"LUCIAN BLAGA" UNIVERSITY SIBIU FACULTY OF MEDICINE "VICTOR PAPILIAN" SIBIU

Transcription

1 "LUCIAN BLAGA" UNIVERSITY SIBIU FACULTY OF MEDICINE "VICTOR PAPILIAN" SIBIU Doctoral thesis Complications of phacoemulsification Abstract COORDINATOR: Prof. Univ. Dr. Adriana STĂNILĂ Ph. D. Student: Adrian Cosmin A. TEODORU Keywords: Phacoemulsification; Intraoperatory complications; Postoperative complications.

2 1. Introduction The history of cataract surgery lay back over 20 centuries. The oldest documents about surgical treatment of cataract come from Celsius (25 BC-50 AD) and Philoxones (300 BC). The term cataract was introduced by Constantinus Africanus (AD 1018). "Conching" was the first method of displacement the cataract in the pupil. The first descriptions of the methods belong to Sushruta, an ancient Indian surgeon. Surgeons entered the eye with the tip of a "knife" and dislocated the crystalline lens. If during the pioneering period of the cataract operation there was practiced the intracapsular crioextraction of the lens, today the ophthalmologist renounced of this method because of the complications intra-and post-operative and particularly because of the visual discomfort due to the optic correction of the aphakik patient. Extracapsular extraction of the lens followed by implantation of artificial lens has become today the worldwide elective method in resolving cataract. The advantages of this method of extraction of the lens is to keep the posterior capsule and to perform the implantation of the lens in the posterior chamber. Phacoemulsification means an important step further. The possibility of maintaining a constant intraocular pressure leads to avoiding the increased pressure in vitreous body, an expulsive choroidal or the iris prolaps. Small incision through which the foldable crystalline lens is inserted minimize the complications due to a large operatory wound: plague dehiscence, iris prolaps, etc., Reducing the postoperative cure time will allow a better visual rehabilitation due to low postoperative astigmatisms. The advantage of using phacoemulsification in cataract surgery is the removal of the nucleus through a wound less than 3.2 mm, compared with the plague of 8-12 mm, specific of the classical extraction. The quick rehabilitation of the eye and, along with the constant upgrading of the technology, the use of viscoelastic substances and foldable lens support the extensive spread of this method. The closed operating physical system permitted in the extracapsulare extraction of cataract by phacoemulsification plays a crucial role in the evolution of favorable surgical intervention. The technique of extracapsulare extraction of the cataract by phacoemulsification has proven its superiority between the previously used methods by maintaining a closed 2

3 system during the operation. The functional and morphological recovery are faster. There are a number of factors that may cause intraoperative complications. The favorably resolving of the complications that may arise during phacoemulsification is based on: recognition, knowledge, skill, trial. The surgeon must react quickly, almost automatically. Te stress of the moment can hamper a clear analysis of the situation. Therefore, the most appropriate way to solve any complications is to prepare for all possibilities. The results of the cataract surgery by phacoemulsification method may be compromised by complications that may occur at different time intervals, postoperative. These may be related primarily to: corneal edema, eye hypertony, opacification of the posterior capsule, endophtamitis. 3

4 2. Aim of study In the present study I tried to emphasize the problems that may occur intraoperatory, immediately post or late in the operation of extracapsulare extraction of the cataract by phacoemulsification. The paper aims to identify the mechanisms and factors that may cause complications during or after surgery and also the establishment of solutions aimed of solving the occurring problems. Paper aims to establish an operatory protocol as close to perfect, to ensure optimal results, with reduced incidence of intra-or postoperative complications. 4

5 3. Material and method The study was conducted prospectively on a sample of 570 patients hospitalized in the Department of Ophthalmology Clinical of the County Emergency Hospital Sibiu during , with the diagnosis of cataract. All cases were operated using the extracapsulare extraction of the cataract by phacoemulsification. All surgeries were performed in loco-regional anesthesia performed with Xiline 2%. The phacoemulsification apparatus used in all cases was Alcon Legacy Irrigation fluid used was BSS (Balanced Salt Solution). To maintain the anterior chamber and for the corneal endothelial protection were used viscoelastic substances: sodium hyaluronate (Provisc), sodium condroitin sulfate 4% + sodium hyaluronate 3% (Viscoat). The implanted lens types were: PMMA (rigid) and Acrysof (Single-piece, Natural). I analyzed the complications that occurred intra operatory and post operatory at various time intervals and the best solutions that have resulted in solving them. Intraoperatory complications were studied according to the surgical stage in which they occurred and the surgical maneuver. I studied visual acuity compared preoperatory and immediately post operatory in a group of 317 patients. To establish the surgical induced astigmatism I have studied corneal topography preand post operatory on a group of 50 patients, consisting of 25 patients who s plague of 3.2 mm was sealed without suture, and a group of 25 patients who s plague was sutured. I used corneal topography TOP CON CA 100. The influence of phacoemulsification on corneal endothelial cells was studied by pahimetric analyzing of the endothelial cell density before and after the operation on a group of 60 patients. For the study of the endothelium I used the specular microscope CSO. Some complications were related to chronic diseases of the patients and their treatments. I analyzed and presented the incidence of all complications occurring during the operation and in the postoperative period. For the statistical processing of the data we used SPSS program - version 10. There were used table combination of two qualitative variables and equality testing environments pairs of two samples (paired-samples T Test). I studied the associations between various groups using the association table (Crosstabs) of two qualitative variables. 5

6 4. Results and discussions 4.3. Results and discussion on intraoperatory complications Complications of anesthesia Patient movements The main drawback of local anesthesia is to enable the patient to perform movements during operation. In 8 cases (1.40%) of 570 I met excessive movement of patients Retrobulbar bleeding Given the vascular plexus of the orbit, reaching any vessel can cause bleeding. Severity of retrobulbar bleeding is varied. Eyeball protrusion occur, massive subconjunctival hematoma appears. Consequent an increase of the intraocular pressure may involve structural changes in the eyeball. In 20 cases (3.51%) of 570 taken in the study, where we performed retrobulbar anesthesia with Xiline 2%, was installed retrobulbar bleeding after local anesthesia. We found a significant statistical correlation (p <0.01) between patients with retrobulbar bleeding and chronic antiagregant or anticoagulant treatment Complications related to incision Conjunctival hydration I encountered this complication in 27 cases - 4, 73% Of the 570 cases studied in 445 I performed a tunnel scleral incision, in 125 cases I performed an incision in clear cornea. All cases where conjunctival hydration occurred were clear corneal incisions Bleeding in the tunnel Bleeding from the tunnel occurred in 14 cases %. In all cases, at the end of the operation, after sealing the plague, bleeding has stopped. No case has required further suture. In none of these cases occurred hiphema next day. I found a significant statistical correlation between the 2 groups of patients: the group who had bleeding in the tunnel and the group of patients treated with anticoagulants or antiagregants (p <0.01). 6

7 Iris prolaps Iris prolaps is a complication which, if not resolved early, can have consequences on the iris integrity. Of the 570 cases, iris prolaps occurred in 11 cases, representing 1.93% of total. In all 11 cases I found associated intraoperatory hypertonic eye, with significant statistical correlation (p <0.01) Bleeding in the anterior chamber Bleeding in the anterior chamber can come from intraoperatory damage of iris. This occurs most frequently in temporal incisions located more posterior and deeper than normal. In these cases there are reached the blood vessels with higher risk of bleeding. In 11 cases (1.93%) I met bleeding in the anterior chamber during surgery. From our analysis it appears that there is no significant statistical correlation with anticoagulant therapy or chronic antiagregant (p> 0.05) Capsulorexis Rexis problems were not likely to influence the conduct the surgery. Thus, in 8 cases I have met the tendency of rexis disruption. After reintroduction of viscoelastic substances, the situations were resolved in a favorable way. There was no need to convert the capsulorexis into an can-opener in any situation. In intumescente cataracts we performed a smaller rexis to avoid its failure. After closing the rexis and cortex aspiration I started broadening the rexis, bringing it to the normal diameter. In 8 cases this maneuver was imposed. In white cataracts (mature, hypermature) I used a colored substance to reveal the anterior capsule, under air protection. There were 2 cases in which, due to the rigidity of the capsule and the solidified cortex, rexis could not be conducted requiring the completing of it with scissors. In 5 cases the rexis edge was injured during the subsequent surgical maneuvers. In all cases the operation continued without incidents The detachment of the Descemet membrane The Descemet membrane detachment was present in 54 cases (9.47%) of the 570. The defect was minimal and in all cases the repositioning was performed without problems. 7

8 Small pupil Miosis and pupilar rigidity I encountered in 7 cases, representing 1.23% of all cataract operations. In all these cases we used the iris retractors for iris dilation. For the statistical analysis of the cases with small pupil I found statistical significance results from the combination with exfoliativ syndrome (p <0.01) Problems during phacoemulsification Small anterior chamber Temporary loss of the chamber I met in 20 cases (3.51%). After adjusting the parameters of aspiration and irrigation and the introduction of viscoelastic substances with high molecular weight the situation was resolved favorably Hypertonic eye I met hypertonic eye in 16 cases (2.81%) All cases of hypertonic eye have been associated with temporary loss of the room earlier, the correlation being statistically significant (p <0, 01). In one case of hypertonic eye, posterior capsule rupture has been associated with vitrectomy needed. Correlation was not statistically significant Thermal injuries In 5 cases (0.88%) there was a minimum thermal injury on the incision Iris injuries In 13 cases (2.28%) the iris was injured intraoperatory Rupture of the posterior capsule and zonular dialysis Rupture of the posterior capsule The posterior capsule rupture during phacoemulsification is a potentially serious complication, which may involve additional problems as loss of material in the vitreous, chronic inflammation, cystoid macular edema, displacement of the lens, retinal detachments. In the group of 570 patients I met this complication in 20 patients (4%). The friability of the posterior capsule is often associated with the presence of the exfoliative syndrome. I took the 2 study groups formed of patients with rupture of the posterior capsule and 8

9 of those with exfoliativ syndrome. The statistical analysis of the 2 groups, revealed that there are significant statistical correlations between them (p <0.01) Zonular dialysis I encountered this complication in 10 cases. In 7 of them the operation could take place without the need for further measures. In 3 cases it required the use of iris retractors to support the capsular bag. The retractors were mounted at the edge of the rexis Results and discussion on postoperative complications Corneal edema Corneal edema is categorized according to severity in reversible and irreversible. In the cases studied I met this complication as follows: reversible corneal edema: - in 7 days: 48 cases %; - in 30 days: 11 cases %; irreversible corneal edema edemato bullous keratopathy - 2 cases %. Reversible corneal edema in 7 days was associated in 2 cases with detachment of the Descemet membrane, statistically insignificant (p> 0.05). In 18 of the 48 cases of edema with remission in 7 days, they were associated with an increase in intraocular pressure (less than 35 mmhg on the first day post). The combination was significantly statistic with a precision of 99%. All cases have responded to antiglaucoma medication with normalization of the intraocular pressure and remission of edema in 72 hours. I found a significant statistical correlation of the corneal edema post faco with the faco-time and the type of cataract, among the latter there are also significant correlations (p <0.5) Corneal endothelial damage I studied corneal endothelial evolution at 1 group of 60 patients. All patients were operated with the same phacoemulsification device and I used the same viscoelastic substances. I studied pre-and postoperatory the corneal thickness pahimetry and the endothelial evolution by specular microscopy. We analyzed the data comparing the visual acuity, the corneal edema, the faco time. 9

10 The endothelial cell density decreased statistically significantly (p <0.05) from an average of 2731 celule/mm2 to 2319 celule/mm2. Visual acuity post significantly increased (p <0.01). Corneal thickness increased significantly post (p <0.05) in average from to µm ìm. There was no significantly statistical correlation between the corneal thickness and faco time (p> 0.05). There are significant statistical correlation between the amount of phaco energy and the postoperative visual acuity. The analysis of phaco time correlated with the decreasing of endothelial cell density revealed a significant statistical correlation (p <0.01). In the group of 60 patients examined by pachimetry and speculat microscopy I found decreases in endothelial cell number after phacoemulsification with an average of 4.24% Wound dehiscence Small wounds, under 3.2 mm, are much less prone to this complication, compared with 8-10 mm wounds of classical operation. The sealing of the wound depends primarily on the quality of the corneo-scleral tissue. This in turn depends on certain intraoperatory complications or certain chronic diseases (Werner syndrome). In the study group I met in 4 cases (0.70%) a lack of sealing of the wound second postoperative day, with small anterior chamber, without iris issue. 2 of these cases occurred after thermal injury of the wound during phacoemulsification, with significant statistical correlation (p <0.05). No case has required reintervention. I applied in all cases a therapeutic contact lens Asymmetric pupil Intraoperatory injury with the phacotyp or instruments and some local or general associated conditions may cause pupil asymmetries. This will translate clinically by decreased visual acuity, lack of adaptation to strong light. In 14 cases (2.46%) there were pupil asymmetries after cataract operation. In 3 of them the pupil margin was affected by the phacotyp. These cataracts were mature, with hard nucleus. In 7 of the 14 cases there was an exfoliativ syndrome present. 10

11 Intraocular inflammation Post operatory intraocular inflammation can be acute and chronic (endophthalmitis). The most feared postoperatory complication of the cataract surgery, endophthalmitis, is due to its increased potential to compromise the eye. Chronic uveal inflammation may occur in weeks, months or years after cataract operation. Under current protocols in all cases we use betadine in the conjunctival bag preoperatory. At the end of surgery we inject subconjunctival gentamicin and dexamethasone. I had no cases of endophthalmitis. In the studied group we encountered 5 cases that had chronic inflammation (0.88%). In one case the surgical reintervention was necessary for washing the chamber. Of the 5 cases, 4 patients had diabetes. We found significant statistical correlations (p <0.01) between post-intraocular inflammation on the one hand and rupture of the capsule associated with diabetes, on the other Posterior capsule opacifiation The risk of posterior capsule opacifiation hindquarters with consequent decrease of visual acuity in patients. Of the 570 cases studied in 20 there appeared partial fibrosis of the capsule with the preservation of visual acuity and in 6 cases there appeared total opacifiation of the capsule with decreased visual acuity (in 2 cases - Soemmering ring in 4 - pearls Elschnig), which required surgery intervention. The correlation of the posterior capsule opacifiation with PMMA implants was statistically significant (p <0.05) Post operatory astigmatism The sealing of the corneal wound causes a deformation of the cornea resulting a post operatory astigmatism. Results of functional visual acuity depend on the corneal astigmatism. The most important parameter, to quantify functional outcomes of cataract surgery, is the visual acuity (VA). I took a group of 317 patients and studied the visual acuity before and after the surgery, correlated with a number of factors which could have an influence on it. On 11

12 average, the pre operatory visual acuity of 317 patients studied was A second day post operatory measurement of the visual acuity revealed an increased VA in these patients on average at Visual acuity improved an average with 57% To analyze the post operatory astigmatism by the type of incision sealing I performed corneal topography in 2 subgroups with and without suture. I found significant statistical correlation between the post op astigmatism and the type of wound sealing (p <0.01) Post operatory Glaucoma In group we studied had chronic increases in intraocular pressure. In 18 cases (without pre-existing glaucoma) I met increased pressure 24 hours after cataract operation. In all these cases there has been associated a corneal edema, significant statistical correlation (p <0.01). Was established topical treatment. The pressure was normalized and the edema resolved in all cases at 72 hours post op. I concluded that in all cases there was some retention of viscoelastic substances in the anterior chamber. 12

13 5. Conclusions 1. Solving the cataract, the most common cause of decreased visual acuity in elderly people, requires much care and precision. The impact of cataract surgery on patients life quality is a major one, where, today, he should resume his daily activities as quickly as possible. 2. The method of phacoemulsification proved clearly superior in functional rehabilitation and socio-professional reintegration of the patient operated for cataract. 3. Intraoperatory and postoperative complications that may compromise the results of this type of operation are linked on the one hand to the general and local state of the patient and, on the other hand to the accuracy of performance and surgical equipment and instruments used. 4. As the patient is not operated under general anesthesia, excessive movements may endanger the normal course of the operation. 5. We found significant statistical correlations between the treatment with antiagregants anticoagulants and the haemorrhagic complications occurrence: retro bulbar bleeding, bleeding from the tunnel (p <0.01). This requires the establishment along with the cardiologist about the opportunity of the interruption or replacement of this treatment. 6. The study revealed significant statistical correlation between hypertonic eye and retro bulbar bleeding (p <0.01). Hypertonic eye is liable for iris prolaps. Intraoperatory injuring of the iris may have adverse effects on postoperative visual acuity. 7. Bleeding in the anterior chamber can impair the normal viewing of the chamber. It is a consequence in most cases of surgical maneuvers that harm the iris. 8. Making a round continuously capsulorexis, with a diameter a bit smaller than the implant has proved crucial for the next surgical maneuvers. In mature and hipermature cataracts I preferred to color the capsule for best viewing of it. The tendence of sideslip stopped by the addition of viscoelastic. 9. The detachment of the Descemet membrane may become a major complication if not recognized and resolved in time. In the cases studied we found a significant correlation (p> 0.05) between off Descemet membrane detachment and corneal edema. 10. The small pupil appeared with an incidence of 1.22% of cases. Exfoliativ 13

14 syndrome proved to be a significant risk factor for small pupils (p <0.01). To resolve this situation we chosed to use pupil retractors. After using retractors it remains a minimum deformation of the pupil, a complication that I consider insignificant. 11. Chamber depth decreasing during operation was statistically significant correlated with hypertonic eye (p <0.01). Adjust parameters, the relatively closed system, allows avoiding serious complications. 12. The thermal injury was statistically significant correlated with the appearance of the wound dehiscence (p <0.01). We demonstrated in the cases studied that the application of a therapeutic contact lens resolved the problem without requiring new suture. 13. Posterior capsule rupture occurred in 4% of the cases. Study revealed a significant statistical correlation (p <0.01) between the incidence of capsule rupture and the association of exfoliative syndrome. 14. There was a significant statistical correlation (p <0.01) between corneal edema and the phaco time, between corneal edema and the type of cataract (mature cataracts and hipermature are requiring a longer phaco time). In 2 cases appeared edemato bullous keratopathy. I emphasize the advantages of applying of the amniotic membrane in reducing corneal edema in these situations. 15. Decreased endothelial cell density is statistically significant related to phaco time (p <0.01). Thus, a goal of the surgery should be to minimize the amount of ultrasound used. 16. The incidence of postoperative opacifiation of the posterior capsule is linked statistically significant (p <0.01) by the type of the used of artificial lens (PMMA). To reduce the incidence of such complications there should be used mainly acrylic lens. 17. Chronic inflammation was statistically significant correlated (p <0.01) with the posterior capsule rupture associated with diabetes. 18. Early post operatory astigmatism is linked significantly (p <0.01) of the sealing type of the incision. Thus, sutured wounds have an increased risk to cause an increased astigmatism. 19. Hypertonic eye is most commonly linked to the retaining of the viscoelastic in the chamber. It requires, therefore, washing out the substances remaining at the end of the surgery as a prophylactic measure to prevent this complication. 20. Solving cataract in children raises additional problems. Opacifiation of the 14

15 posterior capsule appearing in 100% of cases in children, we have prevented it by making a posterior capsulorexis. Functional results of cataract surgery in children require the solving of the amblyopia problem that has an increased risk of occurrence at this age, especially in unilateral cataracts. 21. Continuous improvement of surgical techniques and equipments used tend to permanently reduce any intra and postoperative complications. Knowing and recognizing the signs of possible complications, the accuracy and the attention to surgical gesture will determine the favorable evolution of surgical intervention with the restoring the patient's vision in the most natural way possible. 15