Intraocular lens exchange in patients with negative dysphotopsia symptoms

Dysphotopsia and location of laser iridotomy: a systematic review

This systematic review aimed to clarify the relationship between the location of laser peripheral iridotomy (LPI), a common procedure to prevent or treat angle-closure glaucoma, and the incidence of post-procedure visual disturbances known as dysphotopsias. Understanding this relationship is crucial due to the high frequency of LPIs performed and the significant impact dysphotopsia can have on vision and quality of life. Articles investigating the relationship between LPI location and dysphotopsia in at least five patients were identified via a literature search of OVID MEDLINE (1946-November 19, 2022) and EMBASE (1946-November 19, 2022). Non-comparative and non-English studies were excluded. Studies did not require a control group to be included. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system and Cochrane Risk of Bias 2 (RoB2) tool were used to appraise included studies. Our review included three studies encompassing 1756 eyes from 878 patients. The location of LPI was grouped into superior (604 patients, 889 eyes), inferior (150 patients, 150 eyes), and nasal/temporal (443 patients, 717 eyes). The analysis showed no significant difference in the incidence of any new dysphotopsia types among the location groups post-LPI. Overall, the incidence of lines, ghost images, and blurring significantly increased after LPI, while halos and glare significantly decreased. In conclusion, the current literature suggests that the location of LPI has no significant relationship to the types and rates of dysphotopsia experienced thereafter. While there is a 2-3% risk of linear dysphotopsia after LPI regardless of location, LPI may also resolve pre-existing halos and glare.

Evaluation of a new device to treat negative dysphotopsia

PURPOSE

To evaluate the efficacy and safety of Negative Dysphotopsia (ND) Ring implantation for treating and preventing ND.

SETTING

Multicentric tertiary eye hospitals.

DESIGN

Prospective interventional cohort study.

METHODS

22 patients with ND were enrolled. Eyes with other ocular structural pathologies (corneal, macular, optic nerve head, retinal, neuro-ophthalmological) were excluded. In 15 eyes, the ring was implanted to treat ND (therapeutic group), and in 7 eyes, it was implanted during cataract surgery of the fellow eye as a prophylactic measure (prophylactic group) to prevent the occurrence of ND. Preoperative evaluation included video recording of the patients' complaints aside complete eye examination. Postoperatively, patients were interviewed to confirm resolution of complaints related to ND. The intraoperative difficulties and postoperative adverse events were recorded. A minimum follow-up of 1 year was completed for all eyes.

RESULTS

In the therapeutic group, 14 of 15 eyes (93.3%) patients reported complete resolution of ND on the first postoperative day while 1 patient reported persistence of a smaller and lighter temporal shadow. No ND was reported by any patient in any of the 7 eyes treated prophylactically. No significant adverse intraoperative event was recorded; however, vitreous upthrust was noted in 2 of 22 eyes (9.0%). No permanent drop in visual acuity was recorded in the therapeutic group.

CONCLUSIONS

ND Ring implantation was an easy, safe, and effective approach for both treating and preventing ND.

Peripheral visual field shifts after intraocular lens implantation

PURPOSE

To assess whether intraocular lens (IOL) implantation induces shifts in the peripheral visual field.

SETTING

Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.

DESIGN

Ray-tracing study.

METHODS

Nonsequential ray-tracing simulations were performed with phakic and pseudophakic versions of the same eye model to assess potential shifts in the visual field after IOL implantation. 2 different IOL designs were evaluated and for each design 5 different axial positions and 7 different intrinsic powers were tested. The relation between the physical position of the light source and the location where the retina was illuminated was determined for each eye model. Subsequently, these relations were used to calculate whether the visual field shifts in pseudophakic eyes.

RESULTS

The pseudophakic visual field shift was below 1 degree for central vision in all evaluated models. For peripheral vision, the light rays in the pseudophakic eyes were refracted to a more central retinal location compared with phakic eyes, resulting in a central shift of the peripheral visual field. The magnitude of the shift depended on the IOL design and its axial position, but could be as high as 5.4 degrees towards central vision.

CONCLUSIONS

IOL implantation tends to have little effect on the central visual field but can induce an over 5 degrees shift in the peripheral visual field. Such a shift can affect the perception of peripheral visual complaints.

Dysphotopsias or Unwanted Visual Phenomena after Cataract Surgery

Dysphotopsias are unwanted visual phenomena that occur after cataract surgery. They represent some of the most common reasons for patient dissatisfaction after uncomplicated surgery for cataract phacoemulsification with in-the-bag intraocular lens (IOL) implantation. Depending on the form of the optical phenomenon and the effect it poses on vision, dysphotopsias are divided into positive and negative type. Positive dysphotopsias are usually described by patients as glare, light streaks, starbursts, light arcs, rings, haloes, or flashes of light. Negative dysphotopsias are manifested as an arc-shaped shadow or line usually located in the temporal part of the visual field, similar to a temporal scotoma. In addition to their different clinical manifestations, positive and negative dysphotopsia also have different risk factors. Even though up to 67% of patients may experience positive dysphotopsia immediately after surgery, only 2.2% of the cases have persistent symptoms up to a year postoperatively. Surgical intervention may be indicated in 0.07% of cases. The incidence of negative dysphotopsias is up to 26% of all patients; however, by one year postoperatively, the symptoms usually persist in 0.13 to 3% of patients. For both types of dysphotopsia, preoperative patients' education, accurate preoperative diagnostics, and use of an appropriate IOL design and material is mandatory. Despite all these measures, dysphotopsias may occur, and when noninvasive measures fail to improve symptoms, a surgical approach may be considered.

Intensity simulation of photic effects after cataract surgery for off-axis light sources

Photopsia is a photic phenomenon that can be associated with intraocular lenses after cataract surgery. To calculate the relative light intensity of photic effects observed after cataract surgery at the foveal region as the most sensitive region of the retina, photopsia was simulated using the ZEMAX optical design software. The simulations are based on the Liou-Brennan eye model with a pupil diameter of 4.5 mm and incorporating implanted IOLs. The hydrophilic IOLs implanted in the eye model have a power of 21 diopter (D) with an optic diameter of 6 mm and 7 mm. Four different intensity detectors are located in specific regions of the eye in this simulation. The ray-tracing analysis was carried out for variations of incident ray angle of 0° to 90° (temporally) in steps of 1°. Depending on the range of incident ray angle, the light intensity was detected at detectors located on the fovea, nasal side of the retina, or the edge surface of the IOLs. Some portion of the input light was detected at specific incident angles in the foveal region. By altering the IOLs edge design to a fully reflective or anti-reflective surface, the range over which the light intensity is detected on the fovea can be shifted. Additionally, with the absorbing edge design, no intensity was detected at the foveal region for incident ray angles larger than 5°. Therefore an absorbing edge design can make photic effects less disturbing for patients.

Simulation of photic effects after cataract surgery for off-axis light sources

Photopsia is a phenomenon that sometimes disturbs patients after cataract surgery. To evaluate the impact of the edge design of intraocular lenses (IOL) on the location, shape and relative intensity of photic effects at the retina caused by photopsia in pseudophakic eyes, photopsia was simulated using ZEMAX software. The structural parameters of the pseudophakic eye model are based on the Liou-Brennan eye model parameters with a pupil diameter of 4.5 mm. The IOLs implanted in the eye model have a power of 21 diopter (D) with optical diameter of 6 mm and 7 mm. From the ray-tracing analysis, covering variations of incident ray angle of 50° to 90° from temporally, a photic image is detected at the fovea at specific ray angles of 77.5° (6 mm IOL) and 78.2° (7 mm IOL). This photic image disappears when a thin IOL with an edge thickness of 0 mm or a thick IOL with absorbing edges is replaced in the eye model. With an anti-reflective edge, this photic image remains, but with a fully reflecting edge it disappears at the critical angles and appears with different shapes at other angles. The intensity of this photic image can be reduced by changing the edge design to a frosted surface. Most of the photic patterns in IOLs are not observed with absorbing and thin edge designs. IOLs with anti-reflecting and fully reflecting edges generate disturbing photic effects at different angles on the fovea. IOLs with frosted edges reduce the contrast of the photic effects and make them less disturbing for patients.

Evaluation of intraocular lens position and retinal shape in negative dysphotopsia using high-resolution magnetic resonance imaging

PURPOSE

To assess potential relationships of intraocular lens (IOL) position and retinal shape in negative dysphotopsia (ND).

SETTING

Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.

DESIGN

Case-control study.

METHODS

High-resolution ocular magnetic resonance imaging (MRI) scans were performed in patients with ND and pseudophakic controls, and subsequently used to determine the displacement and tilt of the in-the-bag IOL about the pupil and iris. In addition, anterior segment tomography was used to assess the iris-IOL distance. Furthermore, the retinal shape was quantified from the MRI scans by fitting an ellipse to the segmented inner boundary of the retina. Both the IOL position and retinal shape were compared between groups to assess their potential role in the etiology of ND.

RESULTS

In total, 37 patients with ND and 26 pseudophakic controls were included in the study. The mean displacement and tilt of the IOL were less than 0.1 mm and 0.5 degrees, respectively, in both groups and all directions. The corresponding mean iris-IOL distance was 1.1 mm in both groups. Neither of these values differed statistically significantly between groups (all P values >.6). The retinal shape showed large variations but was not statistically significantly different between the groups in both the left-right (P = .10) and the anterior-posterior (P = .56) directions.

CONCLUSIONS

In this study, the in-the-bag IOL position and retinal shape did not statistically significantly differ between patients with ND and the general pseudophakic population. Given the large variation in retinal shape between subjects, however, it could still be an important factor in a multifactorial origin of ND.

Distinct differences in anterior chamber configuration and peripheral aberrations in negative dysphotopsia

Clinical evaluations combined with ray-tracing analyses in patients with negative dysphotopsia supported the role of an increased angle κ.

Purpose:

To provide insights into the anatomical characteristics associated with negative dysphotopsia using quantitative clinical data.

Setting:

Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.

Design:

Case-control study.

Methods:

Anterior chamber tomography and peripheral aberrometry were measured in 27 pseudophakic patients with negative dysphotopsia and 30 pseudophakic control subjects. Based on these measurements, the total corneal power, anterior chamber depth, pupil location and diameter, iris tilt, and peripheral ocular wavefront up to 30 degrees eccentricity were compared between both groups. In addition, ray-tracing simulations using pseudophakic eye models were performed to establish a connection between these clinical measurements and current hypotheses on the etiology of negative dysphotopsia.

Results:

Twenty-seven patients with negative dysphotopsia and 25 pseudophakic controls were included in the analysis. The patients with negative dysphotopsia had a smaller (P = .03/P = <.01) and more decentered (P < .01) pupil than that of the pseudophakic controls. In addition, an increased temporal-tilted iris (P < .01) and an asymmetric peripheral aberration profile were observed in patients with negative dysphotopsia, of which the latter was also apparent in several ray-tracing models. The combination of these in vivo results and ray-tracing simulations indicated that patients with negative dysphotopsia had a temporal-rotated eye, which confirmed the hypothesized relation between negative dysphotopsia and an increased angle κ.

Conclusions:

Patients with negative dysphotopsia had a smaller pupil and an increased angle κ, which made them more susceptible to experiencing a shadow in the temporal visual field.

Incidence and causes of negative dysphotopsia after uncomplicated cataract surgery - A randomized clinical trial

Purpose:

The purpose of this study is to find incidence of negative dysphotopsia (ND) in eyes undergoing clear corneal phacoemulsification and identify its causes including corneal wound hydration and type of intraocular lens (IOL).

Methods:

In this randomized clinical trial, consenting adult patients undergoing phacoemulsification were randomized to receive a hydrophobic (Alcon Acrysof^® SN60WF) or a hydrophilic acrylic IOL (CT Asphina^® 603P, Carl Zeiss Meditec) in a 1:1 ratio. At time of surgery, eyes were again randomized in 1:1 fashion to receive stromal wound hydration or not (n = 80 each in four groups). Primary outcome measure was the incidence of ND between eyes receiving stromal hydration versus no hydration. Those with ND were observed for 5 years after surgery.

Results:

Of the 320 eyes, 29 (9.06%) reported ND of which 24 (83%) were transient. Eyes with wound hydration had significantly higher proportion of ND (n = 21/160, 13%) compared to no hydration (n = 8/160, 5%) (P = 0.01). Additionally, eyes with wound hydration were three times more likely to experience ND (odds ratio = 3.29, 95% CI = 1.3–8.2, P = 0.01). Majority of eyes (20/21, 95%) with ND after hydration had it transiently while half (4/8, 50%) of those with ND without wound hydration had it persistently at 6 weeks (P < 0.001) and continued to experience ND for 5 years but did not request intervention.

Conclusion:

ND occurred in 9% cases with majority being transient. Corneal wound hydration led to significant higher likelihood of experiencing transient ND. Those with persistent ND for more than 6 weeks (1.5%) continue to experience ND for at least 5 years.

Pseudophakic negative dysphotopsia and intraocular lens orientation: a prospective double-masked randomized controlled trial

PURPOSE

To determine whether horizontal orientation of the intraocular lens optic-haptic junctions has an effect on the incidence of pseudophakic negative dysphotopsia.

METHODS

Single-centre prospective double-masked randomized controlled trial. 220 eyes of 201 participants undergoing routine cataract surgery were randomized to receive their intraocular lens either orientated with the optic-haptic junctions at 180° ('horizontal') or without manipulation following implantation (control). Patients were excluded according to age (<19 and > 99 years), coexisting eye disease affecting visual function and insufficient cognitive function to complete the study. In the fourth postoperative week, a telephone interview was conducted to determine rates of negative dysphotopsia. The data were analysed to provide the relative risk of negative dysphotopsia with horizontal orientation of the intraocular lens (IOL) optic-haptic junctions compared with standard treatment.

RESULTS

Orientating the IOL optic-haptic junctions horizontally halved the incidence of pseudophakic negative dysphotopsia in the fourth postoperative week (9/110 in the intervention group; 18/110 in the control group; RR: 0.50, 95% confidence interval: 0.235-1.064, p = 0.072). The overall incidence of negative dysphotopsia was 12.2% (27/220 participating eyes). No intraoperative adverse effects of intraocular lens rotation were reported.

CONCLUSION

The simple intraoperative manoeuvre of rotating the intraocular lens to orientate the optic-haptic junctions at 180° may be a safe and effective measure to reduce the risk of developing postoperative pseudophakic negative dysphotopsia in the first postoperative month. This is the first report that demonstrates the benefit of horizontal optic-haptic junction positioning to be sustained beyond the first postoperative day.

Pseudophakic Dysphotopsia: Review of Incidence, Cause, and Treatment of Positive and Negative Dysphotopsia

We reviewed the literature concerning positive dysphotopsia (PD) and negative dysphotopsia (ND) regarding cause, incidence, and clinical and surgical management. In addition, we summarized our surgical experience in managing dysphotopsia. A PubMed review, limited to English language articles, yielded 149 citations; multifocal (diffractive optic) and phakic intraocular lens (IOL) dysphotopsia were excluded. Overall, 39 articles were determined to be relevant for the objectives of this investigation. Regarding PD, 7 articles corroborated that the cause of PD is related primarily to internal reflection of oblique light rays that strike the square (truncated) edge of the IOL and are reflected onto the retinal surface. No round-edged foldable IOLs are available in the United States at this time, although IOLs modified with a round anterior edge and square posterior edge show a trend toward decreased incidence of PD. High index of refraction (I/R), surface reflectivity, and IOL optic design are additional causative factors for PD. Regarding the authors' surgical experience, changing the optic material to have a lower I/R improved PD symptoms in the large majority of patients. The cause of ND seems to be multifactorial and less well understood, with some disparity between clinical and laboratory findings. Four articles that explore using ray-tracing optical modeling suggest an "illumination gap," in which some temporally incident light rays to the nasal retina pass anterior to the IOL and some are refracted posteriorly by the IOL, resulting in a gap and resultant temporal shadow. However clinically, ND is associated invariably with well-centered in-the-bag IOLs. Other implicating factors include nasal anterior capsule override, haptic orientation, large-angle κ value, and high hyperopia. Persistent ND has been treated successfully or reduced with reverse (anterior) optic capture, sulcus IOL placement, piggyback IOLs, and neodymium:yttrium-aluminum-garnet nasal capsulectomy. Two articles reference a new optic edge designed to capture the anterior capsulotomy, mimicking reverse optic capture. Persistent dysphotopsia after cataract surgery is a significant cause for patient dissatisfaction. The cause and management of both ND and PD are of significance, and new IOL designs and alternative surgical strategies may help to mitigate these unintended side effects of IOL implantation.

Experimental Model of Far Temporal Field Negative Dysphotopsia Generated in Phakic Eyes

Purpose

The axial separation between the iris and the intraocular lens (IOL) in pseudophakic eyes can cause rays originating from the far temporal field to miss the IOL, resulting in negative dysphotopsia (ND). We developed an experimental model to test the hypothesis that obstruction of rays from the far temporal field can generate ND and an accompanying loss of visual sensitivity in the far temporal field.

Methods

The right eyes of 10 phakic subjects were fitted with soft contact lenses containing a 5.50-mm central clear zone and a 12-mm outer diameter opaque annulus. In three of the subjects, eyes were dilated with 1% tropicamide solution, and effective aperture diameters were determined optically (pupil camera) and psychophysically (narrow beam detection). Visual field extent (Goldmann bowl) and temporal and inferotemporal meridian sensitivities (Octopus perimeter) were measured. A wide-angle model was constructed to quantify the impact of the annular opacity on retinal illuminance.

Results

All 10 subjects observed a dark crescent in the far temporal and inferotemporal fields. The opaque annulus reduced effective horizontal pupil diameters from 8 mm to 5.5 mm on-axis and from >2 mm to <1 mm at 90°. Perimetry revealed a 10° reduction in temporal and inferotemporal field extent and increasing loss of sensitivity beyond 70°. The wide-angle model confirmed significant vignetting (>50% beyond 70°), approaching zero retinal illuminance beyond 85°.

Conclusions

Vignetting of rays originating from the far temporal field by axially separated apertures can create symptoms mirroring perceptual reports of negative dysphotopsia in symptomatic pseudophakic patients.

The Efficacy of Questionnaire-based Evaluation in Determining the Incidence of Recent Pseudophakic Dysphotopsia

Background: Dysphotopsias are optical side effects experienced by patients who underwent cataract surgery. This unwanted photic phenomenon has gained ground and is a major postoperative concern. Visual acuity is not sufficient in evaluating the postoperative visual function.

The aim of this study was to determine the efficacy of using a preexistent questionnaire in determining the presence of dysphotopsia.

Material and method: We conducted a prospective study, using the modified Visual Function Index (VF-14) and the Ocular Surface Disease Index (OSDI) surveys, completed on patients that underwent uncomplicated phacoemulsification with intraocular lens implantation between November 2016 and November 2017. Patients included in the study had no known ocular comorbidities and had no other possible postoperative explanation for these visual phenomena. Three weeks after the surgery, the questionnaire was filled up by one individual examiner.

Results: Of the 50 patients considered, 37 patients met all the inclusion criteria and were successfully enrolled in the study, with a mean age of 75.88 years. Dysphotopsia phenomena were present in 13.51% of cases; 60% of these patients described the presence of positive dysphotopsia, and 40% complained of temporal shadows. The best corrected visual acuity was over 0.8 in 75.67% of the cases.

Conclusion: Although there is no objective test to diagnose this early postoperative complication, pseudophakic dysphotopsia should not be overlooked and additional chair time is needed.

Effect of active evaluation on the detection of negative dysphotopsia after sequential cataract surgery: discrepancy between incidences of unsolicited and solicited complaints

PURPOSE

To evaluate the incidence of negative dysphotopsia after sequential cataract surgery.

METHODS

Retrospective cohort study. The incidence of negative dysphotopsia was assessed by retrospective reviewing of medical records and interviews with patients between 2 and 4 months after sequential cataract surgery. Inclusion criteria were uncomplicated surgery, postoperative corrected distance visual acuity (CDVA) ≥20/25 Snellen and the absence of ocular comorbidity. The majority of intra-ocular lens (IOL) implants were one-piece AcrySof SN60WF (161 eyes). Other IOLs (29 eyes) were toric (SN6AT3-6), spherical (SN60AT), three-piece (MN60MA) and multifocal (ReSTOR SN6AD1, PanOptix TFNT00 and Finevision Micro F trifocal).

RESULTS

The study population was comprised of 95 patients with a mean age of 72 ± 10 years. Unsolicited complaints of negative dysphotopsia were reported by eight patients (8%), and two of them had a resolution of symptoms within 1 month of follow-up. Eighteen patients (19%) reported negative dysphotopsia at the time of the interview. Two patients reported bothersome negative dysphotopsia, and one of them was successfully treated with implantation of a supplementary IOL in the ciliary sulcus. Patients with negative dysphotopsia were younger than patients without dysphotopsia (p = 0.045) and had shorter axial eye length (p = 0.04), a tendency for higher IOL power (p = 0.09) and a higher CDVA (p = 0.001).

CONCLUSION

The incidence of unsolicited negative dysphotopsia after sequential cataract surgery appears to be a substantial underestimation of complaints identified in active interviewing. Although symptoms are not bothersome in the majority of cases, some patients with undiagnosed severe negative dysphotopsia may benefit from reassurance or secondary treatment.

The Complexities of Negative Dysphotopsia

The appearance of a dark shadow in the temporal periphery, otherwise known as negative dysphotopsia, continues to be a problem for some patients after routine uncomplicated cataract surgery. Etiologies include type and design of intraocular lens (IOL), anatomical features and dimensions of the eye, pupil size, angle kappa, relationship of the optic to the anterior capsule, and the position of the optic/haptic junction of the IOL. Although the primary etiology remains controversial, it is clear that the cause is multifactorial. All of the factors should be considered when attempting to prevent or treat this phenomenon.

Research Article. The Prevalence of Dysphotopsia in Patients with Recent Cataract Surgery

Pseudophakic dysphotopsia are becoming increasingly important as unwanted side effect after cataract surgery. Objective: The purpose of this study is to compare the photic symptoms experienced by patients after cataract surgery. Material and method: This is a prospective study that included 105 eyes from 99 patients, which underwent uncomplicated phacoemulsification and IOL implantation, between June 2015 and June 2016, performed at Ophthalmology Clinic Tg Mureș. Patients without visually consequential ocular co-morbidity completed a questionnaire, designed to assess subjectively perceived visual functioning and identify symptoms of dysphotopsia. Results: From the total number of patient, hydrophobic lenses were implanted in 95 patients and 10 patients received hydrophilic lenses. Photic effects were reported in 18% of treated eyes. Although the percentage of dysphotopsia is higher in the hydrophobic lenses category, there was no significant statistical difference between the two categories. Conclusion: The incidence and significance should not be overlooked, thus visual acuity is not enough for evaluating postoperative visual function.

Negative dysphotopsia: A perfect storm

The objective of this review was to provide a summary of the peer-reviewed literature on the etiologies of negative dysphotopsia that occurs after routine cataract surgery. A search of PubMed, Google Scholar, and Retina Medical identified 59 reports. Negative dysphotopsia has been associated with many types of intraocular lenses (IOLs), including hydrophobic and hydrophilic acrylic, silicone, and 1-piece and 3-piece designs. Proposed etiologies include edge design, edge smoothness, edge thickness, index of refraction of the IOL, pupil size, amount of functional nasal retina, edema from the clear corneal incision, distance between the iris and IOL, amount of pigmentation of the eye, corneal shape, prominent globe and shallow orbit, and interaction between the anterior capsulorhexis and IOL. Treatments include a piggyback IOL, reverse optic capture, dilation of the pupil, constriction of the pupil, neodymium:YAG capsulotomy of the nasal portion of the anterior capsule, IOL exchange with round-edged optics, and time alone. This review summarizes the findings.

FINANCIAL DISCLOSURE

Dr. Henderson is a consultant to Alcon Laboratories, Inc., Abbott Medical Optics, Inc., Bausch & Lomb, and Genzyme Corp. Neither author has a financial or proprietary interest in any material or method mentioned.

Is the Memory Effect of the Blind Spot Involved in Negative Dysphotopsia after Cataract Surgery?

We present novel clinical observations on negative dysphotopsia (ND) in eyes that have undergone cataract surgery. In the past, shadow effects were alleged to be located in the far peripheral temporal visual field 50° to 100° away from the optical axis. In a small series of eight patients we found evidence of photic effects, described by the patients as shadows in the periphery that were objectively located much more centrally. In all cases, we could find an association of these phenomena with the blind spot. We hypothesize that the memory effect of the blind spot which is dislocated and changed in magnification due to replacement of the crystalline lens could be one determinant for pseudophakic ND. The scotoma of the optic nerve head and the main arteries and veins of the phakic eye are displaced in the pseudophakic eye depending on the specific characteristics and position of the intraocular lens within the eye.

Vignetting and negative dysphotopsia with intraocular lenses in "far peripheral vision"

At very large visual angles, vignetting can occur at the edge of an intraocular lens (IOL), because it is much smaller than the natural crystalline lens that it replaces. Ray trace calculations show that, by 80-90 deg of input visual angle, it is possible that about half the light is no longer focused by the IOL. This may create curved, peripheral, shadowlike regions, which are a clinical characteristic of negative dysphotopsia. The imaging characteristics for this "far peripheral vision" region are different from those of a phakic eye, whether or not negative dysphotopsia is experienced.

Determinants of patient satisfaction and function related to vision following cataract surgery in eyes with no visually consequential ocular co-morbidity

PURPOSE

To investigate subjectively reported outcomes following cataract surgery and the relationships between such outcomes in the context of falling thresholds for cataract surgery.

SETTING

Large, private, non-refractive cataract practice, Institute of Eye Surgery, Whitfield Clinic, Waterford, Ireland

METHODS

Pre-operative, intra-operative and post-operative data of 2552 eyes undergoing phacoemulsification and implantation of the Tecnis(R) ZCB00 1-piece intraocular lens (IOL) by a single surgeon between July 2009 and October 2013 was analysed. Patients without visually consequential ocular co-morbidity completed two validated questionnaires, designed to assess subjectively perceived visual functioning and identify symptoms of dysphotopsia following cataract surgery.

RESULTS

54.8 % of questionnaire respondents were entirely satisfied (satisfaction 10/10) post-operatively, with 83.7 % reporting satisfaction of ≥7/10. Satisfaction was positively associated with patient age and negatively associated with spectacle dependence, dysphotopsia, and function related to vision (NEI VF-11) score. The mean (±standard deviation[SD]) dysphotopsia score was 1.36 (±1.9; scale 0-10), with 40 % of respondents reporting no dysphotopsia symptoms and 9.8 % reporting clinically meaningful dysphotopsia. The mean (±SD) National Eye Institute visual function-11 (NEI VF-11) score was 0.33 (±0.53; scale 0-4) and reduced function related to vision was associated with increasing severity of dysphotopsia symptoms. When linear regression was applied, 17.5 % of the variation in functionality was attributable to symptoms of dysphotopsia.

CONCLUSION

Dysphotopsia is an important determinant of a patient having difficulty with vision-related tasks following cataract surgery, and patient satisfaction is positively associated with patient age and negatively associated with spectacle in dependence, dysphotopsia and function related to the vision (NEI VF-11) score.

Treatment of negative dysphotopsia with supplementary implantation of a sulcus-fixated intraocular lens

Purpose

Our aim was to evaluate the resolution of negative dysphotopsia after supplementary implantation of a sulcus-fixated intraocular lens (IOL).

Methods

This was a retrospective case series. Patients with severe negative dysphotopsia were treated with supplementary implantation of the Rayner Sulcoflex Aspheric (653 L) IOL. Primary outcome measurements were subjectively reported complaints of dysphotopsia, best corrected distance visual acuity (CDVA), iris-IOL distance, anterior chamber depth (ACD) and volume (ACV), angle opening distance and trabecular-iris space area at 500 and 750 μm.

Results

A Rayner Sulcoflex IOL was implanted in seven patients (nine eyes) with negative dysphotopsias. Symptoms resolved completely in six eyes, partially in one eye and remained unchanged in two eyes. We did not find any significant changes in CDVA. Angle opening distance, ACD, ACV and iris-IOL distance reduced significantly after Sulcoflex IOL implantation.

Conclusions

Supplementary implantation of a Sulcoflex IOL can successfully treat negative dysphotopsia. The decrease in anterior segment dimensions in combination with the displacement of light rays by the rounded edges of a Sulcoflex IOL may contribute to the resolution of symptoms.

Resolution of negative dysphotopsia after laser anterior capsulotomy

It has been suggested that a clear anterior nasal capsule contributes to negative dysphotopsia and that symptoms may resolve with opacification of the capsule. We describe a case in which negative dysphotopsia occurred despite a translucent anterior peripheral capsule and resolved following laser removal of the anterior nasal capsule.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.