinical and genetic associations. MATERIALS AND METHODS: This is a retrospective chart review of 244 patients from the Herscot Center for Tuberous Sclerosis Complex at the Massachusetts General Hospital who underwent complete ophthalmic examination. We describe the clinical and genetic findings in five individuals with TSC and juvenile cataract. RESULTS: Four of five cases (80%) were unilateral. The cataract was described as having an anterior subcapsular component in 3 of 5 cases (60%). Three individuals (60%) underwent lensectomy with intraocular lens (IOL) implant and two individuals (40%) were observed. Genetic testing revealed a known disease-causing mutation in in 100% of cases. CONCLUSIONS: Recent evidence suggests that mTOR signaling may play a role in cataract formation which could explain the relatively high incidence of juvenile cataract in this population. Juvenile cataract is a potentially under-recognized ocular manifestation of TSC.
Tissue adhesives are gaining popularity in ophthalmology, as they could potentially reduce the complications associated with current surgical methods. An ideal tissue adhesive should have superior tensile strength, be non-toxic and anti-inflammatory, improve efficiency and be cost-effective. Both synthetic and biological glues are available. The primary synthetic glues include cyanoacrylate and the recently introduced polyethylene glycol (PEG) derivatives, while most biological glues are composed of fibrin. Cyanoacrylate has a high tensile strength, but rapidly polymerises upon contact with any fluid and has been associated with histotoxicity. Fibrin induces less toxic and inflammatory reactions, and its polymerisation time can be controlled. Tensile strength studies have shown that fibrin is not as strong as cyanoacrylate. While more research is needed, PEG variants currently appear to have the most promise. These glues are non-toxic, strong and time-effective. Through MEDLINE and internet searches, this paper presents a systematic review of the current applications of surgical adhesives to corneal, glaucoma, retinal, cataract and strabismus surgeries. Our review suggests that surgical adhesives have promise to reduce problems in current ophthalmic surgical procedures.
Intraoperative wavefront aberrometry is a relatively new technology that aims to improve refractive outcomes following cataract surgery by optimizing the spherical power of the intraocular lens implant or calculating the appropriate axis and power of toric lenses during cataract surgery in an aphakic state. This article reviews the literature on intraoperative wavefront aberrometry and provides a critical assessment of the benefits and shortcomings of that technology.
PURPOSE OF REVIEW: Continuous curvilinear manual capsulorhexis is currently the standard of cataract surgery. In the past several years, new technologies have been developed to improve the consistency and safety of capsulorhexis creation. This article reviews the most recent technologies in capsulotomy formation and their advantages and disadvantages. RECENT FINDINGS: Guidance devices, femtosecond laser capsulotomy and precision pulse capsulotomy improve the centration, circularity and precision of anterior capsulorhexis and capsulotomy. These developments show particular promise for complex cataract surgeries, though clinical data on the refractive outcomes and complication rates of these technologies are currently limited and warrant additional investigation. SUMMARY: New technological advances in capsulorhexis help surgeons achieve a more ideal capsulotomy geometry. Whether this translates into more predictable refractive outcomes and safer surgeries remains an area of future study.
Connexins are the structural components of gap junctions and hemichannels that mediate the communication and exchange of small molecules between cells, and between the intracellular and extracellular environment, respectively. Connexin (Cx) 46 is predominately expressed in lens fiber cells, where they function in maintaining the homeostasis and transparency of the lens. Cx46 mutations are associated with impairment of channel function, which results in the development of congenital cataracts. Cx46 gap junctions and hemichannels are closely regulated by multiple mechanisms. Key regulators of Cx46 channel function include Ca and calmodulin (CaM). Ca plays an essential role in lens homeostasis, and its dysregulation causes cataracts. Ca associated CaM is a well-established inhibitor of gap junction coupling. Recent studies suggest that elevated intracellular Ca activates Cx hemichannels in lens fiber cells and Cx46 directly interacts with CaM. A Cx46 site mutation (Cx46-G143R), which is associated with congenital Coppock cataracts, shows an increased Cx46-CaM interaction and this interaction is insensitive to Ca, given that depletion of Ca reduces the interaction between CaM and wild-type Cx46. Moreover, inhibition of CaM function greatly reduces the hemichannel activity in the Cx46 G143R mutant. These research findings suggest a new regulatory mechanism by which enhanced association of Cx46 with CaM leads to the increase in hemichannel activity and dysregulation may lead to cataract development. In this review, we will first discuss the involvement of Ca/CaM in lens homeostasis and pathology, and follow by providing a general overview of Ca/CaM in the regulation of Cx46 gap junctions. We discuss the most recent studies concerning the molecular mechanism of Ca/CaM in regulating Cx46 hemichannels. Finally, we will offer perspectives of the impacts of Ca/CaM and dysregulation on Cx46 channels and vice versa.