|Year : 2014 | Volume
| Issue : 4 | Page : 205-208
Role of pterygium in ocular dryness
Tamer H El-Sersy
Department of Ophthalmology, Faculty of Medicine October 6 University, Cairo, Egypt
|Date of Submission||03-Mar-2014|
|Date of Acceptance||08-Aug-2014|
|Date of Web Publication||24-Feb-2015|
Tamer H El-Sersy
MD, FRCS, 11 Montazah St., Heliopolis, Cairo 11311
Source of Support: None, Conflict of Interest: None
Aim of the work
The aim of this study was to find out the relation between tear film function and pterygium.
Patients and methods
This study included 60 patients with unilateral pterygium from the outpatient clinic of October 6 University, with age ranging between 25 and 70 years. Pterygium was treated by simple excision in 20 eyes, by excision with B irradiation in 20 eyes, and with conjunctival autograft technique in the remaining 20 eyes. The results of tear break-up time (TBUT) and Schirmer-1 test were evaluated before and 6 months after surgery. We also included 25 healthy individuals as controls.
This study included 60 patients (32 male and 28 female patients) with a mean age of 44.17 ± 9.25 years. Age and sex were not statistically different between the patients and controls (P = 0.24 and 0.96, respectively). The mean TBUT was 11.70 ± 2.16 s in control eyes (ranged from 8.5 to 16.0 s). However, in eyes with pterygium this value was markedly reduced to 5.91 ± 1.95 s. TBUT was statistically lower among patients compared with controls (P < 0.0001). The mean Schirmer-1 test result was 13.76 ± 2.06 mm (range 11-17 mm/5 min) in normal healthy eyes and 5.85 ± 1.86 mm (range 3-9.5 mm/5 min) in the eyes of patients with pterygium. The difference was statistically different between the patients and controls (P < 0.0001). Before surgery, the average TBUT was 5.90 ± 1.87 s. This was significantly prolonged to 7.95 ± 1.33 ± 6 months postoperatively (t = 9.97, P < 0.0001) in all our cases. Moreover, Schirmer-1 test was 6.29 ± 1.90 mm/5 min preoperatively and significantly prolonged to 9.67 ± 1.57 postoperatively (t = 27.23, P < 0.0001).
Ocular dryness in the presence of pterygium and its improvement after surgery favor the hypothesis that pterygium itself contributes to the phenomenon of disturbed tear film functions in such patients.
Keywords: Ocular dryness, pterygium, Schirmer test, tear break-up time, tear film
|How to cite this article:|
El-Sersy TH. Role of pterygium in ocular dryness. J Egypt Ophthalmol Soc 2014;107:205-8
| Introduction|| |
Pterygium is a common external ocular disease. The prevalence of pterygium increases with age and is higher in people living in sunny climates ,. Environmental factors including exposure to sunlight is thought to be the most important factor of dry eye. Local tear film abnormalities are also included among the theories of pterygium.
Although the etiology of pterygium is still not fully understood, prolonged exposure to ultraviolet B radiation is thought to promote its development ,.
Kadayifçilar and colleagues , noted inadequate tear film stability in pterygium patients and suggested that abnormal tear function may be yet another risk factor related to pterygium development. However, several other studies have shown that tear function is normal in pterygia .Thus, there is an unresolved issue concerning whether the abnormal tear function is directly associated with pterygium, or does the change in the tear function causes pterygium.
The aim of this study was to detect the relation between ocular dryness and pterygium.
| Patients and methods|| |
This study included 60 eyes with pterygium from the outpatient clinic of October 6 University, aged between 25 and 70 years (32 male and 28 female patients), presenting with one of three complaints: cosmetic, optical or due to secondary infection. The study excluded patients who had conjunctivitis, contact lens wearers, those who underwent ocular surgery in the last 6 months, those having a history of intake of medicines known to dry body secretions, those using of eye drops, patients with abnormalities in the cornea or conjunctiva, and patients with allergic ocular diseases and with ocular manifestations of systemic disease. Twenty-five normal (50 eyes), age-matched and sex-matched healthy individuals were studied as controls.
Tear film break-up time measurement with fluorescein and the Schirmer-l test were performed without topical anesthesia. Tear film break-up time was recorded as the average of three successive measurements. The Schirmer-l test result was expressed as the wet length of the strip measured after 5 min.
Tear break-up time (TBUT) test was carried out by putting a fluorescein filter paper in the lower fornix and asking the patient to blink; the interval between the last complete blink and the appearance of the first corneal black spot in the stained tear film was measured three times, and the mean value of the measurements was calculated. The Schirmer-1 test was carried out without topical anesthesia bilaterally, with the standardized strips of filter paper placed in the lateral canthus away from the cornea and left in place for 5 min with the eyes closed. Readings were recorded in millimeters of wet strip. A TBUT value of less than 10 s and a tear secretion value of less than 5 mm were considered as abnormal.
In this study, all patients were subjected to detailed history taking with special attention to ocular dryness symptoms such as itching, burning sensation, foreign body sensation, watering, and discharge.
Pterygium excision was performed as follows: 20 eyes underwent simple excision without stitches, 20 eyes underwent excision followed by B irradiation, and the remaining 20 eyes underwent conjunctival autograft technique with suture. Topical anesthesia was performed with 0.5% Benox. Peribulbar anesthesia was administered for some patients who were uncooperative. The ordinary technique of simple pterygium excision was performed to all eyes. Keratectomy was performed with a 45° scalpel in an attempt to achieve a good separation between the pterygium tissue adhered to the cornea, taking care to avoid leaving remains or lumps.
Subsequently, the pterygium head was removed, together with the underlying Tenon's capsule, to leave bare the sclera bed as well as the perilesion conjunctiva margins, paying special attention to the area next to the caruncle to avoid damaging the insertion of fibers of the medial rectus. Twenty out of the 60 cases underwent B irradiation following this excision. In another 20 eyes the autograft was obtained from the superior conjunctiva of the same eye, measuring the scleral bed with a caliber and carrying the measurement to this area, asking the patient to look downward to obtain an adequate exposure of the area and marking the edges with a surgical pen.
When infiltrating the anesthetic in the area, hydrodissection was utilized whenever possible, separating the conjunctiva from Tenon's capsule. Once the graft was obtained, it was cut at the limbal area and turned over the cornea with great care. The graft was then turned over the cornea to leave it facing the scleral bed, maintaining the juxtalimbal - limbus direction.
The graft was then anchored to the perilesional conjunctiva with 7-0 silk applied in loose stitches. In all our eyes after the operation, a combination of tobramycin - dexamethasone and gentamycin cream was applied with semicompressive occlusion to the eyes that underwent conjunctival autograft. The patients were followed up the following day to remove bandages, maintaining the cream and the combination of steroids and antibiotics for the first month. Follow-up was carried out for 6 months. Statistical analysis was performed.
| Results|| |
This study included 60 patients (32 male and 28 female patients) with a mean age of 44.17 ± 9.25 years. This study also included 25 healthy individuals as controls, with the mean age of 50.00 ± 12.37 years [Table 1].
Age and sex were not statistically different between the patients and controls (P = 0.24 and 0.96, respectively).
In the present study it was found that the mean TBUT was 11.70 ± 2.16 s in normal healthy eyes with a range from 8.5 to 16.0 s. However, in eyes with pterygium this value was markedly reduced to 5.91 ± 1.95 s. TBUT was statistically significantly different between the patients and controls (P < 0.0001).
The mean wetting length of the filter paper in the Schirmer-l test was 13.76 ± 2.06 mm (range 11-17 mm/5 min) in normal healthy eyes and 5.85 ± 1.86 mm (range 3-9.5 mm/5 min) in the eyes of patients with pterygium. The difference was statistically significant between the patients and controls (P < 0.0001).
Before surgery, the average TBUT was 5.90 ± 1.87 s. This was significantly prolonged to 7.95 ± 1.33 at 6 months postoperatively (t = 9.97, P < 0.0001). In addition, Schirmer-l test was 6.29 ± 1.90 mm/5 min preoperatively, which significantly prolonged to 9.67 ± 1.57 postoperatively (t = 27.23, P < 0.0001) [Table 2] and [Table 3].
|Table 2: Comparison between patients and controls with respect to tear film break-up time and Schrimer-1 test parameters|
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|Table 3: Comparison between preoperative and postoperative tear film break-up time and Schirmer-1 test parameters|
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There was no statistically significant difference between the three groups postoperatively concerning the TBUT test and the Schirmer-1 test results. Thus, pterygium affects the tear film function, and the three surgical techniques of its removal used in this study improve the tear film function without any statistically significant difference between the three techniques.
| Discussion|| |
The relationship between pterygia and tear film function has proved difficult to define. Decreased TBUT and/or insufficient tear secretion in some pterygia patients have been noted by some  but not all investigators ,.
As the preocular tear film is the first line of defense against environmental injury, including ultraviolet exposure (which is believed to be the key factor of pterygium development), many authors hypothesize that an abnormal tear function is a risk factor for diseases resulting from ultraviolet exposure, including pterygium . In contrast, other authors suggest the reverse sequence: pathological or eyelid changes in pterygia lead to disturbed tear film function.
Age and sex were not statistically different between the two studied groups of patients and controls. This establishes good basis for comparison of the different variables between groups. This is in agreement with Li et al. , who reported a mean age of 54 ± 15 years. Most of those cases of pterygium were found in the age group 30-40 years.
In our study, TBUT was significantly lower in patients than in controls (P < 0.0001). This is consistent with Rajiv , who reported that TBUT values were significantly reduced in cases of pterygium indicating the inadequacy of tear film in these patients. TBUT has been shown to be shortened significantly in pterygium. Bekibele et al.  also reported that TBUT was lower among cases than among their corresponding control eyes.
We found that Schirmer-1 test results were significantly lower in the patients than the controls (P < 0.0001). This is in agreement with Bekibele et al. , who found that Schirmer test values were lower among cases than their corresponding control eyes. The difference between the mean Schirmer test values of cases and their controls were statistically significant (P = 0.00 for right eyes and P = 0.002 for left eyes). Moreover, Bandyopadhyay et al.  reported that the tear film break-up time and Schirmer strip wetting length were significantly different in study and control groups.
We compared alternations of tear function before and after pterygium excision. Tear function was found to be partially improved as TBUT (P = 0.0000) and Schirmer-1 test (P = 0.00) are prolonged. This is in agreement with Li et al. , who found that tear function in patients with primary pterygium improves after pterygium excision; before surgery, the average TBUT was 9.74 ± 3.43 s. This was significantly prolonged to 11.49 ± 3.76 s 1 month postoperatively. However, Li and colleagues found that there is no significant difference between preoperative and postoperative Schirmer test value (P > 0.05).
Thus, the results of the present follow-up study suggest that pterygium itself leads to abnormal tear film function.
| Acknowledgements|| |
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]