Visual Outcome and Complications in White Mature Cataracts after Phacoemulsification

Abstract

PURPOSE:

To identify risk factors and perioperative complications and assess postoperative visual outcome in patients of white mature cataracts undergoing phacoemulsification surgery.

METHODS:

This cross-sectional study was conducted on 46 patients of white mature cataract undergoing phacoemulsification. Preoperatively, a detailed ocular examination was done, and anterior chamber depth (ACD) and lens thickness (LT) were measured on ultrasound biomicroscopy. Intraoperative and postoperative complications (on days 1, 7, and 30) and best-corrected visual acuity on postoperative day 30 were noted.

RESULTS:

The mean age of patients was 60.78 ± 9.001 years. The study group consisted of 41.3% of males and 58.7% of females. 8 (19.56%) cases encountered complications during phacoemulsification surgery. The intraoperative complications were capsulorhexis-related in 5 (10.86%) patients, posterior capsular rent in 2 (4.3%) patients, and 1 (2.17%) case had zonular dialysis. There was no difference in mean ACD and LT in cases who developed complications and those who underwent uneventful surgery (P > 0.05). The commonly observed postoperative complications on day 1 were corneal edema (41.3%), anterior chamber flare (45.65%), and cells (39.13%) which resolved with routine topical medications. All patients showed a significant reduction in postoperative intraocular pressure (P < 0.001). A total of 37 (80.43%) eyes regained vision between 6/6 and 6/9 postoperatively (P < 0.001).

CONCLUSION:

Phacoemulsification surgery is safe in white mature cataract that results in significant visual improvement. Common intraoperative complications are capsule related, while frequently encountered postoperative complications are corneal edema and anterior chamber reaction. Preoperative ACD and LT have no role in predicting intraoperative complications.

Introduction

Cataract is one of the most prevalent ocular conditions that causes treatable blindness.[1] White cataract is a stage of cataract progression described on the basis of its pearly white appearance.[2] This is due to total opacification of the lens matter. A white cataract can be classified into mature, intumescent, and hypermature cataract on the basis of slit-lamp appearance.[3] A white mature cataract is an advanced form of cataract, wherein the lens cortex becomes hydrated and opaque leading to the loss of red fundus reflex.[1] As per the recent estimate by the World Health Organization, 47.8% of global blindness is due to cataract, and South Asian region has a higher prevalence, which includes India comprising approximately 51% of blindness due to cataract.[2] The burden of advanced cataracts (including white mature type) is more in rural India.[4]

Manual small incision cataract surgery (MSICS) and phacoemulsification are commonly adopted techniques to manage cataract. Although phacoemulsification is a preferred approach of cataract surgery, it is not free of complications, particularly when treating white mature cataracts.[5] Making a continuous curvilinear capsulorhexis (CCC) is one of the biggest challenges in white cataracts. Other common complications include difficulty in emulsification of hard nucleus, nucleus drop, postoperative intraocular pressure (IOP) rise, persistent corneal edema, anterior chamber reaction, and cystoid macular edema.

Literature suggests that in cases of white cataract especially of intumescent type, the anterior chamber depth (ACD) is often shallow, due to white bulging lens with raised intralenticular pressure, and lens thickness (LT) usually gets increased, which results in restricted surgical maneuverability during phacoemulsification, leading to damage to ocular structures and compromised visual outcome.[6] We hypothesized that a hydrated white cataractous lens makes phacoemulsification surgery difficult and complicated, thereby affecting the final visual outcome. Therefore, this study was aimed to assess the preoperative risk factors, intraoperative and postoperative complications, and visual outcome in white mature cataract.

Methods

After approval by the Institutional Ethical Committee (IEC: SAIMS/RC/IEC/2021/68) and conducted in adherence to the tenets of Declaration of Helsinki, this cross-sectional study was performed on 46 eyes of 46 patients between September 2021 and March 2022. Patients above 40 years of age having pearly white cataract with absent fundal red reflex (white mature cataract) undergoing phacoemulsification surgery were enrolled for the study. Exclusion criteria included patients <40 years of age; congenital/developmental cataract; traumatic cataract; other types of white cataract (intumescent and hypermature); white mature cataract with obvious ocular comorbidities; and patients having systemic morbidities.

A detailed history was elicited from the patients about the course of visual loss, associated ocular symptoms, treatment history, and past medical history. A complete preoperative ocular examination was carried out that included visual acuity testing, slit-lamp examination of anterior segment, pupillary reaction to light, and IOP measurement by Goldmann applanation tonometer. The white cataracts were classified clinically on the basis of slit-lamp biomicroscopy into mature cataract, intumescent cataract, and hypermature cataract.[3] Only patients having white mature cataract were included in this study. ACD and anteroposterior LT were measured by ultrasound biomicroscopy (UBM) using OPTOS OTI scan 3000, Marlborough, MA, USA. Posterior segment was evaluated using B-scan ultrasonography. Biometry was done to calculate the power of lens to be implanted.

The patients were explained about the treatment options, the details of procedure, and possible complications. Written informed consent was taken from all of them. They were operated under guarded visual prognosis as dense white cataract precluded the preoperative fundus examination.

All surgeries were performed under peribulbar anesthesia by a single surgeon. Two side port incisions were made at 3 and 9 o’clock hours. After staining the anterior capsule with trypan blue dye, 1.4% sodium hyaluronate (Contacare Ophthalmics and Diagnostics, Vadodara, Gujarat, India) cohesive ophthalmic viscosurgical device (OVD) was injected in the anterior chamber. Capsulorhexis was performed using a 26-gauge needle (cystitome) or Utrata forceps. During the procedure, the leaked liquefied lens cortex obscuring capsulorhexis was either aspirated from the anterior chamber or displaced by repeated injection of OVD to improve the view. Frequent and liberal use of OVD helps fulfill the concept of pressurized chamber surgery.[7] The rotation of nucleus was possible without hydroprocedure. Phacoemulsification was done through a clear corneal incision using direct chop technique. A foldable hydrophilic acrylic lens (from Intra Ocular Care Pvt Ltd., Vadodara, Gujarat, India) was implanted in the capsular bag.

Patients were followed up at periodic intervals to record postoperative complications on day 1, day 7, and day 30. Visual acuity and anterior chamber inflammation were recorded on all visits, while IOP was measured on day 7 and day 30. Subjective refraction was performed on day 30. Corneal edema was graded on the basis of Oxford Cataract Treatment and Evaluation Team (OCTET)[8] where + represents transient corneal edema, ++ represents transient corneal edema with Descemet’s membrane folds <10, and +++ represents transient corneal edema with Descemet’s folds >10. The postoperative inflammation was evaluated subjectively on slit lamp by quantifying and grading of aqueous cells and flare in anterior chamber according to the standardization of uveitis nomenclature (SUN) classification.[9] All patients were given routine postcataract surgery treatment in the form of topical antibiotic and prednisolone in tapering dose over a period of 1 month from postoperative day 1 to day 30.

Statistical analysis

Continuous variables were presented as mean ± standard deviation and categorical variables as absolute numbers and percentage. Categorical variables were analyzed using either the Chi-square test or Fisher’s exact test. Continuous variables were assessed using ANOVA or independent Sample’s t-test. P < 0.05 was considered statistically significant.

Results

A total of 46 eyes of 46 patients with white mature cataract were studied. The mean age of patients was 60.78 ± 9.001 years (range: 43–81 years). There were 27 (58.7%) females and 19 (41.3%) males.

A total of 8 cases encountered intraoperative complications [Table 1]. The most common intraoperative complication seen was capsulorhexis-related complications that occurred in 5 (10.86%) patients. 2 (4.3%) cases had Argentinian flag sign, 1 (2.2%) case showed anterior capsular pseudoelasticity, and 2 (4.3%) cases developed rhexis extension. 1 (2.2%) patient had zonular dialysis during nucleus splitting and 2 (4.3%) cases developed posterior capsular rent with vitreous loss. Anterior vitrectomy was done in both these cases, with IOL implantation in-the-bag in 1 case and in the ciliary sulcus in the other. Conversion to MSICS was needed in 4 (8.7%) patients – one patient had rock hard nucleus, one had zonular dialysis, one case encountered posterior capsular rent at the time of nuclear fragmentation, and one developed Argentinian flag sign that extended up to the equator of the lens.

Table 1.

Intraoperative complications in white mature cataract

Intraoperative complications		Frequency (%)
Capsulorhexis-related complications
Argentinian flag sign		2 (4.3)
Anterior capsular pseudoelasticity		1 (2.2)
Rhexis extension		2 (4.3)
Zonules
Zonular dialysis		1 (2.2)
Posterior capsule
Rent with vitreous loss		2 (4.3)

Preoperative ACD and LT were measured on UBM. The mean ACD and LT were 2.56 ± 0.24 mm and 4.33 ± 0.389 mm, respectively [Table 2]. No significant difference was found in ACD and LT between the patients who developed intraoperative complications and those who underwent uneventful surgery (P > 0.05).

Table 2.

Comparison of preoperative anterior chamber depth and lens thickness in patients with and without intraoperative complications

Parameters		ACD (mm), mean±SD		LT (mm), mean±SD
Patients with no intraoperative complication (n=38)		2.571±0.247		4.34±0.393
Patients with intraoperative complication (n=8)		2.49±0.245		4.281±0.402
P		0.46		0.28

ACD: Anterior chamber depth, LT: Lens thickness, SD: Standard deviation

The postoperative complications on day 1, day 7, and day 30 in white mature cataract cases are shown in Table 3.

Table 3.

Postoperative complications on day 1, day 7, and day 30

Anterior segment findings		Day 1, frequency (%)		Day 7, frequency (%)		Day 30, frequency (%)
Corneal edema		19 (41.3)		4 (8.8)		1 (2.2)
Aqueous flare		21 (45.65)		-		-
Aqueous cells		18 (39.13)		-		-

Corneal edema

On postoperative day 1, corneal edema was seen in 19 (41.3%) patients, 11 (23.9%) cases had grade +1 edema, 6 (13.04%) patients developed grade +2, and 2 (4.3%) had grade +3 edema as per the OCTET grading. On postoperative day 7, there was a significant improvement with 4 patients showing corneal edema: 3 (6.5%) cases had grade +1 and 1 (2.2%) grade +2 edema. Only 1 out of 46 (2.2%) patients showed persistent corneal edema (grade +1) on postoperative day 30 who was put on topical hyperosmotic agent (5% sodium chloride eye drop) that resulted in resolution of edema on subsequent follow-up visit (day 45).

Aqueous flare

Flare was detected in 21 (45.65%) patients on postoperative day 1, out of which 9 (19.56%) cases had grade + 1 aqueous flare, 8 (17.3%) had grade + 2 moderate flare, and 4 (8.6%) patients had grade + 3 flare (as per the SUN classification). All patients improved with disappearance of aqueous flare on postoperative day 7.

Aqueous cells

Anterior chamber cells were observed in 18 (39.13%) cases on day 1, out of which 7 (15.2%) patients had grade +0.5 anterior chamber reaction, 6 (10.86%) cases had grade +1, 4 cases (8.6%) had grade +2, and 1 patient (2.2%) had grade +3 anterior chamber reaction (as per the SUN classification). After instilling frequent topical steroid eye drops, the anterior chamber was clear of cells on day 7.

A significant reduction in IOP was observed on postoperative day 7 and day 30 in all the patients following phacoemulsification surgery [Table 4].

Table 4.

Postoperative reduction in intraocular pressure in white mature cataract

IOP (mmHg)		Mean IOP±SD		SE mean		P
Preoperative		16.80±2.391		0.353
Postoperative day 7		15.87±2.587		0.381		<0.001
Postoperative day 30		15.61±2.049		0.302		<0.001

IOP: Intraocular pressure, SD: Standard deviation, SE: Standard error

A significant improvement in visual acuity on day 30 was noted in all patients (P < 0.001) as shown in Table 5.

Table 5.

Comparison between preoperative and postoperative best-corrected logMAR vision

Vision (logMAR)		Mean±SD		SE mean		P
Preoperative		2.36±0.221		0.032		<0.001
Postoperative		0.158±0.177		0.0261

SD: Standard deviation, SE: Standard error

Discussion

White mature cataracts constitute a significant volume of surgical load in ophthalmic practice, especially in the developing countries.[6] They remain India’s primary cause of blindness due to lack of awareness, access, and affordability.[2] Phacoemulsification is a preferred and clinically superior approach for cataract surgery; however, it is not free of complications, particularly in white cataracts.[1,3,10] Even though surgical intervention for cataract can restore vision, it is suggested to operate these cases under a guarded visual prognosis.[11]

In a population-based study, the prevalence of white mature cataract increased with age and was found to be higher in women than men.[12] In our study, 58.2% of cases with white mature cataract were above 60 years of age. In a study done by Chakrabarti and Nazm, the authors have reported maximum prevalence of bilateral mature cataract in population above 60 years.[3]

Increased prevalence of cataract in females has been reported in previous epidemiological studies.[13,14,15] This may be due to the economic, social, and cultural gender differences. It has been suggested that awareness about cataract surgery and its acceptance tended to be more in males as compared to females.[16] Attitudinal barriers like “could manage daily household work,” “see clearly with fellow eye,” and “fear of surgery” were the common reasons of delay in seeking intervention.[17] Moreover, negligence and cultural insensitivity of family members for female’s health needs play a significant role preventing women to access and avail eyecare services.[18,19,20] We also noted female preponderance (27 out of 46 patients) in the present study.

A detailed preoperative evaluation is crucial to obtain a good surgical outcome. One of the challenges faced in cataract surgery, especially phacoemulsification, is the confined dimension of the anterior chamber space.[21] Damage to surrounding delicate structures can affect the final postoperative visual outcome. Of concern is the irreparable loss of corneal endothelial cells, posterior capsule rupture, zonular dehiscence, etc., Literature from the past has suggested that intraocular manipulations with decreased ACD can increase the risk of trauma to ocular structures.[6] Process of cataractogenesis causes an age-related increase in LT, leading to decreased ACD.[22] Praveen et al. found increased anteroposterior LT with advancing age in eyes with cataract.[23] Others have reported a constant increase in LT with age from 4 mm at the age of 20 years to 4.7 mm at the age of 60 years and beyond 4.7 mm after the age of 60 years.[24,25] Therefore, both aging and maturation of cataract lead to axial enlargement of crystalline lens. Upasna et al. found that shallow ACD was associated with higher percentage of endothelial cell loss.[6] They reported that shallow ACD compromises the use of instruments with ease and is likely to cause more thermal damage to the corneal endothelial cells, thereby reducing corneal endothelial cell density. We assessed ACD and LT before surgery in white, mature cataracts and their association with intraoperative complications and did not find any statistically significant (P > 0.05) correlation between them.

One of the most critical steps in phacoemulsification surgery, especially in cases of white cataracts, is continuous curvilinear capsulorhexis (CCC). Radial extensions (or capsular radializations) are more common in any white cataracts, and not only in intumescent cataracts, because of the consistency of the anterior capsule.[26] Further, compromised red reflex in these cases makes it difficult to complete CCC safely.[27] If rhexis is not intact and complete, intraoperative complications like posterior capsule rupture, vitreous loss, and nucleus drop may occur which had been more commonly reported in white mature cataract.[3] A study by Vasavada et al. achieved CCC in 95% of cases; however, they had to enlarge capsulorhexis in 48% of cases using capsulorhexis forceps.[28] Similarly, in our study, the most common intraoperative complications were capsulorhexis related. These cases were managed using Utrata forceps, aspiration of liquefied lens cortex, or converting to MSICS. For achieving a round and regular rhexis, Balyan et al. punctured the anterior capsule for lenticular decompression with 30-gauge needle of insulin syringe in the center to reduce the intralenticular pressure.[27] Ucar suggested the use of anterior chamber maintainer and spiral capsulorhexis.[29] Others have reported the use of endoilluminator, hemocoloration technique, fluorescein staining of the anterior capsule, and techniques such as precision pulse capsulotomy, diathermic capsulotomy, and femtosecond laser-assisted capsulotomy for the successful completion of CCC.[28,30,31,32]

Hydroprocedure is a crucial and important step in phacoemulsification for the free rotation of nucleus within the capsular bag. However, in white mature cataract, it should be performed gently and carefully due to weak posterior capsule.[1] Only minimal hydrodissection with central tapping is adequate in most of the cases.[33] We could achieve free spinning of nucleus in all our cases without hydroprocedures.

In white cataract, the posterior capsule may be thinned out and stretched by the expanded lens cortex.[1,3] As a result, posterior capsule is weak and flaccid with increased laxity of capsule and its bag due to diffuse zonulopathy, which makes it prone for rupture during phacoemulsification, especially during nuclear fragmentation.[10] Moreover, there is an absence of epinuclear cushion protecting the posterior capsule in these cases. Therefore, there is a high risk of posterior capsular rent and zonular dialysis in white mature cataract.[1] Chakrabarti and Nazm reported incomplete capsulorhexis in 28.3% of cases and posterior capsular tear in 2.8% of cases.[3] Similarly, Ermisş et al. reported posterior capsular rupture in 12% of eyes with white mature cataract during phacoemulsification.[1] They recommended using noncohesive viscoelastic in-the-bag posterior to the nucleus to direct the posterior capsule toward the vitreous cavity during phacoemulsification and to keep the surgical zone safe with less posterior capsule fluctuations. In the present study, 2 (4.3%) patients encountered posterior capsular rent with vitreous loss.

Phacoemulsification of hidden hard nucleus within the milky opaque cortex in white mature cataract requires higher ultrasonic energy.[34] Extended use of high energy for a brief surgical time can cause corneal endothelial damage and corneal burns. This increases the probability of postoperative corneal edema. Moreover, it has been suggested that the endothelial cell loss may also occur due to direct trauma to the corneal endothelium via instrumentations and fluid dynamics if the surgery lasts longer.[35] Further, the corneal endothelial cell count decreases with age; therefore, chances of postoperative corneal edema are higher in elderly patients with white mature cataract.[36] Gul et al. reported postoperative outcome in patients of white mature cataract.[37] They observed postoperative transient corneal edema at 1 week in 10 (20%) eyes and persistent corneal edema and corneal burn in 3 (6%) eyes which resolved in 6 weeks. Vasavada et al. noted transient central corneal edema on the 1^st postoperative day in 26% of eyes, which disappeared in 7 days.[35] We found corneal edema in 19 (41.3%) cases on postoperative day 1 that resolved with routine topical postoperative medications.

The presence of aqueous cells and flare is an indication of ocular inflammation. Surgical intervention causes disruption of blood-aqueous barrier and leakage of proinflammatory mediators, although phacoemulsification induces less inflammation than manual surgical techniques.[38] Furthermore, in some white mature cataract cases, due to the presence of hard nucleus, prolonged use of energy and high power may cause postoperative anterior chamber inflammation.[5] A study reported aqueous cells and flare in 9.61% of eyes at 2 weeks of follow-up.[39] Another study found anterior chamber cell score of 1.64 in the mature cataract postoperatively.[1] In our study, aqueous flare was seen in 21 (45.65%) patients and cells in 18 cases (39.13%) on postoperative day 1 that resolved in a week after instillation of corticosteroid eye drops.

The IOP-lowering effect of cataract surgery is known for quite a long time. Kim et al. reported an early postoperative IOP rise followed by a significant fall within few days postoperatively.[40] The authors found that the surgical removal of crystalline lens causes an approximate 50.5% deepening of anterior chamber that results in a significant reduction in IOP after cataract surgery. A significant decrease (P < 0.001) in IOP was observed on postoperative day 7 and day 30 in all 46 cases in the present study.

Quick and correct intraoperative decision-making is crucial in the effective management of cases that encounter surgical complications. In the present cross-sectional study, conversion to MSICS was required in 4 (8.7%) eyes to achieve the best possible postoperative result. A study by Gul et al. evaluated visual outcome and intraoperative complications in white mature cataract.[37] They reported a conversion rate of 10% to extracapsular cataract extraction (ECCE) due to posterior capsular rent. Jacob et al. in their study on white cataract observed a conversion rate of 3.85% to conventional ECCE due to rhexis extension.[41]

Goenka and Rao evaluated the visual outcome in patients of white mature cataract undergoing phacoemulsification and reported that 52 eyes (89.2%) achieved best-corrected visual acuity (BCVA) of 6/6–6/9, while the remaining eyes ranged between 6/18 and 6/12.[39] A significant improvement (P < 0.001) in BCVA was observed on postoperative day 30 as compared to preoperative visual acuity in our study. 37 out of 46 eyes (80.43%) gained BCVA of 6/6–6/9, while in the remaining 9 (19.57%) eyes, the vision was in the range of 6/12–6/18. Despite surgical challenges and uncertain visual results in patients of white mature cataract, a thorough and meticulous preoperative evaluation and correct intraoperative techniques can fetch encouraging results.

There are few limitations of our study. First, it is a single-center research with a small sample size due to prevalent COVID-19 pandemic during that time. Second, white cataracts were classified clinically using slit-lamp biomicroscope. Preoperative A-scan ultrasonography and intraoperative optical coherence tomography were not used for the classification. Third, the anterior chamber inflammation was measured on slit lamp, which is a subjective method with intra- and interobserver variability. A better option would be to use laser flare photometry. Fourth, the patients were followed up for a short postoperative period of 30 days and, therefore, delayed postoperative complications could not be noted. We recommend similar studies on a larger population with long follow-ups to eliminate bias and validate the results.

Conclusion

Phacoemulsification surgery in white mature cataract is safe that results in significant improvement in vision. Commonest complication seen during surgery was lens capsule related, while corneal edema and anterior chamber inflammation were frequently observed postoperative complications. ACD and LT do not have a role in determining the intraoperative complications.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.