Change in ocular alignment after topical anesthetic cataract surgery

Cataract surgery is not associated with post-operative binocular vision anomalies in age-related cataract patients

PURPOSE

To compare the binocular vision status of patients pre- and post-cataract surgery, and to investigate the risk factors for patients who develop binocular vision anomalies post-surgery.

METHODS

A prospective study of patients (≥50 years) who elected to undergo bilateral cataract surgery was implemented. A comprehensive binocular vision test battery including stereopsis, ocular alignment, fusional vergence, vergence facility, near point of convergence and the Convergence Insufficiency Symptom Survey (CISS) was administered before the first surgery and at the third visit after surgery on the second eye. A detailed diagnostic classification protocol was applied to identify the presence of binocular vision anomalies pre- and post-surgery.

RESULTS

Seventy-three participants were included at baseline, 24 (33%) of whom were diagnosed with non-strabismic binocular vision anomalies (NSBVA), mainly convergence insufficiency (18/73, 25%). Fifty-one participants completed the post-operative evaluation, 17 (33%) of whom had NSBVA pre-surgery and 13 (26%) post-surgery (p = 0.48). There were a number of conversions from NSBVA to normal binocular vision and vice versa. Logistic regression showed that the adjusted odds ratio of pre-existing NSBVA diagnosis for predicting the risk of post-operative NSBVA was 6.37 (p < 0.01). There were no significant changes in most binocular vision measures post-surgery, except for a significant improvement in the CISS score (p < 0.01, Cohen's d = 0.83).

CONCLUSIONS

Binocular vision anomalies, especially convergence insufficiency, are prevalent in the age-related cataract population. Cataract surgery does not appear to be a significant risk factor for the development of new binocular vision anomalies. A pre-existing binocular vision anomaly is the main risk factor for predicting a post-operative binocular vision anomaly in this population.

Preoperative binocular vision characteristics in the age-related cataract population

Background

This study is the first part of the “Binocular Vision Anomalies after Cataract Surgery” study that aimed to investigate the impact of cataract surgery on binocular vision status in adults with age-related cataract. This study aimed to investigate the preoperative binocular vision status of participants with age-related cataract.

Methods

Patients who elected to undergo bilateral cataract surgery (≥50 years of age) were recruited. Clinical measures of binocular vision including stereopsis, ocular alignment, fusional vergence, vergence facility, convergence amplitude and a symptom survey related to binocular vision anomalies were administered. A detailed classification protocol was established to identify the presence of binocular vision anomalies. The frequency of specific binocular vision anomalies and normative data of binocular vision measures were reported.

Results

A total of 73 subjects were evaluated. No strabismus was detected in the cohort. Non-strabismic binocular vision anomalies were detected in 24 subjects (32.9%), of whom 18 (24.7%) had convergence insufficiency, 3 (4.1%) had basic exophoria, 2 (2.7%) had convergence excess, and 1 (1.4%) had fusional vergence dysfunction. Decreased vergence facility and convergence amplitude were more common compared to the pre-presbyopes (P < 0.01).

Conclusion

Binocular vision problems, especially convergence insufficiency, are common in the adults with age-related cataract. The study results demonstrate that the lack of normative binocular vision data for the presbyopic population is a significant gap in the literature and suggest the need for a study of normative data for this population.

Trial registration

The study was registered at ClinicalTrials.gov (NCT03592615, USA).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02418-7.

Evaluation of Eye Alignment before and after Cataract Surgery

Purpose: To assess changes in eye alignment before and after cataract surgery.Subjects and methods: The medical records of 786 cataract patients without eye movement limitation who underwent bilateral cataract surgery under topical anesthesia with monofocal IOL placement were retrospectively reviewed at the Eye Center of Sanno Hospital in Japan.Results: Before cataract surgery, 121 of the 786 patients (15.4%) had constant strabismus, 263 (33.5%) had intermittent strabismus, and 402 (51.1%) had phoria. Among the 121 patients with constant strabismus on the preoperative exam, 64 (52.9%) had exotropia without vertical strabismus, 7 (5.8%) had esotropia without vertical strabismus, and 6 (5.0%) had vertical strabismus without a horizontal component. After surgery, 98 of the 786 patients (12.5%) had constant strabismus, 126 (16.0%) had intermittent strabismus, 562 (71.5%) had phoria. The rate of eye alignment agreement before and after surgery was 72.3% overall. We found that 17 patients (2.2%) who did not have constant strabismus preoperatively developed constant strabismus postoperatively, and all of these patients experienced binocular diplopia. Characteristics of patients at risk for constant strabismus and diplopia postoperatively included patients with vertical deviation preoperatively (intermittent or phoria).Conclusions: Uncomplicated cataract surgery under topical anesthesia did not influence eye alignment classification in 72.3% of patients; however, patients with vertical deviation preoperatively were more likely to transition to constant strabismus after surgery.

Strabismus patterns after cataract surgery in adults

New-onset binocular diplopia after cataract surgery in adults is a rare but significant complication. The aim of this study was to analyze causes, risk factors, and treatment outcomes. Forty consecutive patients with new-onset binocular diplopia after uncomplicated cataract surgery were enrolled in this retrospective study at a tertiary medical center. We evaluated risk factors including type of anesthesia, preoperative presence of strabismus, and others regarding their effect on the development of diplopia after cataract surgery. We further analyzed ocular alignment and motility at presentation and during the clinical course. The majority of the patients with new-onset diplopia presented after cataract surgery on the left eye (28 of 40). Vertical strabismus occurred in 37 of 40 patients, and regional (peri- or retrobulbar) anesthesia was the main risk factor for postoperative diplopia (present in 37 of 40). There were four distinct ocular dysmotility patterns in patients with vertical strabismus: deficient elevation with (type 1a) or without over-depression (type 1b), deficient depression (type 2), or normal motility (type 3). After surgery of the right eye, most patients (6 of 9) showed type 2. After cataract surgery on the left eye, type 1a was most common (20 of 24). Three patients had horizontal strabismus due to a decompensated heterophoria or convergence insufficiency. In total, 17 patients required strabismus surgery (mean 1.3 operations, range 1-3). Regional anesthesia was the main risk factor for new-onset diplopia after cataract surgery in adults. Distinct strabismus patterns were observed for left and right eyes.d.

Strabismus After Ocular Surgery

Many types of ocular surgery can cause diplopia, including eyelid, conjunctival, cataract, refractive, glaucoma, retinal, and orbital surgery. Mechanisms include direct injury to the extraocular muscles from surgery or anesthesia, scarring of the muscle complex and/or conjunctiva, alteration of the muscle pulley system, mass effects from implants, and muscle displacement. Diplopia can also result from a loss of fusion secondary to long-standing poor vision in one eye or from a decompensation of preexisting strabismus that was not recognized preoperatively. Treatment, which typically begins with prisms and is followed by surgery when necessary, can be challenging. In this review, the incidence, mechanisms, and treatments involved in diplopia after various ocular surgeries are discussed. [J Pediatr Ophthalmol Strabismus. 2017;54(5):272-281.].

Diplopia as the Complication of Cataract Surgery

The authors present systematic review of aetiology and treatment of diplopia related to cataract surgery. The problem is set in the modern perspective of changing cataract surgery. Actual incidence is discussed as well as various modalities of therapeutic options. The authors provide the guidance for the contemporary cataract surgeon, when to expect potential problem in ocular motility after cataract surgery.

Aniseikonia induced by cataract surgery and its effect on binocular vision

PURPOSE

This study measured aniseikonia before and after the first and second cataract surgeries in ametropic adults. The relationship of aniseikonia to anisometropia and its effect on stereopsis, ocular alignment, and clinical symptoms were determined.

METHODS

Seventeen patients scheduled to have bilateral cataract surgery with 2 diopters or more ametropia participated. Patients were evaluated before cataract surgery and 4 weeks (±1 week) after the first and second surgery. Visual acuity, refractive error, aniseikonia, stereopsis, ocular alignment, and visual symptoms were determined at each visit.

RESULTS

Aniseikonia increased after the first cataract surgery. The increase in aniseikonia occurred in concert with increased anisometropia and resulted in poorer stereopsis overall. Aniseikonia and anisometropia 1 month (±1 week) after the second cataract surgery returned to near baseline and were associated with better stereopsis. The amount of aniseikonia showed substantial variance and could not be predicted by the amount of induced anisometropia. Changes in ocular alignment were minimal. Statistically significant changes in patient symptoms between study visits were infrequent.

CONCLUSIONS

Aniseikonia induced by cataract surgery may not be a substantial problem for ametropic adults with normal binocular vision, at least in the short term.

Diplopia in adult patients following cataract extraction and refractive surgery

PURPOSE OF REVIEW

The purpose of this article is to report the incidence and cause of diplopia following cataract surgery and laser in-situ keratomileusis (LASIK).

RECENT FINDINGS

Ocular misalignment following cataract extraction with retrobulbar anesthesia has an incidence of approximately 7%. Diplopia ranges in this group of patients from 0.23 to 0.98%. The incidence of ocular misalignment decreases with topical anesthesia for cataract extraction to 5%, and diplopia occurs with an incidence of 0.21-0%. Although there are small case series, the incidence of diplopia following LASIK has not been reported. The causes of diplopia following cataract extraction and LASIK include decompensation of pre-existing strabismus, new-onset accommodative esotropia, concurrent onset of systemic disease, disruption of central fusion, and monocular diplopia. The leading cause for diplopia following retrobulbar anesthesia for cataract extraction is extraocular muscle paresis/restriction and is unique to this type of procedure. In cases of topical anesthesia for cataract extraction and for LASIK procedures, the leading cause of diplopia is decompensation of pre-existing strabismus.

SUMMARY

Detailed history and evaluation for pre-existing strabismus can dramatically decrease the incidence of unexpected diplopia following refractive procedures.