|Year : 2019 | Volume
| Issue : 2 | Page : 660-664
Role of phaco time and microscopic light exposure time in causing dryness after phacoemulsification
Adel G Zaky1, Hatem M Maray1, Khaled El-Gonemy Said1, Ramy N Ahmed2
1 Ophthalmology Department, Faculty of Medicine, Menoufia University, Shebeen El-Kom, Egypt
2 Ophthalmology Department, El-Menya Ophthalmology Hospital, El-Menya, Egypt
|Date of Submission||28-Nov-2017|
|Date of Acceptance||11-Jan-2018|
|Date of Web Publication||25-Jun-2019|
Ramy N Ahmed
Ophthalmology Department, El-Menya Ophthalmology Hospital, El-Menya 35151
Source of Support: None, Conflict of Interest: None
To investigate the effects of phaco time and microscopic light exposure time in patients undergoing phacoemulsification on the development of dry eye.
Phacoemulsification is a widespread surgery; it may produce some sort of dryness. We aimed to study whether phaco time and microscopic light exposure time can cause eye dryness or not.
Patients and methods
A prospective consecutive observational nonrandomized study was carried out on 40 eyes without preoperative dry eye. Lissamine green staining of cornea and conjunctiva, tear break-up time, tear meniscus height, Schirmer's test I, and Schirmer's test II were performed immediately before the surgery and at 1 day, 7 days, 1 month, and 2 months after phacoemulsification surgery, followed by assessment of subjective symptoms. The correlation between these values with the phaco time and the microscopic light exposure time was determined.
There was an increase in subjective symptoms and a marked decrease in the dry eye test values after phacoemulsification surgery. Non significant correlations were found between phaco time and microscopic light exposure time at one hand and dry eye test values at the other hand. Postoperative dry eye test values started to improve 1 month after surgery reaching preoperative values 2 months after surgery. For example the average preoperative Schirmer test I was 17.4 ± 6.11 m; after 1 month, it decreased to 9.23 ± 6.26 m and started to increase at 2 months to 12.30 ± 5.49 m. The preoperative Schirmer test II was 13.5 ± 5.1 m; after 1 month, it decreased to 6.2 ± 3 m and then started to increase at 2 months to 9.3 ± 4 m.
The surgeon should know that more phaco time can produce dry eye. Exposure to the light of the microscope should be decreased.
Keywords: dry eye, microscopic exposure time, phaco time, phacoemulsification
|How to cite this article:|
Zaky AG, Maray HM, Said KE, Ahmed RN. Role of phaco time and microscopic light exposure time in causing dryness after phacoemulsification. Menoufia Med J 2019;32:660-4
|How to cite this URL:|
Zaky AG, Maray HM, Said KE, Ahmed RN. Role of phaco time and microscopic light exposure time in causing dryness after phacoemulsification. Menoufia Med J [serial online] 2019 [cited 2020 May 27];32:660-4. Available from: http://www.mmj.eg.net/text.asp?2019/32/2/660/260917
| Introduction|| |
Cataract surgery by phacoemulsification is one of the most important and advanced surgeries. It enables the plucking out of cataract using mechanical irrigation, aspiration, and ultrasonic vibration by a hand piece introduced through the 3 mm incision.
All benefits of phacoemulsification are because of the small incision. The advantages of a small incision include fewer wound problems and faster visual and physical rehabilitation.
The advantages of clear corneal incision over other techniques of phacoemulsification include faster and easier entry into the anterior chamber and less astigmatism. We can use topical anesthesia to perform the operation instead of other forms of anesthesia.
Khanal et al. found immediate impairment in tear physiology and sensitivity of the cornea after surgery.
Eye dryness has been reported as one of the most important problems against patient satisfaction sfter phacoemulsification, despite significant visual recovery after theses surgeries even with recent advances in the techniques.
Also, Li et al. found that after phacoemulsification, there is an increase in the occurrence of eye dryness. Roberts and Elie also reported dry eye symptoms after cataract removal.
Treatment received after phacoemulsification, duration of microscope light exposure during surgery, and ultrasound energy lead to the formation and release of free radicals; also, the wound incision by micokeratome cuts the nerves of the cornea. All these above factors have been considered as possible causes of eye dryness after phacoemulsification.
| Patients and Methods|| |
This was a prospective observational study that was carried out between May 2016 and May 2017. The study was carried out on 40 patients who did not have eye dryness and was approved by the Ethics Committee of the Institutional Review Board. All patients were aware that their participation was voluntary and they could leave at any time without providing reasons and with no effect on their medical care. Patients were recruited from the Outpatient Clinic of Ophthalmology Department of Menoufia University Hospital and El-Menya Ophthalmology Hospital. Each patient signed consent before inclusion in the study; the criteria for inclusion were that the patients had to be older than 55 years of age, with senile cataract, without pre-existing dry eye. Patients who were smokers, those with systemic or ocular diseases, or drugs intake, those who had undergone ocular surgeries before, and patients with disease of eyelids or any disorders were excluded from the study.
History taking including history of ocular disorders and detailed systemic examination were performed for study patients. Evaluation was carried out in all patients. Immediately or 1 day before phacoemulsification assessment of tear break-up time, tear meniscus height, Shermier test I, and Shermier test II were performed.
First subjective symptoms of dryness were evaluated such as burning or scratchy sensation in the eyes, stringy mucus in or around the eyes, sensitivity to light, eye redness, foreign body sensation, and watery eyes.
Then, Shermier test I was performed using a standardized tear strip without anesthesia in a dimly lighted room. The patient was instructed to sit comfortably and the strip was inserted into the lower temporal fornix after folding it at the lid margin with the patient looking superomedially. After 5 min, we removed the strip from the eye and the length of the moistened area was recorded.
Shermier test II was performed under corneal anesthesia using the same standardized tear strip; the test involved the same steps as the Shermier test I and data were obtained.
Lissamine green staining of the cornea and conjunctiva was performed. For this, an LG filter paper was applied in the lower palpebral conjunctiva and the patient was instructed to blink several times. The grading was performed as per the 0–5 scale Oxford grading scheme of LG staining of the cornea and conjunctiva using a slit lamp.
Then, tear break-up time was measured using a slit lamp with sodium fluorescein and cobalt blue filter. A fluorescein strip was placed in the lower palpebral conjunctiva, and the patient was instructed to blink many times; after some time, the patient was instructed to stop blinking. Presence of lines or black spotsindicate the onset of dry spots and the interval between the last blink and the first detected dry spot was taken as the tear break-up time. The average of many measurements was recorded and a value less than 10 s was considered abnormal.
Then, we attempted to measure tear meniscus height by adjusting the vertical length of the slit beam on the tear meniscus at the center of the lower lid and the readings were noted from the slit-lamp scale, which was very difficult to assess.
The time interval between different tests was at least 10 min. In all the patients undergoing phacoemulsification surgery, we administered peribulbar anesthesia by 5 ml of 2% lidocaine as local anesthesia and topical anesthesia was administered by benox eye drops after obtaining written informed consent from the patients. Pupillary dilatation was performed using eye drops plegica 1.5 h before the operation and three times. Ringer lactate was used as the irrigating solution and the viscoelastic material was hydroxyl propyl methyl cellulose. A standard surgical technique was used in all patients. A 2.8 mm super temporal corneal incision was performed using a calibrated knife. A two paracentesis incision of 1 mmc was made 60°–70° apart with paracentesis kinve. Capsulorhexis, hydrodissection, and nucleus rotation were performed. A phacoemulsifi cation tip was used to emulsify the cataract by “divide and conquer” phacoemulsification technique. Following emulsification of nuclear fragments and irrigation aspiration of residual cortical matter, inside the capsular bag a foldable intraocular lens (IOL) was implanted. The viscoelastic material was removed; the incision was hydrated using a 30 G cannula. The phaco time and duration of microscopic light exposure during the surgery were recorded in every case. All the patients received the same postoperative treatment with prednisolone acetate eye drops and moxafloxacine eye drops at tapering doses for 5 weeks. Patients who developed any complication during surgery and in whom any other postoperative drug was used were excluded from the study. Subjective symptoms of dryness Shermier test 1, Shermier test 11, tear break-up time test, and lissamine green staining were examined on day 1, day 7, 1 month, and 2 months postoperatively.
The data were collected and checked for accuracy on a daily basis and entered into SPSS version 16 (IBM Corporations, SPSS Inc, Chicago, USA).
Correlations of phaco time and duration of microscopic light exposure with subjective symptoms of dryness Shermier test 1, Shermier test 11, tear break-up time test, and lissamine green staining were determined, and were analyzed and studied.
| Results|| |
In this study, the mean age of our patients was 59 ± 4 years; 70% were men. Before the surgery, the subjective symptoms of dryness were 1 ± 1. These symptoms increased postoperatively and did not improve up to 2 months after surgery as shown in [Table 1].
Average tear meniscus height average is 0.38 mm which cannot be assessed at one day postoperative data because of severe watering of the eyes.
Before the surgery, the result of Shermier test 1 was about 17.46 ± 6.77 mm. After phacoemulsification, it decreased markedly when measured on day 7, and then a gradual increase was recorded.
Before surgery, the result of Shermier test 11 was about 13.7 ± 5 mm; after phacoemulsification, it decreased markedly when measured on day 7, and then a gradual increase was recorded.
Before the surgery, tear break-up time was 15.0 ± 2.5 s, which decreased up to 1 month and then showed a gradual improvement.
The changes in Shermier II test, [Figure 1], Shermier II test, [Figure 2], and tear break-up time, [Table 1], were all found to be statistically significant at all postoperative follow-up time-points.
Before surgery, 39 had a lissamine green grading of 0 and 1 patient had a grading of 1. Lissamine green grading increased up to 2 months postoperatively [Table 1].
On the basis of correlations of phaco time and microscopic light exposure time with dry eye test values, the microscopic light exposure time was 17.1 ± 4.5 min and the phaco time was 12.4 ± 6.8 s.
We found a negative correlation between the microscopic light exposure time and phaco time with Shermier test 1, Shermier test 11, tear break-up time test, and Lissamine green staining, but this association was not statistically significant. A positive correlation between the phaco time and the microscopic light exposure time with the subjective symptoms of dryness was noted, but this was not statistically significant [Table 2].
|Table 2: Microscopic light exposure and its correlation with the change in dry eye test values|
Click here to view
| Discussion|| |
This research was carried out to determine the possible reasons for the development of some sort of dryness during surgery, or an increase in symptoms, and to detect changes that may occur in in the tear film following phacoemulsification.
In many studies, it has been reported that phacoemulsification has effects on the tear film status mainly immediately after the operation,,.
Our results indicated that subjective symptoms of dryness Shermier test 1, Shermier test 11, tear break-up time test, and lissamine green staining changed following the operation compared with data collected before the surgery. An increase in phaco time, along with an increase in operating microscope light exposure duration lead to worsening of eye dryness indicators after phacoemulsification.
We also noted a similar trend where Shermier test 1, Shermier test 1I and tear break-up time values started returning to normal level after 1-month.
In 2008, Liu et al. compared 25 diabetic cataract patients with 20 age-matched nondiabetic cataract patients. They detected that tear secretion decreased in diabetic cataract patients after phacoemulsifi cation, which led to an increase in their dry eye symptoms with consequent hazardous effects on the eye.
Roberts and Elie, and Cho and Kim reported postoperative worsening of dry eye symptoms after phacoemulsification.
In Liu's study, symptoms of dry eye were increased in diabetic and non-diabetic patients. It raised in diabetic patient up to day 180 postoperative, but it recovered to levels before phacoemulsification between day 30 and 180 postoperative in non diabetic patients.
In our study, all patients were nondiabetic and all of them developed some sort of eye dryness after surgery, and these symptoms were still present on day 60.
Srinivasan et al. reported that the ocular surface and the tear film were not affected by phacoemulsification.
The significant decrease in TBUT found in our study may have occurred as result of tear film instability in the operated eye either because of a surface irregularity at the site of the section, which causes a rapid break-up of the tear film, or because of reduced mucin production by the conjunctiva.
The results of this study actually confirmed those of other authors. However, more researches are now needed to determine the relationship between the use of eye drops in the postoperative period and development of dry eye.
Many studies have reported increasing iatrogenic retinal phototoxicity related to increasing operating microscope exposure duration,.
We need longer follow-up durations to clarify the exact causes of eye dryness after phacoemulsification.
| Conclusion|| |
Before the operation, patients should be informed that they may develop symptoms of dryness, and artificial eye drops may be used postoperatively.
We noted that the phacoemulsification operation can cause dry eye symptoms and signs. Therefore, although we found an improvement in the tear film and a decrease in symptoms of dryness, 1 month postoperatively, we recommend longer follow-up to detect the time needed for the tear film to return to its status before surgery. Therefore, future studies should focus on other modalities of the phacoemulsification method to identify a safer method in patients with ocular surface disease. The doctors should also be aware that longer phaco time can aggravate dryness, and cause symptoms and signs in eyes that were healthy preoperatively. Minimal use of ultrasound energy is recommended. Intraoperatively, the microscope light exposure time should be reduced.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2]