Ptosis following radial keratotomy. Performed using a rigid eyelid speculum

Lower eyelid involutional entropion following cataract surgery

OBJECTIVES

To determine whether cataract surgery is associated with an increased risk of subsequent lower eyelid entropion and evaluate potential associated factors.

METHODS

This retrospective cohort study included consecutive patients undergoing first eye cataract surgery over a 10-year period at a single institution (n = 14,574). The fellow phakic eye served as control. Patient records were evaluated up until either the time of second eye cataract surgery or any other intraocular or adnexal surgery. The primary outcome was the rate of entropion repair in both the pseudophakic (exposed) group and the phakic control group. Groups were compared using relative risk and Kaplan-Meier analysis. Multivariate logistic regression was used to compare pre-specified characteristics of those patients that underwent entropion repair in their pseudophakic eye with those that did not.

RESULTS

A fourfold higher relative risk of undergoing entropion repair was observed in eyes that had undergone cataract surgery compared with the fellow unoperated eye (95% confidence interval 1.6-9.8; P < 0.001) with an increased risk at all timepoints between 1 and 12 years according to Kaplan-Meier analysis (P = 0.001). Median time to entropion repair after cataract surgery was 58 months (range 3-124). Documented intraoperative patient factors such as patient or eye movement, eyelid squeezing, pain or anxiety were an independent risk factor for subsequent entropion (P < 0.0001).

CONCLUSIONS

Cataract surgery is associated with an increased risk of subsequent lower eyelid entropion. Surgeons should be aware of this risk in the pre- and post-operative assessment of patients undergoing cataract surgery.

A review of acquired blepharoptosis: prevalence, diagnosis, and current treatment options

Blepharoptosis (ptosis) is among the most common disorders of the upper eyelid encountered in both optometric and ophthalmic practice. The unilateral or bilateral drooping of the upper eyelid that characterises ptosis can affect appearance and impair visual function, both of which can negatively impact quality of life. While there are several known forms of congenital ptosis, acquired ptosis (appearing later in life, due to a variety of causes) is the predominant form of the condition. This review summarises the prevalence, causes, identification, differential diagnosis, and treatment of acquired ptosis. Particular attention is paid to the differential diagnosis of acquired ptosis and emerging treatment options, including surgical and pharmacologic approaches.

Postoperative Blepharoptosis After Pars Plana Vitrectomy Procedure

PURPOSE

To describe the frequency of blepharoptosis and factors affecting it after the pars plana vitrectomy (PPV) procedure.

METHODS

In a prospective study, patients were recruited consecutively from October 2016 to June 2018. Upper eyelid margin reflex distance 1 and 2 (MRD1 and 2), upper eyelid crease height, and levator function were measured before, 1 and at least 6 months after surgery by the same investigator. Clinical and Clinically significant ptosis were defined as ≥0.5 and ≥2 mm drop of MRD1.

RESULT

There were 60 eyes from 57 patients. The majority of surgeries were performed by the fellows (63.3%, 38/60) and under general anesthesia (95.0%, 57/60). Clinical and clinically significant ptosis following PPV were 47.2% (25/53) and 11.3% (6/53) at the last follow up (at least 6 months), respectively. MRD2 (p = 0.389) and eyelid crease height (p = 0.057) did not significantly change. Surgeons' level, time of the procedure and other variables were not significantly impacting the frequencies.

CONCLUSION

Persistent clinically significant ptosis was observed in 11% of patients undergoing PPV. No variable was significantly associated with persistent postoperative ptosis after PPV.

Postoperative Blepharoptosis After Modern Phacoemulsification Procedure

PURPOSE

To investigate the frequency of transient (1 month) and persistent (at least 6 months) postoperative ptosis following clear corneal sutureless phacoemulsification and to analyze the factors affecting them.

DESIGN

Cohort study.

METHODS

Patients who underwent phacoemulsification cataract surgery from October 2016 to June 2018 in a tertiary center were enrolled. Margin reflex distance 1 (MRD1), MRD2, and levator function were measured and facial photography was taken before, 1 month, and at least 6 months after the surgery. Clinical ptosis was defined as any postoperative drop of MRD1 and clinically significant ptosis as MRD1 drop of ≥2 mm. Photo-based ptosis was assessed by a masked oculofacial plastic surgeon at the end of the study.

RESULTS

A total of 234 patients (313 eyelids) were included. The majority of surgeries were performed by senior residents (65.5%, 205/313) and under topical anesthesia (78.0%, 244/313). Persistent clinical, clinically significant, and photo-based ptosis were 25.4% (71/279), 3.2% (9/279), and 3.3% (9/276). Eyelids with persistent postoperative ptosis showed a significantly (P = .03) lower preoperative levator function (13.9 vs 15.8 mm). No other factor was significantly different between the eyelids with and without postoperative ptosis.

CONCLUSION

Persistent clinically significant ptosis was observed in more than 3% of patients undergoing clear corneal sutureless phacoemulsification cataract surgery. It should be counseled preoperatively. Lower preoperative levator function was significantly associated with a higher frequency of postoperative ptosis. Duration of surgery, level of surgeons, and other variables did not have any significant effect on the frequency of postoperative ptosis.

An Objective Evaluation of the Upper Eyelid Position after Phacoemulsification Cataract Surgery

Purpose: To objectively measure the upper eyelid position following phacoemulsification cataract surgery and to identify the determinants of postoperative transient ptosis. Methods: This is a single arm prospective study of patients who underwent cataract surgery from January to May 2017 at a tertiary Eye Hospital in Spain. Data comprised of: the type of anesthesia, the duration that the speculum remained in place and the total surgical time (duration of the procedure). The total surgical time was defined as, the time from the beginning of the paracentesis to the closure of the wounds (incision time). Digital photographs were obtained of: the face with the eye in primary gaze, looking inferiorly and superiorly, preoperatively, and 1, 30, 90 and 180 days postoperatively. Measurements for eyelid crease, levator function, and marginal reflex distance 1 (MRD1) were performed using ImageJ. Statistical analysis was performed of the difference between the preoperative and postoperative measurements. Results: The study consisted of 112 patients. The median lid crease was 9.0 mm [IQR (interquartile range) 7.5; 10.0] both preoperatively and at 180 days postoperatively (IQR 8.0; 10.8). No statistical difference was determined in the lid crease measurements between these two times (P = .17). The median levator function differed significantly preoperatively, at day 1 and 30, 60 and 180 days postoperatively (P < .01). MRD1 decreased significantly from a median of 3.01 mm preoperatively to 2.7 mm at 30 days postoperatively (P = .05) but was similar at preoperative and after 180 days (P = .7). The correlation of MRD1 to the duration of the speculum in place (P = .2) and the incision time (P = .57) was not significant. Conclusions: Ptosis, following phacoemulsification cataract surgery, is mild and transient, occurring only in the early postoperative period.

Incidence and risk of ptosis following ocular surgery: a systematic review and meta-analysis

OBJECTIVE

We conducted a systematic review and meta-analysis to evaluate the incidence and risk factors of ptosis following ocular surgery.

METHODS

PubMed, Embase, and Cochrane Library were searched for articles that assessed the incidence or risk factors of ptosis following ocular surgery up to October 2017. We used a fixed effects model to calculate a pooled estimate of incidence, with subgroup analyses to evaluate the effect of different variables. The relative risks (RRs) or odds ratios (ORs) and 95% confidence intervals (CIs) for all available factors were calculated using the fixed effects models.

RESULTS

A total of 16 studies on 2856 eyes were analyzed, including 3 randomized controlled trials (RCTs) and 13 cohort studies. The overall incidence of ptosis following ocular surgery was 11.4% (95% CI 10.1-12.8%). Subgroup analyses showed that the region and the surgery type were significantly associated with the incidence of postoperative ptosis. Men were less likely to get postoperative ptosis than women (OR 0.62; 95% CI 0.43-0.89). However, age (OR 0.77; 95% CI 0.48-1.23), side (OR 1.37; 95% CI 0.84-2.25), type of anesthesia (OR 0.57; 95% CI 0.16-2.05), prior surgery (OR 1.09; 95% CI 0.64-1.83), bridle suture (OR 2.04; 95% CI 0.94-4.42), or combined surgery (OR 0.95; 95% CI 0.58-1.57) did not significantly change the risk of ptosis following ocular surgery.

CONCLUSION

More than one in ten patients who undergo ocular surgery will develop ptosis. Different regions and surgery types may influence the occurrence of this abnormality. Female gender is a risk factor for development of postoperative ptosis.

Eyelid Malpositions after Cataract Surgery

Purpose.

To estimate the incidence and the factors that may play a role in the etiology of eyelid malpositions after cataract extraction.

Methods.

We followed up 124 patients for six months after cataract extraction. Palpebral aperture, levator function, height of the upper lid crease, lower eyelid laxity and position of the punctums were recorded preoperatively and postoperatively. Post-cataract ptosis was defined as a 2 mm or greater drop in the lid margin after correcting for any change in the fellow eye.

Results.

None of the patients developed ectropion or entropion, but five (4%) developed punctal ectropion after surgery. The incidence of post-cataract ptosis was 7.3% at six months. Age, sex, preoperative measurements of levator function, lid crease and dermatochalasis were not predictive for the development of ptosis at six months. However, there was a significant difference in the preoperative palpebral fissure width between the patients with ptosis and those without (p<0.05). There was a positive correlation between the mean volume of local anesthetic and the degree of ptosis on the first postoperative day (p<0.05, r: 0.1873). The presence and amount of ptosis on the first postoperative day was the best predictor of post-cataract ptosis at six months (p<0.001).

Conclusions.

Several factors are involved in the development of post-cataract ptosis. Temporary ptosis may be related to the myotoxicity of the local anesthetic. The presence of ptosis on the first postoperative day is the best predictor for the development of ptosis at six months.

Influence of upper and temporal transconjunctival sclerocorneal incision on marginal reflex distance after cataract surgery

Background

Ptosis incidence following cataract surgery is reduced with a recently developed phacoemulsification technique using a small incision. However, it remains uncertain whether an upper transconjunctival sclerocorneal incision can cause minor blepharoptosis. In the present prospective study, patients underwent cataract surgery with either an upper or temporal 2.4-mm transconjunctival sclerocorneal incision. We measured the marginal reflex distance 1 (MRD1) preoperatively and postoperatively, and compared these measurements between the two different incision types. Further we explored the risk factors of the postoperative MRD1 reduction.

Methods

The study population included patients who underwent cataract surgery on both eyes at Aichi Medical University between October 2013 and September 2015. In each patient, one eye was operated using an upper 2.4-mm transconjunctival sclerocorneal incision, and the other with a temporal incision. We prespecified that an MRD1 difference of ≥0.5 mm between the pre- and post-surgical measurements indicated postoperative ptosis, which was a strict criterion. MRD1 was measured using digital photography, and we calculated the difference between the preoperative and postoperative MRD1 values. This change in MRD1 was compared between the groups with different incision locations. The change in MRD1 was analyzed by using the multivariate regression model including incision position (temporal or upper), preoperative MRD1, and preoperative distance between medial and lateral canthi.

Results

We assessed data from a total of 34 patients. The mean change in MRD1 from pre-operation to post-operation measurements was −0.26 ± 0.93 with the temporal incision and −0.24 ± 0.86 with the upper incision. The mean difference in the change in MRD1 between the different two incision types was −0.02, with a 95 % CI of −0.24 to 0.20, establishing equivalence between these incision types. The multivariate regression analysis showed that the preoperative MRD1 was significantly associated with the reduction of MRD1 after surgery (p = 0.034).

Conclusions

Cataract surgery using upper and temporal 2.4-mm transconjunctival sclerocorneal incisions are clinically equivalent with regards to change in MRD1, and neither incision type caused critical postoperative ptosis. The longer preoperative MRD1 was significantly associated with the reduction of MRD1 after surgery.

Trial registration

Current Controlled Trials UMIN000022310. Retrospectively registered 14 May 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s12886-016-0286-1) contains supplementary material, which is available to authorized users.

Mechanical testing of lid speculae and relationship to postoperative ptosis

AIMS

Postoperative lid malpositions are known complications of routine intraocular surgery and were previously attributed to the use of a bridle suture or the myotoxic effect of retrobulbar or peribulbar anaesthetics. However, lid malpositions are still seen under topical anaesthesia. Recent studies have implicated the lid speculum as a factor. Patients with narrower vertical palpebral apertures have been shown to develop postoperative ptosis more frequently, but the reason is unknown. This is the first study to determine the forces exerted by lid speculae over a range of palpebral apertures.

METHODS

Mechanical testing was undertaken using a Bose 3200 materials testing machine. Tests were undertaken on four disposable and four reusable speculae. The force used to compress each speculum was compared over a range of displacements. A two-sample t-test was used to compare the stiffness of the two types of speculum.

RESULTS

The stiffness of the reusable speculum was significantly greater than the disposable speculum (P=0.002). The stiffness of each speculum was greatest at the range of displacement corresponding to the narrower palpebral apertures.

CONCLUSIONS

Different speculae exert significantly different forces on patients' eyelids during surgery. The patients who experience the greatest compression from the speculae are those with the smallest palpebral apertures. This may explain why these patients are more likely to develop postoperative lid malpositions.

Blepharoptosis following anterior segment surgery: a new theory for an old problem

Blepharoptosis is a well-known complication following anterior segment surgery. However, its precise aetiology remains elusive. There are currently two widely held views on the pathogenesis of persistent postoperative ptosis, namely the speculum and bridle suture theories. However, both suggested explanations fail to address important anatomical and epidemiological features of this condition. Until now, the majority of published literature describing persistent postoperative ptosis following anterior segment surgery has largely concentrated on dehiscence of the levator aponeurosis as the common mechanism underlying this postoperative complication. However, numerous studies have failed to show any correlation between pre or postoperative skin crease positions in such patients. This review article discusses previously proposed mechanisms responsible for both transient and persistent ptosis. Furthermore, we propose an alternative mechanism for the development of ptosis following anterior segment surgery, namely horizontal stretch of the upper eyelid induced by the use of the speculum. This mechanism also provides a plausible explanation for less commonly described oculoplastic complications, such as lower lid malpositions, following anterior segment surgery. Postoperative ptosis may also act as a paradigm for the development of involutional ptosis in general. In view of the frequency with which ophthalmologists perform anterior segment procedures such as cataract surgery, postoperative ptosis represents a significant concern for all ocular surgeons. Identifying the underlying mechanism is imperative, not only to identify those patients at greatest risk, but also to perhaps provide novel surgical approaches to the management of this complication.

The incidence of ptosis following extracapsular and phacoemulsification surgery: comparison of two prospective studies and review of the literature

We prospectively compared 120 patients who underwent either phacoemulsification or extracapsular cataract (ECCE) surgery to establish the incidence of postoperative ptosis between the two techniques. Of the 120 patients, 60 underwent ECCE (unpublished data 1989) and 60 had phacoemulsification. Data was collected prospectively on upper and lower margin reflex distance, upper lid skin crease and levator function, preoperatively and 6 weeks postoperatively. Photographs were taken pre and postoperatively and examined by a blinded observer. At 6 weeks, ptosis was present in 18% of ECCE patients compared with 0% in the phacoemulsification group. By changing from ECCE to phacoemulsification the incidence of postoperative ptosis has reduced. The possibility to induce postoperative ptosis remains, potential mechanisms are discussed.

Unexpected outcomes associated with laser in situ keratomileusis: ptosis, anisocoria, and "curing" of exotropia

Laser in situ keratomileusis (LASIK) is a common and popular procedure that is generally associated with excellent results and few complications. We present 3 cases of unusual LASIK-related complications. In the first case, the patient developed anisocoria after otherwise unremarkable surgery. In the second case, the patient developed mild eyelid ptosis. In the third case, the patient's exotropia resolved after mild refractive overcorrection. In each case, the visual outcome was excellent and no further intervention was necessary.

Ultrasound Biomicroscopy of the Levator Aponeurosis in Congenital and Aponeurotic Blepharoptosis

PURPOSE

To evaluate and measure the thickness of the levator aponeurosis by ultrasound biomicroscopy in congenital dysmyogenic and aponeurotic blepharoptosis.

METHODS

Forty-four upper eyelids of 22 patients who had unilateral blepharoptosis were evaluated by ultrasound biomicroscopy. The patients ranged in age from 13 to 69 years (mean, 35.4 +/- 20.2 years). Fourteen patients were male and 8 patients were female. Seven patients had congenital dysmyogenic blepharoptosis and 15 patients had aponeurotic blepharoptosis. Imaging was performed with a 50-MHz transducer. The thickness of the levator aponeurosis was measured centrally at the upper border of the tarsus.

RESULTS

The levator aponeurosis was imaged in all eyelids except for one eyelid with aponeurotic blepharoptosis. The mean thickness of the levator aponeurosis was 0.39 +/- 0.10 mm in the ptotic eyelid and 0.42 +/- 0.09 mm in the control eyelid of the patients with congenital dysmyogenic blepharoptosis (p = 0.043). The mean thickness of the levator aponeurosis was 0.26 +/- 0.05 mm in the ptotic eyelid and 0.36 +/- 0.04 mm in the control eyelid of the patients with aponeurotic blepharoptosis (p = 0.001). The thickness of the levator aponeurosis was correlated with the palpebral fissure height (p = 0.013, r = 0.644) in aponeurotic blepharoptosis. The thickness of the levator aponeurosis was correlated with the levator function (p = 0.033, r = 0.795) in congenital dysmyogenic blepharoptosis.

CONCLUSIONS

The thickness of the levator aponeurosis can be measured with ultrasound biomicroscopy. The most common pathology in aponeurotic blepharoptosis is thinned-out aponeurosis. The levator aponeurosis of the ptotic eyelid is thinner than the normal eyelid in congenital ptosis.

Surgical blepharoptosis--the bridle suture factor?

AIMS

To evaluate the role of the superior rectus bridle suture in the development of post cataract blepharoptosis.

METHODS

We compared the incidence of postoperative ptosis in two groups of patients undergoing cataract extraction. In the first group (32 patients), a temporal corneal approach was employed with no superior rectus bridle suture. In the second group (38 patients), a superior approach with a bridle suture was used. Both groups of patients underwent phacoemulsification with the use of peribulbar anaesthesia, a pressure lowering device and a speculum. We recorded the lid position at least 12 weeks following surgery and determined the degree of postoperative ptosis. Two-sided Fischer's Exact Test was used to test for significant difference between the two groups (using a statistical software package Instat Version 3.0 for Windows).

RESULTS

Taking 2 mm of ptosis as a significant change, 11.5% of those undergoing temporal section sustained postoperative ptosis whilst it occurred in 12.9% of those who underwent a superior approach.

CONCLUSIONS

The presence or absence of the superior rectus bridle suture and the site of the ocular wound do not significantly contribute to the incidence of postoperative ptosis. We would suggest that the causative factors are peribulbar anaesthesia, a pressure lowering device and the use of the speculum.

Ptosis after cataract surgery

An often over-looked complication of routine cataract surgery is post-operative ptosis. This form of ptosis is often transient, although persistent ptosis may require surgical intervention. The causes include eyelid edema and hematoma, anesthesia myotoxicity, and use of a lid speculum or bridle suture. This review demonstrates that a thorough evaluation of the patient and determination of etiology of post-operative ptosis can help direct the need and timing for intervention.

Upper eyelid ptosis repair after cataract extraction and the importance of Hering's test

Blepharoptosis is a well-documented complication of cataract extraction and other ocular procedures. Few authors have described the surgical findings and outcomes of postcataract blepharoptosis repair. The authors present a review of the causes of postcataract blepharoptosis with emphasis on both clinical findings and recommendations for treatment on the basis of their experience with 13 eyelids in eight patients over the past 10 years. They found that all patients had either partial or total disinsertion of the levator muscle from the tarsal plate. Of the eight patients in this series, five had bilateral blepharoptosis after bilateral cataract extraction. Although a multifactorial cause for postcataract blepharoptosis is commonly assumed, the authors propose that the mechanical forces of intraoperative traction on the levator aponeurosis during cataract surgery are the primary cause. This is further supported by their operative findings in the five patients who developed bilateral ptosis after bilateral cataract extraction. All eyelids in this series were repaired by levator muscle advancement and attachment to the tarsal plate with favorable outcomes and no recurrences during a 1-year follow-up. The importance of Hering's phenomenon of equal innervation is also discussed as it applies to bilateral and to apparent unilateral blepharoptosis. The authors propose "Hering's test" as an important indicative study in the preoperative evaluation of all patients with eyelid ptosis.

Etiology of ptosis after cataract surgery

PURPOSE

To determine whether using a lid speculum with a superior rectus bridle suture in cataract surgery results in levator rectus aponeurosis dehiscence caused by strong fascial attachments between the levator and superior rectus muscles.

SETTING

L.V. Prasad Eye Institute, Hyderabad, India.

METHODS

This study comprised 220 patients having cataract extraction with posterior chamber intraocular lens implantation. The patients were randomly assigned to one of two groups. In the first group (n = 108), a lid speculum was used during surgery. In the second group (n = 112), no speculum was used. All patients had a superior rectus bridle suture. The occurrence of ptosis was analyzed by a masked observer who was not involved in the surgery.

RESULTS

The incidence of ptosis was significantly higher in the speculum (44.4%) than in the no-speculum (23.3%) group (P = .0009).

CONCLUSION

The results indicate that the opposing forces created by the lid speculum and bridle suture can cause levator aponeurosis dehiscence because of the strong fascial attachments between the superior rectus and levator muscles. The occurrence of ptosis in the no-speculum group implies a multifactorial etiology, however.

Postcataract ptosis. A randomized, double-masked comparison of peribulbar and retrobulbar anesthesia

PURPOSE

A randomized, double-masked study of 317 patients was conducted to determine if the incidence of postcataract ptosis is greater with retrobulbar or two-injection peribulbar injection anesthesia.

METHODS

Surgery consisted of a planned extracapsular extraction with posterior chamber lens implantation, and no superior rectus bridle suture was used. Ptosis was quantitatively documented preoperatively and postoperatively at 1, 2, 5, and 90 days by the surgeon, photographically at 90 days by a masked observer, and subjectively by the patients. Postcataract ptosis was defined as a drop in the lid margin of 2 mm or greater after correcting for any change in the fellow eye.

RESULTS

The incidence of ptosis at 90 days in patients given peribulbar anesthesia was 5.8% and in patients given retrobulbar anesthesia 5.5%, and this difference was not statistically significant (P = 0.90). Eighteen percent of patients in both groups reported a change in the appearance of their eyelids. There was a moderate, positive correlation among patients who reported a change in their lid position and objective measurements of ptosis. Preoperative clinical measurements of vertical lid fissure width and levator function, and the appearance of the lid crease or superior sulcus were not predictive for the development of postoperative ptosis at 90 days; the best predictor was the presence of ptosis in the immediate postoperative period.

CONCLUSION

The incidence of postcataract ptosis is the same whether two injection peribulbar or retrobulbar anesthesia is used.

Ptosis following periocular or general anaesthesia in cataract surgery

The incidence and duration of postoperative ptosis was investigated in 64 patients undergoing cataract surgery. Thirty-two patients had a 2-point periocular regional anaesthesia while 32 others were given general anaesthesia. The palpebral aperture and the levator muscle function were measured preoperatively and then on the 1st, 2nd, 4th and 7th postoperative days or as long as ptosis persisted. On the 1st postoperative day, about half of the patients in both groups demonstrated ptosis. On the 2nd day, ptosis was more common in the general anaesthesia group. The ptosis persisted 1 week postoperatively in 2 patients, both belonging to the general anaesthesia group. It is concluded that postoperative ptosis is common both after local and general anaesthesia. In most cases it is shortlasting and may be related to the volume or myotoxicity of a local anaesthetic drug. The use of a superior rectus muscle bridle suture and/or lid speculum may be important in provoking ptosis of longer duration.

Postcataract extraction ptosis: effect of the bridle suture

Postcataract extraction ptosis is a common complication of cataract surgery. While many factors have been implicated in its etiology, trauma to the superior rectus/levator complex is considered the most important factor. We prospectively evaluated the effect of two superior rectus bridling techniques on the degree and severity of ptosis present three months after cataract surgery. All other potential variables were controlled for. Bridling the tendon of the superior rectus muscle using the direct, subconjunctival (open) approach results in significantly less severe ptosis than the standard technique of indirect transconjunctival (closed) bridling.

Complications of radial and transverse keratotomy

Radial keratotomy for myopia and transverse keratotomy for astigmatism are the most commonly performed refractive surgical procedures. A decade of experience with modern techniques has produced considerable literature on the complications of keratotomy. Vision-threatening complications (bacterial keratitis, traumatic rupture of the globe through weakened keratotomy scars, endophthalmitis, cataract formation from surgical trauma to the lens) are quite rare, occurring in less than 1% of eyes in published series. The most common side effects affect most patients in the first few months after surgery: pain for 24 to 48 hours, transient glare and light sensitivity, and fluctuating visual acuity. The most common persistent complications are overcorrection and undercorrection. Persistent irregular astigmatism occurs in almost all cases in the region of the incision scars, but it is rarely severe enough to reduce spectacle acuity. Most individuals have mild glare, but this is rarely disabling. Diurnal variation of refraction in visual acuity occurs commonly, but the magnitude of the fluctuation is seldom enough to require multiple pairs of spectacles. Longterm refractive stability occurs in approximately half of eyes by six months, but approximately one in four eyes will experience continued change over six months to four years. Complications, such as scarring from intersecting keratotomy incisions, irregular astigmatism resulting from multiple reoperations, and overcorrections with the attendant early onset of symptomatic presbyopia are becoming much less frequent.

Traumatic dehiscence of incisions seven years after radial keratotomy

We studied the clinical and pathologic features of a traumatically ruptured eye seven years after radial keratotomy. The radial keratotomy incisions were identified and topographically related to perforation sites. Three radial keratotomy incisions were perforated. Seven additional incisions were partially separated. Radial keratotomy incision depths ranged from 50% to 90% in the remaining incisions. All incisions showed disruption of Bowman's membrane, 15 of 16 showed malapposition of Bowman's membrane, and 14 of 16 showed epithelial plugging. In this case the healing and strength of radial keratotomy incisions were suboptimal seven years after the procedure.

Three-year results of the Prospective Evaluation of Radial Keratotomy (PERK) Study

The Prospective Evaluation of Radial Keratotomy (PERK) study is a nine-center clinical trial of a standardized technique of radial keratotomy in 435 patients who had simple myopia with a preoperative refractive error between -2.00 and -8.00 diopters (D). The authors report results for one eye of each patient. The surgical technique consisted of eight incisions using a diamond micrometer knife with the blade length determined by intraoperative ultrasonic pachymetry and the diameter of the central clear zone determined by the preoperative refractive error. At 3 years after surgery, 58% of eyes had refractive error within 1.00 D of emmetropia; 26% were undercorrected and 16% were overcorrected by more than 1.00 D. Uncorrected visual acuity was 20/40 or better in 76% of eyes. The operation was more effective in eyes with a preoperative refractive error between -2.00 and -4.37 D. Between 1 and 3 years after surgery, the refractive error changed by 1.00 D or more in 12% of eyes, indicating a lack of stability in some eyes. In the 435 eyes, there was a small number of complications including six eyes that lost two or three lines of best-corrected acuity, 16 that experienced vascularization of the incisions, 2 that had delayed bacterial keratitis, and 4 that had recurrent epithelial erosions.