The most common goal of cataract surgery is to improve vision, which is achieved by surgically removing the cataractous lens and replacing it with an appropriate intraocular lens (IOL). However, under certain circumstances, lens remnants may persist in the eye after the primary cataract surgery, potentially leading to vision loss due to corneal edema, intraocular inflammation, glaucoma, retinal detachment, and cystoid macular edema (CME).1–3 Therefore, retained lens material after the primary surgery should be removed at a secondary procedure by an anterior approach (in the case of nuclear remnants lodging in the anterior chamber angle) or a pars plana vitrectomy (in the case of nuclear pieces in the vitreous after a breach in the posterior lens capsule).
For this report, the consecutive video-recorded cataract surgeries (n = 210) performed by the author at a single center (Landskrona Hospital, Sweden) between March 17 and July 8, 2014, were retrospectively reviewed. Two cases were identified with significant amounts of retained lens material after the primary surgery that did not require a secondary intraocular surgical intervention. The 2 cases were recruited for a prospective analysis of retinal function and structure to examine whether any untoward effects on the retina had been caused by the retained lens material.
Informed consent was obtained and clinical inves-tigations were performed. Follow-up time ranged between 70 and 100 days. Visual acuity is presented as Snellen acuity. None of the patients developed an increase in intraocular pressure postoperatively.
A 69-year-old man presented at our department in March 2014. At the age of 15, he had suffered blunt occupational trauma to the right eye and since then, a predominantly cortical cataract had been slowly progressing in that eye. At presentation, the corrected distance visual acuity (CDVA) in the eye was 20/25 (Figure 1).
At the age of 20, the patient had suffered a penetrating corneal occupational trauma in the left eye, which healed by spontaneous iridocorneal apposition without the need of surgery. A cataract developed quickly in that eye. After a few weeks, there was no view of the fundus and the CDVA had decreased to hand motion. A progressive and manifest exotropia had also developed over the years. At the time of presentation, a B-scan was performed to rule out a retinal detachment. The patient agreed to attempt cataract surgery in the left eye under topical and intraocular anesthesia. The risk for postoperative double vision was also discussed with the patient prior to surgery.
Surgery in the left eye involved several techniques that are not part of standard phacoemulsification, including the creation of 2 main incisions for better access to cut posterior synechiae and perform a capsulorhexis on a fibrotic damaged anterior lens capsule, phacoemulsification through the 2 main incisions, a breach in the posterior capsule (which may have been preexisting), and placement of a 3-piece IOL in the sulcus (Video 1). Rubbery-like lens remnants that were tightly adherent to a fibrotic capsular fornix were left at the end of surgery to avoid creating a zonular dialysis. These remnants reinforced the IOL stability in the sulcus in the presence of a damaged posterior capsule. Further phacoemulsification would have risked vitreous traction, and therefore the case was concluded despite the retained lens material.
The postoperative treatment included dexamethasone and nepafenac 0.1% eyedrops. The eye was quiet at the first follow-up at 1 week (Figure 2). At 100 days, full-field electroretinography (ERG) showed normal rod and cone function and a multifocal ERG showed normal retinal function across the posterior pole; optical coherence tomography (OCT) did not show signs of CME (Table 1, Figure 3). The CDVA in the left eye had improved to 20/25 with a spherical correction of −0.50 diopter (D). The patient still had a large-angle strabismus but for most activities of daily life was not bothered by diplopia. He was referred for prism correction and evaluation by an orthoptist.
A 51-year-old woman with a history of anisometropic amblyopia in the right eye presented at our department in April 2014 with a unilateral black cataract in the right amblyopic eye; the CDVA was 20/250. The patient denied trauma to the eye or head. During phacoemulsification surgery, insufficient zonular fibers were noted and the capsulorhexis was difficult to control, leading to a radial tear beyond the pupil. A new flap was started with a capsule scissors, but it also tore out. Finally, a large portion (3 clock hours) of remaining flap was cut with the capsule scissors. Hydrodissection was carefully performed. The remainder of the surgery proceeded uneventfully until the nucleus had been emulsified, at which point no definite extension of the 2 tears toward the posterior capsule was noted. To avoid jeopardizing the zonular fibers and capsular bag and causing posterior extension of the tear in the capsulorhexis, an IOL was injected into the bag without prior removal of thick residual lens cortex. The case was thus concluded without removal of the lens cortex.
One day after surgery, the IOL was well centered but the CDVA had decreased to hand motion and there was no view of the fundus due to thick residual cortex across the entire bag. Postoperative treatment included dexamethasone and nepafenac 0.1% eyedrops. Two days after surgery, a planned neodymium:YAG (Nd:YAG) capsulotomy was performed to clear the visual axis; 8 days after surgery, the CDVA had improved to 20/50 with −0.50 D spherical correction. The eye was quiet at follow-up at 1 week after the primary surgery (Figure 4).
At 70 days after surgery, full-field ERG revealed normal rod and cone function and multifocal ERG revealed regular responses across the posterior pole; the OCT did not show signs of CME (Table 1, Figure 5). The CDVA was 20/32.
Retained lens material after complicated cataract surgery may cause significant damage to intraocular tissues, leading to vision loss. Therefore, it is generally recommended that the retained material be removed at a secondary intraocular surgical procedure. The effect of retained lens material will generally depend on its location (anterior or posterior chamber), amount, and type (nucleus or cortex). For example, a nuclear remnant in the anterior chamber angle may cause corneal edema. Regardless of location, nuclear remnants may cause inflammation, glaucoma, and CME. Other potential complications include retinal detachment and premacular membrane. Furthermore, it is widely accepted that cortical or epinuclear remnants are better tolerated by the eye than nuclear remnants.4 Nevertheless, cortical remnants may cause damage such as increased postoperative inflammation and endophthalmitis.1 Inflammation may in turn lead to CME.
The 2 cases described show that under special circumstances in selected cases, lens material may be left inside the eye without causing noticeable damage. Thus, at times it may be better to refrain from further surgery, which may cause problems such as more vitreous traction and inflammation.
After a long-standing (50 years) traumatic cataract with primary damage to the anterior lens capsule and in the presence of a quiet eye preoperatively, it may be assumed that the cataractous lens matter is inert and does not leak protein that might cause potential problems such as phacolytic glaucoma and inflammation. This was subsequently confirmed in Case 1 after surgery; despite the retained lens material, no harmful effects were noted, not even after a detailed assessment of retinal function by electrophysiology. Curiously, the cataractous lens also appeared with a rubbery-like consistency at the time of surgery and was emulsified relatively easily (Video 1).
Retained lens cortex seems less harmful to the eye than nuclear pieces and shows a greater tendency to absorption over time. Nevertheless, a thick cortical remnant may lead to significant postoperative opacity that requires an early planned intervention with Nd:YAG capsulotomy to clear the visual axis, as demonstrated in Case 2.
In both cases, electrophysiological recordings at follow-up did not reveal any definite abnormalities in the affected eyes that had surgery compared with the fellow eyes that were not operated on. In the full-field ERG, amplitudes in the affected eyes were larger than those in the fellow eye, with the exception of cone 30 Hz flicker amplitudes in Case 2, which were only 16% lower than those in the fellow eye. This difference is probably not significant judged by the criteria established by Fishman et al.,5 who concluded that the threshold for significant change of inter-visit ERG responses at a 95% confidence level may be at or above 25% difference. Furthermore, in Case 1, responses were generally slightly larger in the affected left eye than in the fellow eye (right eye), which would be expected in the presence of cataract in the fellow right eye (Table 1, Figure 1). In Case 2, the central multifocal ERG responses were 40% less in the affected right eye than in the fellow eye (left eye), which may have been caused by preexisting amblyopia in the affected right eye.6,7
This study has significant limitations such as a limited number of cases and the lack of preoperative evaluation with electrophysiology and OCT. However, neither OCT nor multifocal ERG would provide meaningful information in an eye with a dense cataract. Furthermore, retained lens material after cataract surgery is a rare complication and at most times, a secondary procedure to remove the lens matter will be necessary for obvious reasons such as inflammation, glaucoma, corneal edema, or CME. The 2 cases presented are unusual as no obvious complications related to the retained lens material occurred and no harmful effects could be identified after a detailed analysis of retinal function and structure. Further study is necessary to demonstrate the frequency and factors associated with such a relatively benign postoperative course in the presence of retained lens material.
To conclude, all cataractous lens material should be removed at the time of the primary surgery. If complications occur during the primary surgery, it may be safer to conclude surgery and plan a secondary intervention to remove the retained lens material, especially if inflammation, glaucoma, corneal edema, or CME occur postoperatively. Such postoperative complications are obviously detrimental to visual function. Remaining cortex (as opposed to nucleus) or lens matter located within the bag or in the sulcus but away from the iris (as opposed to matter located in the chamber angle or on the retina) along with a small amount of retained lens material may be factors associated with a lower risk for these complications. If there are no obvious harmful effects from the retained lens matter, retinal function and structure should be evaluated with electrophysiology and OCT before deciding on secondary surgery to remove the retained lens matter.
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