Couching of cataractous lens in microphthalmic eyes with irido-fundal coloboma: revisiting the historical technique.

PURPOSE: Cataract surgery in microphthalmic eyes is challenging due to anatomical restraints, hard bulky nucleus. This series aims to evaluate the safety and efficacy of couching of intraocular lens in irido-fundal coloboma with microphthalmos. SETTING: Tertiary care centre in South India. DESIGN: Retrospective non-comparative study in eyes with irido-fundal coloboma, corneal diameter < 7 mm and brown cataract. Visual acuity less than 6/60 in other eye. METHODS: Anterior chamber entry made, zonules broken and lens dislocated into the vitreous cavity in a controlled manner. Baseline Clinico-demographic details, corrected distance visual acuity (CDVA), Intra-ocular pressure (IOP), corneal diameter, axial length, lens status and post-surgery CDVA, IOP and complications recorded and followed up for atleast 6 months. RESULTS: Fifteen eyes of 15 subjects were evaluated with a mean age 49.4 ± 10.9 years. At baseline, mean IOP 14.5 ± 3.8 mmHg, mean axial length 19.3 ± 0.5 mm, mean corneal diameter was 6.5 ± 0.34 mm and CDVA 2 logMAR which improved to 1.5 logMAR at 3 months (p value 0.002). Transient spike in IOP in 33.3% subjects was medically managed with no significant difference in IOP (p > 0.05) at baseline (14.5 ± 3.8 mmHg), 3 months post-surgery (16 ± 2.8 mmHg) and 6 months post-surgery (14.9 ± 2.5 mmHg). One patient underwent re-couching. No other major complications were noted. CONCLUSION: Couching of cataractous lens is an effective and safe method in microphthalmic eyes with irido-fundal coloboma as last resort procedure, where no other surgical procedure may work. It provides an ambulatory gain of visual acuity in previously non-ambulatory subjects. Corneal measurements help in determining the subset of patients where couching offers viable option.

Effects of crystalline lens rise and anterior chamber parameters on vault after implantable collamer lens placement.

BACKGROUND: To analyze vault effects of crystalline lens rise (CLR) and anterior chamber parameters (recorded by Pentacam) in highly myopic patients receiving implantable collamer lenses (ICLs), which may avoid subsequent complications such as glaucoma and cataract caused by the abnormal vault. METHODS: We collected clinical data of 137 patients with highly myopic vision, who were all subsequent recipients of V4c ICLs between June 2020 and January 2021. Horizontal ciliary sulcus-to-sulcus diameter (hSTS) and CLR were measured by ultrasonic biomicroscopy (UBM), and a Pentacam anterior segment analyzer was used to measure horizontal white-to-white diameter (hWTW), anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV), CLR, and postoperative vault (Year 1 and Month 1). The lens thickness (LT) was determined by optical biometry (IOL Master instrument). The predictive model was generated through multiple linear regression analyses of influential factors, such as hSTS, CLR, hWTW, ACD, ACA, ACV, ICL size, and LT. The predictive performance of the multivariate model on vault after ICL was assessed using the receiver operating characteristic (ROC) curve with area under the curve (AUC) as well as the point of tangency. RESULTS: Average CLR assessed by UBM was lower than the average value obtained by Pentacam (0.561 vs. 0.683). Bland-Altman analysis showed a good consistency in the two measurement methods and substantial correlation (r = 0.316; P = 0.000). The ROC curve of Model 1 (postoperative Year 1) displayed an AUC of 0.847 (95% confidence interval [CI]: 74.19-95.27), with optimal threshold of 0.581 (sensitivity, 0.857; specificity, 0.724). In addition, respective values for Model 2 (postoperative Month 1) were 0.783 (95% CI: 64.94-91.64) and 0.522 (sensitivity, 0.917; specificity, 0.605). CONCLUSION: CLR and anterior chamber parameters are important determinants of postoperative vault after ICL placement. The multivariate regression model we constructed may serve in large part as a predictive gauge, effectively avoid postoperative complication.

Research progress on prediction of postoperative intraocular lens position.

With the progress in refractive cataract surgery, more intraocular lens (IOL) power formulas have been introduced with the aim of reducing the postoperative refractive error. The postoperative IOL position is critical to IOL power calculations. Therefore, the improvements in postoperative IOL position prediction will enable better selection of IOL power and postoperative refraction. In the past, the postoperative IOL position was mainly predicted by preoperative anterior segment parameters such as preoperative axial length (AL), anterior chamber depth (ACD), and corneal curvature. In recent years, some novel methods including the intraoperative ACD, crystalline lens geometry, and artificial intelligence (AI) of prediction of postoperative IOL position have been reported. This article attempts to give a review about the research progress on prediction of the postoperative IOL position.

How much does cataract surgery contribute to intraocular pressure lowering?

PURPOSE OF REVIEW: To review the literature evaluating the effect of cataract surgery on intraocular pressure (IOP) in patients with glaucoma. RECENT FINDINGS: Recent high-quality secondary analyses of large and primary trials continue to show IOP lowering following cataract surgery. Likewise, cataract surgery remains a key treatment for angle closure glaucoma. Some micro-invasive glaucoma surgeries (MIGS) have strong evidence to be performed at the time of cataract surgery. Data clarifying when these surgeries should be combined with cataract surgery is emerging. The mechanism underlying IOP lowering after cataract surgery remains unclear. SUMMARY: Patients who are glaucoma suspects with visually significant cataracts would benefit from cataract surgery alone. Those with mild-moderate damage on 1-2 classes of medications would most likely benefit from additional MIGS. Patients with advanced disease would benefit from cataract surgery and a choice of additional surgery, which depends on disease status and patient factors. Clear lens extraction is becoming a more accepted practice as a primary procedure for patients with angle closure and high IOP or glaucoma. The role of additional MIGS in angle closure needs further study.

Systematic and objective wet-lab testing of instruments for phacoemulsification: new Formalin Quadrant Model.

PURPOSE: To validate an improved wet-lab model for systematic and objective efficiency testing of instruments for phacoemulsification. SETTING: Institute of Medical Engineering, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland. DESIGN: Experimental study. METHODS: Porcine lenses were incubated for different time spans in formalin to simulate different cataract densities. Lenses were cut in quadrants and emulsified in a silicone test chamber. The use of ultrasound was restricted to full occlusion and the minimal power needed to promote emulsification. Equivalence to the surgical situation and cataract consistency were judged by an experienced surgeon. Efficiency was rated by effective phacoemulsification time, liquid consumption, and total surgery time. RESULTS: Formalin incubation times of 2 hours, 1.25 hours, and 0.5 hours were validated for hard, middle-hard, and soft cataracts, respectively. Systematic testing of different fluidics settings revealed the unique opportunities of the improved model: Experiments could be performed by laboratory staff without any surgical experience after a short training, and the model provided results in a fast and reproducible manner. Reduced effective phacoemulsification time, shorter total surgery time, and less liquid consumption were observed with higher fluidics settings, confirming and complementing earlier clinical findings. CONCLUSIONS: The Formalin Quadrant Model can be used to test new designs of instrumentation on different cataract densities or various instrument settings for efficiency. Using a validated cataract substitute, it closely represents the clinical situation and thus renders valid results in a short time. Instruments can be tested and improved profoundly before costly and elaborate clinical trials have to be applied.

Single-Use Lens Compromise During Selective Laser Trabeculoplasty.

PRCIS: Damage to disposable selective laser trabeculoplasty (SLT) lenses correlated with the amount of total laser energy. Furthermore, greater lens damage was associated with diminished patient treatment response. PURPOSE: Disposable SLT lenses have been observed to be damaged during use by laser, potentially affecting therapeutic response. This study sought to identify factors associated with the magnitude of lens damage and its effect on treatment outcomes. PATIENT AND METHODS: We analyzed 113 eyes from 82 patients who underwent SLT between 2020 and 2021 at an American academic medical center. For each procedure, we recorded baseline patient characteristics, procedure settings, physician age (as a possible factor causing laser defocus due to accommodation), and area of lens damage. Treatment response was calculated as the difference between preoperative and postoperative intraocular pressure (IOP). RESULTS: Area of lens damage was associated with greater total laser energy ( r =0.34, P <0.001) and greater mean energy per application ( r =0.37, P <0.001). IOP reduction decreased with increasing lens damage ( r =-0.19, P =0.022). Lens damage was not associated with patient characteristics indicative of glaucoma severity or user settings (physician age and slit lamp used). Greater IOP reduction was associated with higher preop IOP ( r =0.46, P <0.001) and a smaller cup-to-disc ratio ( r =0.22, P =0.036). IOP reduction was not associated with retinal nerve fiber layer thickness, patient age, or the number of glaucoma medications. CONCLUSIONS: Increased laser damage to disposable SLT lenses was associated with diminished treatment effect. The amount of damage was correlated with total and average laser energy, but not patient or physician factors. Overall, these findings call for reconsideration of using disposable SLT lenses as part of routine practice.

Monte-Carlo simulation for calculating phakic supplementary lenses based on a thick and thin lens model using anterior segment OCT data.

BACKGROUND: Phakic lenses (PIOLs, the most common and only disclosed type being the implantable collamer lens, ICL) are used in patients with large or excessive ametropia in cases where laser refractive surgery is contraindicated. The purpose of this study was to present a strategy based on anterior segment OCT data for calculating the refraction correction (REF) and the change in lateral magnification (ΔM) with ICL implantation. METHODS: Based on a dataset (N = 3659) containing Casia 2 measurements, we developed a vergence-based calculation scheme to derive the REF and gain or loss in ΔM on implantation of a PIOL having power PIOLP. The calculation concept is based on either a thick or thin lens model for the cornea and the PIOL. In a Monte-Carlo simulation considering, all PIOL steps listed in the US patent 5,913,898, nonlinear regression models for REF and ΔM were defined for each PIOL datapoint. RESULTS: The calculation shows that simplifying the PIOL to a thin lens could cause some inaccuracies in REF (up to ½ dpt) and ΔM for PIOLs with high positive power. The full range of listed ICL powers (- 17 to 17 dpt) could correct REF in a range from - 17 to 12 dpt with a change in ΔM from 17 to - 25%. The linear regression considering anterior segment biometric data and the PIOLP was not capable of properly characterizing REF and ΔM, whereas the nonlinear model with a quadratic term for the PIOLP showed a good performance for both REF and ΔM prediction. CONCLUSION: Where PIOL design data are available, the calculation concept should consider the PIOL as thick lens model. For daily use, a nonlinear regression model can properly predict REF and ΔM for the entire range of PIOL steps if a vergence calculation is unavailable.

Modeling Cataract Surgery in Mice.

Cataract surgery (CS) is an effective treatment for cataracts, a major cause of visual disability worldwide. However, CS leads to ocular inflammation, and in the long term, it can result in posterior capsular opacification (PCO) and/or lens dislocation driven by the post-surgical overgrowth of lens epithelial cells (LECs) and their conversion to myofibroblasts and/or aberrant fiber cells. However, the molecular mechanisms by which CS results in inflammation and PCO are still obscure because most in vitro models do not recapitulate the wound healing response of LECs seen in vivo, while traditional animal models of cataract surgery, such as rabbits, do not allow the genetic manipulation of gene expression to test mechanisms. Recently, our laboratory and others have successfully used genetically modified mice to study the molecular mechanisms that drive the induction of proinflammatory signaling and LEC epithelial to mesenchymal transition, leading to new insight into PCO pathogenesis. Here, we report the established protocol for modeling cataract surgery in mice, which allows for robust transcriptional profiling of the response of LECs to lens fiber cell removal via RNAseq, the evaluation of protein expression by semi-quantitative immunofluorescence, and the use of modern mouse genetics tools to test the function of genes that are hypothesized to participate in the pathogenesis of acute sequelae like inflammation as well as the later conversion of LECs to myofibroblasts and/or aberrant lens fiber cells.

Vitreous management in Yamane's technique for crystalline lens dislocation: anterior vitrectomy or PPV?

OBJECTIVE: To study the postoperative visual outcomes and surgical complications of anterior/pars plana vitrectomy and concurrent Yamane's IOL fixation for crystalline lens dislocation. METHODS: Fifty-three patients (56 eyes) with crystalline lens subluxation/dislocation were enrolled in this retrospective interventional study. Patients received anterior/pars plana vitrectomy and concurrent Yamane's IOL fixation. Main outcome measures were postoperative BCVA and surgical complications. Proportion of spontaneous PVD and preoperative undetected retinal holes/degeneration (PURH/D) were recorded. RESULTS: Twenty-four eyes were treated with anterior vitrectomy (Group AnV) and 32 eyes with pars plana vitrectomy (Group PPV). Overall incidence of PURH/D was 10.7% (6/56). Spontaneous PVD occurred in 68.8% (24/32) in Group PPV. During six months follow-up, one case of postoperative RRD and one case of choroidal detachment occurred in Group AnV. There was no significant difference between anterior vitrectomy and PPV in the final BCVA and postoperative complications. CONCLUSION: Anterior or pars plana vitrectomy, which are both applicable in YAMANE technique for crystalline lens dislocation, exhibit similar surgical outcomes. Patient's age, PVD status and PURH helps to determine the route of vitrectomy. Pediatric patients might be potential candidates for transcorneal vitreolensectomy. For adult, PURH managed with total vitrectomy and intraoperative lase retinopexy might be beneficial to decrease the incidence of postoperative RRD.

Diagnosis, management, and outcome of an intralenticular foreign body in a dog: A case report.

Background: Intra-lenticular foreign bodies are rare in veterinary medicine and uncommon in human medicine. Approximately 50% of perforating ocular injuries in canines have lenticular involvement. Treatment choices include conservative management and surgical options. Retained intra-lenticular foreign body with delayed removal has not been reported in animals. Case Description: A 3-year-old male neutered Lurcher presented with right-sided ocular discomfort and a sealed full-thickness corneal perforation. The full ophthalmic examination could not be performed at the initial presentation due to miosis. Recrudescence of anterior uveitis was seen post-drug cessation. Re-evaluation of the eye with a mydriatic pupil revealed an intra-lenticular foreign body. Surgical removal via phacoemulsification was performed 8 weeks after the initial perforating injury. The eye remains visual, comfortable, and normotensive 50 months post-operatively. Conclusion: This is the first report of an encapsulated, retained intra-lenticular foreign body with delayed removal in a dog. Mydriasis and repeat examinations are of crucial importance when evaluating eyes post-perforation.

Surgical exposure for vitrectomy in retinopathy of prematurity.

Our purpose was to evaluate the efficacy of lateral canthotomy, sub-tenon anesthesia injection, and the use of modified speculum for gaining adequate surgical exposure during surgery for retinopathy of prematurity (ROP). Fourteen eyes of 10 consecutive patients undergoing microincisional vitrectomy surgery (MIVS) for stage 4 and stage 5 ROP were included. There was a significant widening of the palpebral fissure height and length using this technique. No patient developed a lens injury during the surgery. All the canthotomy incisions completely healed at a four-week follow-up visit. This is a safe and effective technique for increasing surgical exposure in cases of ROP requiring vitrectomy.

Comparison of INTREPID® balanced and hybrid tips on anterior capsule rupture in ex vivo porcine eyes.

Phacoemulsification has emerged as the global standard for cataract surgery, and various novel methods, tools, and agents have promoted surgical efficiency and reduced complications. Conventionally, the phaco tip, which cleaves and aspirates the cataractous lens, has been mainly constructed of metal. In this study, the risk of anterior capsule rupture was evaluated under conditions of different power modes, longitudinal (Mode-L), torsional (Mode-T), or both (Mode-LT), and different aspiration powers (0 or 200 mmHg), using a traditional metal phaco tip (Group-M) or a new phaco tip with a high-strength polymer overmold on the needle edge (Group-P), which was developed to reduce the risk of capsule rupture. One hundred twenty porcine eyes were used for experiments within a setting of typical human physiological intraocular pressure. We found that Group-M showed capsule rupture with a smaller ultrasound power than did Group-P, regardless of power mode or aspiration power. In Group-M, there was no significant difference in risk of capsule rupture among power modes, however in Group-P, capsule rupture was least likely to occur with Mode-T. These results provide useful information for inexperienced ophthalmologists to improve surgical safety.

Traumatic dislocation of the iris into the vitreous cavity with intact lens: a case report.

BACKGROUND: Traumatic aniridia occurs when the iris is extruded from the eye and is often accompanied by lens injuries. However, traumatic aniridia due to dislocation of the iris into the vitreous cavity without lens damage has never been reported. CASE PRESENTATION: A 30-year-old man presented with visual loss and pain for 6 h after a thin wire injured his right eyeball. Ophthalmologic examinations manifested a 2 mm full-thickness corneal laceration and total hyphema. An intact clear lens, healthy attached retina, and almost complete iris tissue in the vitreous cavity were found after resolution of hyphema the next day. Further examination revealed that the defect in the zonule below the corneal wound was the path for the iris to enter the vitreous cavity. The patient opted for nonsurgical treatment until pigment granules and opacity were observed in the vitreous cavity after 50 days. Vitrectomy was performed to remove the dislocated iris. CONCLUSIONS: The presentation of this unique case indicates that the torn iris was displaced to the vitreous cavity with an intact lens and missing local zonula instead of out the corneal laceration after a penetrating injury. The type of injury, mechanism, and force on the spot may contribute to the occurrence of this rare condition. Instead of artificial irises, tinted glasses were more appropriate treatment option for this patient. Peripheral retinal examination was essential in the management of this case. In such cases, the iris in the vitreous cavity should be resected to prevent complications.

Outcomes of lensectomy with glued intraocular lens and factors associated with failure in eyes with spherophakia and glaucoma.

Purpose: To evaluate the outcomes of lensectomy with a glued intraocular lens (IOL) in spherophakic eyes with secondary glaucoma and assess factors associated with failure. Methods: We prospectively evaluated outcomes of lensectomy with glued IOL in 19 eyes with spherophakia and secondary glaucoma (intraocular pressure (IOP) ≥22 mm Hg and/or glaucomatous optic disc damage) between 2016 and 2018. The vision, refractive error, IOP, antiglaucoma medications (AGMs), optic disc changes, need for glaucoma surgery, and complications were assessed. Success was defined as complete when IOP was ≥5 and ≤21 mmHg without AGMs; qualified success as similar IOP with up to 3 AGM; the need for >3AGM/additional surgery for IOP control was considered a failure. Results: Preoperatively, the median (interquartile range: IQR) age was 18 (13.5-30) years. IOP was 16 (14-22.5) mmHg on a median of 3 (2,3) AGMs. Median postoperative follow up was 27.7 months (11.9, 39.7). Postsurgery, most patients achieved emmetropia, with significantly decreased refractive error from a median spherical equivalent of -12.5D to + 0.5D, P < 0.0002. The complete success probability was 47% (95% confidence intervals (CIs): 29-76%) at 3 months and was 21% (8 - 50%) at 1 year and 3 years. The qualified success probability was 93% (82-100%) at 1 year, which reduced to 79% (60-100%) in 3 years. None of the eyes had any retinal complications. The higher number of preoperative AGM was found to be a significant risk factor (p < 0.02) for the failure of complete success. Conclusion: One-third of the eyes had IOP control without the need for AGM postlensectomy with glued IOL. Surgery resulted in significant improvement in visual acuity. The higher number of preoperative AGM was associated with poor glaucoma control after glued IOL surgery.

Intraoperative discovery of lens dislocation in a child with Knobloch syndrome.

We present the case of a 14-year-old boy with a known diagnosis of Knobloch syndrome (KS) referred for bilateral cataract evaluation and possible cataract surgery. At time of initial presentation, no lens subluxation was appreciated, and no phacodonesis was detected on slit lamp biomicroscopy. However, 7-weeks later, on the day of surgery, his right eye was found to have a complete lens dislocation into the vitreous cavity, with no zonule attachment. The left eye did not have subluxated lens; however, intraoperatively, after irrigation into the eye, near complete zonular dialysis was observed. This case highlights the importance of regular follow-up of children with KS.

[Phaco surgery in disorders of the capsular-zonular apparatus of the lens]. / Fakokhirurgiya pri narusheniyakh svyazochno-kapsulyarnogo apparata khrustalika.

The article presents authors' original methods of phaco surgery that can be used in disorders of the capsular-zonular apparatus of the lens. The cataract surgery techniques for lens subluxation developed and introduced into clinical practice allow using the most physiologically correct intracapsular intraocular lens (IOL) fixation in the vast majority of cases. The introduction of femtosecond laser at key stages of phacoemulsification in complicated clinical situations reduces the dependence of the results on the human factor and allows performing removal of complicated cataracts at a qualitatively new level.

Eye trauma from a cat scratch with retention of the claw in the anterior chamber in a dog.

Background: Cat scratches and ocular foreign bodies are frequent reasons for consultation in veterinary ophthalmology. Case Description: We here present an unusual case combining trauma to the cornea and lens by a cat scratch with retention of the claw in the anterior chamber. Management consisted of the removal of the claw, reconstruction of the cornea, and mechanized ablation of the lens by phacoemulsification with implantation of an artificial lens. Conclusion: The progression during the follow-up period was considered satisfactory, with positive responses to visual tests and intraocular pressure within the norms. Only dyscoria and a tear of the endothelium and Descemet membrane, secondary to the trauma, remained.

Tear film dysfunction after clear corneal phacoemulsification in diabetics and non-diabetics.

Purpose: A prospective cohort study was conducted in a tertiary eye care centre to study the incidence of tear film dysfunction and its recovery in diabetics and non-diabetics after clear corneal phacoemulsification. Methods: A total of 50 diabetics and 50 non-diabetics underwent clear corneal phacoemuslfication. Schirmer's I test (SIT), tear film break-up time (TBUT), corneal staining, tear meniscus height (TMH), and ocular surface disease index (OSDI) assessment were done preoperatively, postoperatively at 7 days, 1 month, and 3 months in both groups to assess tear film function. Results: Both groups showed decreased SIT and TBUT values on postoperative Day 7, after which they gradually improved. SIT and TBUT values in diabetics were significantly lower than that in non-diabetics postoperatively (P < 0.001). SIT in non-diabetics reached baseline levels at postoperative 3 months. OSDI scores reached peak levels in both groups on postoperative Day 7, but were higher in diabetics than non-diabetics (P < 0.001). OSDI scores gradually improved over 3 months but remained over baseline levels in both groups. Corneal staining was positive in 22% diabetics and 8% non-diabetics at postoperative Day 7. However, none of the patients had corneal staining at 3 months. Tear meniscus height (TMH) did not reveal any significant difference between the two groups at any time interval. Conclusion: We concluded that tear film dysfunction after clear corneal incision occurs in both groups, but is more severe and recovers more slowly in diabetics than non-diabetics.