The meibomian gland (MG) is a modified sebaceous gland in the eyelids which produces meibum, the lipid component of the tear film [1]. Meibum is essential for retarding tear film evaporation, thereby preventing dry eye [1]. Meibum has the ability to lower surface tension, thus aiding in the spreading of the tear film at the ocular surface [2]. Additionally, it possesses some antimicrobial properties believed to prevent ocular surface infections [3]. Meibomian gland dysfunction (MGD) is defined as a chronic, diffuse abnormality of the meibomian glands, commonly characterized by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion.[1][4] This may result in alteration of the tear film, symptoms of eye irritation, clinically apparent inflammation, and ocular surface disease.[5] With a number of changes in lifestyle involving dietary preferences, work habits and the advent of computer usage in all spheres of life, the incidence and prevalence of dry eye has increased dramatically in the general population. MGD may well be the leading cause of dry eye disease throughout the world , but is often overlooked in busy op settings Patients may present with dry eye, redness, irritation, itching, burning sensation, unstable fluctuating vision , and occasionally blurred vision with visual tasks. Recent studies showed that the prevalence of MGD in general population varies between 30.5 and 54.1%.[6][7] MGD is classified into low delivery forms (hyposecretory and obstructive) and high delivery forms (Hypersecretory/Seborrheic). Obstructive MGD is thought to be the most common variety.[8] Both hyposecretory and hypersecretory MGD are influenced by endogenous factors, such as age, sex, hormonal disturbances, as well as by exogenous factors such as topical medications [4]. Dyslipidemia has also been linked to the development of MGD, but direct evidence supporting this relationship is lacking.[9,10,] Dyslipidemia is a disorder of systemic lipid metabolism which is characterized by increased levels of total blood cholesterol (TC), triglycerides (TGs), low-density lipoproteins (LDL) and/or a reduction in high-density lipoproteins (HDL). It is a major component of the metabolic syndrome which includes abdominal obesity, systemic inflammation, insulin resistance, hypertension and hyperglycemia[11,12]. The pathology of MGD is complex and poorly understood. Adopting a lipidomics approach, it should be possible to determine if a particular plasma lipid profile in dyslipidemia causes qualitative (compositional) and quantitative changes in meibum Need of the study The purpose for conduction of this study is to correlate the association between severity of MGD and dyslipidemia in the population of Machilipatnam as there is no relevant study conducted so far in this population. Aim and Objectives : To evaluate the association between severity of meibomian gland dysfunction and dyslipidemia. OBJECTIVES: 1. To analyze the prevalence of lipid abnormalities in patients with meibomian gland dysfunction 2.To analyze association of severity of meibomian gland dysfunction with lipid levels in dyslipidemia patients

A cross-sectional observational study conducted at , Department of Ophthalmology, Govt General teaching Hospital, Machilipatnam with 125 study subjects . The sample size is calculated using n=Z2P(1−P)d2 Where n is the sample size, Z is the statistic corresponding to level of confidence, P is expected prevalence ,d is precision (corresponding to effect size).125 members were included in the study based on prevalence rate of 58.3% lipid abnormalities in meibomian gland dysfunction ,with error rate of 15%. (Lemp MA, Nichols KK. Blepharitis in the United States 2009: A survey-based perspective on prevalence and treatment. Ocul Surf 2009;7:S1-S14.) Inclusion and exclusion criteria: Patients who are 18 year and above with symptoms of dry eye and diagnosed with Meibomian gland dysfunction based on signs and symptoms were included . Patients with lid infections or inflammations , Recent ocular surgery , treatment with topical steroids before 4 weeks, Changes in the draining system of lacrimal apparatus, Ongoing glaucoma medications , keratoconjunctivitis of infectious, , on OCP , antihypertensive medication such as ARBS and ACE inhibitors , Pregnant women were excluded from the study . Procedure: After obtaining informed written consent , A comprehensive ophthalmic evaluation was conducted, including slit lamp examination of the anterior segment and meticulous assessment of the eyelids, followed by measurement of blink rate and interval to gauge tear film stability. Schirmer’s test and tear film break-up time were performed to quantify tear secretion and assess surface integrity, while corneal and conjunctival staining was graded according to the Oxford score for precise documentation of surface changes. Meibomian gland function was assessed by applying pressure on the eyelids under slit lamp to evaluate gland patency, meibum quality, and secretion type. In addition, a fasting blood sample was analyzed using a semi-automated analyzer to determine lipid profile parameters including triglycerides, total cholesterol, LDL, HDL, and VLDL. A detailed slit lamp examination was performed to assess meibomian gland secretion and expressibility, grading each of eight central lower lid glands on a standardized 0–3 scale, while lid margin features such as vascularity, plugging, and dropout were noted to assist in staging meibomian gland dysfunction (MGD); tear film stability was evaluated using TBUT, and tear production was measured with the Schirmer test, with abnormal findings classified according to recognized criteria for secretion quality, gland expressibility, and ocular surface staining severity. The data were entered in Microsoft Excel 2013 and analyzed using Epi Info 7.2, with quantitative data expressed as mean ± standard deviation and qualitative data as frequencies and percentages; the chi-square test assessed associations between variables like age groups, activity type, and disease prevalence, considering p < 0.05 statistically significant.

Total number of patients included in this study diagnosed to have meibomian gland dysfunction was 125 , among which 65 were female and 60 were male. Patients in this study mostly were indoor patients about 83 patients constituting 66% of total MGD patients, and outdoor patients were 42 constituting 34% of total MGD patients. Patients with indoor occupation in this study group mostly were students, software engineers and other company employs. Patients with outdoor occupation included mostly farmers. AGE IN YEARS NUMBER OF CASES(125) PERCENTAGE 20-35 44 35.2% 36-45 31 24.8% 46-55 28 22.4% 56-65 13 10.4% 65-75 9 7.2% Table 1 Age wise distribution of study population Age In Years Stage I MGD Stage II MGD Stage III MGD Stage IV MGD P value 20-35 52% 36% 17% 26% >0.05 36-45 19% 22% 28% 16% 46-55 12% 21% 32% 32% 56-65 10% 13% 11% 15% 66-75 7% 8% 12% 11% 67 MGD patients showed normal serum cholesterol levels while 58 showed abnormally elevated serum cholesterol levels. Elevated serum cholesterol levels were seen in 6 (10%) Of Stage I MGD cases, 23 (40%)stage II MGD cases, 15 (26%)Stage III MGD cases and 14 (24%) stage IV MGD cases. Maximum no patients with serum cholesterol > 200mg/dl belong to stage II constituting 40 %. (Table 2). The results were statistically significant Table 2 : Stage Wise Distribution According To Age Group Stage of MGD TC LDL VLDL HDL TG Normal Abnormal Normal Abnormal Normal Abnormal Normal Abnormal Normal Abnormal Total STAGE I MGD 24(36%) 6(10%) 30(34%) 0 30(28%) 0 30(26%) 0 27(26%) 3(14%) 30 STAGEIIMGD 29(44%) 23(40%) 40(46%) 12(32%) 44(42%) 8(42%) 44(38%) 8(44.4%) 47(45%) 5 (23%) 52 STAGE III MGD 11(16%) 15(26%) 11(13% 15(39.4%) 19(18%) 7(37%) 25(22%) 1(5.5%) 17(16.3%) 9(42%) 26 STAGE IV MGD 3(4%) 14(24%) 6(7%) 11(30%) 13(12%) 4(21%) 8(7%) 9(50%) 13(12.5%) 4(19%) 17 TOTAL 67 58 87 38 106 19 107 18 104 21 125 P Value <0.001 <0.001 <0.005 <0.001 <0.001 Table 3 : Distribution of serum lipds in study population TC: total cholesterol ( Normal <200 mg/dl abnormal : > 200 mg/dl) LDL : Low-Density Lipoprotein ( Normal <130mg/dl Abnormal : > 130mg/dl ) VLDL : Very low-density lipoprotein (Normal: <50mg/dl Abnormal: >50mg/dl) HDL: High-density Lipoprotein( Normal > 40 mg/dl abnormal : < 40mg/dl ) TG: Tri Glycerides ( Normal <150mg/dl Abnormal: >150 mg/dl ) Serum lipid profile (mg/dl) Stage I MGD Mean value Stage II MGD Mean value Stage II MGD Mean value Stage IV MGD Mean value P Value TC 185.1 ± 10.54 190.096±10.44 202.346±13.67 212.64±8.56 <0.001 LDL 118.6333±7.00 123.34± 8.74 135.576±11.33 135.94±7.98 <0.001 VLDL 17.6333± 5.09 21.365±6.55 25±7.98 27.6470±8.97 <0.001 HDL 48.4± 4.76 44.19±4.59 47.7±6.87 34.88±7.45 <0.001 TRIGLYCERIDE S 130.1333±9.15 132.673±10.76 134.923±18.56 141.764± 15.97 <0.001 Table 4: correlation of serum lipid profile with meibomian gland dysfunction

Evaporative dry eye disease has many causes, but one of the main ones is meibomian gland dysfunction. It causes long-term eye discomfort and is rarely observed.(13,14). Numerous investigations revealed that meibum contains different amounts and types of cholesterol (15). Recent research has postulated that elevated cholesterol in the meibum is a significant factor in the pathogenesis of MGD(16). The present study was an observational cross section study conducted to correlate relationship between severity of meibomian gland dysfunction and dyslipidemia in 125 patients with meibomian gland dysfunction. The age range covered by this study was 20 to 75 years old with 52% Female and 44% males (table No 1)Among the 125 MGD patients evaluated 30 had stage I MGD, stage II MGD was seen in 52 patients, stage III MGD was seen in 26 cases, stage IV MGD was seen in 17 cases . In the present study, It was observed that Stage I MGD showed mean serum cholesterol of 185.1 ± 10.54, stage II MGD had mean cholesterol of 190.096±10.44, stage III MGD had mean cholesterol of 202.346±13.67and Stage IV MGD had mean cholesterol of 212.64±8.56. Patients with increasing severity of MGD had an elevated cholesterol level. Elevated LDL levels were seen with increasing severity of MGD. ( Table 4) . Elevated VLDL levels were seen with increasing severity of MGD and modest change in triglycerides and HDL compared to severity of MGD (table 3) . In the current study, population of 125 individuals, 83 indoor patients in which 22 had stage I MGD, 32 had stage II MGD, 18 had Stage III MGD and 11 had stage IV MGD. Among 42 outdoor patients, 8 had stage I MGD, 20 patients had stage II MGD, 8 patients had stage III MGD and 6 patients had stage IV MGD were included. Among these maximum no of patients belonged to stage II both among outdoor and indoor patients. No discernible relationship between MGD and occupation was found in the present study (p =0.7). Michael A. Lemp, et al 2009.'s conducted a survey-based prospective study on the prevalence and management of blepharitis in the United States, which included 5000 people, was similar to the observation made in this study. He discovered 38% of study participants reported becoming itchy after using a computer for more than three hours, suggesting that blepharitis is more prevalent in students and software workers.(17) Correlation of serum lipid profile with meibomian gland dysfunction: In current study ,it was observed that Stage I MGD showed mean serum cholesterol of 185.1 ± 10.54, stage II MGD had mean cholesterol of 190.096±10.44, stage III MGD had mean value of 202.346±13.67 and Stage IV MGD had mean value of 212.64±8.56. Thus in the present study, patients with increasing severity of MGD had elevated cholesterol. In the present study it was observed that Stage I MGD had mean LDL levels of 118.6333± 7.00, Stage II MGD had mean LDL level of 123.34± 8.74, Stage III MGD had mean LDL level of 135.576±11.33 and Stage IV MGD had mean LDL levels of 135.94±7.98. Elevated LDL levels were seen with increasing severity of MGD. In the current study Stage I MGD had mean VLDL levels of 17.6333± 5.09, Stage II MGD had mean VLDL levels of 21.365±6.55, Stage III MGD had mean VLDL level of 25±7.98 and Stage IV MGD had mean VLDL levels of 27.6470±8.9 .Elevated VLDL levels were seen with increasing severity of MGD.