Surgical approaches to posterior polar cataract: a review

Chop and tumble nucleotomy - A technique for safe nuclear emulsification in posterior polar cataract

A modified phaco chop technique for nuclear emulsification in posterior polar cataracts with nuclear sclerosis that avoids hydrodissection or nuclear rotation has been described. After performing a vertical chop maneuver to divide the nucleus, two pie-shaped nuclear fragments are removed from either side of the initial chop. The remaining nuclear fragments are then sequentially tumbled toward the center using the second instrument and emulsified while maintaining an intact epinuclear shell, which safeguards the fragile posterior capsule. The technique was successfully performed in 62 eyes of 54 patients with posterior polar cataract and grade II-IV nuclear sclerosis. The Chop and Tumble nucleotomy is a safe and effective technique for phacoemulsification in posterior polar cataracts with nuclear sclerosis, where hydrodissection and nuclear rotation are typically avoided.

Role of preoperative anterior segment optical coherence tomography in identifying intraoperative posterior capsular dehiscence in posterior polar cataract

INTRODUCTION

The presence of preoperative posterior capsular dehiscence in posterior polar cataracts (PPCs) increases the chances of intraoperative posterior capsular rent. Our study aims to demonstrate the efficacy of preoperative anterior segment optical coherence tomography (ASOCT) to predict intraoperative posterior capsular rupture (PCR) in PPC.

MATERIALS AND METHODS

This was an observational study including patients within 25-75 years of age, having PPC, undergoing phacoemulsification. ASOCT was done for evaluating preoperative posterior capsular status and was graded as "intact" or "dehiscent, and eventually ,intraoperative-posterior capsular status was noted.

STATISTICAL ANALYSIS

SPSS (version 27.0) was used, and P value of ≤ 0.05 was considered statistically significant.

RESULTS

ASOCT of 44 eyes had 9 (20.5%) dehiscent posterior capsules and 35 (79.5%) intact. Out of these 9 eyes, 7 (77.8%) had intraoperative PCR and 2 (22.2%) did not. Out of these 35, 34 (97.1%) were actually intact intraoperatively and 1 (2.9%) had intraoperative PCR. The sensitivity and specificity of ASOCT for detecting dehiscence were 94.4% and 87.5%, respectively. The positive and negative predictive values were 97.1 and 77.8, respectively. The diagnostic accuracy of the test was 95.45% with a Chi-square value of 27.01 (P < 0.0001). The diagnostic validity of ASOCT grading for detecting preoperative dehiscence was confirmed. The association between intraoperative PCR and preoperative dehiscence was statistically significant (Chi-square test - P < 0.0001). Our objective was established.

DISCUSSION AND CONCLUSION

The demographics and clinical parameters were comparable with other studies. Two eyes with preoperative dehiscence on ASOCT had intact posterior capsule during surgery. The cause can be a dense opacity with increased optical density causing an obscured a clear capsule view on ASOCT, an artifact defect, giving a false impression of dehiscence. One eye who had nondehiscent PC on ASOCT was found to have PCR on the table, which can be due to an extremely thin PC or tightly adherent polar opacity to the capsule. According to our study, the diagnostic accuracy of ASOCT for detecting preoperative dehiscence was 94.4% (sensitivity)and of nondehiscence was 87.5%(specificity). 97.1% of eyes with dehiscence on ASOCT, had actual posterior capsular rent (positive predictive value). To conclude, ASOCT can be used as a reliable diagnostic modality.

Comparison of the outcomes of phacoemulsification and manual small-incision cataract surgery in posterior polar cataract - A retrospective study

Purpose

To compare the visual outcomes and intraoperative complications between phacoemulsification and manual small-incision cataract surgery (MSICS) in cases of posterior polar cataract (PPC).

Methods

A retrospective study was carried out involving 142 patients (164 eyes) with PPC who underwent cataract surgery between January and December 2017. Data collected include the demographic details, preoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), type of cataract, intraocular pressure, anterior and posterior segment findings, type of surgery performed, intraoperative complications, postoperative UCVA on the first day, UCVA and BCVA at 1 month after surgery, complications, and resurgery details.

Results

In total, 90 patients (107 eyes) underwent phacoemulsification, and 52 patients (57 eyes) underwent MSICS. There was no significant difference in the mean age, sex, and type of PPC between the two groups (P = 0.326, 0.852, and 0.220, respectively). Patients who underwent phacoemulsification had significantly better preoperative BCVA (P = 0.002). The BCVA on first postoperative day and 1 month after surgery was better in the phacoemulsification group than in the MSICS group (P &lt; 0.001 and 0.002, respectively). The overall incidence of posterior capsular rupture (PCR) was 11.6%, which included the 10.3% in phacoemulsification and 14.0% in MSICS. There was, however, no significant difference in the rates of PCR between the two groups (P = 0.506).

Conclusion

Phacoemulsification delivered better postoperative visual outcomes than MSICS in PPC patients, whereas the complication rates were similar between the two groups.

Evolution of manual small-incision cataract surgery from 8 mm to 2 mm - A comprehensive review

Cataract is the most common cause of reversible blindness worldwide, accounting for approximately 50% of blindness worldwide. Cataract surgery is the most common surgical procedure performed in routine ophthalmic practice. It has undergone tremendous evolution, and the incision size has progressively reduced from 10-12 mm in extracapsular cataract surgery (ECCE) to 6-8 mm for manual small-incision cataract surgery (MSICS) and 2.2-2.8 mm in phacoemulsification. In a developing country like India, with a massive backlog of cataract, everyone cannot afford private surgery like phacoemulsification. Moreover, annual maintenance of the machine, cost of foldable IOLs, need for greater skill, learning curve, and difficulty in performing the surgery in mature and brown cataracts are other barriers. Due to these factors, MSICS is the surgery of choice in the developing world, with profound societal and economic benefits and similar visual recovery compared to phacoemulsification. During the last two decades, MSICS gained popularity in developing countries and has undergone tremendous advances. This article aims to review the various techniques of MSICS and how the surgery has evolved over the years, particularly focusing on the current technique of 2-mm MSICS.

Morphological variations influencing the outcomes in posterior polar cataract

Purpose

To study the intraoperative complications and postoperative clinical outcomes in different types of posterior polar cataract (PPC) following phacoemulsification, based on morphological classification.

Methods

All consecutive patients with PPC who underwent phacoemulsification during the study period from 2016 to 2019 were included and sub-grouped based on the morphological characteristics according to Daljit Singh's classification. Intraoperative complications such as posterior capsular rupture (PCR), vitreous loss, nucleus drop, and Postoperative best-corrected visual acuity (BCVA) at day 1 and day 30 were documented.

Results

A total of 388 eyes of 380 patients were included. Eighty nine (22.9%) eyes belonged to type 1, 135 (34.8%) belonged to type 2, 8 (2.1%) belonged to type 3, and 156 (40.2%) belonged to type 4. Thirty-five (9.3%) eyes had intraoperative PCR, with vitreous loss in 21 (60%) eyes, and nucleus/cortex drop in 5 (1.3%) eyes. Six (75%) eyes of type 3, 14 (10.04%) eyes of type 2, 12 (17.7%) eyes of type 4, and 3 (3.4%) eyes of type 1 PPC had PCR. PCR occurred more during the emulsification of the nucleus (18 cases, 51.4%). A significant correlation was seen between intraoperative PCR and type of PPC with a higher incidence in type 3 (P < 0.001). BCVA was found to be significantly worse on day 1 among patients with PCR compared to those who did not and improved well by day 30.

Conclusion

PPC morphology is significantly co-related with the occurrence of PCR, emphasizing the need for careful grading of posterior polar cataracts in predicting the risk of intraoperative complications.

Visual Function in Children With Posterior Lens Opacities Before and After Surgery

PURPOSE

To evaluate the visual function before and after cataract surgery in children with congenital posterior lens opacities as well as the factors associated with a good visual outcome.

DESIGN

Perspective case-series study.

METHODS

Pediatric patients with posterior lens opacities who underwent cataract surgery were recruited in this study. The cataract type, location, area of opacities, and strabismus were examined perioperatively. Moreover, visual acuity, modulation transfer function (MTF), ocular aberrations, and stereopsis were measured before and after cataract surgery.

RESULTS

Sixty-nine eyes of 63 patients were studied. The mean age of patients at surgery was 6.5 ± 2.9 years. Visual function including corrected distance visual acuity (CDVA), MTF cutoff frequency, and ocular aberrations were significantly affected in eyes with posterior lens opacities. Postoperatively, CDVA was significantly improved from 0.81 ± 0.53 logMAR to 0.40 ± 0.40 logarithm of the minimum angle of resolution (logMAR) (P < .001). Thirty-nine patients (56.5%) achieved a final VA of 20/40 or better. Moreover, MTF cutoff values were significantly improved, and total ocular aberrations were decreased after cataract removal (both P < .001). The stereopsis was also improved postoperatively (P < .001). The multivariate analysis of the risk factors for postoperative CDVA showed that worse preoperative CDVA, larger size of lens opacities, and mean keratometry were the risk factors (all P < .05).

CONCLUSIONS

Visual function can be significantly decreased in children with posterior lens opacities, and surgery was effective in improving visual function. Patients with a CDVA of 0.52 logMAR or better, a size of lens opacity <6.5 mm² and smaller mean keratometry had a greater CDVA postoperatively.

Study 1: Evaluation of the signs of deficient posterior capsule in posterior polar cataracts using anterior segment optical coherence tomography

PURPOSE

To systematically observe and analyze the signs of deficient posterior capsule in posterior polar cataracts.

DESIGN

Ambispective observational study.

PARTICIPANTS

Cases with posterior polar cataracts.

METHODS

Eyes with diagnosed posterior polar cataracts were imaged on anterior segment optical coherence tomography (AS-OCT). A detailed assessment was performed to note the morphology of the posterior opacity, posterior capsule, and the common patterns to indicate their abnormality. In addition, generalized observation of the morphology was also performed about intraoperative surgical experiences.

RESULTS

A total of 101 eyes were included. Mean patient age was 52.85 ± 10.72 years. The posterior capsule integrity was identified as intact in 91 eyes and abnormal/deficient in 10 eyes (9 had intraoperative defective capsule). These deficient/abnormal morphologies were classified into 3 categories: conical (n = 2), moth-eaten (n = 5), and (3) ectatic (n = 3). Similarly, depending on the presence of hypoechoic spaces between the opacity and the capsule, remaining posterior polar cataracts were categorized into 2 generalized morphological types: without hypoechoic areas (n = 40) and with hypoechoic areas (n = 51). In the without hypoechoic areas group, 6 cases developed capsular rent; in the with hypoechoic areas group, 1 case developed capsular rent.

CONCLUSIONS

In posterior polar cataracts, the deficient/abnormal capsular morphology could be specifically categorized into 3 categories, conical, moth-eaten, and ectatic types. In addition, to predict the ease of intraoperative separation between the opacity and the capsule, generalized categorization might help in better case management.

Intraoperative posterior polar cortical disc defect: sign of intact posterior capsule

PURPOSE

To describe the incidence and morphological characteristics of posterior polar cortical disc defect (PPCDD) sign observed during phacoemulsification in posterior polar cataract (PPC).

SETTING

Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.

DESIGN

Prospective case series.

METHODS

Sixty-seven eyes of 56 patients with PPC undergoing phacoemulsification were evaluated. Outcome measures were the incidence and characteristics of the intraoperative PPCDD sign, as well as its relation to the intraoperative surgical dynamics and posterior capsule (PC) dehiscence.

RESULTS

Of the 67 eyes evaluated, the PPCDD sign was seen in 86.5% of eyes (58/67). Among these, 93.1% of eyes (54/58) showed a complete disc defect, whereas 6.9% of eyes (4/58) had a partial disc defect with incomplete margins. In the majority of cases (89.6%; 52/58), the PPCDD sign was seen after epinuclear plate and plaque aspiration. Among the 9 eyes that did not show the PPCDD sign, en bloc separation of the plaque and cortical matter from the PC was observed in 2 eyes, the plaque remained adherent to the PC till the end of cortical fiber aspiration in 3 eyes, and intraoperative PC rupture (PCR) was observed during the plaque separation in 4 eyes. The incidence of PCR in eyes without PPCDD sign was significantly higher (44.4% vs 0%; P < .001).

CONCLUSIONS

The visualization of intraoperative PPCDD sign during phacoemulsification in PPC is suggestive of an intact PC and associated with a significantly lower rate of intraoperative PCR as compared with eyes without the PPCDD sign.

Dropped Nucleus during Cataract Surgery in South India: Incidence, Risk Factors, and Outcomes

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.

Elevated level of uric acid in aqueous humour is associated with posterior subcapsular cataract in human lens

IMPORTANCE

Age-related cataract is the leading cause of blindness worldwide. The pathological mechanisms causing this disease remain elusive.

BACKGROUND

To examine the involvement of uric acid (UA) in the pathogenesis of posterior subcapsular cataract (PSC).

DESIGN

Retrospective study and experimental investigation.

PARTICIPANTS

A total of 180 patients with PSC or non-PSC were included.

METHODS

Samples obtained from the patients were used to analyse content of UA and for histochemical examinations. The effects of UA on human lens epithelial cells were also investigated.

MAIN OUTCOME MEASURES

Aqueous humour UA and urate deposits.

RESULTS

The results showed a significant increase of aqueous humour UA in patients with PSC. After adjustment for potential confounders, elevated aqueous humour UA (odds ratio [OR] = 1.45) showed a stronger association with PSC than serum UA (OR = 1.10). Gomori methenamine silver staining revealed in PSC an intense deposit of urates in the lens fibres in equatorial regions, and in subcapsular fibres in posterior regions of the lens. Such staining was not detected in the lens with non-PSC. Treatment with UA-induced senescence and apoptosis in human lens epithelial cells in a dose dependent manner. Our results suggest that the elevated level of UA in aqueous humour causes a deposition of urates in human lens epithelium, which could possibly lead to dysfunction of these cells that generates opacification in PSC.

CONCLUSIONS AND RELEVANCE

These findings indicate the local action of excessive UA in the pathogenesis of PSC. Control of serum UA level could delay the progression of PSC.

Can preoperative anterior segment optical coherence tomography predict posterior capsule rupture during phacoemulsification in patients with posterior polar cataract?

PURPOSE

To determine whether preoperative assessment of posterior capsule integrity using anterior segment optical coherence tomography (AS-OCT) can predict posterior capsule dehiscence in patients with posterior polar cataract having phacoemulsification.

SETTING

Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Pondicherry, India.

DESIGN

Prospective observational study.

METHODS

Patients with posterior polar cataract who had phacoemulsification between October 2012 and November 2013 were included in the study. Preoperative AS-OCT imaging was performed to assess the integrity of the posterior capsule. Anterior segment OCT images of the posterior capsule were graded as "intact" or "dehiscent." Phacoemulsification was performed by the same surgeon who was masked from the AS-OCT findings. The integrity of the posterior capsule was evaluated by the surgeon intraoperatively.

RESULTS

The study comprised 64 eyes of 62 patients. Preoperative AS-OCT showed 8 eyes (12.5%) to have probable posterior capsule dehiscence and 56 eyes (87.5%) to have intact posterior capsules. Intraoperatively, the surgeon noted posterior capsule dehiscence in 5 eyes (7.8%) and an intact posterior capsule in 59 eyes (92.2%). The sensitivity and specificity of AS-OCT for detecting posterior capsule dehiscence was 100% and 94.92%, respectively. The negative predictive value of AS-OCT was 100%.

CONCLUSION

Anterior segment OCT with its high negative predictive value can be used successfully to predict the risk for posterior capsule rupture during phacoemulsification in eyes with posterior polar cataract.

Phacoemulsification with hydrodelineation and OVD-assisted hydrodissection in posterior polar cataract

BACKGROUND

To evaluate the results and complications of phacoemulsification with hydrodelineation and ophthalmic viscosurgical device (OVD)-assisted hydrodissection for posterior polar cataract (PPC).

METHODS

Medical records of 24 eyes from 17 patients with clinical diagnosis of PPC, who underwent phacoemulsification with hydrodelineation and OVD-assisted hydrodissection, were retrospectively reviewed.

RESULTS

The incidence of posterior capsule rupture (PCR) was 16.67% (4/24): 2 cases occurred during epinucleus removal, and 2 cases occurred during OVD removal after the implantation of the intraocular lens into the bag. No nucleus piece or lens materials dropped into the vitreous during cataract surgery, and no obvious postoperative complications were found during follow-up. All patients had improved best-corrected visual acuity (BCVA) 1 month postoperatively.

CONCLUSION

OVD-assisted hydrodissection could be an effective technique in phacoemulsification to reduce the incidence of PCR and achieve satisfactory postoperative outcomes.

Application of 25 MHz B-Scan Ultrasonography to Determine the Integrity of the Posterior Capsule in Posterior Polar Cataract

Purpose

To report the application of 25 MHz B-scan ultrasonography (MHzB) to determine the integrity of the posterior capsule (PC) in posterior polar cataract (PPC).

Methods

Patients with whom PPC was clinically diagnosed using slit lamp microscopy who underwent 25 MHzB before phacoemulsification were retrospectively reviewed. The status of the PC was determined by 25 MHzB before phacoemulsification and confirmed during cataract surgery.

Results

In total, 21 eyes in 14 clinically diagnosed PPC patients were enrolled in this study. Out of 25 MHzB images, 19 PCs were found to be intact, while 2 showed dehiscence before cataract surgery. During phacoemulsification, 17 PCs were observed to be intact, while 4 PCs showed posterior capsule rupture (PCR). These 4 PCR cases included the above 2 eyes, in which preexisting dehiscence was detected by 25 MHzB. The other 2 PCR cases showed high reflectivity between high echoes in posterior opacities and the PC, indicating synechia between the PPC and PC.

Conclusion

This is the first report to show that 25 MHzB can be used to clearly visualize the status of the PC in PPC. These results, in turn, could be used to select the appropriate treatment and to thereby avoid further complications during PPC surgery.

Radiotherapeutic implications of the updated ICRP thresholds for tissue reactions related to cataracts and circulatory diseases

Radiation therapy of cancer patients involves a trade-off between a sufficient tumour dose for a high probability of local control and dose to organs at risk that is low enough to lead to a clinically acceptable probability of toxicity. The International Commission on Radiological Protection (ICRP) reviewed epidemiological evidence and provided updated estimates of 'practical' threshold doses for tissue injury, as defined at the level of 1% incidence, in ICRP Publication 118. Particular attention was paid to cataracts and circulatory diseases. ICRP recommended nominal absorbed dose threshold for these outcomes as low as 0.5 Gy. Threshold doses for tissue reactions can be reached in some patients during radiation therapy. Modern treatment planning systems do not account for such low doses accurately, and doses to therapy patients from associated imaging procedures are not generally accounted for. While local control is paramount, the observations of ICRP Publication 118 suggest that radiation therapy plans and processes should be examined with particular care. The research needs are discussed in this paper.

Anterior segment optical coherence tomography for demonstrating posterior capsular rent in posterior polar cataract

AIMS/PURPOSE

To report the preoperative use of anterior segment optical coherence tomography (AS-OCT) for the determination of pre-existing posterior capsule defect in patients with posterior polar cataract.

METHODS

Three patients presented with posterior polar cataract and were evaluated preoperatively using AS-OCT, revealing in one patient intact posterior capsule and in the other two a pre-existing posterior capsule defect not detectable by slit-lamp evaluation. All patients underwent phacoemulsification and intraocular lens implantation.

RESULTS

Intraoperatively, AS-OCT findings were confirmed after cataract surgery in all patients. No intra- or late postoperative complications were noted.

CONCLUSION

AS-OCT could be an additional useful imaging modality in these patients, essential for surgical planning and patient consultation.